Ecosystem functioning in the landscape: a meta-ecosystem perspective

在过去的半个世纪里，我们对生物多样性空间分布的理解取得了重大进展。meta-population和meta-community的概念巩固了我们对区域动态重要性的认识，以及我们对景观中种群持久性和物种共存的理解。下一个概念边界是元生态系统概念，有望揭示群落与生态系统生态学之间的机制联系。在这两个领域之间的交叉点是从景观角度看待生物多样性和生态系统功能的关键。然而，群落水平对生态系统对跨生态系统补贴和空间级联响应的约束仍缺乏全面的认识。我的长期目标是更好地理解生态系统内部和生态系统之间的联系，预测扰动如何以及何时最有可能通过这些空间耦合传播，并最终预测景观尺度上的生物多样性分布和生态系统功能。我在本提案中的具体目标是：1)更好地理解驱动接收生态系统对跨生态系统补贴做出反应的突发事件；2)对空间级联概念进行形式化测试；(3)扩展空间级联概念，开发并检验跨生态系统补贴的景观视角。我的工作假设是：a)生物相互作用将对接受者生态系统对跨生态系统补贴的反应施加可预测的约束；b)生物相互作用和景观配置反过来将调节效应如何在景观中传播（空间级联）。为了达到我的目标，我将使用多种实验方法加上实地观察。在Project 1中，我将使用浮游动物中生态系统来解开不同的跨生态系统补贴（数量、质量）对接受者生态系统沿着群落变化梯度的影响。我还将量化补贴的自然变化及其对温带湖泊整体景观的影响。在项目2中，我将使用浮游动物中生态系统，通过测试供体生态系统的收获和温度升高对供体生态系统的动态和过程的影响，对空间级联概念进行正式测试。我还将利用时间观测数据量化水陆边界的空间级联。在项目3中，我将使用带有微生物微观世界的实验景观来测试景观结构通过限制补贴消费者的影响范围来约束空间级联的程度。拟议的研究计划将参与开发景观尺度的理解，以了解扰动如何在空间上级联，接受者生态系统如何响应这些变化，并最终有助于预测生物多样性和生态系统功能的空间变化。

The past half-century has seen significant advances in our understanding of the spatial distribution of biodiversity. The meta-population and meta-community concepts cemented our appreciation of the importance of regional dynamics and our understanding of population persistence and species co-existence in the landscape. The next conceptual boundary, the meta-ecosystem concept, promises to unveil the mechanistic links between community and ecosystem ecology. At the intersection between those two fields lays the key to a landscape perspective on biodiversity and ecosystem functioning. However, we are still lacking a comprehensive understanding of the community level constraints on ecosystem response to cross-ecosystem subsidy and spatial cascades. My long-term objectives are to develop a better understanding of the connections within and among ecosystems, to predict how and when perturbations are most likely to propagate via those spatial couplings, and eventually to predict biodiversity distribution and ecosystem functioning at landscape scales. My specific objectives in this proposal are to: 1) develop a better understanding of the contingencies driving the response of recipient ecosystems to cross-ecosystem subsidy; 2) develop a formal test of the spatial cascade concept; 3) extend the spatial cascade concept to develop and test a landscape perspective on cross-ecosystem subsidy. My working hypotheses are that a) biotic interactions will impose predictable constraints on the response of recipient ecosystem to cross-ecosystem subsidy and b) that both biotic interactions and landscape configuration, in turn, will modulate how effects propagate in the landscape (spatial cascade). To reach my objectives I will use a variety of experimental approaches coupled with field observations. In Project 1 I will use zooplankton mesocosms to disentangle the effect of varying cross-ecosystem subsidy (quantity, quality) on the recipient ecosystem along a gradient of community alteration. I will also quantify those natural variations in subsidy and their effects in temperate lakes across a whole landscape. In project 2 I will set a formal test of the spatial cascade concept by testing the effect of harvesting and increased temperature in the donor ecosystem on the dynamics and processes in the recipient ecosystem, using zooplankton mesocosms. I will also quantify spatial cascades at the terrestrial-aquatic boundary using temporal observational data. In project 3, I will use experimental landscapes with microbial microcosms to test the extent to which landscape structure can constraint spatial cascades by limiting the zone of influence of subsidized consumers. The proposed research program will participate in developing a landscape scale understanding of how perturbations can spatially cascade, how recipient ecosystem might respond to those changes and eventually help to predict spatial variations in biodiversity and ecosystem function.