Impacts of hydraulic redistribution, re-infiltration and plant optimality to plants under different drought conditions

Abstract:

Understanding the interaction between plant and soil water is important in order to construct a comprehensive picture of how the climate change affects the plant and ecosystem patterns. To understand the plant adaption and hydrological responses to climate change is of paramount importance if we are to develop a long term plan to mitigate the adverse impacts of climate change. In this work, we focus on drought impacts since it is one type of extreme weather brought about by climate change with devastating effects: how the drought affects plants and, conversely, how plants’ responses, in turn, affect the drought’s impacts. This is an area that a lot is still not well understood. This study investigates impacts of drought conditions on plant growth associated with hydraulic redistribution re-infiltration and other hydrological processes governed by the mechanism of plant optimality. This is achieved by coupling VIC+, an extended version of the Three-Layer Variable Infiltration Capacity model, to a terrestrial biogeochemical model, the Carnegie Ames Stanford Approach model of carbon, nitrogen, and phosphorus (CASA-CNP), and to a multiscale routing model. With the integration of the CASA-CNP model to VIC+, the dynamic growth of vegetation can be represented. The coupled routing model makes it possible to consider the re-infiltration process along the flow routing paths. The influence to plants and the role of these processes are analyzed through an extended drought period in which results with and without including these processes will be presented and discussed.