ACQUISITION OF AN INSTRUMENTATION ARRAY TO MONITOR AND MODEL WATER, CARBON AND ENERGY FLUXES AT THE HILLSLOPE SCALE IN THE LANDSCAPE EVOLUTION OBSERVATORY

1340912这笔赠款为获得新的环境传感和采样能力提供支持，以加强和实现亚利桑那州甲骨文生物圈2号(B2)的景观进化天文台(LEO)的科学目标。LEO的目标是能够在山坡尺度上对陆地表面水、能量和碳的通量进行受控研究，其中关键的观测数据是在中等复杂地貌的亚米尺度上进行监测的。观测到的通量的时空变异性及其与受控和观测气候参数的关系和反馈将被用来为更大流域、大陆甚至全球尺度上陆地-地表水、能量和碳循环过程的改进模型提供信息。LEO由三个重复的340平方米汇聚的实验流域中系统组成，这些系统建立在B2的5,000平方米环境控制设施内。LEO中隔带的基本设计是三个，长30米，宽12米，深1米，倾斜(水平方向约10度)的钢罐，里面填满了颗粒大小均匀的玄武岩Tephra作为起始土壤。作为其框架设计的一部分，分布式称重传感器阵列允许精确确定整个储罐的重量变化，并位于储罐表面上方的降水模拟系统，该系统是速率可控的，并且可以在土壤储罐表面上变化。设计的一个方面是，当土层饱和时，通过地下抽水和清除水来特别防止地表径流和侵蚀？LEO不是为研究侵蚀过程而设计的。储罐密集地布置了用于抽取孔隙水和气体的采样端口，并且已经增加了许多传感器类型，包括土壤水分探头、土壤温度传感器、土壤水势传感器、土壤水分采样器、土壤气体采样器、二氧化碳传感器、地表热流板、电阻率层析成像探头、压力计以及水流和排水流量计。最初的计划要求对没有维管植物的实验景观进行1-2年的研究，然后种植一系列维管植物类型，以便研究中层物理、化学和生物系统的共同进化及其对水、能量和碳的陆地-大气交换的影响。

1340912TrochThis grant provides support for the acquisition of new environmental sensing and sampling capabilities to enhance and realize the scientific goals of the Landscape Evolution Observatory (LEO) at Biosphere 2 (B2) in Oracle, AZ. The goals of LEO are to permit controlled study of land surface fluxes of water, energy and carbon at the hillslope scale where key observables are monitored at sub-meter scales across a moderately complex landscape. The observed spatial and temporal variability of fluxes and their relationship and feedbacks to controlled and observed climatic parameters would then be used to inform improved models of land-surface water, energy and carbon cycling processes at larger watershed, continental and even global scales.LEO consists of three replicated 340 m2 convergent experimental watershed mesocosms constructed inside a 5,000 m2 environmentally controlled facility at B2. The LEO mesocosms have as their basic design, three, 30 m length, 12 m width, 1 m depth, sloped (approximately 10 degrees from horizontal) steel tanks that have been filled with a grain size homogenized basaltic tephra as a starting soil. The tanks have as part of their frame design, arrays of distributed load cells that permit precise determination of weight changes across the tanks and located above the surface of the tanks are precipitation simulation systems that are rate controllable and can be varied across the surface of the soil tanks. An aspect of the design is that overland flow and erosion is specifically prevented by subsurface pumping and removal of water as the soil horizon saturates ? LEO is not designed for erosion process studies. The tanks are densely arrayed with sampling ports for drawing pore waters and gases and numerous sensor modalities have already been added including soil moisture content probes, soil temperature sensors, soil water potential sensors, soil water samplers, soil gas samplers, CO2 sensors, surface heat flux plates, electrical resistivity tomography probes, piezometers, and water flow and drainage flowmeters. The initial plan calls for 1-2 years of studies of the experimental landscapes devoid of vascular plants followed by the planting of an array of vascular plant types to allow for study of the co-evolution of the physical, chemical, and biological systems in the mesocosms and their influence on the land-atmosphere exchanges of water, energy and carbon.***