Insights on community dynamics from large-scale, long-term data: time series for zooplankton and environmental variates from 35 North American lakes

The NCEAS Community Dynamics Working Group brought together theoretical and empirical ecologists to evaluate the relative importance of intrinsic and extrinsic sources of variability in natural communities. We focused on zooplankton community dynamics, in part because we had access to extensive time series data on zooplankton community structure from 35 North American lakes. Thirty-four of the lakes were concentrated at 5 sites: the North Temperate Lakes LTER site in Wisconsin; the University of Notre Dame Environmental Research Center in Michigan; the Dorset Environmental Research Centre, the Experimental Lakes Area, and the Sudbury region, all in Ontario. We also have data for saline Mono Lake in California. Our database has many strengths, including the length of the time series (5-21 years); consistent sampling methodologies, particularly for zooplankton; and the availability of information on environmental factors, including phytoplankton, physical parameters, and water chemistry. Another unique aspect of our dataset is that it includes data from both undisturbed reference lakes and experimentally manipulated lakes. The whole-lake experiments include food web manipulations, nutrient enrichments, acidifications and limings, and an unplanned invasion of an exotic species. Some of the experimental manipulations are even replicated within and among sites, providing a unique opportunity to explore the extent to which responses to a particular perturbation are consistent across lakes. In addition to determining how manipulations change the dynamics of zooplankton communities, we are using the data from the reference lakes to establish bounds on normal ranges of variability and to explore how this variability differs among lakes at a site vs. between sites. Thus, our joint database is facilitating extensive comparisons of zooplankton community dynamics at the scale of whole lakes.

国家生态分析与合成中心（National Center for Ecological Analysis and Synthesis, NCEAS）群落动力学工作组召集了理论生态学家与实验生态学家，旨在评估自然群落中变异的内在来源与外在来源的相对重要性。本次研究聚焦于浮游动物（zooplankton）群落动力学，部分原因在于我们获取了来自北美35个湖泊的浮游动物群落结构长期时序数据。其中34个湖泊分布于5个研究区域：威斯康星州的北温带湖泊长期生态研究（Long-Term Ecological Research, LTER）站点、密歇根州的圣母大学环境研究中心，以及均位于安大略省的多塞特环境研究中心、实验湖泊区与萨德伯里地区。此外我们还拥有加利福尼亚州咸水水体莫诺湖的相关数据。本数据库具备多项显著优势：时序数据跨度较长（5至21年）、采样方法统一规范（尤其针对浮游动物），且可获取涵盖浮游植物（phytoplankton）、物理参数与水体化学性质等在内的全面环境因子信息。本数据集的另一独特之处在于，同时包含未受干扰的参照湖泊与经过实验操控的湖泊的数据。全湖实验涵盖食物网操控、营养富集、酸化与石灰调控，以及一次意外发生的外来物种入侵事件。部分实验操控在区域内部及区域间进行了重复，这为探究特定扰动下不同湖泊的响应一致性程度提供了难得的研究契机。除了分析实验操控如何改变浮游动物群落动力学特征之外，我们还借助参照湖泊的数据确定群落变异的正常波动范围，并探究同一区域内湖泊间与不同区域间的群落变异模式差异。因此，本联合数据库为全湖尺度下的浮游动物群落动力学对比研究提供了有力支撑。