Belowground Plant Responses to Changes in Precipitation: Effects of Amount, Duration, and Direction

Christopher Vito

While there exists a large body of research addressing the impacts of changes in precipitation on aboveground net primary production (ANPP), considerably less work has been done to examine belowground net primary production (BNPP). Similarly, there exists a gap in knowledge pertaining to the effect of changes in precipitation over time on BNPP, such as response lags and legacy effects. Therefore, examining belowground plant functioning in the Chihuahuan Desert over long temporal scales is a necessary step in improving our understanding of dryland ecosystem response to changes in precipitation conditions. 

This research aims to answer the following question: What are the effects of long-term changes in precipitation on the belowground net primary production of dominant dryland plant species? Long-term data from existing experiments will be utilized alongside newly established experiments in order to quantify belowground net primary productivity responses to rainfall manipulation through time. This will be accomplished via a combination of minirhizotron imagery, ingrowth cores, and biomass cores. Additionally, relationships between the aboveground size of dominant plants and their rooting distributions will be examined via lithium chloride tracer injections in order to shed light on resource acquisition strategies. The combination of these investigations will expand our understanding of both dryland responses to change and the mechanisms underlying these responses through time.