SGER: Effects of Wildfire on Aquatic and Terrestrial Ecology in an Oak Woodland - Chaparral Ecosystem

1999年10月16日发生在北加州的4万英亩的野火提供了一个非常宝贵的科学机会来解决关于水生生态系统和陆生植物群落对扰动反应的新问题。水生研究将检验(1)营养物质的富集是“级联上升”交替的营养水平（如有时在简单的实验系统中发现的那样）还是在所有营养水平上增加丰度（如在复杂的自然系统中通常发现的那样）；(2)间歇溪流中较简单的无脊椎动物群与较复杂的永久溪流中动物群的恢复速度；(3)营养物富集是否导致该系统中汞的生物吸收量增加。陆地研究将研究与种子源的空间隔离如何影响草地植物群落的恢复，以及火灾对植物群落的影响（包括外来物种的优势）是否取决于基质和放牧历史。该项目的结果与多年的火灾前数据库相结合，将为了解不常见的大型火灾如何影响流域尺度上的多样性模式提供新的见解。

AbstractSusan P. HarrisonU of California - Davis0072804The 40,000-acre wildfire in Northern California that occurred 16 October 1999 presents a very valuable scientific opportunity to address new questions about aquatic ecosystem and terrestrial plant community responses to perturbation. Aquatic studies will examine (1) whether nutrient enrichment 'cascades up' alternating trophic levels (as sometimes found in simple experimental systems) or increases abundances at all trophic levels (as typically found in complex natural systems); (2) the speed of recovery of the simpler invertebrate faunas of intermittent streams in comparison to more complex faunas of permanent streams; and (3) whether nutrient enrichment leads to higher biological uptake of mercury in this system. Terrestrial studies will examine how spatial isolation from seed sources influences the recovery of the grassland plant community and whether the effects of fire on the plant community (including its dominance by alien species) depends on substrate and grazing history. The results of this project coupled with a multi-year pre-fire database will provide new insights into how large infrequent fires influence patterns of diversity at the watershed scale.