Department of Environmental Science and Policy, University of California, Davis, CA, USA.
Graduate Group in Ecology, University of California, Davis, CA, USA.
Ecol Lett. 2021 Sep;24(9):1917-1929. doi: 10.1111/ele.13828. Epub 2021 Jul 4.
Ecosystem patterning can arise from environmental heterogeneity, biological feedbacks that produce multiple persistent ecological states, or their interaction. One source of feedbacks is density-dependent changes in behaviour that regulate species interactions. By fitting state-space models to large-scale (~500 km) surveys on temperate rocky reefs, we find that behavioural feedbacks best explain why kelp and urchin barrens form either reef-wide patches or local mosaics. Best-supported models in California include feedbacks where starvation intensifies grazing across entire reefs create reef-scale, alternatively stable kelp- and urchin-dominated states (32% of reefs). Best-fitting models in New Zealand include the feedback of urchins avoiding dense kelp stands that can increase abrasion and predation risk, which drives a transition from shallower urchin-dominated to deeper kelp-dominated zones, with patchiness at 3-8 m depths with intermediate wave stress. Connecting locally studied processes with region-wide data, we highlight how behaviour can explain community patterning and why some systems exhibit community-wide alternative stable states.
生态系统的模式可能源于环境异质性、产生多种持久生态状态的生物反馈，或者是它们的相互作用。反馈的一个来源是行为的密度依赖性变化，这种变化调节着物种间的相互作用。通过将状态空间模型拟合到大尺度（~500km）的温带岩石礁调查中，我们发现行为反馈最能解释为什么巨藻和海胆荒地形成了要么是全礁范围的斑块，要么是局部镶嵌的模式。在加利福尼亚州最支持的模型包括反馈，其中饥饿会加剧整个珊瑚礁的放牧，从而形成珊瑚礁规模的、稳定的巨藻和海胆主导的状态（占珊瑚礁的 32%）。在新西兰，最适合的模型包括海胆避开密集巨藻群的反馈，这可以增加磨损和捕食风险，从而从较浅的海胆主导区过渡到较深的巨藻主导区，在 3-8 米深度具有中等波浪应力的斑块。将局部研究的过程与区域范围的数据联系起来，我们强调了行为如何解释群落的模式，以及为什么有些系统表现出群落范围的稳定状态。
