Diversity Pattern Of Ground-dewlling Soil Macro-arthropod In Black Soil Cropland, Northeast China

Cropland is an important way of agricultural land use and an important land resource.Black soil cropland of Northeast China is an important commodity grain base and plays a vital role in our food security.As an important part of agricultural biological resources,ground-dwelling soil macro-arthropods play an important role in the decomposition of soil organic matter,the formation of humus,and the transformation of soil material and energy.The composition and changes of ground-dewlling soil macro-arthropod diversity are important indicators for evaluating the agriculture environmental quality and soil fertility and it is also the basis for sustainable agricultural development.Protecting the soil arthropod diversity is important to ensuring agriculture ecosystem service functions,natural pest control and disease prevention.However,in recent years,over-utilization and development of black soil cropland has led to a decline in soil biodiversity,which affects the quality and fertility of black soil,and which in turn affects regional ecological security and food production.To study the diversity pattern of ground-dwelling soil macro-arthropods in black soil cropland,revealling the relationship between traditional cropland land use and cropland biodiversity in black soil areas,and promoting the long-term use of cultivated land resources and improve farmland service functions by protecting cropland biological resources.In this study,we set up three experimental plots to investigate the ground-dwelling soil macro-arthropods diversity(small scale of cropland,regional scale of black soil cropland,different land use in black soil agricultural areas),and study their diversity composition,their spatial distribution pattern and diversity form factors,intended to provide a basis for proposing farmland biodiversity conservation measures.The results showed that:(1)On the field scale,the ground-dwelling soil macro-arthropods had the highest diversity and richness in the heading stage of crop growth;the soil macro-arthropod community exhibited strong or moderate spatial dependence,and the soil macro-arthropods formed patches with sizes from 30 to 108 m.the spatial variables was significantly higher than the environmental variables,The dispersal limitation of species has a greater impact on the formation of community diversity patterns.(2)At the black soil regional scale,the number of surface arthropods gradually decreased from low latitudes to high latitudes.The diversity characteristics showed higher animal diversity in high latitudes and higher soil dominance in low latitudes.Kind of obvious.The study of its diversity formation mechanism shows that the formation mechanism of surface arthropod diversity still depends mainly on the spread of animals,and the part of the spatial environment factors that play a role in the large-scale arthropod diversity on the surface has a greater ability to explain.(3)Among the different land use in black soil agricultural areas,the individual number?species number and the diversity index of arthropod species in the maize field are significantly lower than other land use types.The soil organic matter have shown negative relationship with soil macro-arthropods.The effects of soil environmental factors on the composition of soil arthropod community in corn field were not significant,indicating that plant and soil environmental homogeneity in farmland restricted the diversity of arthropods.According to the research results,we propose agricultural biodiversity conservation measures.On the field scale,we must ensure the integrity of cropland plots,and also strengthen the heterogeneity of cropland soil and vegetation environment,such as implement no-tillage,crop rotation and other farming methods;It is also necessary to consider the establishment of protection mechanisms on the landscape scale,from the protection of landscape heterogeneity around the cropland and setting the ecological corridors,to the establishment of national land use planning and ecological compensation mechanisms.In addition,the establishment of long-term monitoring network of cropland soil animals is also important,multi-scale and long-term survey of the diversity pattern of ground dwelling soil macro-arthropods is more helpful to understand the changes of cropland biodiversity,and to reveal the mechanism of species diversity maintenance.The result will provide basic data for the protection of cropland biological resources.