Okubo A, Maini P K, Williamson M H, Murray J D
Marine Sciences Research Center, State University of New York, Stony Brook 11794-5000.
Proc R Soc Lond B Biol Sci. 1989 Nov 22;238(1291):113-25. doi: 10.1098/rspb.1989.0070.
We present a diffusion-competition model to describe the interaction between the externally introduced grey squirrel and the indigenous red squirrel in Britain. We estimate the model parameters from field data. Solution of the model predicts waves of grey squirrel invasion with speed of invasion typical of that observed in the field. Numerical solution of the model on a two-dimensional domain gives population distributions qualitatively similar to those observed. We suggest that competition alone could account for the observed displacement of the red squirrel by the grey in large regions of Britain. The solutions are qualitatively similar to those for a single species spreading in the absence of competition. The quantitative difference is because competition slows down the speed of advance of the invading species.
我们提出了一个扩散竞争模型，以描述外来引入的灰松鼠与英国本土红松鼠之间的相互作用。我们根据实地数据估计模型参数。该模型的解预测了灰松鼠入侵的浪潮，其入侵速度与实地观察到的典型速度一致。在二维区域上对该模型进行数值求解，得到的种群分布在定性上与观察到的相似。我们认为，仅竞争就可以解释在英国大片地区观察到的灰松鼠取代红松鼠的现象。这些解在定性上与单一物种在没有竞争的情况下扩散的解相似。定量差异在于竞争减缓了入侵物种的前进速度。
