Quantifying the importance of deep and shallow roots for plant water use and redistribution using a novel cave system to 20 m depth

Duke University, Durham NC

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The uptake of water is essential for trees, grasses, and crops to grow and survive, particularly during droughts and hot summer months. While many scientists have studied water uptake and movement from the ground to the top of trees, half or more of plants remains unstudied in most species and ecosystems. The goal of this proposal is to compare the functioning of deep (5-20 meters underground) and shallow roots for trees growing in the southern United States. It uses a novel cave system developed by the PIs in central Texas to study tree roots underground and uses molecular-based fingerprinting of these roots to match them to their respective shallow counterparts, much like the forensic approaches that detectives use. The research questions include, 1) How much water that trees use comes from deep underground? 2) What are the unique physical characteristics of deep roots that promote water transport? and 3) To what extent do specialized water channels in plants contribute to their ability to take up and transport water? The proposed activities provide numerous potential benefits to society, including measurements of groundwater use and recharge by trees in the central U.S. For outreach and training, the Jackson lab has involved more than 30 undergraduate students and nine high school students (three of them minorities) in NSF-funded research in the last five years. Jackson has also done extensive outreach with local high schools, including teaching in 8 Environmental Studies classes at Broughton High School in Raleigh, NC and mentoring in an environmental science class at High Point High School in High Point, NC.