Type: report

Article abstract: Monitoring to detect ecological change is an important component of many environmental and conservation programs. Developing effective monitoring programs for conservation plans is scientifically and logistically challenging. The Nature Reserves of Orange County (NROC) hold 38,000 acres enrolled within the Orange County NCCP. NROC is obligated to monitor the condition of conservation values through time and has identified vegetation communities as targets for long term monitoring. The Nature Conservancy holds conservation easements on properties adjacent to NROC NCCP lands, and both entities have similar monitoring requirements. The objective of this project is to evaluate the precision and accuracy of different sampling designs and field protocols for monitoring vegetation communities in the Orange County conservation lands, primarily coastal sage scrub (CSS), chaparral, and grasslands in central Orange County. This information addresses many of the fundamental questions surrounding the selection of both response designs and sampling designs and provides a foundation for long-term monitoring. Initial sampling effort was stratified across vegetation types, including coastal sage scrub (CSS), chaparral and grasslands. Although the OC NCCP and TNC easement lands encompass many more vegetation types, CSS, chaparral and grasslands were prioritized based on previous work in the San Diego MSCP. This stratification across habitat types was coordinated with sampling in the San Diego MSCP to improve the power of the analysis and expand our understanding to the entire southern California region. This larger, combined data set will provide both sponsors a more robust set of conclusions and dramatically advance our ability to monitor southern California vegetation communities. Methods: We set up eight plots throughout the inland portions of open space in central Orange County. A total of six plots were established on TNC easement lands with the remaining two established on NROC NCCP lands. We used plots that were 20m by50 m (0.1ha) and included ten 100m2 (10mx10m) subplots, two 50m point-intercept transects and the twenty 1m2 quadrats. All three data collection protocols were used by each team at all visited plots. Plot set-up was performed in late April, and field sampling was conducted by two teams in mid-May. Our field protocols recorded a number of response variables, including the species richness of the vegetation being sampled and the cover of individual spe