Testing conceptual models of early plant succession across a disturbance gradient

作者：Cynthia Chang, Charles B. Halpern, Joseph A. Antos, Meghan L. Avolio, Abir Biswas, James E. Cook, Roger del Moral, Dylan G. Fischer, Andrés Holz, Robert J. Pabst, Mark E. Swanson, Donald B. Zobel · 发表于：Journal of Ecology · 年份：2018 · DOI：10.1111/1365-2745.13120 · 被引用次数：70 · 研究领域：Ecology and Vegetation Dynamics Studies、Plant and animal studies、Species Distribution and Climate Change

Abstract Studies of succession have a long history in ecology, but rigorous tests of general, unifying principles are rare. One barrier to these tests of theory is the paucity of longitudinal studies that span the broad gradients of disturbance severity that characterize large, infrequent disturbances. The cataclysmic eruption of Mount St. Helens (Washington, USA) in 1980 produced a heterogeneous landscape of disturbance conditions, including primary to secondary successional habitats, affording a unique opportunity to explore how rates and patterns of community change relate to disturbance severity, post‐eruption site conditions and time. In this novel synthesis, we combined data from three long‐term ( c. 30‐year) studies to compare rates and patterns of community change across three ‘zones’ representing a gradient of disturbance severity: primary successional blast zone, secondary successional tree blowdown/standing snag zone and secondary successional intact forest canopy/tephra deposit zone. Consistent with theory, rates of change in most community metrics (species composition, species richness, species gain/loss and rank abundance) decreased with time across the disturbance gradient. Surprisingly, rates of change were often greatest at intermediate‐severity disturbance and similarly low at high‐ and low‐severity disturbance. There was little evidence of compositional convergence among or within zones, counter to theory. Within zones, rates of change did not differ among ...