Ecosystems are defined, studied, and managed according to boundaries constructed to conceptualize patterns of interest at a certain scale and scope. The distinction between ecosystems becomes obscured when resources from multiple origins cross porous boundaries and are assimilated into food webs through repeated trophic transfers. Ecosystem compartments can define bounded localities in a heterogeneous landscape that simultaneously retain and exchange energy in the form of organic matter. Here we developed and tested a framework to quantify reciprocal reliance on cross-boundary resource exchange and calculate the contribution of primary production from adjacent ecosystem compartments cycling through food webs to support consumers at different trophic levels. Under this framework, an integrated ecosystem can be measured and designated when the boundary between spatially distinct compartments is permeable and the bidirectional exchange of resources contributes significantly to sustaining both food webs. Using a desert river and riparian zone as a case study, we demonstrate that resources exchanged across the aquatic–riparian boundary cycle through multiple trophic levels. Furthermore, predators on both sides of the boundary were supported by externally produced resources to a similar extent, indicating this is a tightly integrated river–riparian ecosystem and that changes to either compartment will substantially impact the other. Using published data on lake ecosystems, we demonstrated that benthic and pelagic ecosystem compartments are likely not fully integrated, but differences between lakes could be used to test ecological hypotheses. Finally, we discuss how the integrated ecosystem framework could be applied in urban-preserve and field-forest ecosystems to address a broad range of ecological concepts. Because few systems function in complete isolation, this novel approach has application to research and management strategies globally as ecosystems continue to face novel pressures that precipitate cascading ecological repercussions well beyond a bounded system of focus.

中文翻译：

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综合生态系统：通过相互依赖资源连接食物网

根据构建的边界来定义、研究和管理生态系统，以在一定规模和范围内概念化感兴趣的模式。当来自多个来源的资源跨越多孔边界并通过重复的营养转移被同化到食物网中时，生态系统之间的区别变得模糊。生态系统隔间可以定义异质景观中的有界位置，同时以有机物质的形式保留和交换能量。在这里，我们开发并测试了一个框架来量化对跨境资源交换的相互依赖，并计算相邻生态系统隔间循环通过食物网以支持不同营养级别的消费者的初级生产的贡献。在这个框架下，当空间上不同的隔间之间的边界是可渗透的并且资源的双向交换对维持两个食物网有显着贡献时，就可以测量和指定一个综合生态系统。我们使用沙漠河流和河岸带作为案例研究，证明资源通过多个营养级别跨水生-河岸边界循环进行交换。此外，边界两侧的捕食者在相似程度上得到了外部生产资源的支持，表明这是一个紧密结合的河流 - 河岸生态系统，任何一个分区的变化都会对另一个产生重大影响。使用已发表的湖泊生态系统数据，我们证明底栖和远洋生态系统部分可能没有完全整合，但湖泊之间的差异可用于测试生态假设。最后，我们讨论了如何将综合生态系统框架应用于城市保护区和野外森林生态系统，以解决广泛的生态概念。由于很少有系统是完全孤立运行的，因此随着生态系统继续面临新的压力，导致级联生态影响远远超出有限的焦点系统，这种新颖的方法可以应用于全球的研究和管理策略。