Effects Of Landscape Pattern On Community Composition Of Pollinators In Jujube Orchard In Southern Xinjiang

Aksu Prefecture is located in southern Xinjiang,with extensive jujube planting area and high yielding production,causing huge profit for local farmers.With the advancement of urbanization and agricultural intensification,the landscape pattern has changed significantly,and the adjustment of planting structure has changed the food resources and habitats of pollinators and their response degree to landscape composition and configuration.Based on the reality of agricultural production in southern Xinjiang,this study selected a total of 29 sites in Aksu Prefecture in 2019 and 2020,and the response of pollinators to habitat composition and configuration at different landscape scales(500,1000,1500 and 2000m)in jujube orchard were systematically analyzed by sampling pollinators by pan traps and using landscape ecology theory.The main research results are as follows:During the flowering stage,landscape pattern significantly affected pollinator community composition in jujube orchard at flowering stage,and the effects of different habitat types on pollinator community were not consistent.The increase of the proportion of orchards(apples,pears,walnuts,etc.)except jujube and semi-nature habitats(forest belts,ridges,fallow fields,etc.)would decrease the abundance of overall pollinators,bees,and wild bees in the central jujube orchards,but promoted the increase of species diversity.Increasing the proportion of small crops could increase the abundance of overall pollinators and wild pollinators within the 500 m scale.The proportion of jujube orchard had no significant effect on the composition of pollinating insect community.And at the flowering stag,the landscape edge density at the scale of 1000 m significantly promoted the species richness of pollinators,while the landscape Shannon diversity index and Average perimeter area ratio had no significant effect on the community composition of pollinators.Landscape composition and landscape configuration also affected pollinators' community composition in jujube orchard at the fruiting stage.The increase of the proportion of orchards except jujube orchard and semi-nature habitats could reduce the total pollinators and wild pollinators abundance,and lead to the decrease of bee abundance at the scale of 1500 m and 2000 m.However,with the increase of the proportion of other orchards and semi-nature habitats,the total pollinator Pielou evenness increased.The increase of the proportion of small crops also promoted the overall pollinator anundance and wild pollinators abundance in the 500 m scale,and increased the overall pollinator diversity.The increase of the proportion of jujube had a negative effect on the diversity of pollinators.When the average perimeter-area ratio what reflecting patch shape parameters in landscape area increased,the overall species diversity of pollinators increased.At the larger scale(1500m and 2000m),the average perimeter-area ratio reflecting patch shape parameters increased with the increase of overall pollinator species diversity.Landscape edge density and Shannon diversity index both promoted the species richness at the 1000 m scale.Based on the above conclusions,the landscape composition(Qrchard,the small crop and the semi-nature habitat)and landscape configuration(Edge density,Shannon diversity index and Average perimeter area ratio)affected the community composition of pollinators to varying degrees.The rational distribution of farmland landscape pattern and the improvement of landscape diversity are crucial to the conservation of pollinators.The findings have important theoretical and practical significance for the conservation of pollinators in different stages,and will provide a reference basis for the development of sustainable agricultural development suitable for the local production model of southern Xinjiang.