Species Diversity Of Artificial Grazing Grassland Spiders In Northwestern Guizhou

To explore the spider species diversity of artificial grassland in karst areas and its relationship with environmental factors,here,a preliminary study of spider species diversity in New Zealand pastures in the Youshan River in Northwest Guizhou from September 2019 to August 2020,was carried out by methods of combining sample,trap and line sampling.The main findings are as follows:(1)The composition of spider species diversity in the study area was preliminary revealed.3337 specimens of spiders,belonging to 18 families 80 genera 127 species,were captured in the study.Among them,9 were newly recorded in Guizhou(Araneus diffinis?Lathys subalberta?Hahnia himalayaensis?Philodromus fallax?Lysiteles conflatus?Synema nangok?Odontodrassus yunnanensis?Lycosa suzukii?Pseudicius zabkai).There are three dominant spider families,Araneidae,Linyphiidae and Thomisidae,with individual number accounting for 47.98% of the total individuals obtained.The dominant genus is Araneus,which accounts for 11.84% of the individual number of spiders obtained.Six abundant species,separately Araneus diffinis,Philodromus fallax,Pardosa laura,Enoplognatha caricis,Xysticus lesserti and Ebrechtella tricuspidate,account for 41.23% of the total individual number of spiders obtained.And the order of individual number of functional groups is: Round-web spiders > Ambush spiders > Wandering-spiders > Net-web spiders > Burrowing spiders.(2)The results of dynamic changes of spider species diversity on artificial grasslands of karst areas show that the values of individuals number,species number,diversity index and richness index,from month to month,were all the highest in August and the lowest in December,except the evenness index(the highest in September,the lowest in January)and the dominance index(the highest in December,the lowest in January).Individual number of spiders in January and August were all significantly higher than the number in December(P<0.05).Species number of spider in May and August were all significantly higher than the number separately in September,October,November and December(P<0.05).Values of diversity indices of spider in May,June,July and August were all significantly higher than the Values in November and December(P<0.05).Values of richness indices of spider richness in May,June,July and August were all significantly higher than values in November and December(P<0.05).Values of evenness indices of spider in September,October,December,June and July were all significantly higher than value in January(P<0.05);Value of dominance index of spider in December was significantly higher than values in June and July(P<0.05).(3)The results of correlation analysis between spider diversity and environmental factors and insect diversity in karst areas show that: soil temperature and air temperature have a significant positive correlation effect on diversity index of spider(P<0.05);soil moisture content has a significant negative impact on diversity index of spider(P<0.05),Plant height,weed height and species number of plant have a significant positive correlations effect on diversity index of spider(P<0.05).All values of individual number,species number,diversity index and richness index about insect have a significant negative correlation effect on the spider's species number and diversity index(P<0.05),but a significant positive correlation effect on the individual number of spider(P<0.05).Regression analysis found that plant height,weed height,soil temperature and air temperature have a significant positive correlation effect on individuals number of spider(P<0.05),and soil moisture content has a significant negative impact on individuals number of spider(P<0.05).Canonical correspondence analysis shows that weed height,air temperature and soil temperature have the strongest positive correlation effect on individual number of spider,and soil moisture content has the strongest negative correlation effect on individuals number of spider.(4)Comparing the changes of spider species diversity in the period of before,during and after grazing in karst areas,the results show that grazing will significantly reduce the values of spider's individual number,species number,diversity index and richness index(P<0.05),but increase the its evenness index and dominance index.(5)The correlation studies about 4 functional groups' spider species diversities between environmental factors and insect diversity show that the greatest impacts on their species diversities were soil temperature,air temperature,soil moisture content and individual number of insect.Among them,soil temperature and air temperature respectly were,respectively,significantly negative correlation with the dominance index of Round-web spiders(P < 0.05),significantly positive correlation with the species number and diversity index of Ambush spiders(P<0.05),significantly positive correlation with the individual number,species number,evenness index,diversity index and richness index of Wangdering-spiders(P<0.05),and much significantly negative correlation with the dominance of Wangdering-spiders(P < 0.01).The individual number and species number of insects were,respectively,significantly positive correlation with the individual number and diversity index of Ambush spiders(P<0.05),significantly positive correlation with the diversity of Wandering-spiders(P<0.05),significantly negative correlation with the individual number of Net-web spiders(P<0.05),but not significantly correlation with the any index of Round-web spiders.