该项目将测量花旗松幼苗的水力传导性，并确定幼苗的水力传导性在土壤水分限制条件下的变化情况。爱达荷州每年种植数十万株花旗松幼苗，这些幼苗要经受各种环境条件的考验。实地观察表明，栽种的花旗松幼苗无法存活；栽种地点土壤水分有限被怀疑是幼苗死亡的原因之一。该项目将利用植物水力生理学学科的工具和机制，包括高压流量计、Sperry 仪器和 METER 仪器，解决植苗无法存活这一林业问题。我们将在栽种前后测量秧苗的形态和生理特征。对照组幼苗将在整个实验过程中得到充足的水分，而处理组幼苗将经历中等或极端干旱条件。实验结果将通过方差分析进行分析。实验结果将阐明秧苗的水力生理如何应对种植，这将有助于提高秧苗的存活率，确保实现重新造林和恢复的目标。
DEVELOPING A LIFE-CYCLE DEGREE DAY MODEL FOR MELOIDOGYNE HALPA (NORTHERN ROOT KNOT NEMATODE) TO IMPROVE WASHINGTON WINE GRAPE MANAGEMENT STATE
Root-knot nematodes are endoparasitic organisms that infest plant roots and form galls that disrupt normal translocation of sugars and water. Declines in vigor in older vineyards and poor establishment or death of young vines in replant situations have been attributed to nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent species of root-knot nematode found in Washington wine grape vineyards. Knowing when the different life stages of M. hapla are present in the soil will allow growers to target those stages that are more susceptible to management intervention.
We know that the rate of M. hapla development and infectivity is most dependent on soil temperature and moisture. As such, we foresee the ability to develop a life-cycle model based on the temperature proxy of growing degree days. Over the next two years, I will intensively sample both soil and roots for life stages of M. hapla in two vineyards, and compare that to various environmental parameters such as air-based growing degree-days, soil temperature, and soil moisture. I plan on collecting the soil parameters using the METER 5TM soil moisture and temperature sensors and Em50data loggers.
MICROTENSIOMETER TO CONTINUOUSLY MONITOR WATER POTENTIAL IN PLANTS
Water potential (Ψ) is the best measure of a plant’s hydration relative to growth and product yield/quality. Unfortunately, directly measuring Ψ in plant tissue is only possible through labor-intensive, destructive methods such as the leaf pressure bomb and stem psychrometer. A common alternative is to use ‘set-and-forget’ soil tensiometers to measure soil water potential (Ψsoil) as a proxy for plant water potential (Ψplant), but this method is unreliable for plants with high hydraulic resistance (e.g., vines and woody species) where often Ψplant << Ψsoil.
Although very accurate and simple to use, tensiometers also have two drawbacks: they are large and bulky, and tend to cavitate in even slightly dry soils. My project involves using MEMS technology to develop a miniature tensiometer (microtensiometer) that overcomes these drawbacks and thus can be embedded in plant stems to directly measure Ψplant, is easily mass-manufactured, is stable for months, and communicates digitally.
Now that we have a functional prototype, I will use the AquaLab 4TE dew point water activity meter to produce solutions of specific activity to test, calibrate, and characterize the microtensiometer. My intent is to improve the design of this sensor so it can be used in the field to, for instance, continuously monitor and control Ψplant in vineyards, and consistently produce high-quality wine grapes with an exact flavor/aroma profile.
在本项目中，将使用 METER 5TM 湿度探头来评估土工合成材料加固土层中离散位置的体积含水量和温度在热注入过程中的变化。此外，还将使用 METERKD2Pro系统来确定土壤热特性与饱和度之间的非等温关系。这套仪器将用于评估热传导和水流耦合过程的量化，以及随着时间的推移对非饱和土壤沉积中地热效率的相关影响。
我的研究调查了积雪量的变化是否会影响加利福尼亚内华达山脉两种外来灌木（苏格兰扫帚和西班牙扫帚）的种群增长率。这两种灌木可能对春季积雪减少导致的生长季节提前很敏感，因为在土壤温度低至 4 °C 的情况下，它们可以通过光合作用活跃的绿色茎干生长。不过，提前融雪和提前消耗土壤水分之间可能存在权衡，这可能会导致长期干旱胁迫和碳增量减少。初步数据表明，耐旱性更强的灌木西班牙扫帚比苏格兰扫帚对冬季积雪减少的反应更积极。
METER 仪器将收集一系列试验性积雪处理和森林冠层结构的积雪覆盖和土壤湿度 的全面记录，以记录这两个因素的相互作用以及它们解释入侵植物表现的机制。
这项研究的主要目的是确定关键环境和生理变量的状况，在这些变量的作用下，两个水力不同的葡萄品种（格雷纳德和西拉）可以达到理想的压力水平。 我们将从这两个栽培品种的葡萄藤中排除水分，并使用 METER 的含水量传感器、数据记录器和稳态孔隙度计来监测诱发水分胁迫时的土壤和植物参数。 这些信息将有助于种植者做出水分管理决策，并将用于评估在该地区为优质葡萄生产达到适当压力水平的可行性。
露水的时空变异性调查对植物病害管理和土壤水分遥感都有影响。 在这项研究中，将通过确定冠层中露水量最高和最低区域的 LAI 对冠层总 LAI 的贡献，研究露水点测量到冠层尺度的缩放过程。 将使用叶片湿度传感器来确定大豆冠层中露水持续时间（和露水量）最长的区域。 将对田地周围的地点进行调查，以了解田地内露水的变化情况。