高原鼠兔时空动态的元胞自动机模拟

利用高寒草甸和高原鼠兔(Ochotona curzoniae)的生态特征建立了元胞自动机模型,并通过模拟得到了高原鼠兔种群时空动态的规律。结果表明:高原鼠兔有效洞口的扩散量与扩散力的变化基本一致,扩散可减轻高原鼠兔对高寒草甸的危害;高原鼠兔对原栖息地的留恋指数α越小,高原鼠兔越易扩散;退化草甸上高原鼠兔密度越大,对已治理草地的入侵就越远;退化草甸恢复后,植被低矮时,入侵距离短、危害重,而植被较高时,入侵距离远、危害轻;全球气候变暖后,如果高原鼠兔的繁殖期不延长,则增温前后的种群动态相差不大;如果增温后高原鼠兔的生长期延长,在非退化高寒草甸上,增温前后种群动态差别不大,在退化高寒草甸上,高原鼠兔种群将迅速增大。

Simulation of spatio temporal dynamics of Ochotona curzoniae by using a cellular automata model

Based on the ecological characteristics of alpine grasslands and Ochotona curzoniae, a cellular automata model was developed to investigate the spatio–temporal dynamics of O. curzoniae populations. The variation of the dispersal of effective holes is approximately consistent with that of the dispersal force of O. curzoniae. Dispersal of O. curzoniae can reduce damages to the alpine grasslands caused by its overabundance. It is easy for O. curzoniae to disperse when the reluctance parameter α of plateau pika to its previous habitat is small. When the density of O. curzoniae inhabiting in degraded grasslands is high, O. curzoniae invades far. When the height of restored vegetation is low, the invading distance of O. curzoniae is short and the induced damages are heavy. Contrarily, the invading distance is long and the damage is light when the restored vegetation is high. If the growing season of O. curzoniae is not prolonged with global warming, the population dynamics of O. curzoniae is similar before and after global warming. If the growing season of O. curzoniae is prolonged after global warming, the population dynamics of O. curzoniae inhabiting in undegraded grasslands is similar before and after warming. The population of O. curzoniae inhabiting in degraded grasslands will swell up quickly.