Ecology of Biological Invasion - Spatial Spread by Stratified Diffusion

生物入侵生态学 - 分层扩散的空间传播

• 批准号: 06640818
• 负责人: SHIGESADA Nanako
• 金额: $ 1.28万
• 依托单位: Nara Women's University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640818/
• 关键词: stratified diffusion; reaction-diffusion eq.; biological invasion; spread rate; range expansion; cellular automaton; patch dynamics; reaction-diffusion eq.; cellular automaton model

1. When a species colonizes a new area, it spreads across that area in the form of an invasion wave. The speed of this wave is determined by not only by random movement into adjacent areas, but also by long-distance dispersal. We studied the invasion process by using a stratified diffusion model, in which both the short and long range dispersal are taken into account. Expansion rates are calculated from numerical simulations and compared with those previously obtained from the analytical model. The results suggest that the stratified diffusion model should provide a basic framework for exploring the mechanisms underlying range expansion. Applying models to the invasion of the House Finch, we evaluate the effects of long- and short-distance dispersals on the range expansion, separately.2. We investigated the speed of invasion waves in a simple stochastic cellular automaton model for a single species on a homogeneous landscape. We show that stochasticity can dramatically increase the speed of invasion waves compared to a simple deterministic version of the model. To explain this phenomenon mathematically, we developed several approximations to the stochastic model. These showed that the increased wave speed in the stochastic model is due to the irregularity in the shape of the wave front, which is present in the stochastic but not the deterministic model.

1.当一个物种在一个新的地区定居时，它会以入侵波的形式在该地区传播。这波的速度不仅取决于随机移动到邻近地区，而且还取决于长距离扩散。本文利用一个分层扩散模型研究了入侵过程，该模型同时考虑了短距离扩散和长距离扩散。膨胀率从数值模拟计算，并与以前获得的分析模型。结果表明，分层扩散模型应该提供一个基本的框架，探讨潜在的范围扩大的机制。应用模型对家雀的入侵，我们分别评估了长距离和短距离扩散对范围扩展的影响。我们研究了一个简单的随机元胞自动机模型中的入侵波的速度为一个单一的物种在一个均匀的景观。我们表明，随机性可以显着增加入侵波的速度相比，一个简单的确定性版本的模型。为了从数学上解释这一现象，我们提出了几种近似的随机模型。这表明，在随机模型中的波速增加是由于波前形状的不规则性，这是目前在随机的，但不是确定性的模型。

项目成果

Tayasu, T.: "Predator-mediated coexistence of epiphytic grass shrimps that compete for refuges." Ecological Modelling. 84. 1-10 (1996)

Tayasu, T.：“捕食者介导的附生草虾共存，争夺避难所。”

I.Tayasua: "Predator-mediated coexistence of epphytic grass shrimps that compete forrefuges." Ecological Modelling. 84. 1-11 (1996)

I.Tayasua：“捕食者介导的附生草虾共存，竞争避难所。”

T.Koyama: "A size-distribution-based model of forest dynamics over a thermal gradient along latitude." Vegetatio. (in press).

T.Koyama：“基于尺寸分布的沿纬度热梯度森林动态模型。”

Malchow, H.: "Non equilibrium plankton community structures in an ecohydrodynamic model system." Nonlinear Processes in Geophysics.1. 3-11 (1994)

Malchow, H.：“生​​态水动力模型系统中的非平衡浮游生物群落结构。”

川崎廣吉: "バクテリアのコロニー・パターン形成の数理モデル" 計測と制御. 34. 812-817 (1995)

Hiroyoshi Kawasaki：“细菌菌落模式形成的数学模型”测量与控制 34. 812-817 (1995)。