Niche Dynamics And Potential Range Shifts Between Global Staple Food Crops And-their Wild Species

Climate change is one of the important factors affecting species distribution patterns at large scales,and may also lead to crop yield reductions,seriously threatening global food security and sustainable development.The main difference between crop cultivars and their wild species,which have the same origin and high genetic proximity,may be that the climatic adaptability or ecological niches of cultivars may be strongly influenced by human cultivation activities,which in turn leads to a clear differentiation of climatic ecological niches and potential distribution areas between cultivars and their wild species.However,past studies on crop ecological niches and potential distribution areas have mainly focused on small scales;moreover,the methods used to study potential distribution areas are mainly single models such as maximum entropy models;the studies are mostly concerned with predicting the potential distribution areas of crops under future climate change scenarios.Therefore,in order to understand the impact of climate change on global crop production and ensure food security,it is of great theoretical and practical importance to explore the ecological niche dynamics and potential range differentiation between global crop cultivars and wild species.This study explores the global ecological niches and potential range dynamics between maize,rice,wheat,potato,soybean and cassava cultivars and their wild species based on global distribution data and climatic data using a combined COUE scheme and Biomiod2 model.It provides guiding significance and application value for agricultural production.The main findings are as follows:(1)The climatic variables affecting the ecological niche dynamics and potential range differentiation between cultivated and wild species are mainly temperaturerelated variables,followed by precipitation;(2)The ecotone widths of rice,potato,cassava,wheat and maize are larger than those of their wild species,while the ecotone widths of soybean are smaller than those of their wild species;(3)The ecological niche conservation hypothesis is supported between rice,soybean and cassava and wild species,while the ecological niche conservation hypothesis is rejected between potato and maize and wild species;(4)The potential distribution area of the cultivated species is significantly larger than that of the wild species,and the center of gravity of the distribution as a whole shows a tendency to move to higher latitudes;(5)While rice,soybean,potato,wheat and maize reject the potential range conservativeness hypothesis,cassava does the opposite and a smaller expansion in ecotone width may lead to a larger expansion of its potential range.