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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。水的吸收对于树木，草和作物的生长和生存至关重要，特别是在干旱和炎热的夏季。虽然许多科学家已经研究了水分的吸收和从地面到树顶的运动，但在大多数物种和生态系统中，仍有一半或更多的植物未被研究。这项提案的目的是比较美国南部树木深根（地下5-20米）和浅根的功能。它使用了德克萨斯州中部的PI开发的一种新型洞穴系统来研究地下的树根，并使用这些树根的分子指纹来将它们与各自的浅层对应物相匹配，就像侦探使用的法医方法一样。研究问题包括：1）树木使用的水有多少来自地下深处？ 2)深层根系促进水分运输的独特物理特征是什么？ 3）植物中专门的水通道在多大程度上有助于它们吸收和运输水分的能力？拟议的活动为社会提供了许多潜在的好处，包括测量地下水的使用和美国中部树木的补给。在过去的五年里，杰克逊实验室在NSF资助的研究中，有30多名本科生和9名高中生（其中三名是少数民族）参与了推广和培训。杰克逊还与当地高中进行了广泛的外联，包括在北卡罗来纳州罗利的布劳顿高中的8个环境研究班授课，以及在北卡罗来纳州高点高中的一个环境科学班进行辅导。

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.