Interactions in Time and Space Variability in a Chihuahuan Desert Ecosystem: Jornada LTER

这个研究项目将检验一般假设， 沙漠化改变了以前相对统一的 通过增加水氮的空间分布， 和时间的异质性，导致社区的变化， 奇瓦瓦沙漠的组成和地球化学过程 生态系统 Jornada实验牧场（南部新 墨西哥），拥有75年的牧场研究历史， 记录了植被覆盖的广泛变化-从常年 从草原到几种灌木丛--这是一个结果 荒漠化的影响。 这项工作将包括测量净 初级生产力，根系生长，分解，土壤水分 动力学，地表水文学，动物种群的动力学， 动物引起的土壤扰动、氮循环过程和 广泛分布的氮和碳的稳定同位素分布 生态系统，从黑格兰玛（Bouteloua eriopoda） 草原，荒漠化，持久的灌木丛的chreosotebush （Larrea tridentata）、tarbush（Flourencia cernua）和牧豆树 （Prosopis gladulosa）. 荒漠化概念模型将 通过长期的水强化和机械测试 水和养分的均匀化。 这些研究的数据 将用于参数化过程模型。 测量 水、风和气体的输送和径流分流 实验将为沙漠景观模型提供数据。 数据 从卫星遥感植被和土壤 将纳入一个动态地理信息 Jornada盆地的系统模型。 机构支持仍然是极好的， 这个项目 酒店的设施非常好。三大制度 涉及多名调查人员的合作安排， 经过深思熟虑，应该证明是非常有益的 和生产力。 这项研究项目的结果应该会产生重大发现 这是生态学领域的基础。 此外，结果应该对未来很重要， 干旱土地资源的开明管理。

This research project will examine the general hypothesis that desertification has altered a previous, relatively uniform distribution of water and nitrogen by increasing their spatial and temporal heterogeneity, leading to changes in community composition and biogeochemical processes in Chihuahuan Desert ecosystems. The Jornada Experimental Ranch (southern New Mexico), with a 75-year history of rangeland research, has documented extensive changes in vegetation cover - from perennial grassland to several kinds of shrublands - which are one result of desertification. The work will include measurements of net primary production, root growth, decomposition, soil water dynamics, surface hydrology, dynamics of animal populations, animal-produced soil disturbance, nitrogen cycling processes and stable isotope distributions of nitrogen and carbon in widespread ecosystems, ranging from black grama (Bouteloua eriopoda) grassland, to desertified, persistent shrublands of chreosotebush (Larrea tridentata), tarbush (Flourencia cernua) and mesquite (Prosopis gladulosa). A conceptual model of desertification will be tested by long-term water augmentation and mechanical homogenization of water and nutrients. Data from these studies will be used to parameterize process models. Measurements of water, wind, and gaseous transport and run-on diversion experiments will provide data for a desert landscape model. Data derived from satellite remote sensing of vegetation and soils will be incorporated into a dynamics geographic information system model of the Jornada Basin. Institutional support remains excellent for the continuation of this project. Facilities are very good. The three-institution collaborative arrangement involving several investigators has been well thought out and should prove to be highly beneficial and productive. Results from this research project should yield major finding that are fundamental to the broad field of ecology. Additionally, results should be important to the future, better enlightened management of arid land resources.