Schreiber Sebastian J
Department of Mathematics, The College of William and Mary, Williamsburg, Virginia 23187-8795, USA.
J Math Biol. 2006 Jun;52(6):719-32. doi: 10.1007/s00285-005-0346-2. Epub 2006 Apr 24.
A discrete-time host-parasitoid model including host-density dependence and a generalized Thompson escape function is analyzed. This model assumes that parasitoids are egg-limited but not search-limited, and is proven to exhibit five types of dynamics: host failure in which the host goes extinct in the parasitoid's presence or absence, unconditional parasitoid failure in which the parasitoid always goes extinct while the host persists, conditional parasitoid failure in the host and the parasitoid go extinct or coexist depending on the initial host-parasitoid ratio, parasitoid driven extinction in which the parasitoid invariably drives the host to extinction, and coexistence in which the host and parasitoid coexist about a global attractor. The latter two dynamics only occur when the parasitoid's maximal rate of growth exceeds the host's maximal rate of growth. Moreover, coexistence requires parasitism events to be sufficiently aggregated. Small additive noise is proven to alter the dynamical outcomes in two ways. The addition of noise to parasitoid driven extinction results in random outbreaks of the host and parasitoid with varying intensity. Additive noise converts conditional parasitoid failure to unconditional parasitoid failure. Implications for classical biological control are discussed.
分析了一个包含宿主密度依赖性和广义汤普森逃逸函数的离散时间宿主-寄生蜂模型。该模型假设寄生蜂受卵的限制但不受搜索的限制，并且被证明表现出五种动态类型：宿主失败，即宿主在有或没有寄生蜂的情况下灭绝；无条件寄生蜂失败，即寄生蜂总是灭绝而宿主持续存在；条件寄生蜂失败，即宿主和寄生蜂根据初始宿主-寄生蜂比例灭绝或共存；寄生蜂驱动的灭绝，即寄生蜂总是驱使宿主灭绝；以及共存，即宿主和寄生蜂围绕一个全局吸引子共存。后两种动态仅在寄生蜂的最大增长率超过宿主的最大增长率时发生。此外，共存需要寄生事件充分聚集。已证明小的加性噪声会以两种方式改变动态结果。向寄生蜂驱动的灭绝中添加噪声会导致宿主和寄生蜂以不同强度随机爆发。加性噪声将条件寄生蜂失败转变为无条件寄生蜂失败。讨论了对经典生物防治的影响。
