Spatial and Temporal Heterogeneity of Resource Availability in the Sagebrush-steppe Ecosystem: Perception and Exploitation by Plants

鼠尾草草原生态系统资源可用性的时空异质性：植物的感知和利用

• 批准号: 9208212
• 负责人: Martyn Caldwell
• 金额: $ 180万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-12-15 至 1998-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9208212&HistoricalAwards=false
• 关键词: Spatial; Temporal; Heterogeneity; Resource; Availability

Characterization of resource heterogeneity in space (patches) and time (pulses) at scales of days to weeks and decimeters to meters will be undertaken. In addition to chemical and physical measures of resource heterogeneity, assessments of how this resource variability is perceived by plants will be pursued, including: Root and foliage characteristics that reflect local resource availability, acquisition of resources, competition with other plants and microbes for resources, and translation of resources gleaned from patches and pulses into fitness and seedling recruitment. Plant response to incongruity of resources and factors that might smoothe heterogeneity (mycorrhizae and water efflux from roots) will also be investigated. Parameters to be measured include nutrient pools, flux rates through nitrogen pools, microbial biomass, soil water potential, plant nutrient acquisition, photosynthesis, root uptake kinetics, respiration and growth, and biomass and seed production. Stable isotopes will feature prominently in the work including new isotopic dilution procedures. Data collected in addressing 21 hypotheses will also be applied in a new modeling application of Ecological Field Theory and kriging interpolation. The study features two species each of shrubs, perennial grasses and exotic annual grasses. The current conversion of the sagebrush steppe from a perennial system to exotic annuals is also addressed. This research will produce findings of importance to the general ecology and ecosystem function of arid lands as well as to the management of grazing land resources.

空间（斑块）资源异质性的表征， 时间（脉冲），以天到周和分米到米为刻度 将进行。 除了化学和物理措施外， 资源的异质性，评估这种资源 变异性是由植物感知将追求，包括：根 以及反映当地资源的植物特征 可获得性、资源获取、与其他组织的竞争 植物和微生物的资源，以及资源的转化 从斑块和脉冲收集到健身和幼苗 招聘 植物对资源与因子不协调的响应 这可能会平滑异质性（真菌和水流出， 根）也将进行调查。 需要测量的参数包括 养分库，氮库通量，微生物，氮素库，氮素库 生物量、土壤水势、植物养分获取、 光合作用、根吸收动力学、呼吸作用和生长，以及 生物量和种子生产。 稳定同位素将以 包括新的同位素稀释程序。 在解决21个假设中收集的数据也将应用于 生态场理论和克里格法的一种新的建模应用 插值 这项研究以两种灌木为特色， 多年生禾本科和外来的一年生禾本科。 当期转股 从多年生植物到外来的一年生植物的转变， 也解决了。 这项研究将产生重要的发现 干旱地区的一般生态和生态系统功能 对牧场资源的管理。