Forest Monitoring

The forest monitoring study at Pepperwood is creating a vital baseline for the health of Northern California forests that will be valuable to researchers for decades to come. In the short term, the data we’re collecting is helping us understand the effects of extreme weather events like California’s historic drought.

Pepperwood hosts 50 long-term forest monitoring plots in partnership with Dr. David Ackerly and the Ackerly Lab at UC Berkeley’s Department of Integrative Biology. Graduate students and researchers return to the plots each year and collect data on woody vegetation. Located across the preserve, these plots are adjacent to weather sensors that enable scientists to determine how variability among our micro-climates impacts plant life over time.

Monitoring by Forest Type

1. Mixed hardwood vegetation is being monitored through UC Berkeley’s long-term forest research program (Ackerly et al. 2013). Study plots are designed to test the role of microclimate diversity in driving species composition, and to provide a framework for monitoring change over time.
2. Oak forests are being monitored as part of a long-term forest monitoring project established in 2013 (Ackerly et al. 2013). The purpose of this project is to monitor the direct and indirect impacts of climatic heterogeneity and 21st century climate change on native California oak forests. The primary objectives of this project are to examine oak forest vegetation community structure and composition across fine-scale topographic gradients, provide a baseline for testing hypotheses and modeling forest dynamics in response to climate change, and create an infrastructure for future projects.
3. Redwood forests at Pepperwood are minimal. The Pepperwood summer TeenNat internship program mapped the majority of individual redwood trees growing on Grouse Hill in 2013, documenting diameter at breast height, stump sprout counts and average heights, and evidence of fire and mortality. Starting in 2014, the program used the Save the Redwoods League’s monitoring protocol to collect annual data on western sword fern populations—an important indicator of redwood community health. The TeenNat program also collects annual observational data on herbaceous and animal species found in redwood forests during the month of July. A woody vegetation monitoring plot was established in Redwood Canyon in 2015 by Pepperwood biologists and the California Native Plant Society using a modified long-term forest monitoring plot protocol (Ackerly et al. 2013). Species composition, seedling and sapling abundance, and tree girth will be monitored every six years in concert with Pepperwood’s 50 long-term forest monitoring plots. The 2015 monitoring results were incorporated into the Sonoma County Veg Map program’s classification system for the county (Klein et al. 2015a, 2015b).