Abstract
The concept of alternative stable states has long been a dominant framework for studying the influence of historical contingency in community assembly. This concept focuses on stable states, yet many real communities are kept in a transient state by disturbance, and the utility of predictions for stable states in explaining transient states remains unclear. Using a simple model of plant community assembly, we show that the conditions under which historical contingency affects community assembly can differ greatly for stable versus transient states. Differences arise because the contribution of such factors as mortality rate, environmental heterogeneity and plant-soil feedback to historical contingency changes as community assembly proceeds. We also show that transient states can last for a long time relative to immigration rate and generation time. These results argue for a conceptual shift of focus from alternative stable states to alternative transient states for understanding historical contingency in community assembly.
Highlights
It is increasingly recognised that the species composition and diversity of ecological communities can be greatly influenced by the history of community assembly
Comparing two scenarios of community assembly, one with positive feedback and one without (Fig. 1), we find, for stable communities, that beta diversity is higher when there is positive feedback. This is an expected result: in general, when the strength of positive feedback ( f ) = 0, there is only a single stable state that is approached by the assembled communities, but when f > 0, alternative stable states exist, as confirmed by the fact that beta diversity is greater than 0 at t = 1600, even when only species with more than 100 individuals in a given community are regarded as members of that community (Fig. S3; see Figs S4–S7)
The alternative stable states concept has greatly contributed to improving our understanding of the role of historical contingency in community assembly
Summary
It is increasingly recognised that the species composition and diversity of ecological communities can be greatly influenced by the history of community assembly. If historical contingency is important, restoring native diversity in degraded sites may require specific sequences of species removal and introduction to be successful (Fukami et al 2005; Young et al 2005; Suding & Hobbs 2009; Kardol & Wardle 2010) In this light, much research has been directed toward identifying the environmental factors that determine the importance of assembly history, such as habitat productivity (Steiner & Leibold 2004), ecosystem size (Fukami 2004a), disturbance frequency (Jiang & Patel 2008) and environmental heterogeneity (Shurin et al 2004; Van Nes & Scheffer 2005)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
