Longleaf Pine Ecosystems with greater native understory recovery more rapidly from drought

Ecosystems obtain energy in the form of carbon, which is then utilized in structures like leaves and roots to support ecosystem function. Studying energy input and expenditure during photosynthesis and other metabolic activities can give us insight into how vegetation responds to disturbances like drought, which may be useful to predict ecosystem responses to more frequent extreme weather events associated with climate change. Three southern U.S. woodland savannas with differences in soil water availability and historic soil disturbances were selected to measure variation in metabolic activity and energy storage. All sites were exposed to extreme drought from 2010 through 2013. Sites with greater native understory plant diversity stored more energy over the course of this study and responded to drought more rapidly by lowering energy use. In contrast, a site without native understory species but with greater abundance of woody understory and overstory vegetation had a longer recovery from drought. This disturbed site relied on stored energy twice as often than more diverse sites due to lower overall energy accumulation and used more energy during drought. This study separates base rates of ecosystem metabolic activity from changes in photosynthetic activity and energy accumulation during disturbances, which helps us understand how energy is used in ecosystems.

Wiesner, S., Stoy, P. C., Staudhammer, C. L., & Starr, G. (2020). Using metabolic energy density metrics to understand differences in ecosystem function during drought. Journal of Geophysical Research: Biogeosciences, 125(3), e2019JG005335. https://doi.org/10.1016/j.agrformet.2020.108252