Rocky Mountain Research Station

ICP Level II at Sierra Ancha

Project Objectives

The overall objective of the proposed network is to strengthen the role of the EFR by providing more internationally standardized data which will benefit the entire US EFR network – all 77 sites. The network will contribute to a better understanding of the relationships between the condition of forest ecosystems and anthropogenic (in particular air pollution) as well as natural stress factors through intensive monitoring on a number of selected permanent observation plots and to study the development of important forest ecosystems. Further, the network will provide a deeper insight into the interactions between the various components of forest ecosystems by compiling available information from related studies, and in close co-operation with the ICP on modeling and mapping will contribute to the calculation of critical levels/loads and their exceedances in forest ecosystems. Ideally this will improve collaboration with other environmental monitoring programs as well and contribute to the monitoring activities to other aspects of relevance for forest policy at national and global level, such as effects of climate changes on forests, sustainable forest management and biodiversity in forests. Lastly, the network will provide policy-makers and the general public with relevant information.

The Sierra Ancha EF in particular plays three important roles in this network: (1) It is the southernmost EF in the contiguous US; (2) it is downwind from the nation’s fourth largest metropolitan area; and (3) it is the driest EF in the network.

One important selection criterion is that the Level II plots should be located in such way that the most important forest species and most widespread growing conditions are represented. The plot itself shall be as homogeneous as possible (regarding e.g. tree species, stand type and site conditions). The plot has a minimum size of 0.25 ha and is surrounded by a buffer zone with a minimum width of 10 m, if possible. There should be no differences in the management of the plot, its buffer zone and surrounding forest (e.g. management operations should be comparable and fencing should be limited to a minimum). However, the disturbance of the monitoring activities should be minimized. Trees felled in the plot or in the buffer zone should be registered and if possible used for increment analysis. Appendix 1 visualizes the standard Level II-plot design. All trees in the total plot are to be included in the sample for the tree assessment (e.g. crown inventory, increment assessment).

 

Table 1: Surveys carried out on Level II plots

If all measurements mentioned under points a – k (Table 1) are carried out at the same plot, this plot is then called a key plot. All countries are invited to establish at least 10% of their Level II plots as key plots. While all Level II plots contribute at a certain degree to improve the understanding of the cause-effect relationship (objective b) the key plots will provide the supplementary information necessary to fulfill objective c (to provide a deeper insight into the interactions between the various components of forest ecosystems by compiling available information from related studies).

The exact protocol for data collection in the US ICP Level II network is still to be determined. Currently, two station personnel travel on a bi-weekly basis to the Sierra Ancha EF to download the data which is collected continuously. This data includes:

Meteorology

Meteorological measurements will be taken on a continuous basis using an automated weather station described below. A NADP type wet/dry collector will also be deployed.

Water Flow

Streamflow will be measured on three supercritical, trapezoidal flumes located on the Workman Creek North, Middle and South Forks. Water yield based on stage height and flume ratings will be measured with modern electronic stage height sensors. Stream stage heights are converted to flow volumes based on hydraulic rating formulas.

Ambient Air Quality

Ambient air quality is measured by two methods: (1) A Ozone monitor measures atmospheric ozone in the concentration range1.5 ppbv to 100 ppmv using the established technique of UV absorption at 254 nm. This data is recorded with a data logger which will be downloaded during site visits. (2) Passive samplers will collect samples for nitric oxide, nitrogen dioxide, sulfur dioxide & ammonia. Most likely these samples will be shipped to the PSW Riverside station for testing and analysis. Again the exact protocol is yet to be determined.

Soils

Soils are evaluated every ten years (solid phase) as well as continuously (liquid phase). The solid phase evaluation will begin in 2010. Soil solutions will be collected together with the other continuously compiled data and will is collected by an integrated soil and groundwater pollution monitoring unit. The sampler will collect soil water, soil gas, monitor soil moisture, temperature and conductivity, and store soil water samples in the soil until further analysis can be performed.

Vegetation

Overstory composition, understory, and forest floor will be determined on the established monitoring site at given time intervals (Table 1).

Litterfall

Throughfall collection systems will be located throughout the monitoring site and will be co-located with the lysimeters and near the deposition samplers. The physical samples will be collected on a monthly basis with the remaining continuously recorded data.

The data collected at the Sierra Ancha Experimental Forest will contribute to a better understanding of the relationships between the condition of forest ecosystems and anthropogenic (in particular air pollution) as well as natural stress factors through intensive monitoring on a number of selected permanent observation plots and to study the development of important forest ecosystems. Further, the results will provide a deeper insight into the interactions between the various components of forest ecosystems by compiling available information from related studies, and in close co-operation with the ICP on modeling and mapping will contribute to the calculation of critical levels/loads and their exceedances in forest ecosystems. Ideally this will improve collaboration with other environmental monitoring programs as well and contribute to the monitoring activities to other aspects of relevance for forest policy at national and global level, such as effects of climate changes on forests, sustainable forest management and biodiversity in forests. Lastly, the network will provide policy-makers and the general public with relevant information.

Appendix 1: Standard Level II plot design (example)