Sevilleta LTER: Long Term Ecological Research in a Biome Transition Zone

Sevilleta LTER(SEV)研究地点位于新墨西哥州中部的Sevilleta国家野生动物保护区，在那里，四个生物群(大平原草原、大盆地灌木草原、奇瓦瓦沙漠和山地针叶林)的交界处提供了丰富的生物群过渡区(BTZ)。与高度多变的气候、海拔范围、复杂的地形、地质和土壤相互作用，这为该项目提供了一个复杂的时空模板。SEV结合了长期研究和越来越多的合作短期研究努力，范围从遗传学到景观遥感，重点是草类和灌木生命形式之间过渡的动植物特性，以奇瓦瓦沙漠生物群的两个组成部分及其与大平原短草草原生物群的交界处为代表。拟议的新工作将建立和扩大自1989年以来进行的基础研究，并启动新的长期景观实验和测量，以开发和测试BTZ动态的一般理论。一个新的概念框架将扩展过去的研究，侧重于斑块规模动态、生物和非生物驱动因素，以及不同斑块类型、大小及其镶嵌对景观和区域规模动态的影响。将启动一系列实验，重点关注植物-土壤-动物-微生物相互作用和与生态系统动力学反馈的重要性。迭代方法将合成模拟模型与从短期和长期跨学科研究收集的数据相结合，作为将我们的概念模型扩展到未来更多过渡的框架。这些结果将为在SGS LTER的短草草原生物群和JRN LTER的奇瓦瓦沙漠生物群内进行的研究提供重要的区域背景。未来的研究将扩展到SEV的其他主要生物群代表(例如，科罗拉多高原的灌木草原、松柏林地)。这些关于SEV上存在的其他BTZ和交错带的研究将进一步开发和测试适用于理解和预测生态系统对全球变化的反应的BTZ理论。模拟模型将被用来预测在气候和干扰制度变化下，BTZ的位置和组成随时间的变化。由于该地区可能经历长达十年的干旱、气候的方向性变化和大气沉积的增加，因此了解驱动斑块和交错带动态的关键过程对于管理和保护这些系统的生物多样性和自然资源至关重要。可以在多种比例下对多种类型的边界使用通用属性和填充图案。从斑块镶嵌、过程和动态到景观和区域的推断也将是确定塞维莱塔对区域和全球生物多样性和生物地球化学循环的贡献的关键。

The Sevilleta LTER (SEV) research site is located on the Sevilleta National Wildlife Refuge in central New Mexico, where a junction of four biomes (Great Plains Grassland, Great Basin Shrub-steppe, Chihuahuan Desert and Montane Coniferous Forest) provides a rich assortment of Biome Transition Zones (BTZs). Interacting with a highly variable climate, elevational range, complex topography, geology, and soils, this provides a complex spatial and temporal template for this project. SEV combines long-term research and an increasing array of collaborative, short-term research efforts that range from genetics to remote sensing of the landscape and focus on the floral and faunal properties of transitions between grass and shrub life forms represented by two components of the Chihuahuan Desert biome and their junctions with the Great Plains shortgrass steppe biome. The proposed new work will build upon and expand foundation studies ongoing since 1989 and initiate new long-term landscape experiments and measurements to develop and test a general theory of the dynamics of BTZs. A new conceptual framework will expand past studies to focus on patch-scale dynamics, biotic and abiotic drivers, and the consequences of different patch types, sizes, and their mosaics to landscape and regional scale dynamics. A series of experiments will be initiated that focus on the importance of plant-soil-animal-microbe interactions and feedbacks with ecosystem dynamics. An iterative approach combines a synthetic simulation model with data collected from short- and long-term interdisciplinary studies as a framework for extending our conceptual model to additional transitions in the future. Results will provide an important regional context for studies conducted within the shortgrass steppe biome at the SGS LTER and within the Chihuahuan Desert biome at the JRN LTER. Future studies will expand to other major biome representatives at SEV (e.g., shrubsteppe of the Colorado Plateau, Pinon -Juniper woodlands). These studies on other BTZs and ecotones present at SEV will further develop and test BTZ theory applicable to understanding and predicting ecosystem response to global change. Simulation modeling will be used to predict changes in the location and composition of BTZs through time under changes in climate and disturbance regime. Because the region is likely to experience a decade-long drought, directional changes in climate, and increases in atmospheric deposition, an understanding of the key processes driving patch and ecotone dynamics is critical to an ability to manage and preserve the biodiversity and natural resources of these systems. Common properties and patterns that can be used for many types of boundaries at many scales are expected. Extrapolating from patch mosaics, processes, and dynamics to the landscape and region will also be critical in determining the contribution of the Sevilleta to regional and global biodiversity and biogeochemical cycles.