LTER: Long - Term Research at the Jornada Basin (LTER VII)

在世界许多地区，包括美国西南部，曾经被草覆盖的土地开始看起来像沙漠。随着科学家更多地了解为什么会发生这种情况，他们开始意识到，这些土地并不总是成为沙漠。还有其他可能的结果，比如栖息地有大量灌木，植物从其他地方迅速蔓延(非本土或“入侵”物种)。这个项目的目标是测试关于是什么导致了这些变化的新想法。大学和美国农业部(USDA)的科学家将合作在奇瓦瓦沙漠进行实验并收集数据，在那里可以从以不同方式发生变化的地区学到很多东西。这项研究特别有价值和不同寻常，因为它已经进行了100多年。科学家们不仅对为什么会发生变化感兴趣，还对这些变化如何影响“生态系统功能”感兴趣，“生态系统功能”是植物和动物生长、繁殖以及相互作用和与环境相互作用的方式。研究结果将帮助世界各地的科学家预测和预防环境变化的有害影响。该项目的一部分将包括培训学生从事研究并成为科学家。这些学生中的许多人将来自附近的拉美裔大学。参与该项目的科学家还将接触当地小学、初中和高中的学生和教师。他们将通过激动人心的课程、实地考察和研讨会参与进来。该项目的发现将通过研讨会、讲座、网站和手机应用程序分享。奇瓦瓦沙漠景观展示了世界各地干旱和半干旱地区的生态条件、脆弱性和管理挑战。Jornada盆地长期环境研究(LTER)计划的总体目标是了解和量化在旱地产生替代状态的关键过程和因素，并预测未来状态及其对生态系统服务提供的影响。基于美国农业部农业研究局从1915年开始的长期数据库，研究将包括四种类型的动态：(1)从多年生草原向沙化灌丛的转变，(2)向草原状态的逆转，(3)灌木为主的州之间的转变，以及(4)非本地牧草的入侵。这些转变对LTER研究的5个核心主题所反映的进程产生了深远的影响。在这一长期变化研究更新项目中，了解和预测旱地地貌状态变化动态的“触发-反馈-异质性”框架将得到扩展，以促进关于以下问题的新兴生态学理论：(A)替代状态和复原力，(B)生态系统对全球变化的敏感性，以及(C)跨尺度相互作用。新的方法将整合关于以下方面的知识和长期数据：(1)生物过程，(2)土壤-地貌模板中的空间异质性，以及(3)从多条证据线(即，观察、实验操作、分析和数值模型、图像产品、概念模型推理和理论)提取的环境驱动因素的可变性。信息管理系统将扩展为旱地数据科学综合系统，该系统将使Jornada成果能够转换到奇瓦瓦沙漠的其他地点和全球旱地。LTER研究将导致：(1)对状态变化的新理解，这些变化导致理论发展、可验证的假设和新的实验；(2)可访问的数据、派生的数据产品和适用于多个尺度的可视化工具；以及(3)驱动因素、模式和过程之间的解释性和预测性关系，这些关系可用于(4)预测新地点或未来条件下的替代状态的动态，并评估其对生态系统服务的影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In many parts of the world, including the southwestern United States, lands once covered by grass are starting to look like deserts. As scientists learn more about why this is happening, they are starting to realize that these lands do not always become deserts. There are other possible outcomes, such as habitats with lots of shrubs and with plants that spread rapidly from elsewhere (non-native or "invasive" species). The goal of this project is to test new ideas about what causes these sorts of changes. Scientists at universities and at the United States Department of Agriculture (USDA) will work together to run experiments and collect data in the Chihuahuan Desert, where a lot can be learned from areas that have been changing in different ways. The study is especially valuable and unusual because it has been going on for more than 100 years. Scientists are not only interested in why changes are taking place but also in how those changes affect "ecosystem function," which is the way that plants and animals grow, multiply and interact with each other and with the environment. Results will help scientists around the world predict and prevent harmful impacts of environmental change. Part of the project will involve training students to do research and become scientists. Many of these students will be from nearby Hispanic-serving universities. Scientists on the project will also reach out to students and teachers at local elementary, middle and high schools. They will become engaged through exciting lessons, field trips, and workshops. Discoveries from this project will be shared through workshops, talks, websites, and mobile phone Apps.Chihuahuan Desert landscapes exemplify the ecological conditions, vulnerability, and management challenges in arid and semi-arid regions around the world. The overall goal of the Jornada Basin Long-Term Environmental Research (LTER) Program is to understand and quantify the key processes and factors that generate alternative states in drylands, and to predict future states and their consequences for the provisioning of ecosystem services. Based on long-term databases from Agricultural Research Service of the USDA beginning in 1915, studies will include four types of dynamics: (1) a shift from perennial grasslands to desertified shrublands, (2) a reversal to grassland states, (3) transitions among shrub-dominated states, and (4) invasion by non-native grasses. These transitions have profound implications for the processes reflected in the 5 core LTER research themes. In this LTER renewal project, the "trigger-feedback-heterogeneity" framework for understanding and predicting the dynamics of state changes in dryland landscapes will be expanded to contribute to emerging ecological theory on: (a) alternative states and resilience, (b) ecosystem sensitivity to global change, and (c) cross-scale interactions. The novel approach will integrate knowledge and long-term data on: (1) biological processes, (2) spatial heterogeneity in the soil-geomorphic template, and (3) variability in environmental drivers drawn from multiple lines of evidence (i.e., observations, experimental manipulations, analytical and numerical models, products from imagery, conceptual model reasoning, and theory). The information management system will be expanded into a Data Science Integrated System of drylands that will allow Jornada results to be translated to other locations in the Chihuahuan Desert and to drylands globally. LTER research will result in: (1) new understanding of state changes that lead to theory development, testable hypotheses, and new experiments; (2) accessible data, derived data products, and visualization tools applicable at multiple scales; and, (3) explanatory and predictive relationships among drivers, patterns, and processes that can be used to (4) predict dynamics of alternative states at new locations or future conditions with assessments of their impacts on ecosystem services.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.