Desert Microbial Activity in the Rhizosphere Oasis

在沙漠生态系统中，植物的生长和繁殖受到水分供应的限制，但也受到氮和其他土壤养分的限制。土壤真菌和细菌负责将死亡物质中的营养物质转化为植物可以利用的形式，但低水分可用性会限制土壤微生物进行这种转化的能力。有趣的是，一些深根沙漠植物的根可以作为被动水运动的管道，从潮湿的土层进入碎屑丰富的浅干土层，这个过程被称为水力再分配。水进入干燥土壤的这种运动可能会刺激根部周围的微生物活动。该研究项目将包括综合温室和实地研究，利用tridentata蒿（普通荞属植物）在美国西部景观中将水分从湿润土层重新分配到干燥土层的能力。利用温室试验中的微生物传感器，以及犹他州田间土壤、植物和微生物分析，将研究山艾树根系对水的水力再分配，以促进土壤养分循环和养分有效性的能力。养分有效性的提高可能反过来导致植物主动重新分配水分的光合作用、生长和繁殖产量的提高。作为研究的伙伴，伍斯特生态动物园将举办一个展览，提供几个主要信息，包括：1。土壤中充满了有益的微生物；根是双行道，既能吸水又能放水。

In desert ecosystems, plant growth and reproduction are limited by water availability, but also by nitrogen and other soil nutrients. Soil fungi and bacteria are responsible for recycling nutrients from dead material into forms that plants can use, but low water availability can limit the ability of soil microbes to carry out such transformations. Interestingly, the roots of some deep-rooted desert plants can act as conduits for passive water movement from moist soil layers into shallow, drier layers where detritus is abundant, in a process called hydraulic redistribution. Microbial activity may be stimulated around roots by this movement of water into dry soil. This research project will include integrated greenhouse and field studies that take advantage of the ability of Artemisia tridentata (common sagebrush) to redistribute water from wetter to drier soil layers in Western U.S. landscapes. Using microbiosensors in greenhouse experiments, and soil, plant, and microbial assays in Utah field sites, hydraulic redistribution of water by sagebrush roots will be examined for its ability to promote soil nutrient cycling and nutrient availability. Enhanced nutrient availability may in turn lead to enhanced photosynthesis, growth, and reproductive yield of plants actively redistributing water. As a companion to the research, an exhibit will be developed at the Worcester Ecotarium that provides several primary messages, including: 1. Soil is alive with beneficial microbes, and 2. Roots are two-way streets which can both take up and release water.