The Effect of Fire, Extreme Precipitation and Drought on Ecosystem Fluxes of Water-Limited Ecosystems

Abstract:

Current observations reveal substantial changes in precipitation patterns across globally distributed water-limited ecosystems. Consequently, changes in the amount and frequency of rainfall will influence biophysical drivers that regulate the strength and timing of ecosystem fluxes including soil CO₂ efflux, gross primary productivity, and evapotranspiration. First, a classic example is presented using fire and changes in precipitation to illustrate how soil CO₂ efflux rates respond to these disturbances in arid grasslands. Second, multi-year evapotranspiration patterns are explored in an arid shrubland subject to monsoon rains, arguably extreme water pulses for these water-limited ecosystems. Finally, a multi-year record of ecosystem scale CO₂ fluxes and evapotranspiration is presented for coastal water-limited shrublands, where the effects of extreme precipitation and drought are explored along with potential transport of moisture from the ocean. Water-limited ecosystems are subject to different disturbances and climate extremes; however, is still unclear how ecosystems respond and which are the variety of processes that may provide resilience to these events.