Spatial Models of Rocky Subtidal Communities

CASWELL 9811267岩石潮下带群落的空间模型硬底质上的潮下带群落具有高度多样性、对空间的激烈竞争、小规模的周转和大规模的稳定性等特征。本研究项目将使用缅因州海湾的详细长期数据集，为潮下带群落开发一系列四个模型。模型I是一个线性马尔可夫链模型，描述了社区内个体的更替，并使用随机过程理论的工具来描述社区内的演替和收敛，并开发扰动分析来描述对转移概率变化的反应。模型2是模型1的非线性版本;它包括密度依赖性的过渡率，并将纳入新的，最大似然为基础的参数估计方法。 模型3是一个随机元胞自动机，它将模型I和模型2的框架嵌入到一个明确的空间环境中。该模型将用于研究潮下带群落的空间格局效应。模型4也是一个元胞自动机，但直接从产生物种转变的机制（招募，生长，干扰和竞争）的测量中发展而来。这项研究将为研究群落动态提供新的方法，并增加对岩石潮下带群落的了解。

CASWELL 9811267Spatial Models of Rocky Subtidal CommunitiesSubtidal communities on hard substrates are characterized by high diversity, intense competition for space, small-scale turnover, and large-scale stability. This research project will develop a series of four models for subtidal communities, using a detailed, long-term data set from the Gulf of Maine. Model I is a linear Markov chain model describing the replacement of individuals within the community and using tools from stochastic process theory to characterize succession and convergence in the community and develop perturbation analysis to characterize the response to changes in transition probabilities. Model 2 is a nonlinear version of Model 1; it includes density-dependence in rates of transition and will incorporate new, maximum likelihood-based methods for parameter estimations. Model 3 is a stochastic cellular automaton, which embeds the framework of Models I and 2 in an explicit spatial setting. This model will be used to investigate the effects of spatial pattern in subtidal communities. Model 4 is also a cellular automaton, but is developed directly from measurements of the mechanisms (recruitment, growth, disturbance, and competition) that generate species transitions. This research will provide new methods for studying community dynamics in general, and an increased understanding of rocky subtidal communities.