Plant Ecology (www.rms.nau.edu/publications/madrean/ for full bibliography) Adams, R. M. 1984. Desert natives: Adaptations to drought. American Horticulturist 63: 14-19. Adams, R. P. 1973. Reevaluation of the biological status of Juniperus deppeana var. sperryi Correll. Brittonia 25: 284-289. Adams, R. P., and T. A. Zanoni. 1979. The distribution, synonymy, and taxonomy of 3 junipers of southwestern USA and northern Mexico. The Southwestern Naturalist 24: 323-330. Adams, R. P., T. A. Zanoni, E. Von Rudloff, and L. Hogge. 1981. The southwestern U.S.A. and northern Mexico one-seeded junipers: Their volatile oils and evolution. Biochemistry and Systematic Ecology 9: 93-96. Aguilar, J. M., and W. J. Boecklen. 1992. Patterns of herbivory in the Quercus grisea x Quercus gambelii species complex. Oikos 64: 498-504. Aguirre-Bravo, C., L. Eskew, and A. B. Vllia-Salas, technical editors. 1995. Partnerships for sustainable forest ecosystem management: Fifth Mexico/U.S. biennial symposium. USDA Forest Service, General Technical Report RM-GTR-266. Aide, M., and Auken O. W. Van. 1985. Chihuahuan desert vegetation of limestone and basalt slopes in West Texas. The Southwestern Naturalist 30: 533-542. Alcorn, S. M., McGregor, S. E., Butler, G. D., and E. B. Kurtz. 1961. Pollination of saguaro cactus by doves, nectar feeding bats, and honeybees. Science 133: 1594-95. Aldon, E. F. 1977 Survival of three grass species after inundation. USDA Forest Service Res. Note RM-344. Alexander, B., F. Ronco, Jr., E. L. Fitzhugh, and J. A. Ludwig. 1987. A classification of forest habitat types of the Lincoln National Forest, New Mexico. USDA Forest Service, Southwestern Region, Albuquerque, New Mexico. Alexander, R. R., and F. Ronco, Jr. 1987. Classification of the forest vegetation on the national forests of Arizona and New Mexico. USDA Forest Service, Research Note RM-469. Al-Hazzouri, A. A., P. F. Ffolliott, and D. A Bennett. 1988. Germination and seedling survival tests of oak species. In: Ffolliott, P. F., and J. D. Hasbrouck, editors. Oak woodland management: Proceedings of the workshop. School of Renewable Natural Resources, University of Arizona, Tucson, Arizona, pp. 27-30. Allred, K. W. 1990. New Mexico grass types and a selected bibliography of New Mexico grass taxonomy. The Great Basin Naturalist 50: 73-82. Almeida-Martinez R., and G.B. Donart. 1987. Pastoreo simulado en tres etapas vegetativas de Muhlenbergia porteri. In: Aldon, E.F.,C. E. Gonzales V., and W.H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 177-178. Almeida-Martinez R., H. Fraga M., and J. Agundez. 1987. Indice de diversidad de especies para determinar tama¤o de muestra en vegetacion de Baja California sur. In: Aldon, E.F., C.E. Gonzales V., and W.H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 49-52. Anable, M. E. 1990. Alien plant invasion in relation to site characteristics and disturbance: Eragrostis lehmanniana on the Santa Rita Experimental Range, Arizona. PhD Dissertation, University of Arizona, Tucson, Arizona. Anable, M. E., M. P. McClaran, and G. B. Ruyle. 1992. Spread of introduced Lehmann lovegrass Eragrostis lehmanniana Nees. in southern Arizona, USA. Biological Conservation 61: 181-188. Andrade, I. F. 1979. Growth response of sideoats grama to seasonal herbage removal and competition from adjacent vegetation. PhD Dissertation, University of Arizona, Tucson, Arizona. Ansley, R. J., P. W. Jacoby, and G. J. Cuomo. 1990. Water relations of honey mesquite following severing of lateral roots: Influence of location and amount of subsurface water. Journal of Range Management 43: 436-442. Ansley, J. J., P. W. Jacoby, C. H. Meadors, and B. K. Lawrence. 1991. Soil and leaf water relations of differentially moisture-stressed honey mesquite (Prosopis glandulosa Torr). Journal of Arid Environments 22: 147-159. Aranda, Y., J. M. Serrano, and F. Bermudez-De-Castro. 1990. Litter decomposition in Populus nigra L. Revue D'Ecologie Et De Biologie Du Sol 27: 395-406. Archer, S. A. 1994. Woody plant encroachment into southwestern grasslands and savannas: Rates, patterns and proximate causes. In: Vavra, M., W. Laycock, and R. Pieper, editors, Ecological implications of livestock herbivory in the west. Society for Range Management, Denver, Colorado, pp. 13-68. Archer, S. A., D. S. Schimel, and E. A. Holland. 1995. Mechanisms of shrubland expansion: Land use, climate or CO2? Climatic Change 29: 91-99. Archer, S. A., C. J. Scifres, C. R. Bassham, and R. Maggio. 1988. Autogenic succession in a subtropical savanna: Conversion of grassland to thorn woodland. Ecological Monographs 58: 111-127. Argus, G. W. 1995. Salicaceae: Willow family. Journal of the Arizona-Nevada Academy of Science 29: 39-62. Armentrout, S. M., and R. D. Pieper. 1988. Plant distribution surrounding Rocky Mountain pinyon pine and one-seed juniper in south-central New Mexico. Journal of Range Management 41: 139-143. Arnold, J. F. 1950. Changes in ponderosa pine bunchgrass ranges in Arizona resulting from pine regeneration and grazing. Journal of Forestry 48: 118-126. Arnold, J. F., D. A. Jameson, and E. H. Reid. 1964. The pinyon-juniper type of Arizona: Effects of grazing, fire, and tree control. USDA Forest Service, Production Research Report 84. Asplund, K. K., and M. T. Gooch. 1988. Geomorphology and the distributional ecology of fremont cottonwood (Populus fremontii) in a desert riparian canyon. Desert Plants 9: 17-27. Atmar, W. and B. D. Patterson. 1992. On the measure of order and disorder in the distribution of species on archipelagos. In: Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 119-122. Austin, D. F. 1986. Moth pollinated Ipomoea longifolia (Convolvulaceae). Desert Plants 8: 15-16. Austin, M. P. 1992. Modelling the environmental niche of plants: Implications for plant community response to elevated CO2 levels. Australian Journal of Botany 40: 615-630. Axelrod, D. I. 1950. Classification of the Madro-Tertiary flora. Carnegie Institution of Washington Publication 59: 3-22. Axelrod, D. I. 1958. Evolution of the Madro-Tertiary geoflora. Botanical Review 24: 433-509. Axelrod, D. I. 1975. Evolution and biogeography of Madrean-Tethyan sclerophyll vegetation. Annuals of the Missouri Botanical Gardens 12: 280-334. Axelrod, D.I. 1979. Age and origin of the Sororan Desert vegetation. Occasional Papers of the California Academy of Science 132: 1-74. Azpiri, H. S., and J. A. Galarza. 1987. Manejo ecol¢gico de un bosque de pinos pi¤oneros en Tamaulipas. In: Aldon, E.F., C.E. Gonzales V., and W.H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 164-168. Babb, G. D. 1993. Sprouting response of Quercus arizonica and Quercus emoryi following fire. MS Thesis, University of Arizona, Tucson, Arizona. Bah, M., R. Bye and R. Pereda-Miranda. 1994. Hepatotoxic pyrrolizidine alkaloids in the Mexican medicinal plant Packera candidissima (Asteraceae: Senecioneae). Journal of Ethnopharmacology 43: 19-30. Bahre, C. J. 1977. Land-use history of the research ranch, Elgin, Arizona. Journal of the Arizona Academy of Science 12, Supplement 2. Bahre, C. J. 1985. Wildlife in Southeastern Arizona between 1859 and 1890. Desert Plants 7: 190-194. Bahre, C. J., and D. E. Bradbury. 1978. Vegetation change along the Arizona-Sonora boundary. Annals of the Association of American Geographers 68: 145-165. Bahre, C. J., and M. L. Shelton. 1993. Historic vegetation change, mesquite increases, and climate in southeastern Arizona. Journal of Biogeography 20: 489-504. Balling, R. C., Jr. 1988. The climate impact of the Sonora vegetation discontinuity. Climate Change 13: 99-109. Barbault, R., and G. Halffter, editors. 1981. Biology of the Chihuahuan Desert. Instituto de Ecologia, Mexico, D.F. Barger, R. L., Ffolliott, P. F. 1972. Physical characteristics and utilization of major woodland tree species in Arizona. USDA Forest Service, Research Paper RM-83. Barrett, J. W., P. M. McDonald, F. Ronco, Jr., and R. A. Ryker. 1980. Interior ponderosa pine. In: Eyre, F. H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., pp. 114-115. Bartel, J. A. 1993. Cupressaceae: Cypress family. Journal of the Arizona-Nevada Academy of Science 27: 195-200. Barth, R. C. 1975. Spatial distribution of carbon and nitrogen in some desert shrub ecosystems. PhD Dissertation, University of Arizona, Tucson, Arizona. Barth, R. C., and J. O. Klemmedson. 1982. Amount and distribution of dry matter, nitrogen, and organic carbon in soil-plant systems of mesquite and palo verde. Journal of Range Management 35: 412-418. Barth, R. C., and J. O. Klemmedson. 1986. Seasonal and annual changes in biomass nitrogen and carbon of mesquite and palo verde ecosystems. Journal of Range Management 39: 108-112. Bartlett, E. T. 1967. The effect of several herbicides on creosotebush in relation to carbohydrate and moisture levels. MS Thesis, University of Arizona, Tucson, Arizona. Barton, A. M. 1991. Factors controlling the elevational positions of pines in the Chiricahua Mountains, Arizona: Drought, competition, and fire. PhD Dissertation, University of Michigan, Ann Arbor, Michigan. Barton, A. M. 1992a. Factors controlling lower elevational limits of plants: Responses of pines to drought in the Chiricahua Mountains, Arizona. In: Ffolliott, P.F., G.J. Gottfried, D.A. Bennett, V. M. Hernandez C., A. Ortega-Rubio, and R. H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the Southwestern United States and Northern Mexico. USDA Forest Service, General Technical Report RM-215, pp. 191-194. Barton, A. M. 1992b. Factors controlling plant distributions: Drought, competition, and fire in pines in the Chiricahua Mountains. In: Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 19-22. Barton, A. M. 1993. Factors controlling plant distributions: Drought, competition, and fire in montane pines in Arizona. Ecological Monographs 63: 367-397. Barton, A. M. and S. A. Sloane, editors. l979. Proceedings of the Chiricahua Mountains research symposium. Southwest Parks and Monuments Association, Tucson, Arizona. Barton, A. M., and J. A. Teeri. 1993. The ecology of elevational positions in plants: Drought resistance in five montane pine species in southeastern Arizona. American Journal of Botany 80: 15-25. Bashir, E. Y. 1982. Carbohydrate reserves in roots and stem bases of blue panicgrass (Panicum antidotale Retz.) as affected by interval and frequency of cutting. PhD Dissertation, University of Arizona, Tucson, Arizona. Bassett, R. L. 1987. Silvicultural systems for pinyon-juniper. In: Everett, R.L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical Report INT-215, pp. 273-278. Beck, L. R., C. F. Hutchinson, and J. Zaunderer. 1990. A comparison of greenness measures in two semiarid grasslands. Climate Change 17: 287-303. Bell, R. A., and M. R. Sommerfeld. 1987. Algal biomass and primary production within a temperate zone sandstone. American Journal of Botany 74: 294-297. Benkman, C. W., R. P. Balda, and C. C. Smith. 1984. Adaptations for seed dispersal and the compromises due to seed predation in limber pine. Ecology 65: 632-642. Bennett, D. A. 1985. Evaluation of growing media for arizona white oak seeds. School of Renewable Natural Resources, University of Arizona, Tucson, Arizona. Bennett, D. A. 1992. Fuelwood extraction in southeast Arizona. In: Ffolliott, P. F., G. J.Gottfried, D. A. Bennett, C. V. M. Hernandez, A. Ortega-Rubio, R. H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-218, pp. 96-97. Bennett, P. 1993. Madrean flora will help answer management questions. Bajada 1: 11. Bennett, P. S., and M. R Kunzmann. 1992. Terrain roughness, a feature related to high plant species richness in the madrean biogeographic region. In: Proceedings of the Border States Conference. U.S. Department of the Interior, Park Services, Las Cruces, New Mexico. Bennett, P. S. and M. R. Kunzmann. 1993. Factors affecting plant species richness in the Madrean archipelago north of Mexico. In: Andrew M. Barton, A. M., and S. A. Sloane, editors. Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 50-52. Tucson, Arizona, pp. 23-26. Benson, L., and R. A. Darrow. 1981. Trees and shrubs of the southwestern deserts. University of Arizona Press, Tucson, Arizona. Bentley, R. G., Jr. 1964. The effects of three moisture levels applied to Lehmann lovegrass grown on a fertilized desert grassland soil. PhD Dissertation, University of Arizona, Tucson, Arizona. Betancourt, J. L. 1986. Paleoncology of pinyon-juniper woodlands: Summary. In: Everett, R. L., compiler. Proceedings - pinyon- juniner conference. USDA Forest Service, General Technical Report INT-215, pp. 129-139. Blumer, J. C. 1909. On the plant geography of the Chirichaua Mountains. Science 32: 72-74. Blumer, J. C. 1910. Comparison between Two Mountain sides. Plant World 13: 134-140. Blumer, J. C. 1911. Change of aspect with altitude. Plant World 14: 236-248. Bock, J. H. 1986. Velvet mesquite seedling development in three southwestern soils. Journal of Range Management 39: 331-334. Bock, J. H., and C. E. Bock. 1985. Patterns of reproduction in wright's sycamore. in: Johnson, R. R., C. D. Ziebell, D. R. Patton, P. F. Ffolliott, and R. H. Hamre, technical coordinators. Riparian ecosystems and their management: Reconciling conflicting uses. USDA Forest Service, General Technical Report RM-120, pp.493-494. Bock, J. H., and C. E. Bock. 1986. Habitat relationships of some native perennial grasses in southeastern Arizona. Desert Plants 8: 3-14. Bock, C. E., J. H. Bock, K. L. Jepson, and J. C. Ortega. 1986. Ecological effects of planting african lovegrasses in Arizona. National Geographic Research 2: 456-463. Bogusch, E. R. 1950. A bibliography on mesquite. The Texas Journal of Science 4: 528-538. Borelli, S. 1990. Natural regeneration of oak woodlands in southeastern Arizona: A survey. MS Thesis, University of Arizona, Tucson, Arizona. Borelli, S., P. F. Ffolliott, and G. J. Gottfried. 1994. Natural regeneration in encinal woodlands of southeastern Arizona. The Southwestern Naturalist 39: 179-183. Bowden, C., J. W. Dykinga, and P. S. Martin. 1993. The secret forest. University of New Mexico Press. Albuquerque, New Mexico. Bowers, J. E. 1980. Flora of Organ Pipe Cactus National Monument. Journal of the Arizona-Nevada Academy of Sciences 15: 1-11, 33-47. Bowers, J. E. 1981. Local floras of Arizona; An annotated bibliography. Madrono 28: 193-209. Bowers, J. E. 1982. Local floras of the Southwest, 1920-1980: An annotated bibliography. The Great Basin Naturalist 42: 105-112. Bowers, J. E. 1993. Shrubs and trees of the southwest deserts. Southwest Parks and Monuments Association, Tucson, Arizona. Bowers, J. E., and S. P. McLaughlin. 1982. Plant species diversity in Arizona. Madro¤o 29: 227-233. Bowers, J. E., and S. P. McLaughlin. 1987. Flora and vegetation of the Rincon Mountains, Pima County, Arizona. Desert Plants 8: 51-94. Bowers, J. E., and S. P. McLaughlin. 1995. Flora of the Huachuca Mountains, Cochise County, Arizona. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 135-143. Brady, W. 1973. Patterns of vegetative diversity in the Huachuca Mountains. PhD Dissertation, Colorado State University, Fort Collins, Colorado. Brady, W., and C. D. Bonham. 1976. Vegetation patterns on an altitudinal gradient, Huachuca Mountains, Arizona. The Southwestern Naturalist 21: 55-66. Brady, W. W., M. R. Stromberg, E. F. Aldon, C. D. Bonham, and S. H. Henry. 1989. Response of a semidesert grassland to 16 years of rest from grazing. Journal of Range Management 42: 284-288. Brandegee, T. S. 1891. Flora of the Cape District of Baja California. In: Proceedings from California Academy of Science, Series 2 3: 8-182. Branscomb, B. L. 1956. Shrub invasion of a New Mexico grassland range. MS Thesis, University of Arizona, Tucson, Arizona. Bravo-Hollis, H. 1978. Las Cactaceas de Mexico, Volume I. Universidad Nacional Autonoma de Mexico, Mexico D.F. Bravo-Hollis, H., and H. Sanchez-Mejorada. 1991a. Las Cactaceas de Mexico, Volume II. Universidad Nacional Autonoma de Mexico, Mexico, D.F. Bravo-Hollis, H., and H. Sanchez-Mejorada. 1991b. Las Cactaceas de Mexico, Volume III. Universidad Nacional Autonoma de Mexico, Mexico, D.F. Breceda A., D. F., L. Arriaga y Y. Maya. 1992. Recursos maderables de la Selva Baja Caduciforlia y de la vegetacion de la Ca¤ada. In: Ortega A., editor. Uso y manejo de los recursos naturales en La Sierra de la Laguna Baja California Sur. Centro de Investigaciones Biol¢gicas de Baja California Sur, Publication 5. pp. 205-229. Breceda, A., J. L. Le¢n de la Luz, and L. Arriaga. 1995. Tropical dry forest of the Sierra de La Laguna: A phytogeographical analysis. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 620-623. Britton, N. L. and T. H. Kearney. 1894. An enumeration of the plants collected by Dr. Timothy E. Wilcox, U. S. A., and others in southeastern Arizona during the years 1892-1894. Transactions of the New York Academy of Sciences 14: 21-43. Brock, J. H. 1986. Velvet mesquite seedling development in three southwestern soils. Journal of Range Management 39: 331-334. Brooks, K. N. 1970. The effects of antitranspirant chemicals on the transpiration and physiology of Tamarix species. PhD Dissertation, University of Arizona, Tucson, Arizona. Brooks, R. H., L. Kaplan, H.C. Cutler, and T.W., Whitaker. 1962. Plant material from a cave on the R¡o Zape, Durango, Mexico. American Antiquity 27: 356-369. Brown, A. L. 1950. Shrub invasion of southern Arizona desert grassland. Journal of Range Management 3: 172-177. Brown, D. E. 1973. The natural vegetative communities of Arizona. (map, scale 1: 500,000). State of Arizona, Arizona Resources Information System, Phoenix, Arizona. Brown, D. E., editor. 1982a. Biotic communities of the American southwest - United States and Mexico. Desert Plants 4. Brown, D. E. 1982b. Chihuahuan desert-scrub. Desert Plants 4: 169-179. Brown, D. E. 1982c. Madrean evergreen woodland. Desert Plants 4: 59-65. Brown, D. E. 1982d. Relict conifer forests and woodlands. Desert Plants 4: 70-71. Brown, D. E. 1982e. Sinaloan thorn-scrub. Desert Plants 4: 101-105. Brown, D. E. 1982f. Sonoran savanna grassland. Desert Plants 4: 137-141. Brown, D. E., and C. H. Lowe. 1974a. A digitized computer-compatible classification for natural and potential vegetation in the Southwest with particular reference to Arizona. Journal Arizona Academy Science 9, Supplement 2: 1-11. Brown, D. E., and C. H. Lowe. 1974b. The Arizona system or natural and potential vegetation-illustrated summary through the fifth digit for the North American Southwest. Journal Arizona Academy Science 9, Supplement 3: 1-56. Brown, D. E., and C. H. Lowe. 1980. Biotic communities of the Southwest. USDA Forest Service, General Technical Report RM-78. Brown, D. E., C. H. Lowe, and C. P. Pase. 1979. A digitized classification system for the biotic communities of north America, with community (series) and association examples for the Southwest. Journal of Arizona-Nevada Academy of Science 14: 1-16. Brown, D. E., C. H. Lowe, C. P. Pase. 1980. a digitized systematic classification for ecosystems with an illustrated summary of natural vegetation of North America. USDA Forest Service, General Technical Report RM-73. Brown, D. E., W. L. Minckley, and J. P. Collins. 1982. Historical background to southwestern ecological studies. Desert Plants 4: 17-24. Brown, D. E., F. Reichenbacher, and S. E. Franson. 1995. A classification system and map of the biotic communities of North America. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 109-125. Brown, J. R., and S. Archer. 1990. Water relations of a perennial grass and seedlings versus adult woody plants in a subtropical savanna, Texas. Oikos 57: 336-374. Brunt, J. W., M. R. Conley, and G. L. Cunningham. 1988. Sex in Ephedra trifuca (Ephedraceae) with relation to Chihuahuan desert habitats. The American Midland Naturalist 119: 137-142. Buchmann, S. L., M. K. O'Rourke, C. W. Shipman, S. C. Thoenes and J. O. Schmidt. 1992. In: Stone, C. P., and E. S. Bellantoni, editor. Proceedings of the Symposium on Research in Saguaro National Monument, Tucson, Arizona, pp. 149-156. Buckley, B. M. 1989. Dendroclimatic aspects of engelmann spruce in southern Arizona and New Mexico. MS Thesis, Arizona State University, Tempe, Arizona. Buffington, L. C. and C. H. Herbel. 1965. Vegetational changes on a semidesert grassland range from 1858 to 1963. Ecological Monographs 35: 139-164. Burd, M. 1994. Bateman's principle and plant reproduction: The role of pollen limitation in fruit and seed set. Botanical Review 60: 83-111. Burgess, T. L. 1985. Agave adaptation to aridity. Desert Plants 7: 39-50. Burgess, T. L. 1995. Desert grassland, mixed shrub savanna, shrub steppe, or semidesert scrub? - the dilemma of coexisting growth forms. In: McClaran, M., and T. R. Van Devender, editors. The Desert grassland. University of Arizona Press, Tucson, Arizona, pp. 31-67. Burgess, T. L., J. L. Betancourt, and J. R. Busby. 1995. Geographic variation in plant species richness: Lessons from the Sororan Desert, USA and Mexico, and Northern Territory, Australia. In: DeBano, L. F., P. F.Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 84-90. Burgess, T. L., J. E. Bowers, and R. M. Turner. 1991. Exotic plants at the Desert Laboratory, Tucson, Arizona. Madrono 38: 96-114. Burkholder, D. A. 1967. Interspecific differences among five southern desert grasses as affected by varying moisture and fertilizer levels. PhD Dissertation, University of Arizona, Tucson, Arizona. B£rquez, A., A. Mart¡nez-Yr¡zar, and P. S. Martin. 1992. From the high Sierra Madre to the coast: Changes in vegetation along highway 16, Maycobo-Hermosillo. In: Clark, K. F., J. Roldan-Quintana, and R. Schmidt, editors. Northern Sierra Madre Occidental Province, M‚xico, guidebook. El Paso Geological Society. El Paso, Texas, pp. 239-252. Bush, J. K. and O. W. Van Auken. 1991. Importance of time of germination and soil depth on growth of Prosopis glandulosa (Leguminoseae) seedlings in the presence of a C4 grass. American Journal of Botany 78: 1732-1739. Bye, R. 1979. Hallucinogenic plants of the Tarahumara. Journal of Ethnopharmacology 1: 23-48. Bye, R. 1981. Quelites - ethnoecology of edible greens-past, present and future. Journal of Ethnobiology 1: 109-123. Bye, R. 1985. Medicinal plants of the Tarahumara Indians of Chihuahua, Mexico. In: Tyson, R. A. and D. V. Elerick, editors. Two mummies from Chihuahua: A multidisciplinary study. San Diego Museum Papers 19: 77-104. Bye, R. 1986. Medicinal plants of the Sierra Madre: Comparative study of Tarahumara and Mexican market plants. Economic Botany 40: 103-124. Bye, R. and D. E. Soltis. 1979. Parnassia townsendii (Saxifragaceae), a Mexican endemic. The Southwestern Naturalist 24: 209-222. Bye, R., R. Mata and J. E. Pimentel V zquez. 1991. Botany, ethnobotany and chemistry of Datura lanosa (Solanaceae) in Mexico. Anales del Instituto de Biolog¡a, Universidad Nacional Autonoma de Mexico, Serie Botanica 61: 21-42. Bye, R., Cruz N. Meres, and Zacarias C. C. Hernandez. 1987. Conservation and development of food and medicinal plants in the Sierra Tarahumara, Chihuahua, Mexico. In: Aldon, E. F., C. E. Gonzales Vicente, and W. H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 66-70. Cable, D. R. 1969. Competition in the semidesert grass-shrub type as influenced by root systems, growth habits, and soil moisture extraction. Ecology 50: 27-38. Cable, D. R. 1971. Lehmann lovegrass on the Santa Rita Experimental Range, 1937-1968. Journal of Range Management 24: 17-21. Cable, D. R. 1975a. Influence of precipitation on perennial grass production in the semidesert southwest. Ecology 56: 981- 986. Cable, D. R. 1975b. Vegetation responses to grazing, rainfall, site condition, and mesquite control on semidesert range. USDA Forest Service, Research Paper RM-149. Cable, D. R. 1980. Seasonal patterns of soil water recharge and (water) extraction (by perennial grasses and native shrubs) on semidesert ranges. Journal of Range Management 33: 9-15. Cable, D. R., and S. C. Martin. 1973. Invasion of semidesert grassland by velvet mesquite and associated vegetation changes. Journal of the Arizona Academy of Science 8: 127-134. Callison, J. C. 1988. Site quality indices for Emory oak. In: Ffolliott, P. F., and J. D. Hasbrouck, editors. Oak woodland management: Proceedings of the workshop. School of Renewable Natural Resources, University of Arizona, Tucson, Arizona, pp. 39-43. Callison, J. C. 1989. Site quality indices for the Emory oak woodlands of southeastern Arizona. PhD Dissertation, University of Arizona, Tucson, Arizona. Campbell, R. S. and J. G. Keller. 1932. Growth and reproduction of Yucca elata. Ecology 13: 364-374. Carter, M. G. 1964. Effects of drought on mesquite. Journal of Range Management 17: 275-276. Cartledge, T. R., and J. G. Propper. 1993. Pi¤on-juniper ecosystems through time: Information and insights from the past. In: Aldon, E. F., and D. W. Shaw, technical coordinators. Managing pi¤on-juniper ecosystems for sustainability and social needs. USDA Forest Service, General Technical Report RM-236, pp. 63-71. Case T. L. and M. L. Cody, editors. 1983. Island biogeography in the Sea of Cortez. University of California Press, Berkeley, California. Cepeda-Pizarro, J. G., and W. G. Whitford. 1990. Decomposition patterns of surface leaf litter of six plant species along a Chihuahuan Desert watershed. The American Midland Naturalist 123: 319-330. Chew, R. M. 1982. Changes in herbaceous and suffrutescent perennials in grazed and ungrazed decertified grassland in southeastern Arizona, 1958-1978. The American Midland Naturalist 108: 159-169. Chew, R. M. 1987. Population dynamics of colonies of three species of ants in desertified grassland, southeastern Arizona, 1958-1981. The American Midland Naturalist 118: 177-188. Chew, R. M., and A. E. Chew. 1965. The primary productivity of a desert shrub (Larrea tridentata) community. Ecological Monographs 35: 355-375. Chojnacky, D. C. 1988. Juniper, pinyon, oak, and mesquite volume tables for Arizona. USDA Forest Service, Research Paper INT-391. Chojnacky, D. C. 1991. Growth prediction for Arizona's mesquite (Prosopis velutina) woodlands. Forest Ecology and Management 42: 293-310. Cholewa, A. F., and D. M. Henderson. 1993. Iridaceae: Iris family. Journal of the Arizona-Nevada Academy of Science 27: 215-217. Clary, W. P., and D. A. Jameson. 1981. Herbage production following tree and shrub removal in the pinyon-juniper type of Arizona. Journal of Range Management 34: 109-113. Claveran, R. A. 1965. Survival and spreading ability of endemic and exotic grasses on a desert grassland site. PhD Dissertation, University of Arizona, Tucson, Arizona. Cleaveland, M. K., E. R. Cook, and D. W. Stahle. 1992. Secular variability of the southern oscillation detected in tree-ring data from Mexico and the southern United States. In: Diaz, H. S., and V. Markgraf, editors. El Ni¤o: Historical and paleoclimatic aspects of the southern Oscillation. Cambridge University Press, Cambridge, England, pp. 271-293. Cody, M. L. 1993. Do cholla cacti (Opuntia spp., subgenus Cylindropuntia) use or need nurse plants in the Mojave Desert? Journal of Arid Environments 24: 139-154. Colhoun, J. 1979. Predisposition by the environment. In: Plant disease, an advanced treatise. Volume IV - how pathogens induce disease. Academic Press, Inc., New York, pp. 75-96. Columbus, J. T., III. 1988. Flora of Cooke's Range, southwestern New Mexico. MS Thesis, University of New Mexico, Albuquerque, New Mexico. Cooper, C. F. 1960. Changes in vegetation, structure, and growth of southwestern pine forests since white settlement. Ecology 42: 493-499. Cornelius, J. M, P. R. Kemp, J. A. Ludwig, and G. L. Cunningham. 1991. The distribution of vascular plant species and guilds in space and time along a desert gradient. Journal of Vegetation Science 2: 59-72. Cotecoca. 1974. Vegetaci¢n del Estado de Sonora. Secretara de Agricultura y Ganaderia, Hermosillo, Sonora, Mexico. Cox, J. R. 1984. Shoot production and biomass transfer of big sacaton (Sporobolus wrightii). Journal of Range Management 37: 377-380. Cox, J. R. 1985. Above-ground biomass and nitrogen quantities in a big sacaton (Sporobolus wrightii) grassland. Journal of Range Management 38: 273-276. Cox, J. R. 1988. Seasonal burning and mowing impacts on Sporobolus wrightii grasslands. Journal of Range Management 41: 12-15. Cox, J. R. 1992. Lehmann lovegrass live component biomass and chemical composition. Journal of Range Management 45: 523-527. Cox, J. R., and G. L. Jordan. 1983. Density and production of seeded range grasses in southeastern Arizona (1970-1982). Journal of Range Management 36: 649-651. Cox, J. R., G. B. Ruyle, and B. A. Roundy. 1990. Lehmann lovegrass in southeastern Arizona: Biomass production and disappearance. Journal of Range Management 43: 367-372. Cox, J. R., M. H. Martin-R, F. A. Ibarra F., and H. L. Morton. 1986. Establishment of range grasses on various seedbeds at creosotebush (Larrea tridentata) sites in Arizona, U.S.A. and Chihuahua,Mexico. Journal of Range Management 39: 540-546. Cox, J. R., G. B. Ruyle, J. H. Fourie, and C. Donaldson. 1988. Lehmann lovegrass-central South Africa and Arizona, USA. Rangelands 10: 53-55. Cox, J. R., H. L. Morton, T. N. Johnsen, Jr., G. L. Jordan, S. C. Martin, and L. Cerro. 1984. Vegetation restoration in the Chihuahuan and Sororan Deserts of North America. Rangelands 6: 112-116. Cregg, B. M. 1992. Leaf area estimation of mature foliage of Juniperus. Forest Science 38: 61-67. Crosswhite, F. S. 1979. J. G. Lemmon & wife, plant explorers in Arizona, California, and Nevada. Desert Plants 1: 12-21. Cunningham, R. S. 1972. Evaluation on transpiration suppressants as an alternative to the eradication of salt cedar thickets. MS Thesis, University of Arizona, Tucson, Arizona. Currie, P. O., M. J. Moriss, and D. L. Neal. 1973. Uses and capabilities of electronic capacitance instruments for estimating standing herbage. Journal of the British Grassland Society 28: 155-160. Davey, J. R. 1980. Energy flow dynamics of a desert grassland ecosystem. PhD Dissertation, Northern Arizona University, Flagstaff, Arizona. D vila Aranda, P. D., and M. T. Germ n Ram¡rez. 1991. Colecciones Biol¢gicas Nacionales del Instituto de Biolog¡a. Herbario Nacional de M‚xico, Universidad Nacional Aut¢noma de M‚xico, M‚xico, D.F. Davis, O. K. 1987. Palynological evidence for historic juniper invasion in central arizona: A late-quaternary perspective. In: Everett, R.L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical Report INT-215, pp. 120-124. Davis, O. K., and R. M. Turner. 1986. Palynological evidence for the historic expansion of juniper and desert shrubs in Arizona, USA. Review of Paleobotany and Palynoloov 49: 177-193. Day, A. D., and F. R. H. Katterman. 1992. Sewage sludge provides plant growth factors in arid environments. Journal of Arid Environments 23: 229-233. Dempster, L. T. 1995. Rubiaceae: Madder family. Journal of the Arizona-Nevada Academy of Science 29: 29-38. Dick-Peddie, W. A. 1993. New Mexico vegetation: Past, present and future. University of New Mexico Press, Albuquerque, New Mexico. Dodson, G. 1987. Xanthoteras sp. (Hymenoptera: Cunipidae) Gall abundance on shinnery oak (Quercus havardii) in New Mexico: An indicator of plant stress? The Southwestern Naturalist 32: 462-468. Duenez, R. L., Jr. 1987. Oak fuelwood volume estimation in the Huachuca Mountains of Arizona (Emory oak). MS Thesis, University of Arizona, Tucson, Arizona. Earle, W. Hubert. 1980. Cacti of the Southwest. Rancho Arroyo Book Distributor, Tempe, Arizona. Ecker, L. S. 1994. Factors effecting the distribution and evolution of Agave chrysantha Peebles and Agave palmeri Engelm. (Agavaceae). In: DeBano, L. F., A. N. Garibay, and A. Ortega-Rubio, compilers. Conference on biodiversity and management of the Madrean archipelago. Abstracts: 74-75. Elias, T. S., J. Bock, O. Dorado, A. Liston, K. Tomlinson, and J.L.Villasenor. 1989. Checklist of the vascular plants of the Research Ranch, Elgin, Arizona. The Research Ranch Sanctuaiy, Elgin, Arizona. Elmore, F. H. 1976. Shrubs and trees of the Southwest uplands. Southwest Parks and Monuments Association, Tucson, Arizona. Everitt, B. L. 1968. Use of the cottonwood in an investigation of the recent history of a floodplain. American Journal of Science 266: 417-439. Ezcurra, E., M. Equihua, and J. L¢pez-Portillo. 1987. The desert vegetation for El Pinacate, Sonora, Mexico. Vegetation 71: 49-60. Faeth, S. H. 1992. Interspecific and intraspecific interactions via plant responses to folivory: An experimental field test. Ecology 73: 1802-1813. Fay, J. M. 1978. Vegetation and flora of the Patagonia-Sonoita Creek Sanctuary, Patagonia. The Nature Conservancy, Tucson, Arizona. Felger, R. S. 1990. Mesquite, a world food crop. Aridus 2(1): 1-3. Felger, R. S. 1991. Senecio pinacatensis (Asteraceae), a new species from the Pinacate region of Sonora, Mexico. Phytologia 74: 326-332. Felger, R. S. 1993. Synopsis of the vascular plants of northwestern Sonora, Mexico. Ecologica 2: 11-44. Felger, R. S. and M. Fishbein. 1993. Noteworthy collections. Mexico. Madro¤o 40: 270-271. Felger, R. S., and M. B. Johnson. 1995. Trees of the northern Sierra Madre Occidental and sky islands of southwestern North America. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp.71-83. Felger, R. S., and M. F. Wilson. 1995. Northern Sierra Madre Occidental and it's Apachian outliers: A neglected center of biodiversity. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 36-59. Felger, R. S., P. L. Warren, S. A. Anderson, and G. P. Nabhan. 1992. Vascular plants of a desert oasis: Flora and ethnobotany of Quitobaquito, Organ Pipe Cactus National Monument, Arizona. In: Proceedings of the San Diego Society of Natural History 8: 1-39. Felker, P., G. H. Cannell, P. R. Clark, J. F. Osborn, and P. Nash. 1983. Biomass production of Prosopis species, Leucaena, and other leguminous trees grown under heat/drought stress. Forest Science 29: 592-606. Fenner, P., W. W. Brady, and D. R. Patton. 1984. Observations on seeds and seedlings of Fremont cottonwood. Desert Plants 6: 55-58. Fenner, P., W. W. Brady, and D. R. Patton. 1985. Effects of regulated water flows on regeneration of Fremont cottonwood. Journal of Range Management 38: 135-138. Ffolliott, P. F. 1980. Western live oak. In: Eyre, F.H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., p. 118. Ffolliott, P. F. 1988a. Characteristics of the oak woodlands. In: Ffolliott, P. F., and J. D. Hasbrouck, editors. Oak woodland management: Proceedings of the workshop. University of Arizona, Tucson, Arizona, School of Renewable Natural Resources, pp. 1-6. Ffolliott, P. F. 1988b. Initial survival and growth of tree seedlings in a water harvesting agrisystem. Hydrology and Water Resources in Arizona and the Southwest 18: 43-47. Ffolliott, P. F. 1989. Arid zone forestry program: State of knowledge and experience in North America. Agricultural Experiment Station, University of Arizona, Technical Bulletin 264, Tucson, Arizona. Ffolliott, P. F., and D. P. Guertin. 1987. Opportunities for multiple use values in the encinal oak woodlands of North America. In: Aldon, E.F., Gonzales Vicente, C.E., and Moir, W.H., technical coordinators. Strategies for classification of natural vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 182-189. Ffolliott, P. F., and D. P. Guertin. 1995. Simulation of changes in stand structure of woodlands in the Madrean archipelago region. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 608-611. Ffolliott P. F., M. Fogel y G. Gottfried. 1992. Recursos forestales de la Sierra de La Laguna. In: Ortega A., editor. Uso y manejo de los recursos naturales en La Sierra de la Laguna Baja California Sur. Centro de Investigaciones Biol¢gicas de Baja California Sur, Publicacion 5. pp. 111-121. Ffolliott, P. F., G. J. Gottfried, L. F. DeBano, and A. Ortega. 1994. A bibliography for the northern madrean biogeographic province. Conference on the biodiversity and management of the Madrean archipelago: The sky islands of the southwestern United States and Northern Mexico, University of Arizona, Tucson, Arizona. Ffolliott, P. F., W. O. Rasmussen, and D. P. Guertin. 1988. STAND: An inter-active model to simulate the growth and yield of woodlands in the Southwest. In: Ek, A. R., Shifley, S. R., Burk, T. E., editors. Forest growth modelling and prediction: Proceedings of the IUFRO conference. USDA Forest Service, General Technical Report NC-120, pp. 968-975. Fishbein, M. and R. S. Felger. 1993. Noteworthy collections. Mexico. Madro¤o 40: 271. Fishbein, M., R. S. Felger, and F. Garza. 1995. Another jewel in the crown: a report on the flora of the Sierra de los Ajos, Sonora, Mexico. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and Management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 126-134. Fisher, J. T., G. A. Fancher, and E. F. Aldon. 1990. Factors affecting establishment of one-seed juniper (Juniperus monosperma) on surface-mined lands in New Mexico. Canadian Journal of Forest Research 20: 880-886. Fisher, J. T., G. A. Fancher, and R. W. Neumann. 1986. Survival and growth of containerized native juniper (Juniperus monosperma) on surface-mined lands in New Mexico. Forest Ecology and Management 16: 291-299. Fisher, J. T., P. A. Glass, and J. T. Harrington. 1995. Temperate pines of northern Mexico: Their use, abuse and regeneration. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 165-173. Fisher, J. T., J. G. Mexal, and R. D. Pieper. 1988. Pinyon-juniper woodlands of New Mexico: A biological and economic appraisal. Agricultural Experiment Station, New Mexico State University, Special Report 73, Las Cruces, New Mexico. Fisher, P. C. 1989. 70 common cacti of the Southwest. Southwest Parks and Monuments Associations, Tucson, Arizona. Fletcher, R. A. 1972. A floristic assessment of the Datil Mountains. MS Thesis, University of New Mexico, Albuquerque, New Mexico. Fletcher, R. A. 1985. Differentiation of Juniperus erythrocarpa and Juniperus monosperma. USDA Forest Service, Southwestern Region, Albuquerque, New Mexico. Floyd, D. 1987. The desert oasis. Arizona Land and People 18: 11-15, 17-18. Folk, D. A., and P. Warren. 1994. Status report and monitoring recommendations for rare plants of the Coronado National Forest. The Nature Conservancy of Arizona, Tucson, Arizona. Fowler, W. P. 1990. Variable-density yield tables for Emory oak of southeastern Arizona. PhD Dissertation, University of Arizona, Tucson, Arizona. Frasier, G. W., J. R. Cox, and D. A. Woolhiser. 1987. Wet-dry cycle effects on warm-season grass seedling establishment. Journal of Range Management 40: 2-6. Friedman, S. K., and E. H. Zube. 1992. Assessing landscape dynamics in a protected area. Environmental Management 16: 363-370. Frost, W. E. 1986. Development of resource value ratings and estimation of carrying capacity of southern Arizona rangelands. PhD Dissertation, University of Arizona, Tucson, Arizona. Fryxell, P. A. 1993. Malvaceae: Mallow family (All genera except Sphaeralcea). Journal of the Arizona-Nevada Academy of Science 27: 222-236. Gama-Castro, J. E. y I. Reyes-Jaramillo. 1992. Caracterizaci¢n de la variaci¢n del medio ambiente donde se distribuyen algunas species de encino. In: III Seminario nacional sobre Utilizaci¢n de Encinos. Programa y Res£menes, Linares, N.L., M‚xico, pp. 25-26. Garcia-Fernandez, M. 1989. Secuela de secado para madera de encino rojo (Quercus spp.). Thesis, Instituto Tecnologico Forestal No. 1, El Salto, Durango, Mexico. Garza, S. F. 1985. Una contribuci¢n al conocimiento de la vegetaci¢n de la reserva Nacional Forestal Lote 4 en el Noreste de Sonora. Tesis de Licenciatura, Facultad de Sciencias Biol¢gicas, Universidad Nacional Aut¢noma de M‚xico, M‚xico, D.F. Garza, S. F. 1993. Sistema de areas naturales protegidas del estado de Sonora (SANPES). Gobierno del Estado de Sonora, Secretaria de Infraestructura Urbana y Ecologia, Centro Ecologico de Sonora, Hermosillo, Mexico. Gatewood, J. S. 1950. Use of water by bottom-land vegetation in lower Safford Valley, Arizona. U.S. Department of the Interior, Geological Survey, Washington, D.C. Gawith, E. L. 1987. Possible causes of alligator juniper (Juniperus deppeana) invasion in southeastern Arizona. MS Thesis, University of Colorado, Boulder, Colorado. Gehlbach, F. H. 1981. Mountain islands and desert seas: A natural history of the US-Mexican borderlands. Texas A & M University Press, College Station, Texas. Genery, H. S. 1982. Sinaloan deciduous forest. Desert Plants 4: 73-77. Gentry, H. S. 1942. Rio Mayo Plants: A study of the flora and vegetation of the valley of the Rio Mayo. Carnegie Institute, Publication 527, Washington, D.C. Gentry, H. S. 1946a. Notes on the vegetation of Sierra Surutato in northern Sinaloa. Torrey Botanical Club Bulletin 73: 451-462. Gentry, H. S. 1946a. Sierra Tacuichamona - a Sinaloa plant locale. Bulletin of the Torrey Botanical Club 73: 356-362. Gentry, H. S. 1972. The Agave family in Sonora. USDA Agriculture Handbook 399, Washington, D.C. Gentry, H. S. 1978. The Agaves of Baja California. California Academy of Sciences, San Francisco, California. Gentry, H. S. 1982. Agaves of continental North America. University of Arizona Press, Tucson, Arizona. Gibbens, R. P. 1981. Grass and forb production on sprayed and nonsprayed mesquite (Prosopis glandulosa Torr.) dunelands in south-central New Mexico. In: Smith, J. A., and V. W. Hay, editors. Proceedings of the XIV International Grassland Congress. Westview Press, Boulder, Colorado, pp. 437-440. Gibbens, R. P., and R. F. Beck. 1987. Increase in number of dominant plants and dominance-classes on a grassland in the northern Chihuahuan Desert. Journal of Range Management 40: 136- 139. Gibbens, R. P., and R. F. Beck. 1988. Changes in grass basal area and forb densities over a 64-year period on grassland types of the Jornada Experimental Range. Journal of Range Management 41: 186-192. Gibbens, R. P., R. F. Beck, R. P. McNeely, and C.H. Herbel. 1992. Recent rates of mesquite establishment in the northern Chihuahuan Desert. Journal of Range Management 45: 585-588. Gibbens, R. P., K. M. Havstad, D. D. Billheimer, and C. H. Herbel. 1993. Creosote bush vegetation after 50 years of lagmorph exclusion. Oecologia 94: 210-217. Gilbertson, R. L. 1969. A new species of Inonotus on southwestern sycamores. The Southwestern Naturalist 14: 123-125. Gilbertson, R. L., and J. P. Lindsey. 1978. Basidiomycetes that decay junipers in Arizona. II. The Great Basin Naturalist 38: 42-48. Gilbertson, R. L., H. H. Bursdall, and E. R. Canfield. 1976. Fungi that decay mesquite in southern Arizona. Mycotaxon 3: 487-551. Gilmartin, A. J. and M. L. Neighbours. 1978. Flora of the Cape Region of Baja California Sur. In: National Geographic Society, Research Report 1969 Projects, pp. 219-225. Gingrich, R. W. 1993. The political ecology of deforestation in the Sierra Madra Occidental of Chihuahua. Master's Professional Paper, University of Arizona, Tucson, Arizona. Glendening, G. E., and D. E. Brown. 1982. Mesquite (Prosopis juliflora) response to severe freezing in southern Arizona. Journal of the Arizona-Nevada Academy of Science 17: 15-18. Goldberg, D. E. 1982. The distribution of evergreen and deciduous trees relative to soil type: An example from the Sierra Madre, Mexico and a general model. Ecology 63: 942-951. Goldberg, D. E., and R. M. Turner. 1986. Vegetation change and plant demography in permanent plots in the Sororan Desert. Ecology 67: 695-712. Goldman, A. F. 1945. A new pronghorn from Sonora. Proceedings Biological Society Washington 58: 3-4. Goldman, E. A., and R.T. Moore. 1945. Biotic provinces of Mexico. Journal of Mammalogy 26: 347-360. Gomez Pompa, A. 1963. El genero Agave. Cact. Suculent. Mexico 8: 3-28. Gonz lez-Elizondo, S. 1983. La Vegetaci¢n de Durango. CIIDIR-IPN-Unidad Durango Vicente Guerrero, Durango, Mexico. Gonz lez-Elizondo, S., and M. Gonz lez-Elizondo. 1992. El g‚nero Arbutus en la Sierra Madre Occidental, consideraciones sobre su taxonom¡a y distribuci¢n. Boletin del Instituo de Bot nica 1: 39-41. Gonz lez-Elizondo, M. S. y M. Gonz lez-Elizondo. 1992. Los Encinos de Durango, Mexico. 1992. III Seminario Nacional sobre Utilizaci¢n de Encinos. Programa y Res£menes. Linares, N.L., Mexico, pp. 22-23. Gonz les-Elizondo, M. S., M. Gonz lez-Elizondo, and Herrera A. 1991. Listados flor¡sticos de M‚xico. IX. Flora de Durango. Universidad Nacional Aut¢noma de M‚xico, Mexico, D.F. Gonzalez Hernandez, J. J. 1986. Analisis y perspectivas de la actividad forestal en El Estado de Chihuahua. MS Thesis, Universidad Autonoma Chapingo, Chapingo, Mexico Goodding, L. N. 1950a. Grasses on the Fort Huachuca Wildlife Area. In: Wallmo, C. O., editor. Fort Huachuca Wildlife Area surveys 1950-1951. Arizona Game and Fish Commission, Phoenix, Arizona, pp. 3-11. Goodding, L. N. 1950b. Plants of the Huachuca Mountains. In: Wallmo, C. O., editor. Fort Huachuca Wildlife Area Surveys 1950-1951. Arizona Game and Fish Commission, Phoenix, Arizona, pp. 12-19. Gordon, A. G. 1968. Ecology of Picea chihuahuana Martinez. Ecology 49: 880-896. Gori, D. 1992. Sensitive plant studies in the sky island mountain ranges of southeastern Arizona. In: A. M. Barton and S. S. Sloane, editors. Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 27-30. Gould, F. W. 1951. Grasses of the southwestern United States. University of Arizona Press, Tucson, Arizona. Graham, A. 1993. Historical factors and biological diversity in Mexico, In: Ramamoorthy, T. P., R. Bye, A. Lot, J. Fa, editors. Biological diversity in M‚xico: Origins and distribution. Oxford University Press, New York, pp. 109-127. Grant, V., and K. A. Grant. 1965. Flower pollination in the phlox family. Columbia University Press, New York Gray, A. 1886. Contributions to American botany. 2. Sertum Chihuahuense. Proceedings of the American Academy of Arts and Sciences 21: 378-409. Gross, F. A., and W. A. Dick-Peddie. 1979. A map of primeval vegetation in New-Mexico USA. The Southwestern Naturalist 24: 115-122. Grover, H. D., and H. B. Musick. 1990. Shrub land encroachment in southern Mexico, USA: An analysis of desertification processes in the Mexican Southwest. Climate Change 17: 305-330. Gutierrez, A. F. 1987. Ensayo de ocho clones de nopal tunero en Aguascalientes, Mexico. In: Aldon, E. F., C. E. Gonzales V., and W. H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 239-241. Hanks, J. P., and W. A. Dick-Peddie. 1974. Vegetation patterns of the White Mountains, New Mexico. The Southwestern Naturalist 18: 371-382. Haque, Z., A. Younga, K. C. McDaniel, and R. D. Pieper. 1991. Two-phase pattern in mesquite-herbland vegetation in southern New Mexico. The Southwestern Naturalist 36: 54-59. Hardegree, S. P. 1989. Diecrepancies between water potential isotherm measurements on Pinus ponderosa seedling shoots: Xylem hysteresis and apoplasmic osmotic potentials. Plant, Cell and Environment 12: 57-62. Hardegree, S. P., and W. E. Emmerich. 1991. Variability in germination rate among seed lots of Lehmann lovegrass. Journal of Range Management 44: 323-326. Hardegree, S. P., and W. E. Emmerich. 1993. Germination response of hand-threshed Lehmann lovegrass seeds. Journal of Range Management 46: 203-207. Hastings, J. R. 1959. Vegetation change and arroyo cutting in southeastern Arizona. Journal of Arizona Academy of Science 1: 60-67. Hastings, J. R. 1963. Historical changes in the vegetation of a desert region. PhD Dissertation, University of Arizona, Tucson, Arizona. Hastings, J. R. and R. M. Turner. 1965. The changing mile. University of Arizona Press, Tucson, Arizona. Hastings, J. R., R. Turner, and D. K. Warren. 1972. An atlas of some plants distribution in the Sororan Desert, University of Arizona, Institute of Atmospheric Physics, Technical Report 21, Tucson, Arizona. Hawksworth, F. G., and D. Wiens. 1993. Viscaceae: Mistletoe family. Journal of the Arizona-Nevada Academy of Science 27: 241-245. Heald, W. F. 1951. Sky Islands in Arizona. Natural History 60: 56-63, 95-96. Heald, W. F. 1967. Sky Island. Van Nostrand, Princeton, New Jersey. Heald, W. F. 1975. The Chiricahua Mountains: Formerly Sky Island. University of Arizona Press, Tucson, Arizona. Hendrickson, D. A., and W.L. Minckley. 1985. Ci‚negas - vanishing climax communities of the American Southwest. Desert Plants 6: 131-176. Henrickson, J. 1972. A taxonomic revision of the Fouquieriaceae. Aliso 7: 439-537. Hennessy, J. T., R. P. Gibbens, J. M. Tromble, and M. Cardenas. 1985. Mesquite (Prosopis glandulosa Torr.) dunes and interdunes in southern New Mexico: A study of soil properties and soil water relations. Journal of Arid Environments 9: 27-38. Herbel, C. H. 1985. Vegetation changes on arid rangelands of the Southwest. Rangelands 7: 19-21. Hernandez Diaz, J., J. Prieto Ruiz and A. Barretero Jaquez. 1991. La actividad forestal de Durango en CIFRAS. Centro de Investigacion, Region al del Norte Centro Campo Experimental Valle del Guadiana, INIFAP, Durango, Durango. Mexico. Hess, W. J., and J. Henrickson. 1987. A taxonimic revision of Vauquelinia. SIDA 12: 101-163. Hodgson, W. 1994. Bixaceae: Lipstick family. Journal of the Arizona-Nevada Academy of Science 27: 188-189. Horton, J. S. 1964. Notes on the introduction of deciduous tamarisk. USDA Forest Service Research Note RM-16. Horton, J. S. 1977. The development and perpetuation of the permanent the permanent tamarisk zone of the Southwest. In: Johnson, R. R., an D. A. Jones, technical coordinators. Importance, preservation, and management of riparian habitat: A symposium. USDA Forest Service, General Technical Report RM-43, pp. 124-127. Horton, J. S., F. C. Mounts, and J. M. Kraft. 1960. Seed germination and seedling establishment of phreatophyte species. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Station Paper 48. Houck, B., and S. Ambrose. 1978. Fuelwood inventory and management plan. USDA Forest Service, Coronado National Forest, Douglas, Arizona. Howell, D. 1972. Physiological adaptations in the syndrome of chiropterophily with emphasis on the bat Leptonycteris lydekker. PhD Dissertation, University of Arizona, Tucson, Arizona. Howell, D. J. and B. S. Roth. 1981. Sexual reproduction in agaves: The benefits of bats: The cost of semelparous advertising. Ecology 62: 3-7. Hubbard, J. P. 1977. A biological inventory of the Animas Mountains, Hidalgo County, New Mexico. New Mexico Department of Game and Fish Endangered Species Program, Albuequerque, New Mexico. Humphrey, R. R. 1958. The desert grassland: A history of vegetational change and an analysis of causes. The Botanical Review 24: 193-253. Hutto, R. L., J. R. McAuliffe, and L. Hogan. 1986. Distributional associates of the saguaro (Carnegiea gigantea). The Southwestern Naturalist 31: 469-476. Idso, S. B. 1992. Shrubland expansion in the American Southwest. Climate Change 22: 85-86. Idso, S. B., B. A. Kimball, M. G. Anderson, and J. R. Mauney. 1987. Effects of atmospheric CO, enrichment on plant growth: The interactive role of air temperature. Agriculture, Ecosystems, Environment 20: 1-10. Jenkins, M. B., R. A. Virginia, and W. M. Jarrell. 1988. Depth distribution and seasonal populations of mesquite-nodulating rhizobia in warm desert ecosystems. Soil Science Society of America Journal 52: 1644-1650. Jenkins, M. B., R. A. Virginia, and W. M. Jarrell. 1989. Ecology of fast-growing and slow-growing mesquite-nodulating rhizobia in Chihuahuan and Sororan Desert ecosystems. Soil Science Society of America Journal 53: 543-549. Johnsen, T. N., Jr. 1966. Factors affecting one-seed juniper invasion of Arizona grasslands. PhD Dissertation, Duke University, Durham, North Carolina. Johnsen, T. N., Jr. 1987. Seeding pinyon-juniper sites in the Southwest. In: Everett, R.L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical Report INT-215, pp. 465-472. Johnsen, T. N., and J. W. Elson. 1979. Sixty years of change on a central Arizona grassland-juniper woodland ecotone. USDA Agricultural Research Service, Agricultural Reviews and Manuals ARM-W-7. Johnson, M. B. 1992. The genus Bursera (Burseraceae) in Sonora, Mexico and Arizona. Desert Plants 10: 126-144. Johnson, W. T. 1988. Flora of the Pinaleno Mountains, Graham County, Arizona. Desert Plants 8: 147-162, 175-191. Johnson-G., D., and A. Navarro-C. 1992. Zacate buffel biodiversidad en el Desierto Sonorense. Ecolog¡a, recursos naturales y medio ambiente en Sonora. Gobierno del Estado de Sonora y el Colegio de Sonora, Hermosillo, Sonora, Mexico. Jones, M. E. 1930. Botanizing in Arizona. Contributions to Western Botany 16: 1-31. Kariscak, M. M. 1973. Aspects of thorn development on Prosopis juliflora (Swartz) DC var. veluntina (Woot.) Sarg. and Cercidium australe [I. M. Johnson]. MS Thesis, University of Arizona, Tucson, Arizona. Karpiscak, M. M. 1980. Secondary succession of abandoned field vegetation in southern Arizona. PhD Dissertaion, University of Arizona, Tucson, Arizona. Karpiscak, M. M., and O. M. Grosz. 1979. Dissemination trails of russian thistle (Salsola kali) in recently fallowed fields. Journal of the Arizona-Nevada Academy of Science 14: 50-52. Kaufmann, M. R., W. H. Moir, and R. L. Bassett, technical coordinators. 1992. Old growth forests in the Southwest and Rocky Mountain Regions: Proceedings of a workshop. USDA Forest Service, General Technical Report RM-213. Kearney, T. H. and R. H. Peebles. 1942. Flowering plants and ferns of Arizona. USDA Miscellaneous Publication 423. Kearney, T. H., and R. H. Peebles. 1960. Arizona flora. University of California Press. Los Anageles, California. Keeley, J., A. Massihi, and R. Goar. 1992. Growth form dichotomy in subspecies of Arctostaphylos peninsularis from Baja California. Madrono 39: 285-287. Kellogg, R. S. 1902. Forest conditions in southern Arizona. Forestry and Irrigation 8: 501-505. Kenney, W. R. 1983. Patterns of post-grazing succession in the semi-desert grassland of southeastern Arizona, with respect to the shrub Baccharis pteronioides. MA Thesis, University of Colorado, Boulder, Colorado. Kenney, W. R., J. H. Bock, and C. E. Bock. 1986. Responses of the shrub, Baccharis pteronioides, to livestock enclosure in southeastern Arizona. The American Midland Naturalist 116: 429- 431. Kurmes, E. A., and D. E. Wommack. 1980. Arizona cypress. In: Eyre, F. H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., p. 117. Laferriere, J. E. 1993a. Dipsacaceae: Teasel family. Journal of the Arizona-Nevada Academy of Science 27: 201-202. Laferriere, J. E. 1993b. Juglandaceae: Walnut family. Journal of the Arizona-Nevada Academy of Science 27: 219. Laferriere, J. E. 1993c. Menispermaceae: Moon-seed family. Journal of the Arizona-Nevada Academy of Science 27: 237. Laferriere, J. E. 1993d. Plantanaceae: Sycamore or plane tree family. Journal of the Arizona-Nevada Academy of Science 27: 238. Laferriere, J. E. 1993e. Santalaceae: Sandalwood family. Journal of the Arizona-Nevada Academy of Science 27: 240. Lamb, S. H. 1971. Woody plants of New Mexico and their value to wildlife. New Mexico Game and Fish Department, Bulletin 14, Albuquerque, New Mexico. Landrum, L. R. 1993. Fagaceae: Oak family. Journal of the Arizona-Nevada Academy of Science 27: 203-214. Landrum, L. R. 1995. Aceraceae: Maple family. Journal of the Arizona-Nevada Academy of Science 29: 2-5. Lanner, R. M. 1974. Natural hybridization between Pinus edulis and Pinus monophilla in the American Southwest. Silvae Genetica 23: 99-134. Larson, F. R. 1980. Pinyon-Juniper. In: Eyre, F. H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., pp. 116-117. Lee, J. A. 1986. Origin of mounds under creosote bush (Larrea tridentata) on terraces of the Salt River, Arizona. Journal of the Arizona-Nevada Academy of Science 21: 23-27. Lehr, J. H. 1978. A catalog of the flora of Arizona. Desert Botanical Garden, Phoenix, Arizona. Lehr, J. H. and D. J. Pinkava. 1980. A catalogue of the flora of Arizona. Supplement I. Journal of the Arizona-Nevada Academy of Science 15: 17-32. Lehr, J. H. and D. J. Pinkava. 1982. A catalogue of the flora of Arizona. Supplement II. Journal of the Arizona-Nevada Academy of Science 17: 19-26. Leithliter, J. R. 1980. Vegetation and flora of the Chiricahua Wilderness Area. PhD Dissertation, Arizona State University, Tempe, Arizona. Leopold, A. 1924. Grass, brush, timber and fire in southern Arizona. Journal of Forestry 22: 1-10. LeSueur, H. 1945. The ecology of the vegetation of Chihuahua, Mexico, north of the parallel twenty-eight. University of Texas, Publication 4521, Austin, Texas. Levin, G. A. 1995. Euphorbiaceae: Spurge family. Journal of the Arizona-Nevada Academy of Science 29: 18-24. Linares, E. and R. Bye. 1987. A study of four medicinal plant complexes of Mexico and adjacent United States. Journal of Ethnopharmacology 19: 153-183. Little, A. 1943. Revisions of status of southwestestern desert trees and shrubs. Amererican Journal of Botany 30: 235. Little, E. L., Jr. 1950. Southwestern trees: A guide to the native species of New Meixco and Arizona. USDA Agricultural Handbook 9. Lowe, C. H. 1961. Biotic communities in the sub-mogollon region of the inland Southwest. Arizona Academy Science Journal 2: 40-49. Lowe, C. H. 1964. Arizona's natural environment. University of Arizona Press, Tucson, Arizona. Lowe, C. H., and D. E. Brown. 1973. The natural vegetation of Arizona. Arizona Resource Information Systems, No. 2. Luz, J. L. L. 1988a. Quercus arizonica Sargent (Fagaceae). Madrono 35: 280. Luz, J. L. L. 1988b. Quercus oblongifolia Torr. (Fagaceae). Madrono 35: 280. Luz, J.L.L., R.D. Cadena, M.D. Le¢n, and R.C. Benet. 1995. Flora of the woodlands of the Sierra de La Laguna, Baja California Sur, M‚xico. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 144-151. MacGregor, A. N., and D. E. Johnson. 1971. Capacity of desert algal crusts to fix atmospheric nitrogen. Soil Science of America Proceedings 35: 843-844. MacMahon, J.A., and F.H. Wagner. 1985. The Mojave, Sonoran and Chihuahuan deserts of North America. In: Evenari, M., I. Noy-Meir, and D.W. Goodall, editors. Ecosystems of the world. Elsevier Publishers, New York. Maingi, J. K. 1992. Specific gravity and estimated physical properties of Emory oak in southeastern Arizona. MS Thesis, University of Arizona, Tucson, Arizona. Maingi, J. K., and P. F. Ffolliott. 1992. Specific gravity and estimated physical properties of Emory Oak in southeastern Arizona. In: Ffolliott, P. F., G. J. Gottfried, D. A. Bennett, V. M. Hernandez C., A. Ortega-Rubio, and R. H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-215, pp. 147-149. Malusa, J. 1992. Xylem pressure potentials of single and double-needles pinyon pines. The Southwestern Naturalist 7: 43-48. Marshall, J. T. 1977. Highlights of research on the Santa Rita Experimental Range. In: Arid Shrublands. Proceedings of the Third Workshop of the United States/Australia Rangelands Panel. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, pp. 51-57. Martin, P. S. 1963. The Last 10,000 Years: A fossil pollen record of the American Southwest. University of Arizona Press, Tucson, Arizona. Martin, S. C. 1961. Burroweed on southern Arizona range lands. Agricultural Experiment Station, University of Arizona, Technical Bulletin 146, Tucson, Arizona. Martin, S. C. 1975. Ecology and management of southwestern semidesert grass-shrub ranges: The status of our knowledge. USDA Forest Service General Technical Report RM-156. Martin, S. C. 1980. Mesquite. In: Eyre, F. H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., pp. 116-117. Martin, S. C., and H. L. Morton. 1980. Responses of false mesquite (Calliandra eriophylla), native grasses and forbs, and Lehmann lovegrass (Eragrostis) after spraying with Picloram. Journal of Range Management 33: 104-106. Martin, S. C., and H. L. Morton. 1993. Mesquite control increases grass density and reduces soil loss in southern Arizona. Journal of Range Manaqement 46: 170-175. Martin, S. C., and H. G. Reynolds. 1973. Santa Rita Experimental Range: Your facility for research on semidesert ecosystems. Journal of the Arizona Academv of Science 8: 56-67. Martin, S. C. and F. S. Tschirley. 1962. Mesquite seeds live a long time. Progressive Agriculture in Arizona 14: 15. Martin, S. C. and R. M. Turner. 1977. Vegetation change in the Sororan Desert region, Arizona and Sonora. Journal of the Arizona Academy of Sciences. 12: 59-69. Mart¡nez, M. 1948. Los pinos mexicanos. Segunda edici¢n, aumentada considerablemente. Ediciones Botas, M‚xico. Martinez, M. 1981. Los Encinos de Mexico. Comision Forestal, Mexico, D.F. Martinez-Islas, L. 1992. Distribution of oak (Quercus spp.) in the State of Sonora, Mexico. In: Ffolliott, P. F., G. J. Gottfried, D. A. Bennett, V. M. Hernadez C., A. Ortega. and R. H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-218, p. 49. Martinez-Morales, R., and S.E. Meyer. 1985. A demographic study of Maguey verde (Agave salmiana ssp. crassispina) under conditions of intensive utilization. Desert Plants 7: 61-64. Martinez-Ojeda, E., and J. Morello. 1977. El medio fisico y las unidades fisonomico-floristicas del Bolson de Mapimi. Instituto de Ecologia, Publication 3, Mexico, D.F. Mason, C. T., Jr. 1975. Apacheria chiricahuensis: A new genus and species from Arizona. Madrono 23: 105-108. Mathiasen, R. L. 1979. Distribution and effect of dwarf mistletoes parasitizing Pinus strobiformis in Arizona, New Mexico, and northern Mexico. The Southwestern Naturalist 24: 455-461. McAuliffe, J. R. 1984. Sahuaro-nurse tree associations in the Sororan Desert: Competitive effects of sahuaros. Oecologia 64: 319-321. McAuliffe, J. R. 1994. Landscape evolution, soil formation, and ecological patterns and processes in Sororan Desert bajadas. Ecological Monographs 64: 111-148. McClaran, M. P. and M. E. Anable. 1992. Spread of introduced Lehmann lovegrass along a grazing intensity gradient. Journal of Applied Ecology 29: 92-98. McClaran, M. P. and T. R. Van Devender, editors. 1995. The desert grassland. University of Arizona Press, Tucson. McConnell, W. J., and G. F. Adams. 1974. Emory oak (Quercus emoryi) litter phenolics as environmental hazards for aquatic animals in southeastern Arizona. Journal of the Arizona Academy of Science 8: 111-115. McCormick, J., and J. W. Andresen. 1963. A subdioecious population of Pinus cembroides in southeast Arizona. Ohio Journal of Science 63: 159-163. McDade, L. A. and S. Kinsman. 1980. The impact of floral parasitism in two neotropical hummingbird-pollinated plant species. Evolution 34: 944-958. McLaughlin, S. P. 1986. Floristic analysis of the southwestern United States. The Great Basin Naturalist 46: 46-65. McLaughlin, S. P. 1992a. Are floristic areas hierarchically arranged? Journal of Biogeography 19: 21-32. McLaughlin, S. P. 1992b. Notes on the botany of the "Sky-Islands" region of southeastern Arizona. Office of Arid Lands Studies, University of Arizona, Tucson, Arizona. McLaughlin, S. P. 1992c. Vascular flora of Buenos Aires National Wildlife Refuge (including Arivaca Cienega), Pima County, Arizona. Phytologia 73: 353-377. McLaughlin, S. P. 1993a. Additions to the flora of the Pinaleno Mountains, Arizona. Journal of the Arizona-Nevada Academy of Sciences 27: 1-27. McLaughlin, S. P. 1993b. Apocynaceae: Dogbane Family. Journal of the Arizona-Nevada Academy of Science 27: 164-168. McLaughlin, S. P. 1994. Floristic plant geography: The classification of floristic areas and floristic elements. Progress in Physical Geography 18: 185-208. McLaughlin, S. P. 1995. An overview of the flora of the Sky Islands, southeastern Arizona: Diversity, affinities, and insularity. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, R. H., and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 60-70. McLaughlin, S. P., and J. E. Bowers. 1990. A floristic analysis and checklist for the northern Santa Rita Mountains, Pima Co., Arizona. The Southwestern Naturalist 35: 61-75. McPherson, G. R. 1992. Ecology of oak woodlands in Arizona. In: Ffolliott, P.F., Hernandez C., A. Ortega-Rubio, and R.H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-218, pp. 24-33. McPherson, G. R. 1993. Effects of herbivory and herbs on oak establishment in a semi-arid temperate savanna. Journal of Vegetation Science 4: 687-692. McVaugh, R. 1972. Botanical exploration in Nueva Galicia, Mexico. Contributions form the University of Michigan Herbarium 9, Ann Arbor, Michigan. Mercado, C., and L. Arriaga. 1995. Seed bank and tree fall gaps in a Mexican temperate forest. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C.. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 599-601. Merriam, G. H. 1890. Results of a biological survey of the San Francisco Mountains region and desert of the Little Colorado in Arizona. USDA, North American Fauna 3, Washington, D.C., pp 136. Meyer, J. W. 1989. First year coppice regeneration of Quercus emoryi and Quercus arizonica in the Huachuca Mountains, Arizona. MS Thesis, University of Arizona, Tucson, Arizona. Meyer, S. E., and E. Garcia-Moya. 1989. Plant community patterns and soil moisture regime in gypsum grasslands of north central Mexico. Journal of Arid Environment 16: 147-155. Miller, R. B. 1985. Hawkmoth pollination of Aquilegia chrysantha (Ranunculacaea) in southern Arizona. The Southwestern Naturalist 30: 69-76. Miller, S. A. 1987. Scanning electron microscope studies of botanical specimens from a female mummy from Chihuahua, Mexico, In: Tyson, R.A. and D.V. Elerick, editors. Two mummies from Chihuahua, Mexico - A multidisciplinary study. San Diego Museum Papers 19: 65-70, 205-357. Mogensen, H. L. 1970. Syncotyly in Quercus arizonica. American Journal of Botany 57: 1207-1210. Moorhead, D. L., and J. F. Reynolds. 1993. Changing carbon chemistry of buried creosote bush litter during decomposition in the northern Chihuahuan Desert. The American Midland Naturalist 130: 83-89. Moir, W. H. 1979. Soil-vegetation patterns in the central Peloncillo Mountains, New Mexico. The American Midland Naturalist 102: 317-331. Moir, W. H. 1983. A series vegetation classification for Region 3. In: Proceedings of the Workshop on Southwestern Habitat Types. USDA Forest Service, Southwestern Region, Albuquerque, New Mexico, pp. 91-95. Moir, W. H. 1987. Forest and woodland habitat types of Arizona south of the Mogollon Rim and southwestern New Mexico. USDA Forest Service, Southwest Region, Albuquerque, New Mexico. Moir. W. H. 1995. Persistence of uncommon cryopedic plants in the Chiricahaua Mountains spruce forest island. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264. pp. 214-218. Moir, W. H., and J. O. Carleton. 1987. Classification of pinyon-juniper sites on national forests in the Southwest. In: Everett, R.L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical ReportINT-215, pp. 216- 226. Moir, W. H., and J. H. Dietrich. 1988. Old growth ponderosa pine from succession in pine-bunchgrass forests in Arizona and New Mexico. Natural Areas Journal 8: 17-24. Moir, W. H., and M. Dodd. 1973. Natural areas of the Chiricahua National Monument. Chiricahua National Monument, Willcox, Arizona. Moir, W. H., and M .J. Larson. 1985. Forest and woodland habitat types of southern New Mexico and southern Arizona. USDA Forest Service, Southwestern Recion, Albuquerque, New Mexico. Moir, W. H., and J. A. Ludwig. 1979. A classification of spruce-fir and mixed conifer habitat types of Arizona and New Mexico. USDA Forest Service, Research Paper RM-207. Molina, F. F. E., and V. A. E. Castellanos. 1981. Aspectos demograficos de semillas y plantulas de jojoba (Simmondsia chinensis). Instituto Nacional de Investigaciones Forestales, Publicacion Especial 31. Moran, R. 1993. Crassulaceae: Stonecrop family. Journal of the Arizona-Nevada Academy of Science 27: 190-1194. Morgan, D. L., W. O. Pruitt, and F. J. Lourence. 1971. Analyses of energy momentum and mass transfers above vegetative surfaces: Fort Huachuca, Arizona. Atmospheric Sciences Laboratory, University of Arizona, Tucson, Arizona. Mosjidis, J. A. 1985. Detection and control of sandblast injury to jojoba (Simmondsia chinensis [Link] Schneider) seedlings. Desert Plants 7: 25-26. Muldavin, E. H., and R. L. DeVelice. 1987. A forest habitat type classification of southern Arizona and its relationship to forests of the Sierra Madre Occidental of Mexico. In: Aldon, E. F., C. E. Gonzales Vicente, and W. H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 24-31. Muldavin, E., F. J. Ronco, Jr., and E. F. Aldon. 1990. Consolidated stand tables and biodiversity data base for southwestern forest habitat types. USDA Forest Service General Technical Report RM-190. Muma, M. H. 1979. Arid-grassland Solpugid population variations in southwestern New Mexico (Eremobates spp.). The Florida Entomologist 62: 320-328. Munz, P. A. 1946. Aquileia - the cultivated and wild columbines. Gentes Herbarum 7: 1-150. Murrieta, X. 1978. Aprovechamiento de los recursos floristicos de las zonas aridas. Ciencia Interamericana 19: 10-17. Nabhan, G. P. 1980. Ammobroma sonorae, an endangered parasitic plant in extremely arid North America. Desert Plants 2: 188-196. Nabhan, G. P., W. Hodgson, and L. Hernandez. Plant genetic resources threatened in North American deserts: The FLORUTIL Conservation Project. In: Aldon, E. F., C. E. Gonzales Vicente, and W. H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 59-65. Nash, T. H. 1973. Additions to the lichen flora of Arizona. I. Bryologist 74: 545-548. Nash, T. H., and W. A. Weber. 1975. Additions to the lichen flora of Arizona. Bryologist 77: 472-474. Nesom, G. L. 1990. Taxonomy of the Erigeron coronarius group of Erigeron (Asteraceae: Astereae). Phylolouia 69: 237-253. Nesom, G. L., and V. D. Roth. 1981. Erigeron scopulinus (Compositae), an endemic from the southwestern United States. Journal of the Arizona-Nevada Academy of Science 16: 39-42. Nichol, A. A. 1952. The natural vegetation of Arizona. Agricultural Experimental Station, University of Arizona, Technical Bulletin 127, Tucson, Arizona, pp. 189-230. Nicholson, R. A., C. D. Bonham. 1977. Grama communities in a southeastern Arizona grassland. Journal of Range Management 30: 427-433. Niering, W. A., and C. H. Lowe. 1984. Vegetation of the Santa Catalina Mountains: Community types and dynamics. Vegetation 58: 3-28. Nilsen, E. T., P. W. Rundel, and M. R. Sharifi. 1981. Summer water relations of the desert phreatophyte Prosopis glandulosa in the Sororan Desert of southern California. Oecologia 50: 271-276. Nixon, K. 1993. The genus Quercus in Mexico. In: Ramamoorthy, T. P., R. Bye, A. Lot, and J. Fa, editors. Biological diversity of Mexico: Origins and distribution. Oxford University Press, New York, pp. 447-458. Nobel, Park S. l989. Temperature, water availability, and nutrient levels at various soil depths-consequences for shallow- rooted desert succulents, including nurse plant effects. American Journal of Botany 76: 1486-1492. Nyandiga, C. O. 1991. Storage and germination of Quercus emoryi and Quercus arizonica acorns. MS Thesis, University of Arizona, Tucson, Arizona. Nyandiga, C. O., and G. R. McPherson. 1991. Germination of Emory oak in different microsites. Proceedings Supplement to Journal of the Arizona-Nevada Academy of Science, Proceedings Supplement 20: 20. Nyandiga, C. O., and G. R. McPherson. 1992. Germination of two warm-temperate oaks, Quercus emoryi and Quercus arizonica. Canadian Journal of Forest Research 9: 1395-1401. Olsen, M. W., and I. J. Misaghi. 1984. Responses of guayule (Parthenium argentatum) seedlings to plant growth promoting fluorescent pseudomonads. Plant and Soil 77: 97-101. O'Shea-Stone, M. 1988. The seed bank in a semidesert grassland of southeastern Arizona, and its relationship to seed rain and vegetation. MA Thesis, University of Colorado, Boulder, Colorado. Parfitt, B. D. and C. M. Christy. 1992. Coronado National Memorial plant checklist a synonymized lits of the vascular plants. Department of Botany, Arizona State University, Tempe, Arizona. Parker, A. J. 1977. Aspects of the ecology, population structure, and reproductive strategy of Arizona cypress (Cupressus arizonica Greene) in southeastern Arizona. MS Thesis, University of Wisconsin, Madison, Wisconsin. Parker, A. J. 1980a. Site preferences and community characteristics of Cupressus arizonica Green (Cupressaceae) in southeastern Arizona. The Southwestern Naturalist 25: 9-22. Parker, A. J. 1980b. The successional status of Cupressus arizonica. The Great Basin Naturalist 40: 254-264. Parker, K. C. 1987. Seedcrop characteristics and minimum reproductive size of organ pipe cactus (Stenocereus thurberi) in southern Arizona. Madrono 34: 294-303. Parker, K. C. 1989. Height structure and reproductive characteristics of senita, Lophocereus schottii (Cactaceae), in southern Arizona. The Southwestern Naturalist 34: 392-401. Parker, K. F. 1990. An illustrated guide to Arizona weeds. University of Arizona Press, Tucson, Arizona. Parker, K. W., and S. C. Martin. 1952. The mesquite problem on southern Arizona ranges. USDA Circular 908. Pase, C. P., and D. E. Brown. 1982. Rocky Mountain (Petrean) and Madrean montane conifer forests. Desert Plants 4: 43-51. Patton, D. R., and P. F. Ffolliott. 1975. Selected bibliography of wildlife and habitats for the southwest. USDA Forest Service, General Technical Report RM-16. Patten, D. T., and J. C. Stromberg. 1995. Dynamics of landscape patches in the old growth forest on Mt. Graham (Pinaleno Mountains), Arizona. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 174-179. Paulsen, H. A. 1956. The effect of climate and grazing on black grama. New Mexico Agricultural Experiment Station, New Mexico State University, Las Cruces, New Mexico. Peck, R. A. B. and G. R. McPherson. 1994. Shifts in lower treeline: The role of seedling fate. Annual Meeting of the International Association of Landscape Ecology. Abstracts: 9: 105-106. Perry, J. P. Jr. 1991. The pines of Mexico and central America. Timber Press, Portland, Oregon. Phillips, F. J. 1912. Emory oak in southern Arizona. USDA Forest Service, Circular 201. Pieper, R. D. 1977. The southwestern pinyon-juniper ecosystem. In: Aldon, E. F., and T. J. Loring, technical coordinators. Ecology, uses and management of pinyon-juniper woodlands. USDA Forest Service, General Technical Report RM-39, pp. 1-6. Pieper, R. D. 1992. Species composition of woodland communities in the Southwest. In: Ffolliott, P.F., G.J. Gottfried, D.A. Bennett, V.M. Hernandez C., A. Ortega-Rubio, and R.H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-215, pp. 119-124. Pieper, R. D. 1993. Spatial variation of pi¤on-juniper woodlands in New Mexico. In: Aldon, E.F., and D.W. Shaw, technical coordinators. Managing pi¤on-juniper ecosystems for sustainability and social needs. USDA Forest Service, General Technical Report RM-236, pp, 89-92. Pieper, R. D., and G. A. Lymbery. 1987. Influence of topographic features on pinyon-juniper vegetation in south-central New Mexico. In: Everett, R. L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical Report INT-215, pp. 53-57. Pierson, E. A., and J. R. McAuliffe. 1995. Characteristics and consequences of invasion by sweet resin bush into the arid southwestern United States. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 219-230. Pinkava, D. J. 1995a. Cactaceae: Part I: Cactus family. Journal of the Arizona-Nevada Academy of Science 29: 6-12. Pinkava, D. J. 1995b. Cactaceae: Part II: Cactus family. Journal of the Arizona-Nevada Academy of Science 29: 13-14. Pinkava, D. J., and M.A. Baker. 1985. Chromosome and hybridizationn studies of agaves. Desert Plants 7: 93-100. Pinkava, D. J., M. A. Baker, R. A. Johnson, N. Trushell, G. A. Ruffner, R. S. Felger, and R. K. Van Devender. 1992. Additons, notes and chromosone numbers for the vascular flora of Organ Pipe Cactus National Monument, Arizona. Journal of the Arizona-Nevada Academy of Science 24-25: 13-18. Pollisco, R. R. A. 1995. Characterization of the overlap area between encinal and pinyon-juniper woodlands. PhD Dissertation, University of Arizona, Tucson, Arizona. Pollisco, R. R., P. F. Ffolliott, and G. J. Gottfried. 1995. Ecological conditions in the overlap areas of the pinyon-juniper and encinal woodlands. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264. pp. 594-596. Porter, D. M. 1963. The taxonomy and distribution of the Zygophyllaceae of Baja California, Mexico. Contributions from the Gray Herbarium 192: 99-135. Pratt, J. J. 1963. Fort Huachuca check list of flora and fauna. U. S. Army Electronic Proving Ground, Fort Huachuca, Arizona. Pulliam, H. R., M. R. Brand. 1975. The production and utilization of seeds in the plains grasslands of southeastern Arizona. Ecology 56: 1158-1166. Quinn, J. A. 1982. Relationships between environment and chaparral, juniper, and oak woodlands in Arizona. PhD Dissertation, Arizona State University, Tempe, Arizona. Ramamoorthy, T. A., R. Bye, A. Lot, and J. Fa , editor. 1993. Biological diversity of Mexico: Origins and distribution. Oxford University Press, New York. Read, R. A., and J. Sprackling. 1980. Cotton-willow. In: Eyre, F. H., editor. Forest cover types of the United States and Canada. Society of American Foresters, Washington, D.C., pp. 113. Rebman, J. P. 1995. Simmondsiaceae: Jojoba family. Journal of the Arizona-Nevada Academy of Science 29: 63-64. Reeder, J. R., and R. S. Felger. 1989. The Arisida californica-Glabrata complex (Gramineae). Madrono 36: 187-197. Reeder, J. R., and C. G. Reeder. 1985. Notes on Arizona grasses. Desert Plants 7: 313-321. Reeves, T. 1976. Vegetation and flora of Chiricahua National Monument, Cochise County, Arizona. MS Thesis, Arizona State University, Tempe, Arizona. Reichenbacher, F. W. 1990. Tumamoc globe-berry studies in Arizona and Sonora, Mexico. U.S. Department of the Interior, Bureau of Reclamation, Phoenix Office Contract Report BR8802-FR 1-109. Reid, W. H., P. Sensiba, and C. E. Freeman. 1988. A mixed pollination system in Penstemon pseudospectabilis M. E. Jones (Scrophulariaceae). The Great Basin Naturalist 48: 489-494. Renfrow, C. 1995. Shifty trees in southeastern Arizona. University of Arizona, Tucson, Arizona. Agricultural Experiment Station, University of Arizona, Research Report, Tucson, Arizona, pp. 4-5. Rice, R. C. 1975. Diurnal and seasonal soil water uptake and flux within a Bermudagrass root zone. Soil Science Society of America Proceedings 39: 394-398. Ricketson, J. 1995a. Callitrichaceae: Water-starwort family. Journal of the Arizona-Nevada Academy of Science 29: 15-16. Ricketson, J. 1995b. Ceratophyllaceae: Coontail family. Journal of the Arizona-Nevada Academy of Science 29: 17. Ricketson, J. 1995c. Hippuridaceae: Mare's-Tail family. Journal of the Arizona-Nevada Academy of Science 29: 25. Ricketson, J. 1995d. Nymphaeaceae: Waterlily family. Journal of the Arizona-Nevada Academy of Science 29: 26-28. Robberecht, R. 1988. Big galleta grass-a warm-season bunchgrass in the Sonoran and Mojave Deserts. Rangelands 10. Robinett, D. 1992. Lehmann lovegrass and drought in southern Arizona. Rangelands 14: 100-104. Rollins, R. C. 1950. The guayule rubber plant and its relatives. Contribution from the Gray Herbarium 172. Rondeau, R. 1991. Flora and vegetation of the Tucson Mountains, Pima County, Arizona. MS Thesis, University of Arizona, Tucson, Arizona. Roundy, B. A. and G. L. Jordan. 1988. Vegetation changes in relation to livestock exclusion and root plowing in southeastern Arizona. The Southwestern Naturalist 33: 425-436, Roundy, B. A., G. B. Ruyle, and J. Ard. 1986. Estimating production and utilization of jojoba. In: Patton, D.R., C.E. Gonzales V., A.L. Medina, L.A. Segura T., and R.H. Hamre, technical coordinators. Management and Utilization of Arid Land Plants: Symposium Proceedings. USDA Forest Service, General Technical Report RM-135, pp. 17-23. Roundy, B. A., J. A. Young, L. B. Sumrall, and M. Livingston. 1992. Laboratory germination responses of 3 love-grasses to temperature in relation to seedbed temperature. Journal of Range Management 45: 306-311. Rothkugel, M. 1909. Brief notes on Mexican forests. Journal of Forestry 7: 277-278. Ruffner, G. A. and R. A. Johnson. 1991. Plant ecology and vegetation mapping at Coronado National Memorial, Cochise Sounty, Arizona. Cooperative National Park Resources Studies Unit, School of Renewable Resources, University of Arizona, Technical Report 41, Tucson, Arizona. Ruiz, A. M., Q. M. Enriquez, and G. R. Oliva. 1981. Ensayo de cinco esquemas de muestreo aplicados al inventario de datilillo (Yucca valida) y Cardon (Pachycereus pringlei). In: Lund, H. G., M. Caballero, R. H. Hamre, R. S. Driscoll, and W. Bonner, technical coordinators. Arid lands resource inventories: Developing cost-efficient methods. USDA Forest Service, General Technical Report WO-28, pp. 407-415. Rzedowski, J. 1973. Geographical relationships of the flora of Mexican dry regions. In: Vegetation and vegetational history of northern Latin America. Elsevier Scientific Company, Amsterdam, The Netherlands, pp. 61-62. Rzedowski, J. 1978. Vegetaci¢n de Mexico. Editorial Limosa S.A., Mexico, D.F. Rzedowski, J. 1991. Diversidad y or¡genes de la flora fanerog mica de M‚xico. Acta Bot nica Mexicana 14: 3-21. Rzedowski. J. 1993. Diversity and origins of the phanerogamic flora of Mexico. In: Ramamoorthy, T. P., R. Bye, A. Lot, and J. Fa editors. Biological diversity in Mexico: Origins and distributions. Oxford University Press, New York, pp. 129-144. Sammis, T. W., and L. W. Gay. 1979. Evapotranspiration from an arid zone plant (Larrea tridentata) community. Journal of Arid environments 2: 313-321. Samuels, M. L., and J. L. Betancourt. 1982. Modeling the long term effects of fuelwood harvests on pinyon-juniper woodlands. Environmental Management 6: 505-515. Sanchini, P. J. 1981. Population structure and fecundity patterns in Quercus emoryi and Quercus arizonica. PhD Dissertation, University of Colorado, Boulder, Colorado. Sandquist, D. R., W. S. F. Schuster, L. A. Donovan, S.L. Phillips, and J.R. Ehleringer. 1993. Differences in carbon isotope discrimination between seedlings and adults of southwestern desert perennial plants. The Southwestern Naturalist 38: 212. Saunier, R. E. 1964. Factors affecting the distribution of shrub live oak (Quercus turbinella). MS Thesis, University of Arizona, Tucson, Arizona. Saunier, R. E., and R. F. Wagle. 1967. Factors affecting the distribution of shrub live oak (Quercus turbinella Greene). Ecology 48: 35-41. Sawyer, D. A., and T. B. Kinraide. 1980. The forest vegetation at higher altitudes in the Chiricahua Mountains, Arizona. The American Midland Naturalist 104: 224-241. Schaffer, W. M. and M. V. Schaffer. 1977. The reproductive biology of Agavaceae: I. Pollen and nectar production in four Arizona agaves. The Southwestern Naturalist 22: 157-168. Schaffer, W. M. and M. V. Schaffer. 1979. The adaptive significance of variations in reproductive habit in the Agavaceae II: Pollinator foraging behavior and selection for increased reproductive expenditure. Ecology 60: 1051-1069. Schickendanz, J. G. 1974. Seasonal growth, development, and carbohydrate reserves of three native range grasses in response to seasonal moisture and nitrogen fertilization. PhD Dissertation, University of Arizona, Tucson, Arizona. Schmutz, E. M., M. K. Sourabie, and D. A. Smith. 1985. The Page Ranch story: Its vegetative history and management implications. Desert Plants 7: 13-21. Segura, G., and L. C. Snook. 1992. Stand dynamics and regeneration patterns of a pinyon pine forest in east central Mexico. Forest Ecology and Management 47: 175-194. Senock, R. S., J. R. Barrow, R. P. Gibbens, and C. H. Herbel. 1991. Ecophysiology of the polyploid shrub Atriplex canescens (Chenopodiaceae) growing in situ in the northern Chihuahuan. Journal of Arid Environments 21: 45-57. Sepulveda, B. J. I. 1986. Manejo de Poblaciones Silvestres de Jojoba en Baja California. In: Patton, D. R., C. E. Gonzales V., A. Medlina, L. A. Segura T., and R. H. Hamre, technical coordinators. Management and utilization of arid land plants: Symposium proceedings. USDA Forest Service, General Technical Report RM-135, pp. 13-16. Severson, K. E., and A. L. Medina. 1983. The Santa Rita Experimental Range. In: Patton, D. R., J. M. de la Puente-E., P. F. Ffolliott, S. Gallina, and E. T. Bartlett, technical coordinators. Wildlife and range research needs in northern Mexico and southwestern United States: Workshop proceedings. USDA Forest Service, General Technical Report WO-36, pp. 56-59. Sharifi, M. R., F. C. Meinzer, E. T. Nilsen, P. W. Rundel. Virginia, W. M., J. D. Jarrell, D. J. Herman, and P. C. Clark. 1988. Effect of manipulation of water and nitrogen supplies on the quantitative phenology of Larrea tridentata in the Sororan Desert of California. American Journal of Botany 75: 1163-1174. Sherbrooke, W. C. 1989. Seedling survival and growth of a Sororan Desert shrub, jojoba (Simmondsia chinensis) - during the first 10 years. The Southwestern Naturalist 34: 421-423. Sherbrooke, W. C. 1993. Native plants and space. The Plant Press, Arizona Native Plant Society 17: 9. Shreve, F. 1915. The vegetation of a desert mountain range as conditioned by climatic factors. Carnegie Institute of Washington, Washington D.C. Shreve, F. 1919. A comparison of the vegetational features of two desert mountain ranges. The Plant World 22: 291-307. Shreve, F., 1937. Vegetation of the Cape Region of Baja California. Madro¤o: 105-113. Shreve, F. 1951. Vegetation of the Sororan Desert. In: Shreve F., and I. L. Wiggins, editors. Flora and vegetation of the Sororan Desert. Stanford University Press, Palo Alto, California. Shreve, F. and I. Wiggins. 1964. Vegetation and flora of the Sororan Desert. Stanford University Press, Palo, Alto, California. Shupe, H. V., and R. B. Solether. 1973. Timber policy statement: Coronado National Forest. USDA Forest Service, Southwestern Region, Albuquerque, New Mexico. Simpson, B. B. 1977. Mesquite: Its biology in two desert scrub ecosystems. Dowden, Hutchinson and Ross, Stroudsburg, Pennsylvania. Simpson, B. B., and J. L. Neff. 1987. Pollination ecology in the arid southwest. Rancho Santa Ana Botanic Garden 11: 417-440. Skarpe, C. 1992. Dynamics of savanna ecosystems. Journal of Vegetation Science 3: 293-300. Smith, C. R. 1994. Seasonality and synchrony: A site comparison of reproductive phenology in three neotropical figs. MS Thesis, University of Arizona, Tucson, Arizona. Smith, M. O., S. L. Ustin, J. B. Adams, and A. R. Gillespie. 1990. Vegetation in deserts: II. Environmental influences on regional abundance. Remote Sensing of Environment 29: 27-52. Smith, N. 1988. Growing natives: Manzanitas for ground cover. Fremontia 16: 23-25. Smith, S. D., and J. A. Ludwig. 1978. The distribution and phytosociology of Yucca elata in southern New Mexico. The American Midland Naturalist 100: 202-212. Soares, J. R. P. 1973. Taxomomic keys to the species listed in Rio Mayo plants. PhD Dissertation, University of Arizona, Tucson, Arizona. Solomon, J. A., and E. A. Stull. 1976. The phyto plankton of Lake Patagonia, Santa Cruz County, Arizona. Journal of Phycology 12: 19. Sorensen, P. D. 1969. Revision of the genus Dahlia (Compositae, Heliantheae-Coreopsidinae). Rhodora 71: 309-416. Sorensen, P. D. 1987. Arbutus tessellata (Ericaceae), new from Mexico. Brittonia 39: 263-267. Sourabre, K. M. 1982. Dynamics of a desert grassland range in relation to drought, fire and grazing. MS Thesis, University of Arizona, Tucson, Arizona. Spellenberg, R. 1988. Hybridization in Chihuahuan oaks (Quercus: Fagaceae). American Journal of Botany 75: 207. Sprugel, D. G. 1991. Disturbance, equilibrium, and environmental variability: What is 'natural' vegetation in a changing environment? Biological Conservation 58: 1-18. St. Clair, L. L., and C. C. Newberry. 1992. Lichens as biomonitors of air quality in the Chiricahua Mountains of Arizona. In: Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 113-116. Stahle, D. W. and M. K. Cleaveland. 1993. Southern oscillation extremes reconstructed from tree rings of the Sierra Madre Occidental and southern Great Plains. Journal of Climate 6: 129-140. Standley, P. C. 1920-1926. Trees and shrubs of Mexico. Contributions from the United States National Herbarium 23. States, J. S. 1993. Distribution of mushrooms, mycophagists and conifers on sky islands of the Southwest. In: Barton, A. M., and S. A. Sloane, editors. Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 43-45. Steenberg, W. F., and C. H. Lowe. 1971. Ecology of the saguaro: I. The role of freezing weather in a warm-desert plant population. U.S. Department of the Interior, National Park Service. Symposium Series, Washington D.C. Steenberg, W. F., and C. H. Lowe. 1977. Ecology of the saguaro: II. Reproduction, germination, establishment, growth, and survival of the young plant. U.S. Department of the Interior, National Park Service, Scientific Monograph Series 8, Washington D.C. Steenberg, W. F., and C. H. Lowe. 1983. Ecology of the saguaro: III, growth and demography. U.S. Department of the Interior, National Park Service Scientific Monograph Series 17, Washington D.C. Stephen, G., and W. G. Whitford. 1993. Responses of Bouteloua eriopoda to irrigation and nitrogen fertilization in a Chihuahuan desert grassland. Journal of Arid Environments 124: 415-421. Stroehlein, J. L., P. R. Ogden, and B. Bahe. 1968. Time of fertilizer application on desert grasslands. Journal of Range Management 21: 86-89. Stromberg, J. C., and D. T. Patten. 1991. Dynamics of the spruce-fir forests on the Pinale¤o Mountains, Graham County, Arizona. The Southwestern Naturalist 36: 37-48. Stromberg, J. C., and D. T. Patten. 1993. Seed and cone production by Engelmann spruce in the Pinaleno Mountains, Arizona. Journal of the Arizona-Nevada Academy of Science 27: 79-88. Stromberg, J. C. and D. T. Patten. 1994. Islands within islands: Vegetation dynamics of the spruce-fir forests of the Pinaleno Mountains. Part III, Chapter 1. In: Istock, C., editor. Storm over a mountain island: Conservation biology and the Mt. Graham affair. University of Arizona Press, Tucson, Arizona. Stromberg, J. C., J. A. Tress, S. D. Wilkins, and S. D. Clark. 1992. Response of velvet mesquite to groundwater decline. Journal of Arid Environments 23: 45-58. Styles, B. 1993. Genus Pinus: A Mexican purview, In: Ramamoorthy, T. P., R. Bye, A. Lot and J. Fa , editors. Biological diversity of Mexico: Origins and distributions. Oxford University Press, New York, pp. 397-420. Sule, B. 1974. Growth, development, and carbohydrate reserves of sideoats grama and plains lovegrass. MS Thesis, University of Arizona, Tucson, Arizona. Sumrall, L. B. 1991. Seedbed ecology and emergence of Lehmann lovegrass. MAI 29: 68. Sundell, E. 1993. Asclepiadaceae: Milkweed family. Journal of the Arizona-Nevada Academy of Science 27: 169-187. Sutherland, S. D. 1982. The pollination biology of paniculate agaves: Documenting the importance of male fitness in plants. PhD Dissertation. University of Arizona, Tucson, Arizona. Sutherland, S. 1986. Floral sex ratios, fruit-set, and resource allocation in plants. Ecology 67: 991-1001. Sutherland, S. 1987. Why hermaphroditic plants produce many more flowers than fruits: Experimental tests with Agave mckelveyana. Evolution 41: 750-759. Sutherland, S. and L.F. Delph. 1984. On the importance of male fitness in plants: Patterns of fruit-set. Ecology 65: 1093-1104. Szaro, R. C., and C. P. Pase. 1983. Short-term changes in a cottonwood-ash-willow association on a grazed and an ungrazed portion of Little Ash Creek in central Arizona. Journal of Range Management 36: 382-384. Taylor, C. 1980. The coppery-tailed trogon: Arizona's bird of paradise. Borderland Productions, Portal, Arizona. Taylor, R. J., T. F. Patterson, and R. J. Harrod. 1994. Systematics of Mexican spruce - revisited. Systematic Botany 19: 47-59. Thomas, P. A. 1991. Response of succulents to fire: A review. International Journal of Wildland Fire 1: 11-22. Thomas, P. A., and P. Goodson. 1992. Conservation of succulents in desert grasslands managed by fire. Biological Conservation 60: :91-100. Thompson, A. E., D. A. Dierig, and E. R. Johnson. 1989. Yield potential of Lesquerella fendleri (Gray) Wats., a new desert plant resource for hydroxy fatty acids. Journal of Arid Environments 16: 331-336. Thompson, R. S., and T. R. VanDevender. 1982. Late pleistocene vegetational records from desert grassland in the Santa Catalina Mountains, Arizona. In: Markgraf, V., L. B. Brubaker, and S. E. Chernicoff, editors. Character and timing of rapid environmental and climatic changes. National Conference of the American Ouaternary Association. Abstracts: 7: 167. Thornber, J. J. 1906. Alfilaria (Erodium cicutarium), as a forage plant in Arizona. Agricultural Experiment, University of Arizona, Station Bulletin 52, Tucson, Arizona. Thornber, J. J. 1909. Vegetation groups of the Desert Laboratory domain. In: Spalding, V. M., editor. Distribution and movements of desert plants. Carnegie Institution of Washington Publication 113: 103-112. Thornber, J. J. 1910. The grazing ranges of Arizona. Agricultural Experiment Station, University of Arizona, Station Bulletin 65, Tucson, Arizona. Tiedemann, A. R. 1970. Effect of mesquite (Prosopis juliflora) trees on herbaceous vegetation and soils in the desert grassland. PhD Dissertation, University of Arizona, Tucson, Arizona. Tiedeman, J. A., R. Beck, and R. V. Ecret. 1991. Dependence of standing crop on range condition rating in New Mexico. Journal of Range Management 44: 602-605. Toledo, V. M. and M. J. Ord¢¤ez. 1993. The biodiversity scenario of Mexico: A review of terrestrial habitats. In: Ramamoorthy, T. P., R. Bye, A. Lot and J. Fa , editors. Biological diversity of Mexico: Origins and distributions. Oxford University Press, New York, pp. 757-777. Tookey, H. L. and H. S. Gentry. 1969. Proteinase of Jarilla chocola, a relative of papaya. Phytochemistry 8: 989-991. Toolin, L. J. 1980. Final report on the flora of Ramsey Canyon. Arizona Nature Conservancy, Tucson, Arizona. Toolin, L. J., T. R. Van Devender, and J. M. Kaiser. 1979. The flora of Sycamore Canyon Pajarito Mountains, Santa Cruz County, Arizona. Journal of Arizona-Nevada Academy of Science 14: 66-74. Touchan, R. 1992. Effects of coppice thinning on growth and yield of oak sprouts in southeastern Arizona (Quercus emoryi). PhD Dissertation, University of Arizona, Tucson, Arizona. Touchan, R., D. A. Bennett, and P. F. Ffolliott. 1992. Coppice thinning of Emory oak sprouts: Effects on growth, yield, and harvesting cycles. In: Ffolliott, P. F., G. J. Gottfried, D. A. Bennett, V.M. Hernandez C., A. Ortega-Rubio, and R. H. Hamre, technical coordinators. Ecology and management of oak and associated woodlands: Perspectives in the southwestern United States and northern Mexico. USDA Forest Service, General Technical Report RM-218, pp. 174-176. Toumey, J. W. 1891. Notes on some of the range grasses of Arizona. Agricultural Experiment Station, University of Arizona, Station Bulletin 2, Tucson, Arizona. Tschirley, F. H., and S. C. Martin. 1961. Burroweed on southern Arizona range lands. Argicultural Experiment Station, University of Arizona, Technical Bulletin 146, Tucson, Arizona. Tucker, J. M. 1963. Studies of the Quercus undulata Complex: III. The Contribution of Quercus arizonica. American Journal of Botany 50: 699-708. Turner, R. M. 1990. Long-term vegetation change at a fully protected Sororan Desert site. Ecology 71: 464-477. Turner, R. M. 1992. Long-term saguaro population studies at Saguaro National Monument. In: Proceedings of the Symposium on Research in Saguaro National Monument, Tucson, Arizona, pp. 3-11. Turner, R. M., and D. E. Brown. 1982. Sororan Desert scrub. Desert Plants 4: 181-221. Upson, A., W. J. Cribbs, and E. B. Stanley. 1937. Occurrence of shrubs on range areas in southeastern Arizona: A condensed report of the results of a cooperative survey by the Arizona Agricultural Experiment Station. Agricultural Experiment Station, University of Arizona, Tucson, Arizona. USDA Forest Service. 1982. Proposed Coronado National Forest land and resource management plan. USDA Forest Service, Southwestern Region, Alburquerue, New Mexico. USDA Forest Service. 1987. Forest and woodland habitat types (plant associations) of Arizona south of the Mogollon Rim and southwestern New Mexico. USDA Forest Service, Southwestern Region, Albuquerque, New Mexico. USDA Forest Service 1988. Final environmental impact statement, proposed Mt. Graham astrophysical area, Pinaleno Mountains, Coronado National Forest. USDA Forest Service, Coronado National Forest, Tucson, Arizona. US Forest Service. 1993. Coronado National Forest, Forest Plan Five Year Review Report, FY 1987-FY 1991. USDA Forest Service, Coronado National Forest, Tucson, Arizona. Vandemeer, J. 1980. Saguaros and nurse trees: A new hypothesis to account for population fluctuations. The Southwestern Naturalist 25: 357-360. Van Devender, T. R. 1977. Holocene woodlands in the southwestern deserts. Science 198: 189-192. Van Devender, T. R. 1987. Late quaternary history of pinyon-juniper-oak woodlands dominated by Pinus remota and Pinus edulis. In: Everett, R.L., compiler. Proceedings - pinyon-juniper conference. USDA Forest Service, General Technical Report INT-215, pp. 99-103. Van Devender, T. R. . 1990. Late quaternary vegetation and climate of the Sororan Desert, United States and Mexico. In: Betancourt, L. L., T. R. Van Devender and P. S. Martin, editors. Packrat middens: The last 40,000 years of biotic change. The University of Arizona Press, Tucson, Arizona. Van Devender, T. R., and T. L. Burges. 1985. Late pleistocene woodlands in the bolson de Mapimi: A refugium for the Chihuahua desert biota. Quaternary Research 24: 1-8. Van Devender, T. R., and W. G. Spaulding. 1979. Development of vegetation and climate in the southwestern United States. Science 204: 701-710. Van Devender, T. R., T. L. Burgess, R. S. Felger, and R. M. Turner. 1990. Holocene vegetation of the Hornaday Mountains of northwestern Sonora, Mexico. Proceedings of the San Diego Society of Natural History 2: 1-9. Van Devender, T. R., J. I. Mead, and A. M. Rea. 1991. Late quaternary plants and vertebrates from Picacho Peak, Arizona. The Southwestern Naturalist 36: 302-314. Van Devender, T. R., R. S. Thompson and J. L. Betancourt. 1987. Vegetation history of the deserts of southwestern North America; The nature and timing of the Late Wisconsin-Holocene transition: Chapter 15. In: Ruddiman, W. F., and H. E. Wright, Jr., editors. North America and adjacent oceans during the last deglaciation. Geologic Society of North America Volume K-3, Boulder, Colorado. Van Sickle, C. and G. Newman. 1981. Fuelwood inventory - Sierra Vista District. USDA Forest Service, Coronado National Forest, Sierra Vista, Arizona. Vasek, F. C. 1980. Creosote bush: Long-lived clones in the Mojave Desert. American Journal of Botany 67: 246-255. Vega-Avina, R. 1988. Flora de Sinaloa. Universidad Autonoma de Sinaloa, Culiacan, Sinaloa, Mexico. Vines, R. A. 1960. Trees, shrubs, and woody vines of the Southwest. University of Texas Press, Austin, Texas. Voorhies, G. and T. G. Huntsberger 1983. Heat of combustion of ponderosa pine and selected species indigenous to the Rocky Mountain region. Northern Arizona University, Arizona Forestry Notes 19, Flagstaff, Arizona. Wagner, W. L. 1973. Floristic affinities of Animas Mountain, southwestern New Mexico. MS Thesis, University of New Mexico, Albuquerque, New Mexico. Wagner, W. L. 1979. New records to the Animas Mountain flora, New Mexico. The Southwestern Naturalist 24: 291-296. Waldon, H. B. 1987. Sororan Desert rhizobia found to nodulate Acacia constricta. Desert Plants 8. Wallmo, C. O. 1955. Vegetation of the Huachuca Mountains, Arizona. The American Midland Naturalist 54: 466-480. Warren, A., J. Holeshek, and M. Cardenas. 1996. Honey mesquite influences on Chihuahuan Desert vegetation. Journal of Range Management 49: 46-52. Warren, D. K., and R. M. Turner. 1975. Saltcedar (Tamarix chinensis) seed production, seedling establishment, and response to inundation. Journal of the Arizona Academy of Science 10: 135- 144. Warren, P., J. Malusa, D. Gori, and M. Fishbein. 1994. Biogeography of rare and endemic plants in the mountain islands of southeast Arizona. In: DeBano, L.F., A. N. Garibay, and A. Ortega-Rubio, compiler. 1995. Conference on Biodiversity and Management of the Madrean archipelago: Abstracts: 30. Warren, P. L. 1981. Sampling and description of vegetation for large scale mapping at Organ Pipe Cactus National Monument. In: Lund, H. G., M. Caballero, R. H. Hamre, R. S. Driscoll, and W. Bonner, technical coordinators. Arid lands resource inventories: Developing cost-efficient methods. USDA Forest Service, General Technical Report WO-28, pp. 352-358. Warren, P. L., and L. S. Anderson. 1980. Annotated checklist of the plants of George Whittell Wildlife Preserve. In: Johnson, T. B., editor. 1980 progress report for the biological survey of the George Whittell Wildlife Preserve, Graham and Pinal counties, Arizona. Arizona Natural Heritage Program, Tucson, Arizona, pp. 80-124. Warren, P. L., and C. Dunford. 1983. Vegetation sampling with large-scale aerial photography. Remote Sensina Newsletter 832: 1-6. Warren, P. L. and F. W. Reichenbacher. 1991. Sensitive plant survey of Fort Huachuca, Arizona. Fort Huachuca, Arizona. Warren, P. L., M. S. Hoy, and W. E. Hoy. 1992. Vegetation and flora of Fort Bowie National Historic Site, Arizona. Cooperative National Park Resources Studies Unit, University of Arizona, Technical Report NPS/WRUA/NRTR-92/43, Tucson, Arizona. Warren, P. L., M. s. Hoy, W. Moir, and B. E. Hoy. 1980. Vegetation of Fort Bowie National Historic Site, Arizona. Cooperative National Park Service Resource Studies Unit, University of Arizona, Tucson, Arizona. Warren, P. L., P. A. Knapp, C. F. Hutchhinson, M. C. Parton, and R.A. Schowengerdt. 1988. Monitoring arid land vegetation change with remote sensing: An example from southern Arizona. In: Whitehead, E. E. C. F. Hutchinson, B. N. Timmermann, and R. G. Varady, editors. Arid lands: Today and tomorrow. Westview Press, Boulder, Colorado, pp. 251-259. Warshall, P. 1986. Biogeography of the high peaks of the Pinalenos. USDA Forest Service, Coronado National Forest, Tucson, Arizona. Watson, S. 1886. Contributions to American Botany. 1. List of plants collected by Dr. Edward Palmer in southwestern Chihuahua, Mexico, in 1885. Proceedings of the American Academy of Arts and Sciences 21: 414-445. Wells, S. G. and D. R. Haragan. 1983. Origin and evolution of deserts. University of New Mexico Press, Albuquerque, New Mexico. Weltzin, J. F., and G. R. McPherson. 1995. Potential effects of climate change on lower treelines in the southwestern United States. In: DeBano, L. F., P. F. Ffolliott, A. Ortega-Rubio, G. J. Gottfried, H. Robert, and C. B. Edminster, technical coordinators. 1995. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM-GTR-264, pp. 180-193. Wentworth, T. R. 1976. The vegetation of limestone and granite soils in the mountains of southeastern Arizona. PhD Dissertation, Cornell University, Uthica, New York. Wentworth, T. R. 1981. Vegetation on limestone and granite in the Mule Mountains, Arizona. Ecology 62: 469-482. Wentworth, T. R. 1982. Vegetation and flora of the Mule Mountains, Cochise County, Arizona. Journal of the Arizona-Nevada Academy of Science 17: 29-44. Wentworth, T. R. 1983. Distributions of C4 plants along environmental and compositional gradients in southeastern Arizona. Vegetatio 52: 21-34. Wentworth, T. R. 1985. Vegetation on limestone in the Huachuca Mountains, Arizona. The Southwestern Naturalist 30: 385-395. White, A. S. 1985. Presettlement regeneration patterns in a southwestern ponderosa pine stand. Ecology 66: 589-594. White, S. S. 1948. The vegetation of flora of the region of the R¡o de Bavispe in northeastern Sonora, Mexico. Lloydia 11: 229-302. White, S. 1974. Seed and vegetation patterns with respect to grazing on a southern Arizona rangeland. MS Thesis, Arizona State University, Tempe, Arizona. Whitford, W. G., and J. R. Gutierrez. 1989. Effects of water and nitrogen supplementation on phenology, plant size, tissue nitrogen, and seed yield of Chihuahuan desert annual plants. The Southwestern Naturalist 34: 546-549. Whitford, W. G., J. F. Reynolds, and G. L. Cunningham. 1987. How desertification affects nitrogen limitation of primary production on Chihuahuan Desert watersheds. In: Aldon, E. F., C. E. Gonzales V., and W. H. Moir, technical coordinators. Strategies for classification and management of native vegetation for food production in arid zones. USDA Forest Service, General Technical Report RM-150, pp. 143-153. Whitford, W. G., K. Stinnet, and Y. Steinberger. 1988. Effects of rainfall supplementation on microarthropods on decomposing roots in the Chihuahuan Desert. Pedobiologia 31: 147-155. Whittaker, R. H., and W. A. Niering. 1964. Vegetation of the Santa Catalina Mountains, Arizona. I. Ecological classification and distribution of species. Journal of the Arizona Academy of Science 3: 9-34. Whittaker, R. H., and W. A. Niering. 1965a. Vegetation of the Santa Catalina Mountains, Arizona. II. A gradient analysis of the south slope. Ecology 46: 429-452. Whittaker, R. H., and W. A. Niering. 1965b. Vegetation of the Santa Catalina Mountains, Arizona. IV. Limestone and Acid Soils. Journal of Ecology 56: 523-544. Whittaker, R. H., and W. A. Niering. 1968. Vegetation of the Santa Catalina Mountains, Arizona. III. Species distribution and floristic relations on the north slope. Journal of the Arizona Academy of Science 5: 3-21. Whittaker, R. H., and W. A. Niering. 1975. Vegetation of the Santa Catalina Mountains, Arizona. V. Biomass, production and diversity along the elevation gradient. Ecology 56: 771-790. Wiggins, I. L. 1964. Flora of the Sororan Desert. In: Shreve, F., and I. L. Wiggins, editors. Flora and vegetation of the Sororan Desert, 2 volumes. Stanford University Press, Palo Alto, California. Williams, C. P. 1964. Lehmann lovegrass-velvet mesquite invasion relationships in the desert grassland. MS Thesis, University of Arizona, Tucson, Arizona. Winkel, V. K., B. A. Roundy, and J. R. Cox. 1991. Influence of seedbed microsite characteristics on grass seedling emergence. Journal of Range Manaqement 44: 210-214. Wissler, C. 1991. A spatial modeling approach to predicting forage production and utilization in a semidesert grassland. MS Thesis, University of Arizona, Tucson, Arizona. Wood, T. 1992. Management of a rare lily, Lilium parryi, at Ramsey Canyon Preserve. In: Proceedings of the Chiricahua Mountains Research Symposium. Southwest Parks and Monuments Association, Tucson, Arizona, pp. 50-52. Woodhouse, R. M. 1987. The physiological ecology of the desert evergreen shrub Simmondsia chinensis. PhD Dissertation, Arizona State University, Tempe, Arizona. Woodward, S. L. 1972. Spontaneous vegetation of the Murray Springs area, San Pedro Valley, Arizona. Journal of the Arizona Academy of Science 7: 12-16. Wooton, E. O. and P. C. Standley. 1915. Flora of New Mexico. Contributions from the United States National Herbarium, Volume 19. Wright, R. A. 1960. Increase of mesquite on a southern New Mexico desert grassland range. MS Thesis, New Mexico State University, Las Cruces, New Mexico. Wright, R. A. 1982. Aspects of desertification in Prosopis dunelands of southern New Mexico. Journal of Arid Environments 5: 277-284. Wright, R. G., and G. M. Van Dyne. 1981. Population age structure and its relationship to the maintenance of a semidesert grassland undergoing invasion by mesquite. The Southwestern Naturalist 26: 13-22. Yang, T. W. 1970. Major chromosome races of Larrea divaricata in North America. Journal of Arizona Academy of Science 6: 41-45. Yatskievych, G. 1993a. Lennoaceae: Lennoa family. Journal of the Arizona-Nevada Academy of Science 27: 220-221. Yatskievych, G. 1993b. Rafflesiaceae: Rafflesia fammily. Journal of the Arizona-Nevada Academy of Science 27: 239. Yatskievych, G. A. 1980-81. Ferns and fern allies of the Garden Canyon area of the Huachuca Mountains, Cochise County, Arizona. Desert Plants 2: 237-243. Yavitt, J. B., and E. L. Smith, Jr. 1983. Spatial patterns of mesquite and associated herbaceous species in an Arizona desert grassland. The American Midland Naturalist 109: 89-93.