Three variables shown above were used to predict the succession of California redwood forests and include: Minimum temperature change, maximum temperature change, and precipitation change. These variables are important as input to statistical models for predicting succession and encroachment of vegetation types into redwood forests. Data are overlaid on a Landsat TM5 supervised classification from July 2011. All climate datasets were obtained from the PRISM Climate Group at Oregon State University.
Authors: Wei-Chen Hsu, Alex Remar, Emily Williams, Adam McClure, Soumya Kannan, Robert Steers
Advisors/Science Mentors: Dr. Jay Skiles, Cyndi Schmidt
Abstract: California’s land-ocean interface is one of its most diverse biogeographical zones. This zone maintains a rich biodiversity of coastal grasslands, shrublands, and forests. Studies have shown that this biodiversity relies on constant climate variables such as precipitation, wind prevalence, fog, cloud cover, and temperature. However, changing summer marine fog events along California’s Pacific Coast have declined by an estimated 33% in frequency since the early 1950s. As fog is one of the main sources of water for vegetation during the otherwise dry summer months, historical coastal ecosystems such as that of the coastal redwood tree, Sequoia sempervirens, have been dramatically affected. The rapid colonization of conifers into regions previously identified as shrubland and grassland is hypothesized to be related to the changing fog patterns. This advancement of conifer forests poses a management challenge to park and forest personnel. The primary objectives of this project are to identify the changing vegetation by geospatially mapping its colonization into shrubland and grassland, to determine the succession rates of conifer forests, and to identify climate and ecosystem variables which contribute to the success of conifer establishments. Vegetation change was investigated using C-CAP and Landsat TM5 satellite images for a time-series change detection to identify the areas and rates of conifer encroachment. MODIS and GOES satellite sensors were used in conjunction with visibility data to create overlying fog and precipitation maps. These data were used to analyze the relationship between conifer encroachment and changing fog patterns in the California coastal region.
Video transcript available here.