Impact of wetland loss on metapopulation with the Allee-like effect and the strategy: a study case of Yancheng in Jiangsu Province
生境丧失对具有似Allee效应集合种群的影响及对策——以江苏盐城为例

The Allee-like effect is a destabilizing factor in species persistence.Rare animals are more susceptible to the effect as it will increase extinction risk of those rare living in fragmented habitats.But so far there is still no adequate attention paid to its influence on multi-metapopulation and its application for rare biological conservation.In this paper,the Allee-like effect is introduced into a dynamical metapopulation model of multi-species under habitat loss to study the 29 rare species living in Yancheng wetland of Jiangsu Province.By means of numerical simulation,we demonstrate that:(1) Allee-like effects result in periodic fluctuation of metapopulation abundance of multi-species so that coexistence may become impossible and species could even go extinction.(2) Severe Allee-like effect is disadvantageous to the persistence of several sub-dominant and inferior metapopulation,and the severer the Allee-like effect is,the shorter the extinction time will be.(3) In the case of 29% of Natural wetlands lost in Yancheng,the metapopulation of 11 rare species will go extinct from the poorest to stronger with a time delay of 304-890 years in response to the past habitat loss,and these bound to extinction are the typical 'living dead' as named by Hanski.(4) As for the reservation strategies,an adding of about 1801-2064 km2 habitat restoration would effectively guarantee the persistence of all the 29 kinds of rare metapopulation on the base of the existing 3200km2 natural wetlands,and at the same time,other protection measures should be taken to increase the metapopulation abundance of those rare species.Our results can be helpful for species diversity conservation and provide theoretical guidance to nature reserve construction.