Environmental Engineering Sciences, Engineering School for Sustainable Infrastructure and Environment, University of Florida, PO Box 116580, Gainesville, FL 32611, USA; Carbon Containment Lab, Yale School of the Environment, Yale University, Prospect Street, New Haven, CT 06520, USA.
Environmental Engineering Sciences, Engineering School for Sustainable Infrastructure and Environment, University of Florida, PO Box 116580, Gainesville, FL 32611, USA.
Curr Biol. 2020 Apr 20;30(8):1562-1571.e4. doi: 10.1016/j.cub.2020.02.031. Epub 2020 Mar 19.
Facilitation cascades are chains of positive interactions that occur as frequently as trophic cascades and are equally important drivers of ecosystem function, where they involve the overlap of primary and secondary, or dependent, habitat-forming foundation species [1]. Although it is well recognized that the size and configuration of secondary foundation species' patches are critical features modulating the ecological effects of facilitation cascades [2], the mechanisms governing their spatial distribution are often challenging to discern given that they operate across multiple spatial and temporal scales [1, 3]. We therefore combined regional surveys of southeastern US salt marsh geomorphology and invertebrate communities with a predator exclusion experiment to elucidate the drivers, both geomorphic and biotic, controlling the establishment, persistence, and ecosystem functioning impacts of a regionally abundant facilitation cascade involving habitat-forming marsh cordgrass and aggregations of ribbed mussels. We discovered a hierarchy of physical and biological factors predictably controlling the strength and self-organization of this facilitation cascade across creekshed, landscape, and patch scales. These results significantly enhance our capacity to spatially predict coastal ecosystem function across scales based on easily identifiable metrics of geomorphology that are mechanistically linked to ecological processes. Replication of this approach across vegetated coastal ecosystems has the potential to support management efforts by elucidating the multi-scale linkages between geomorphology and ecology that, in turn, define spatially explicit patterns in community assembly and ecosystem functioning.
促进级联是正相互作用的链，其发生频率与营养级联一样高，是生态系统功能的同等重要驱动因素，其中涉及初级和次级（或依赖）栖息地形成基础物种的重叠[1]。尽管人们普遍认识到，次要基础物种斑块的大小和配置是调节促进级联生态效应的关键特征[2]，但由于它们在多个时空尺度上运作，因此通常难以辨别控制其空间分布的机制[1,3]。因此，我们将美国东南部盐沼地貌和无脊椎动物群落的区域调查与捕食者排除实验相结合，以阐明控制区域性丰富的促进级联（涉及栖息地形成的沼泽草和肋状贻贝聚集）建立、持续和对生态系统功能影响的地貌和生物驱动因素。我们发现，一系列物理和生物因素可预测性地控制了这种促进级联在溪流域、景观和斑块尺度上的强度和自组织。这些结果大大提高了我们根据与生态过程具有机制联系的易于识别的地貌指标，对跨尺度沿海生态系统功能进行空间预测的能力。在植被覆盖的沿海生态系统中复制这种方法有可能通过阐明地貌和生态学之间的多尺度联系来支持管理工作，而这些联系反过来又定义了群落组装和生态系统功能的空间明确模式。
