Multi-scale Effects Of Landscape Heterogeneity On Pollinators' Diversity In The Lower Reaches Of The Yellow River

The ecosystem services provided by biodiversity in agricultural landscape include pest control,disease prevention,pollination and so on,which are the basis for the ecosystem to maintain stability.Pollination insect is an important part of the ecosystem,and it plays a key role in the pollination service and maintenance of the ecosystem.In recent years,the increasing degree of agricultural intensification and the great changes of land use types have resulted in the loss of biodiversity.Agricultural landscape in natural and semi natural habitats is biological habitat,lack of natural and semi natural habitat is a serious threat to pollinators and habitat and food resources,caused a sharp decline in the diversity of pollinators.Reducing the diversity of pollination insects will not only reduce the probability of pollination and fertilization,affect the yield of crops,but also reduce the pollination service function of the ecosystem,and affect the healthy development of human being and agriculture.In this paper,the study area was set up in Gongyi County,according to its typical topography(mountain-hilly area-plain)type to explore at three different scales,which are landscape,geomorphic type and habitat,how landscape heterogeneity affects the diversity of pollinators.In the range of different landforms,how the differences between geomorphic categories influence the diversity of species was analyzed.And at landscape scale,We established different buffer radii(250?500?750?1000?1250?1500?1750?2000 m)at the plot scale,based on a multi-scale(landscape,habitat,and geomorphic categories)approach.The correlation analysis was taken to discover the relationship between landscape heterogeneity and species diversity,by using the landscape index of SHDI on 2000 m,which divided the level of landscape heterogeneity into high and low.Pan traps were used to obtain pollinators in this study.The effects of agricultural landscape heterogeneity at multi-scales on the diversity of pollinators were analyzed by using multivariable ANOVA,which Sampling time is from April 29,2015 to May 16,2015.Finally,in order to explore the importance of non-agricultural habitat Gongyi City area in hilly and mountainous areas bee pollination area for pollinating insects.Twenty one samples were selected from northeast to the central area,and pan traps were used as an effective method to capture pollinators in farmland and woodland habitats.The main results of the paper are as follow:(1)The results showed that a total of 67012 pollinator individuals that belonged to 86 classes and 7 subjects were classified.Pollinator taxa are mainly Diptera(69.1%),Coleoptera(3.5%),Hymenoptera(26.3%),Lepidoptera(1.1%).The dominant groups included Syrphidae and Anthomyiidae,accounted for 59.5% of the number of captured;The common groups included Drosophilidae,Calliphoridae,Bombyliidae,Pipunculidae,Cantharidae,Cynipidae,Vespidae,Chalalcididae,Megachilidae and Apidae,accounted for 32.5% of the number of captured;The other rare groups were 74 types,although the subjects were more,but the total number of rare taxa accounted for only 8% of the total amount.In the two habitats of farmland and forest land,there were more pollination insects,which accounted for 63.4% of the total capture amount,while the forest land was 36.6%;From the point of view of the main species in the habitat,Diptera and Coleoptera are distributed in the two habitats,and they have a great advantage.In addition,the distribution of Drosophila,Cynipidae,Vespidae,Chalalcididae and Apidae in the farmland habitat is relatively large.(2)The number of individuals in the farmland on the level of pollinating insects showed hills>plain>mountain,at forest land showed hills>mountain>plain;At the level of species richness,the results shows hills farmland>mountain farmland>plain farmland,hills forest>mountain forest>plain forest;Shannon index and Pielou evenness index showed mountain forest>hills forest>plain forest,mountain farmland>hills farmland>plain farmland.From the number of individual pollinators,differences in species and individual number of Woodland Hills plain and mountain forest species significantly(P<0.05).The individual number of species in different landform types was not significant;The species richness and Shannon index,in hilly and mountainous areas in two habitats in species richness and Shannon index and plain significant regional differences(P<0.05);From the Pielou index,Pielou index was significantly higher than that in hilly and mountainous area plain(P<0.05).(3)Geomorphic categories showed the most significant impact on pollinators(P<0.001),suggesting that hilly and mountainous areas were the pollinators' ground of nectar.It was followed by habitat scale(P<0.05),with non-significant effect on the scales of landscape and the interaction between scales.The effect of landscape heterogeneity on the diversity of pollinators in hilly and mountainous areas provided a theoretical support for landscape planning and biodiversity conservation on the local area with different geomorphic categories.(4)The stepwise analysis and linear fitting present that the landscape simplification influence the richness and abundance of pollinators directly,while the proportion of farmland has a significant negative correlation with the richness and abundance of the species(P<0.05).The effects of landscape simplification on different pollinator groups also have discrepancy,for example,the effect of landscape simplification on Coleoptera is the most significant(R2=0.27),the next are Hymenoptera and Diptera(R2=0.14,R2=0.11).Landscape simplification also caused individual increase of Lepidoptera;With landscape simplification,Hymenoptera abundance decreased significantly in farmland habitat,while the change of Hymenoptera is not obvious in woodland.In the future planning of landscape,there should be an emphasis on the habitat change and food resources of the Coleoptera taxa in pollinating insects.The results also suggest that more attention need to be paid on the protection of existing natural vegetation communities in woodland habitats,in addition,certain areas of nectar plants could be planted in artificial forest.Agricultural landscape biodiversity conservation in experienced a small scale management mode change,to emphasize the process of habitat conditions and landscape scale management,effect of landscape heterogeneity in Hilly and mountainous areas of pollinator diversity provides the theoretical support for different types of landscape in the region landscape planning and biodiversity protection.In the pollination insects Diptera,Hymenoptera,Coleoptera,Lepidoptera,four species in the landscape,simplified effect on Coleoptera more closely in the future agricultural landscape planning should be considered Coleoptera taxa and habitat distribution of food resources protection.With the simplified landscape,many Hymenoptera decreased,in farmland habitat,this trend is more evident.On the basis of rational planning of weed communities and semi-natural habitats in farmland,linear landscape plants can be planted as the food source of pollinators.Based on the protection of the original natural habitat,such as weed community,linear artificial landscape with suitable area can be planted in the boundary of farmland,which has significant ecological meaning to protect the resource insects like Hymenoptera.In the gradient change of landscape simplification,species richness was greatly changed.Then,how to maintain a high diversity of pollination insects in the agricultural landscape with the proportion of farmland and semi natural habitats?The results show that the proportion of farmland could affect the abundance and richness of pollinator directly,and in certain area,the appropriate proportion of farmland and semi-natural habitats still needs more consideration on the balance of agricultural and ecological land use,and the relationship between decision makers and stakeholders.