Bistability in a differential equation model of oyster reef height and sediment accumulation

JOURNAL OF THEORETICAL BIOLOGY

卷:289

Article

Jordan-Cooley, William C.¹  Lipcius, Romuald N.²  Shaw, Leah B.³  Shen, Jian²  Shi, Junping¹ 

[1] Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA

[2] Coll William & Mary, Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA

[3] Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA

关键词: Oyster restoration;    Differential equation model;    Alternative stable states;    Bifurcation;   

DOI  :  10.1016/j.jtbi.2011.08.013

来源: Elsevier

【 摘 要 】

Native oyster populations in Chesapeake Bay have been the focus of three decades of restoration attempts, which have generally failed to rebuild the populations and oyster reef structure. Recent restoration successes and field experiments indicate that high-relief reefs persist, likely due to elevated reef height which offsets heavy sedimentation and promotes oyster survival, disease resistance and growth, in contrast to low-relief reefs which degrade in just a few years. These findings suggest the existence of alternative stable states in oyster reef populations. We developed a mathematical model consisting of three differential equations that represent volumes of live oysters, dead oyster shells (=accreting reef), and sediment. Bifurcation analysis and numerical simulations demonstrated that multiple nonnegative equilibria can exist for live oyster, accreting reef and sediment volume at an ecologically reasonable range of parameter values; the initial height of oyster reefs determined which equilibrium was reached. This investigation thus provides a conceptual framework for alternative stable states in native oyster populations, and can be used as a tool to improve the likelihood of success in restoration efforts. (C) 2011 Elsevier Ltd. All rights reserved.

【 授权许可】

Free