| Forest is an important part of terrestrial ecosystem.Litter and understory vegetation not only provide habitat for the majority of organisms,but also play an important role in maintaining aboveground and underground biodiversity and ecosystem nutrient cycle.In order to ensure the better growth of trees,litter and understory vegetation removal that are often used as traditional forest management measures.However,the removal of litter and understory vegetation will change the soil microclimate conditions,inhibit the growth of soil organisms,reduce the soil nutrient cycle,which have a negative impact on the soil ecosystem.Ants are an important part of soil organisms.Apart from their great contribution to biodiversity,they also play an important roles on ecological function and are regarded as “ecosystem engineers”.On the one hand,in the process of foraging and nesting,ants will mix soil particles and organic matter from different locations and different soil layers,the formation of corridors in ant nests will also have an important impact on the physical and chemical properties of soil and microbial community structure,which play an important bottomup effect in the ecosystem.On the other hand,ants play an important top-down effect in the ecosystem.They are an important part of the ecosystem food web,which can regulate the structure of many animal and plant communities through plant feeding,predation,internal predation and mutualism.However,there are few studies on the response of ants to litter and understory vegetation removal.In this study,Dinghu Mountain(DHS)located in the subtropical zone,Baotianman(BTM)located in the transition zone from the north subtropical zone to the warm temperate zone and Changbai Mountain(CBS)located in the middle temperate zone were selected as the study areas,and the same four treatments were set in each study area,namely: CK,litter removal(LR),understory removal(UR),and litter and understory removal(LUR).Through the trap method,we collected the ant samples in each treatment quadrat to obtain its abundance and diversity,and mainly explored the following scientific questions:(1)What is the impact of forest ecosystems on ant community diversity in different climatic zones?(2)What is the response of ant community to litter and understory vegetation removal in different forest ecosystems?In view of the above scientific problems,this study collected ants and soil samples from DHS,BTM and CBS,which under different treatments to analyze and determine the abundance,diversity index and soil physical and chemical properties.(1)The vegetation types of forest ecosystems in different climatic zones had significant effects on the total abundance and diversity index of ant community.The results showed that the total abundance of ant community was the highest in DHS,followed by CBS and BTM.Shannon-Wiener index,Richness index and Evenness index of ant community decreased with the increase of latitude(DHS > BTM > CBS),and Dominance index increased with the increase of latitude(CBS > BTM > DHS).Vegetation types,litter removal and understory removal had significant interaction effects on the total abundance and diversity index of ant community in different climatic zones.(2)In DHS,understory removal significantly reduced the total abundance and Richness index of ant community.The amount of litter is small,but the understory vegetation is dense in DHS.As an important habitat for ants,the removal of understory vegetation reduced the soil MBC,and the soil nutrients,changed the microenvironment,and then reduced the food sources of ants,thus led to the reduction of the total abundance and Richness index of ant community.(3)The interaction of litter and understory vegetation removal significantly affected the total abundance,Shannon-Wiener index and Richness index of ant community in BTM located in the transition area from north subtropical to warm temperate.Litter and understory vegetation removal affected abundance of ant community,Shannon-Wiener index and Richness index by reducing soil moisture content,p H and soil nutrient content.(4)In the middle temperate zone of CBS,the litter removal significantly reduced the Shannon-Weiner index of ant community,but the total abundance of the species did not change significantly.This may be due to the thickness of the surface litter layer in CBS,the change of the habitat environment of the ants after the litter removal,and the influence of sensitive species.Moreover,litter removal significantly reduced soil moisture content,reduced soil available nitrogen(AN),available phosphorus(AP),total nitrogen(TN),total carbon(TC)and total phosphorus content(TP),soil water and nutrient content decreased is not conducive to the survival of sensitive species in ant community,Shannon-Weiner index decreased,and tolerance species to sensitive species balance role may be one of the important reasons for the total number of species not significantly changed.In conclusion,the vegetation types of forest ecosystems in different climatic zones had significant effects on the total abundance and diversity index of ant community,and the response of ant community to litter and understory vegetation removal was also different under different vegetation types of forest ecosystems in different climatic zones.In DHS sample plot of subtropical zone,understory vegetation removal can changed the habitat of ant community by reduced soil microbial carbon content,reduced its food source,and then reduced the total abundance and Richness index of ant community;in BTM sample plot of typical transition zone from north subtropical zone to warm temperate zone,the interaction effect of litter and understory vegetation removal on the total abundance,Shannon-Wiener index and Richness index of ant community were significantly affected,which may be caused by the change of soil water content,p H value and nutrient content caused by the removal of litter and understory vegetation;in the middle temperate zone of CBS,the surface litter layer was thick,the ant habitat changed after the removal of litter,the soil water and nutrient content decreased,and the species was rich. |
