Linking water availability with plant productivity and nutrient dynamics in complex watersheds

Department of Hydrology & Atmospheric Sciences
Weekly Colloquium
Thursday, November 29, 2018
4:00 pm in Harshbarger 206 ~ Refreshments at 3:45 pm
 
Jia Hu

Assistant Professor, School of Natural Resources and the Environment (SNRE)

Abstract:

In temperate forest of the western U.S., tree growth is often tightly linked to water availability. However, because seasonal climate patterns are expected to change, tree dependency on different sources of moisture may also shift (or have already shifted). In high elevation montane ecosystems, declines in winter snowpack can also increase the severity of summer droughts, with the potential to impact soil nitrogen availability and tree nitrogen use strategies. In this seminar, I will present three case studies that examine how topography modulates the sensitivity of tree growth, water acquisition strategies, and nitrogen use to climate, within a montane watershed in western Montana. Some specific questions I will address include: 1) Where along the soil depth profile are trees sourcing water from and have shifts in source water use occurred over the last 100 years? 2) How do different sources of moisture availability influence forest productivity? 3) How does snowpack influence soil nitrogen availability and subsequent nitrogen uptake by trees? I will show that snowpack dynamics on watershed hydroloclimate can be complex, often producing unexpected results both spatially and temporally.