Indicator
Grass Lake (sphagnum fen)
2015 Evaluation
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2015 Evaluation
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Status
Insufficient Data to Determine Status or No Target Established
Trend
Insufficient Data to Determine Trend
Confidence
Low
Evaluation Map
Grass lake map.jpg
Description

Map showing location of Grass Lake and surrounding area.

Rationale Details
Insufficient data to determine status. Although Grass Lake is located near a major state route, the wet conditions and unstable sphagnum substrate deter hikers and cyclists. In addition, the RNA status protects the site from off-road vehicles, grazing, and water diversions. Recreational use is mainly limited to cross-country skiing in the winter. Recent threshold evaluation reports have assessed the status of Grass Lake as in attainment based on qualitative evaluations of recreation impacts and management actions, rather than any direct measurements of factors that contribute to the integrity of the community (TRPA, 2012e, 2007). Moss monitoring plots showed that plots with intermediate Sphagnum spp. (5 to 50 percent cover) decreased between 2009 and 2010 by 30 percent, but plots with high cover (50 to 100 percent) increased. Meesia triquetra was present only at intermediate cover in 2009, and this cover class increased by 31 percent in 2010, and 0.18 hectares was mapped in the high cover class in 2010 (Shana Gross, pers. comm).
Insufficient data to determine trend. No new quantitative data is available since the 2011 Threshold Evaluation Report.
Confidence Details
Low. Where insufficient data is available to determine status the confidence is determined to be low.
Low. Where insufficient data is available to determine trend the confidence is determined to be low.
Low
Outcomes
Programs and Actions Implemented to Improve Conditions
U.S. Forest Service designation as an RNA and CAR provide protections to Grass Lake. TRPA and partners implement regulations and programs related to the protection of stream environment zones and uncommon plant communities. Anthropogenic activities known to impact these areas are prohibited. Extensive roadwork on State Route 89 was completed in 2011, with the central objective to safeguard water quality in Grass Lake and Lake Tahoe. Fuels reduction treatments in the surrounding area include 100 acres that were mechanically thinned on the west side of Grass Lake in 2008.
Effectiveness of Programs and Actions
Runoff from State Route 89 has likely been a source of water pollution, but recent road improvements were designed to divert surface road flow away from Grass Lake. Current regulations and protection measures appear effective.
Interim Target
Insufficient data is available at this time to establish and interim target.
Target Attainment Date
Not applicable.
Recommendations
Analytic Approach
Data from the U.S. Forest Service long term meadow monitoring plots are expected to provide a standardized quantitative measure of meadow health and long term trends.
Agencies monitor and report on different cycles. Threshold reporting is on a four-year cycle, and the LTBMU is monitoring vegetation plots on a five-year cycle. Synchronization would be beneficial. Web-based reporting in the future will enable more continuous reporting and data analysis.
Monitoring Approach
The LTBMU monitoring methods (meadow health plots, moss monitoring plots, permanent photo points) appear to be a robust assessment of the status and trends of Grass Lake. Remote sensing has been effective in detecting change in fens in the Sierra Nevada (Drexler et al., 2013) and its ability to assess status and trend should be evaluated.
Modification of the Threshold Standard or Indicator
No baseline has been established against which the nondegradation of the community standard can be objectively evaluated. Objective determination of “attainment” status for standards without a specific target is a recurrent challenge both in the Region and in the larger field of monitoring and evaluation (M&E). The standard should be assessed against best practice for the establishment of standards and indicators for M&E, and amended as necessary to improve the evaluability of the standard and the information it provides for management.
Attain or Maintain Threshold
No recommended changes.
Additional Figures and Resources

No photos available.

No documents available.