COLLABORATIVE RESEARCH: Biocomplexity and Environmental Change in a Vegetated Estuarine Ecosystem

由于人类的影响，世界各地的生态系统正在经历前所未有的规模和速度的变化。同时发生的气候变暖、富营养化、过度捕捞和外来入侵使我们迫切需要了解压力源是如何相互作用的。在全球变化的许多这样的方面中，最不可逆转的是生物多样性的灭绝。因此，了解变化的生物多样性如何调节生态系统过程对于基础生态学和全球变化对生态系统及其为人类提供的服务的影响的实际预测都是至关重要的。特别是，群落组成变化的影响往往是通过营养相互作用介导的，这使得将食物网生态学整合到生物多样性研究中成为理解复杂自然生态系统动态的重要前沿。跨越这一前沿将需要整合多营养群落的长期时间序列数据、群落相互作用的实验分析和新的动态建模方法。这项研究建立在对切萨皮克湾鳗草（Zostera marina）生态系统进行了十年研究的基础上，以实现这一目标。该研究将一位实验生态学家和一位生物数学家聚集在一起，采用一套互补的实验，对三个营养水平的持续长期监测数据进行分析（迄今为止8年的每月采样），并进行模拟建模，以构建和参数化切萨皮克湾大叶藻群落的动态食物网模型。本研究将建立切萨皮克海草食物网作为少数生态系统之一，其中必要的实地数据和相互作用强度的实验表征可用于这种动态建模，促进其作为一个模型系统用于探索一般生态学和应用生态学的问题。本研究的广泛影响包括：(1)为大量不同层次的学生以及K-12教师提供实地研究经验；(2)与水质、水下植被和鱼类群落的长期监测项目相辅相成；(3)有价值的长期基线数据，用于评估和预测气候变暖、捕捞压力变化、富营养化和其他压力因素对经济上重要的河口生态系统的影响。

Ecosystems worldwide are undergoing changes of unprecedented magnitude and speed as a result of human influence. Simultaneous climate warming, eutrophication, overfishing, and exotic invasions create an urgent need to understand how stressors interact. Of the many such facets of global change, the most irreversible is extinction of biodiversity. Thus, understanding how changing biodiversity mediates ecosystem processes is central to both basic ecology and to practical prediction of global change impacts on ecosystems and the services they provide to humanity. In particular, effects of changing community composition are often mediated through trophic interactions, making the integration of food web ecology into BDEF research an important frontier in understanding the dynamics of complex natural ecosystems. Crossing this frontier will require integration of long-term time series data on multitrophic communities, experimental analyses of community interactions, and new dynamic modeling approaches. This research builds on a decade of research in a Chesapeake Bay eelgrass (Zostera marina) ecosystem to address this goal. The proposed research brings together an experimental ecologist and a biomathematician, employing a complementary suite of experiments, analyses of continuing longterm monitoring data across three trophic levels (eight years of monthly sampling to date), and simulation modeling, to construct and parameterize a dynamic food web model of a Chesapeake Bay eelgrass community. This research will establish the Chesapeake seagrass food web as one of a small number of ecological systems in which the requisite field data and experimental characterization of interaction strengths are available for such dynamic modeling, facilitating its use as a model system for exploring problems in both general and applied ecology. Broader impacts of this research include: (1) field research experiences for a large number of students at several levels, as well as K-12 teachers, (2) complementary integration with long-running monitoring programs for water quality, submerged vegetation, and fish assemblages, and (3) valuable long-term baseline data with which to evaluate and forecast effects on economically important estuarine ecosystems of climate warming, changes in fishing pressure, eutrophication, and other stressors.