Effects Of Multi-level Farmland Landscape Characteristics On Epigaeic Arthropod Diversity

In recent decades,in order to cope with the food crisis caused by continuous population growth,farmland land is constantly expanding,and tends to scale and intensive development.As a result,the non-arable habitat in farmland landscape was reclaimed into arable land,and the farmland landscape became increasingly homogenized and fragmented,which directly led to the loss of farmland biodiversity.In order to analyzes the mechanism of action of multi-level farmland landscape characteristics and epigaeic arthropods in Changtu County,a typical agricultural county in Liaoning Province,Pearson Correlation Analysis and Akaike Information Criterion were used to analyze the correlation between landscape indices and epigaeic arthropods and construct the optimal model.Heatmap and Analysis of Variance analysis were used to analyze the impact of different habitat types on the composition and diversity of epigaeic arthropods.PCA and RDA were used to analyze the impact of vegetation composition and structure on the epigaeic arthropods community.The results show that:(1)The individual number and community structure of epigaeic arthropods were different in different habitats,but the dominant groups were similar.A total of 9389 epigaeic arthropods were captured in this study,including 2148 from arable habitats,4403 from the boundary between arable and non-arable habitats,and 2838 from nonarable habitats.All of them belonged to Arthropoda,belonging to 5 classes,10 orders,25 families and 44 species.The dominant species were Gryllusmitratus Burmeister and Loxoblemmus doenitzi Stein of Gryllidae,5768 heads were captured,accounting for 61.4% of the total number of capture.(2)1500m was the optimal radius of the impact of farmland landscape characteristics on arable epigaeic arthropod diversity.Under the optimal radius,the increase of farmland landscape heterogeneity was beneficial to arable epigaeic arthropod diversity.The correlation between landscape indices and arable epigaeic arthropods increased firstly and then decreased with the increase of buffer radius,and reached the peak value at 1500 m.Within the optimal radius buffer zone of 1500 m,the number of arthropod species(S)was significantly correlated with the LPI,PRD,CONTAG,IJI and SHDI.Shannon diversity index(H)was significantly correlated with PRD and SHDI.The optimal species number(S)model was S=-1.783+0.190* X3+7.606* X5(AICc=50.945),and the optimal Shannon diversity index(H)model was H=0.138+1.256* X4(AICc=13.046).(3)Different types of habitats had significant effects on epigaeic arthropods.Other woodlands could maintain high arthropod diversity,while orchards were more beneficial to the arthropod diversity of adjacent arable.The epigaeic arthropod diversity was more maintained at the edge of the habitat than in the arable and non-arable habitats.The arthropod compositions of grassland(SJ4),other woodland(SJ6),arbor woodland(SJ8)and their adjacent arable were similar,but they were different from those adjacent to the orchard arable(SJ1),orchard(SJ2).Habitat type had significant effects on the number of arthropod species(S),Pielou evenness index(E)and individual number(P < 0.05),but had no significant effects on Shannon diversity index(H).The number of arthropod individuals and species(S)at the boundaries of four landscape combinations in the sample area were significantly higher than those in the adjacent arable and non-arable habitats,but the Pielou evenness index(E)was low.(4)The responses of different epigaeic arthropod species to herbaceous vegetation structure were different.Herbaceous vegetation coverage and Shannon diversity were the main factors affecting the composition of epigaeic arthropod community.Herbaceous vegetation coverage and Shannon diversity had significant effects on the composition of epigaeic arthropod community(P<0.05).At the boundary,higher herb shannon diversity was beneficial to increase the population of common predatory species — Holotrichia Pallidipennis Moraw,Dolichus halensis,Harpalus simplicidens Schauberger,Harpalus vicarious Harold and Phalangiidae,while higher herb coverage was beneficial to the common predatory species — Holotrichia Pallidipennis Moraw,Chlaenius micans Fabricius and Agelenidae.