Chapter 9: Research Needs

Although there is an adequate scientific basis to justify the need for maintaining and restoring healthy forests, numerous information gaps remain in the understanding of Southwestern ecosystems, application of techniques, and assessment of cultural and social values. Evans (1996) presents the conclusions of a review and workshop to identify research needs for management of National Forest lands in the Southwest. That effort categorizes research needs and current work into four priorities: 1) inventory, monitoring, and assessment; 2) ecosystem health, disturbance, and restoration; 3) wildlife habitat relations with emphasis on TES; and 4) human needs and values. Many of the information gaps identified in Evans (1996) relate directly or indirectly to forest ecosystem health issues and concerns described in the previous chapters of this assessment. The following research needs are those specifically identified by the assessment team as critical for implementing adaptive management to maintain and restore forest ecosystem health in the Southwest.

UNDERSTANDING HISTORIC VARIABILITY

Improved information concerning reference conditions for Southwestern forests is needed, specifically the historical ranges and rates of change of numerous ecosystem variables. Information which characterizes ecosystem composition, structure, and function through time, including the frequency, intensity, duration, and spatial patterns of disturbance at multiple scales is fundamental. This information provides managers with a better understanding of the historic variability of these complex ecosystems. This historic variability should be described both in terms of mean (central tendency) and variation (dispersion). Models can present this information in graphical form similar to normal distribution curves (histograms) and display the frequency with which these systems remain near average status or deviate toward extremes under slowly or rapidly changing conditions. Such information contributes to improving our overall understanding of the dynamic behavior of these ecosystems in the absence of human disturbance and management.

In view of the substantial changes brought about in Southwestern forests by European settlement, an improved understanding of ecological succession, as modified and influenced by these changes, is needed. In ecosystems that have undergone significant change or degradation, successional pathways have been altered and plant communities are currently proceeding along trajectories for which no historical analog exists. The ultimate result of such successional change is largely unknown. A better understanding of this dynamic change is crucial to the success of ecological restoration and efforts to achieve desired conditions in the ecosystems of the future.

A much improved working model of forest ecosystems in the Southwest is needed, one which explains dynamic behavior across multiple levels of the ecological hierarchy. The basic ecological building blocks of genes, genotypes, and species need to be functionally integrated with populations, communities, and landscapes to more fully identify emergent system properties characteristic of each forest ecosystem. Numerous modeling approaches could be used to achieve this integration, including individualist models, process models, and spatial models. Just the exercise of constructing such models should provide improved insights into the mechanisms which influence ecosystem behavior such as decomposition, nutrient cycling, growth and development, patch dynamics, and species dispersal and migration.

Even though humans have been an integral component of the Southwestern landscape for over 12,000 years, the archaeological and paleoenvironmental record of human habitation is often sparse and fragmentary. It is generally recognized that humans have significantly affected ecosystem conditions within the last century, but little is known about the impacts of prehistoric cultures on the landscape. Additional research is needed to better understand the interactions of prehistoric cultures and forest ecosystems through time.

UNDERSTANDING FOREST ECOSYSTEM HEALTH

Ecological variables which serve as appropriate indicators of ecosystem health are needed. These variables must be affordable, measurable, and reliable indicators of the health status of the ecosystem. Whether these variables are structural or functional characteristics, a reference database that describes acceptable (i.e., normal) and pathological (i.e., abnormal) ranges for each greatly enhances the utility of such measurements. Models which improve managers' understanding of species populations and trends, patch dynamics, disturbance effects, and human interactions need to be developed. Comparative analyses of the effects of wildfire and prescribed fire on resource values, air quality, and human health are also needed.

UNDERSTANDING INSECT AND PATHOGEN INTERACTIONS

More needs to be learned concerning how landscapes and ecosystems, under various management regimes, are affected by and respond to insects and pathogens at different temporal and spatial scales. Better hazard rating and damage prediction models need to be developed that describe the effects of insects and pathogens in a manner readily understandable by agency personnel and members of the public.

The most critical needs vary by ecosystem and insect or pathogen. In woodland and riparian ecosystems, we need an inventory of potentially harmful insects and pathogens, their effects on various resource values, and in particular the effects of dwarf mistletoe on pinyon nut production. We need to know how thinning may prevent Ips beetle outbreaks in woodland ecosystems or reduce the susceptibility of mixed conifer forests to western spruce budworm. For southwestern white pine, we need reliable estimates for the rates of spread and intensification of blister rust and levels of natural resistance to blister rust. We need to quantify the effects of uneven-aged management on the spread and intensification of dwarf mistletoe in ponderosa and mixed conifer forests. Information is lacking on the causes of aspen regeneration dieback and how to prevent it.

UNDERSTANDING WILDLIFE HABITAT REQUIREMENTS

Information concerning the habitat requirements of TES species is needed, (e.g., the Mexican spotted owl). Models which address the needs of multiple wildlife species would also be highly useful. These should include provisions for the influences of climate, competition, predation, and disturbance on community niche sizes and overlaps.

The scales at which each wildlife species are best managed and the habitat components that influence each species and group at each scale need to be identified. A better understanding of the influence of management practices on ecological processes at multiple scales is also needed. This information allows managers to ascertain the effects of management applied at one scale upon other scales and determine where to optimally apply management for the most desirable results across the hierarchy.

In the interest of maintaining viable wildlife populations, information concerning the spatial distribution of habitat necessary for unimpaired movement of populations and individuals is needed. Information relevant to the effects of size, shape, and juxtaposition of patches and corridors on specific species and communities is essential. Critical population thresholds that threaten viability need to be determined. Specific data types relevant to the determination of species viability needs to be added to habitat relationship databases. And finally, quantifiable data are required on effects of bark beetle outbreaks to TES species populations and habitat.

DEVELOPING TECHNIQUES TO RESTORE AND MAINTAIN ECOSYSTEMS

Additional research is required in several areas before an improved understanding of forest ecosystems can be implemented. In particular, these areas include use of prescribed fire, wood utilization of small trees, and weed detection and control. Information is needed to ensure safe and effective use of prescribed fire in fuel reduction and vegetation management. Equipment technologies for economical harvesting of small trees (3 to 4 inches dbh) needs to be developed or imported from other regions and adapted to Southwestern conditions. Economic markets for small trees, such as poles and posts, chip-and-saw, chips, pressure composites, and pulp need to be developed. New product development in cooperation with the Forest Products Laboratory in Madison, Wisconsin, may be helpful in this matter. Work is needed in the detection of exotic plant infestations and the evaluation of the efficacy of mechanical, chemical, biological, and natural control methods.

CULTURAL AND SOCIAL ASSESSMENTS

A better understanding of the cultural context for forest health is needed. Improved insight into public perceptions concerning what constitutes a healthy forest and what kinds and levels of management activities are acceptable is essential, as well as a better understanding of the expectations of forest visitors and users. Better models for tribal consultation and a better knowledge base for evaluating historic and contemporary traditional uses is important to facilitate collaborative partnerships. A greater understanding of the effects of various recreational activities on forest health, especially in riparian ecosystems, is also crucial.