| Biodiversity is the core of food safety and human health,which directly affects local livelihoods and economic development.But with habitat destruction,deforestation,environment pollution,and global climate change,biodiversity decreases sharply.Habitat destruction is the main cause of the sharp decrease in biodiversity.So it has great significance to study the impact of habitat destruction,especially the habitat destruction caused by human activities on biodiversity.And it can be archived by simulating the dynamics of populations under different environments through ecological models.Traditional ecological models pay more attention to the quantitative characteristics and less attention to the spatial characteristics of populations,so we combine the geographic information technology with the traditional ecological models to establish the individual-based spatially explicit model,to simulate the temporal the spatial dynamics of terrestrial mammal population under the influence of human activity.In this paper.The specific research contents are as follows:(1)The model divides the study area into several relatively homogeneous patches,taking into account the habitat isolation caused by the water body,the habitat semiisolation caused by road,and the difference of habitat suitability caused by physical factors,biological factors,and human activities.The difference of accidental mortality at different location,and the difference of vegetation growth rate and population birth rate in different seasons are also took into account.The model simulates key aspects of each individual animals and its interactions with herb,herbivores or carnivores,which provides quantitative and visualization tools for predicting the temporal and spatial dynamics of terrestrial mammal populations under the influence of human activities.(2)Under the data structure of vector,the model divides the study area into several patches according to the road and the water.The relationship between patches is determined by the type of adjacent patches.During the simulation,the individual animals move to the adjacent patch of highest suitability continuously,the eating and breeding activities occur within the current patch and step buffer area.Under the data structure of raster,the model divides the study area into 1×1km grid as the sub-patch.The patch of different species is defined as the combination of the sub-patch.The relationship between patches is determined by the topological relationship between patch center,road,study area boundary,and water.During the simulation,the individual animals move to the adjacent patch of highest suitability continuously,the eating and breeding activities occur within the current patch.(3)This paper discussed the method of analysis and expression of spatial and temporal dynamic.Reflect temporal dynamics such as quantitative characteristics,age structure,the source of death,through the quantity change curve,age structure diagram,pie chart of death source.Reflect the spatial distribution of population through the patch density map,point density map,and kernel function density map.Reflect the spatial distribution pattern of the whole population and the different spatial scales through the average nearest neighbor index,and the Repley's K function.The spatial and temporal dynamics of population was simulated by using the model in Hainan province,herbivores and carnivores are presented by sheep and wolves respectively.The spatial and temporal characteristics of the population were analyzed and expressedIn conclusion,this paper establishes an individual-based spatially explicit model,providing a quantitative and visualization tool for simulating the temporal and spatial dynamics of terrestrial mammal population under the influence of human activity.The result of population temporal and spatial characteristics are consistent with those of previous studies and basic ecological laws,which indirectly prove the correctness of the model. |
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