Chaparral succession following the Coyote Fire at Sky Oaks Field Station
This project formed the Masters thesis research of Heather Karnes Schmalbach who completed her degree in December 2005. The main findings are summarized below. Read more about the Sky Oaks Field Station, a long term ecological research site, here: Field Stations Program
Schmalbach, Heather, 2005, Patterns of post-fire regeneration in the chaparral community at Sky Oaks Field Station, Thesis (M.S.)-- San Diego State University (Biology)
Schmalbach, H., J. Franklin and J. F. O’Leary, 2007, Patterns of post-fire regeneration in a southern California mixed chaparral community, Madroño 54(1): 1-12
Effects of pre-fire stand age, fire severity, and hillslope position on postfire vegetation recovery during the first two postfire seasons were studied in two contrasting stands of mixed chaparral at San Diego State University’s Sky Oaks Field Station (San Diego County, CA). The old stand was approximately 60-year old and the young stand was 12-years old when both burned in the July 2003 Coyote Fire.
The two stands showed contrasting patterns of postfire community composition among different plant groups based on their modes of postfire regeneration. Fire severity was significantly higher in the older stand. Increased fire severity was positively correlated with the establishment of Ceanothus greggii var. perplexans (an obligate seeder) seedlings, and negatively correlated with Adenostoma fasciculatum (a facultative seeder) seedling abundance. Hillslope position was also important in determining patterns of abundance, suggesting that soil erosion and deposition following fire may have a significant effect on postfire community recovery in these steep sites. Alternatively, prefire differences in the chaparral community that were correlated with hillslope position may account for these differences.
The postfire herbaceous community in the first year was dominated by Phacelia brachyloba (a fire annual). Contrary to expectations, this species was found in greater abundance in the old stand than in the young. Fire annuals were largely absent from the community in the second year, and were replaced in abundance by a variety of opportunistic native and exotic annuals.