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

1340912 troch这笔拨款为获取新的环境传感和采样能力提供支持，以增强和实现位于亚利桑那州甲骨文生物圈2号（B2）的景观演变观测站（LEO）的科学目标。LEO的目标是允许在山坡尺度上对水、能量和碳的地表通量进行控制研究，在亚米尺度上监测一个中等复杂景观的关键可观测物。观测到的通量的时空变异性及其与受控和观测到的气候参数的关系和反馈，然后将用于为更大流域、大陆甚至全球尺度上的陆地地表水、能源和碳循环过程的改进模型提供信息。LEO由三个复制的340平方米的会聚实验流域生态系统组成，这些生态系统建在B2的5000平方米的环境控制设施内。LEO中生态系统的基本设计为三个，长30米，宽12米，深1米，倾斜（与水平方向约10度）的钢罐，其中填充了颗粒大小均质玄武岩罐作为起始土壤。这些水箱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水箱的重量变化，位于水箱表面上方的降水模拟系统是速率可控的，可以在整个土壤水箱表面变化。该设计的一个方面是通过地下抽水和土壤层饱和时的排水来特别防止地面流动和侵蚀。LEO不是为侵蚀过程研究而设计的。水箱密集排列着用于提取孔隙水和气体的采样端口，并且已经添加了许多传感器模式，包括土壤水分含量探头，土壤温度传感器，土壤水势传感器，土壤水采样器，土壤气体采样器，二氧化碳传感器，表面热通量板，电阻率层析探头，压电计以及水流和排水流量计。最初的计划要求对缺乏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，以研究中生态系统中物理、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.***