Spatial and temporal drivers of variation in tree hydraulic processes and their consequences for climate feedbacks

Trees can cool the global climate by storing carbon during photosynthesis and can cool the local climate by pulling moisture out of the ground with their roots and releasing it from pores in their leaves as water vapor; a process known as transpiration.  Photosynthesis and transpiration generally increase when trees have access to sufficient water in the soil and decrease during dry periods when soil water is less abundant.  While we have a general understanding that these processes depend on soil moisture (and humidity), and that these relationships differ by tree species, less is known about how a tree’s past exposure to water stress affects its later response to water availability.  In this proposal, the investigators will study the water responses of trees growing in different positions across the landscape that afford different levels of access to water (e.g., hilltops vs. streamsides), as well as trees that have been deliberately exposed to different levels of reduced precipitation in recent years.  The research will focus on species growing in hardwood forests of northern and southern Indiana that have different levels of response to water stress.  How different are the water responses of individuals of the same species that have experienced different conditions?  How do the differences within a species compare to differences between species?  The researchers will develop ways to represent these within-species differences in model representations of trees, in order to more realistically simulate the functioning of trees within the land component of the E3SM

Energy Exascale Earth System Model (E3SM)

The Energy Exascale Earth System Model (E3SM) project includes Earth System Models, simulations, and predictions to investigate energy-relevant science using code optimized for DOE's advanced supercomputers.

Source: NVCL Web Page Source

climate model.