Cross-Site Comparisons, Syntheses and Internationalization: LTER-NTL Site

9416810马格努森项目包括关于温带湖泊在区域和全球范围内的长期时间和空间动态的三项国际努力。利用广泛分布的多个湖区的数据解决了三个问题。这些问题是：1.当在区域和全球尺度上考虑湖泊区域时，湖泊生态系统的生态变异性和组织发生了什么模式？2.单个湖泊物种的得失模式是否与区域内湖泊物种发生的总体模式有关？3.全球范围内的湖泊冰冻结和分解物候的分析能否被用来描述和理解大尺度的气候动态和趋势？湖区生态变异性和湖泊组织研究将考察湖区内湖泊的时间变异格局(连贯性)，探索不同湖区湖泊景观位置与湖泊变异性的关系，以及湖泊变异性与湖泊地貌和土地利用等因素的关系。比较将提供机会，以确定在北部高地湖区观察到的模式是否发生在世界各地的湖区。对鱼类和浮游动物物种得失的分析将调查不同湖区物种得失和周转率的区域动态，将这些动态与这些区域内湖泊之间相互联系的程度和强度联系起来，并调查人类活动如何影响这些过程。对北半球湖冰物候、气候变化和可变性的分析将分析融化和冻结日期的年际变化，并在可能的情况下分析之前的气候变化。在威斯康星州观察到的北半球较大区域的模式普遍存在吗？模式是基于分手日期的最近变暖，以及与ENSO事件和年代际或更长时间尺度相关的可变性。预期的模式将通过全球气候和冰冻模型来生成。

9416810 Magnuson This project encompasses three international efforts on the long-term temporal and spatial dynamics of temperate lakes at regional to global scales. Three questions are addressed with data from widely scattered, multiple lake districts. These questions are: 1. What patterns occur in ecological variability and organization of lake ecosystems when lake districts are considered at regional and global scales? 2. Can patterns of gains and losses of species from individual lakes be related to the overall patterns of species occurrence for lakes within a region? 3. Can analyses of lake ice freeze and breakup phenologies around the globe be used to describe and understand large scale dynamics and trends in climate? The study of ecological variability and organization of lake districts will examine temporal variability patterns (conherence) of lakes within lake districts, explore the relationship between landscape position and lake variability across lakes in different lake districts, and examine relations between lake variability and factors such as lake morphometry and land use. Comparisons will provide opportunities to determine whether patterns observed at the Northern Highland Lake District occur across lake districts worldwide. The analyses of gains and losses of fish and zooplankton species will investigate regional dynamics of species gains, losses, and turnover rates in different lake districts, relate these dynamics to the extent and strength of interconnections among lakes within these regions, and investigate how human activities may influence these processes. The analyses of lake ice phenology, climate change, and variability in the Northern Hemisphere, will analyze interannual variability in thaw and freeze dates and where possible the antecedent climatic variability. Are observed patterns in Wisconsin general for larger regions of the northern hemisphere? Patterns are the recent warming based on breakup dates, and variabili ty associated with ENSO events and inderdecadal or longer time scales. Expected patterns will be generated through global climate and ice freeze modeling.