Research On The Community Structure Of Moss Mites In Different Grades Of Rocky Desertification Environment In Karst Area

Mites belong to Arthropoda,Arachnida and Acari,and are one of the most abundant and diverse small arthropod groups in the stone desertification ecosystem,with characteristics of extreme sensitivity,high tolerance,wide distribution and mixed food habits.Its species community structure diversity and spatial and temporal distribution are easily influenced by climatic conditions and survival environment,and it is an important indicator species for ecological management and restoration in rocky desertification areas.The moss layer is not only an important habitat for mites to grow,develop and reproduce,but also an important food source for them.While providing habitat protection for mites,it also plays an irreplaceable role in soil improvement,water conservation,vegetation succession and biodiversity increase in rock desertification areas.In the present study,the community structure of stony moss mites and their response to environmental factors in stone desertification habitats are rarely studied.In the study area,we selected five levels of stone desertification habitats: no stone desertification,potential stone desertification,mild stone desertification,moderate stone desertification,and intense stone desertification,and used mites in stone mosses as research objects,The number of individuals,taxa,dominance,diversity,richness,evenness index and similarity of moss mites were studied and analyzed using Excel 2019,Past4.10,SPSS22.0 and Canoco5 data software to get a preliminary understanding of the species diversity and the relationship with environmental factors of stony moss mites in different levels of stone desertification habitats in the study area.The main results of the study are as follows:(1)There are abundant and diverse mite species in sphagnum mosses of different levels of sphagnum habitats.35258 moss mite specimens were captured in this study,including 171 genera of 100 families in 3 orders in autumn,173 genera in 93 families in 3 orders in winter,and 139 genera in91 families in 3 orders in summer.On the whole,the fungus mite genus Scheloribates,the pendant shield mite genus Scutovertex,the coverhead mite genus Tectocepheus,and the hairy large winged mite genus Trichogalumna were the dominant taxa.(2)The community structure of stony moss mites changed with the deepening of stone desertification,and the number of individuals of stony moss mites in autumn was the most abundant in the intensity stone desertification habitat;the number of taxa was the most abundant in the non-stone desertification habitat;the dominance index was the highest in the intensity stone desertification habitat;the diversity index was the highest in the non-stone desertification habitat.In winter,the number of individuals,taxa and diversity indices of stony moss mites were the most abundant in the no-stone desertification class;the evenness index was the highest in light stone desertification and the least in no-stone desertification.The number of individuals and taxa and richness index of stony moss mites in summer were highest in no-stone desertification habitat and lowest in intensity stone desertification;the dominance index was highest in intensity stone desertification habitat;the diversity index was highest in potential stone desertification;and the evenness index was highest in light stone desertification and lowest in no-stone desertification.(3)Seasonal changes also affected the mites in sphagnum mosses.The number of individuals,taxa,dominance index and richness index were the highest in winter,while the diversity index and evenness index were the lowest in no-stone desertification habitat and potential stone desertification habitat.The number of taxa and richness indices decreased gradually with the seasonal changes of autumn,winter and summer in mildly stony desert habitats.In moderate sphagnum habitats,the number of individuals and taxa of sphagnum moss mites decreased gradually from autumn to summer,but the diversity index and evenness index showed the highest value in summer.In the intensity sphagnum habitat,all the biodiversity indices of moss mites were the lowest in summer,however,the evenness index was the highest in summer.(4)The overall similarity of sphagnum mite communities of different classes of stone desertification in the study area was at a moderately dissimilar level.The values of Jaccard similarity index for different classes of sphagnum mite communities ranged from 0.3247 to 0.4957 in autumn,0.2534 to 0.4923 in winter,and 0.1481 to 0.504 in summer.Because of the high vegetation cover,low rock exposure rate,thick soil layer and similar forest,irrigation and grass vegetation types,both no rocky desertification and potential rocky desertification have high mite community structure similarity.The degree of similarity between moss mite communities in moderate rock desertification and intense rock desertification was more consistent.In contrast,the large environmental heterogeneity in the nostone desertification habitat and the intense stone desertification habitat led to a great difference in mite communities,a low degree of similarity and obvious differences in gradients.(5)By correlating the mite communities of stony mosses in the study area with the biological influencing factors such as rock temperature,atmospheric temperature,atmospheric humidity and light,the results showed that rock temperature,atmospheric temperature and humidity were all correlated with moss mites,with rock temperature being the main factor.In autumn,rock temperature was positively correlated with the number of individuals,diversity index and evenness index;in winter,rock temperature significantly affected the number of taxa and richness index,while atmospheric humidity affected the diversity index and evenness index;in summer,rock temperature was closely correlated with the diversity index and evenness index of moss mites,atmospheric temperature affected the number of taxa,and light intensity showed positive correlation with the number of individuals and dominance index Atmospheric temperature affects the number of taxa,and light intensity correlates with the number of individuals and dominance index.