Ant Communities And Feeding Habits Of Dominant Ants At Huoditang Forest Region In Qinling Mountains

Ant is the most abundant animal group in terrestrial ecosystem,which has a huge biomass and occupies a variety of ecological environment.They are closely related to other species and are an important part of the ecosystem food chain and food network.The feeding habits of ants are complex,and their nesting and foraging activities are very sensitive to the changes of ecological environment,which is often used as an indicator species to study the stability of ecosystems.Huoditang forest region of Qinling Mountains is located on the southern slope of Qinling Mountains,and the vertical zone spectrum of vegetation is obvious.It is an ideal area to study the relationship between species diversity and ecological environment.The purpose is to understand the composition of the ant communities and the feeding habits of ants at Huoditang forest region in Qinling Mountains.In this study,sample plot survey and trap method were used to systematically investigate the composition and diversity of ant communities in six typical habitats at Huoditang forest region in Qinling Mountains.Based on the investigation of food composition and stable isotope method,the feeding habits of dominant ant species in Huoditang forest region were analyzed.The main results were as follows:1.In Huoditang forest region,25 species of ants belonging to 12 genera and 4subfamilies were collected.They include 24 known species and 1 undetermined species.Among them,there were 13 species in 5 genera of Formicidae,10 species in 5 genera of Myrmicinae and 1 species in each of Ponerinae and Dolichoderinae.At the genus level,the Myrmicahave had the most species with 6 species,followed by the Lasius with 4 species.M.scabrinodis and M.yunnanensis were the first recorded ants in Shaanxi.Formica japonica?F.sanguinea?F.gagatoides and Myrmica luteola were the dominant species.2.There are differences in the distribution of ant species among different forest types.There are 18 species in type I?Pinus tabulaeformis-Quercus aliena var.accuteserrat mixed forest?,14 species in type II?P.tabulaeformis forest?,15 species in type III?Larix principis-rupprechtii forest?and 9 species in type IV?Picea asperata forest?.There are 10species of type V?P.armandii forest?and 11 species of type VI?Abies fargesii forest?.M.luteola?M.scabrinodis?F.japonica?F.sanguinea?F.Gagatoides and Camponotus herculeanus were distributed in six forest types.Odontomachus monticola?Pheidole flaveria?Liometopum sinense?C.japonicus?Lasius flavus and Nylanderia vividula appear in type I.M.weii only appear in type?.3.In Huoditang forest region,ant flora included Palaearctic and Oriental species.Among them,there are 10 Oriental species,9 Widespread species and 5 Palaearctic species,which showed that Qinling mountains was at the boundary between the Palaearctic realm and the qriental realm.The Formicidae has 8 Widespread species,3 Oriental species and 1Palaearctic species.There are 5 Oriental species,4 Palaearctic specieshad and 1 Widespread species in the Myrmicinae.There are one species of Oriental species each in the Ponerinae and Dolichoderinae.In all forest types,Oriental species and Widespread species showed a decreasing trend with the rise in altitude.4.Among the six forest types in Huoditang forest region,the number of ant species,individuals,richness index and diversity index showed a relatively low altitude habitat compared with a high altitude habitat.Dominance index showed the opposite rule.In all forest types of the Huoditang forest region,the similarity of the communities was generally at a moderate level of dissimilarity.Among them,the ant communities in Pinus tabulaeformis forest and Larix principis-rupprechtii forest?0.611?,Pinus armandii forest and Abies fargesii forest?0.615?,had higher similarity which was of medium similarity level.The ant communities in the Pinus tabulaeformis-Quercus aliena var.accuteserrat mixed forest and Abies fargesii forest had the lowest similarity?0.318?,which was of medium dissimilarity level.The distribution of ant community had the rule of vertical zonality.5.Among the 25 ants of the 4 subfamilies collected in Huoditang forest region,the moderate vertical niche species are the majority?10 species?,and the narrow vertical niche species are the least?7 species?.With the exception of Prenolepis naoroji,the niche selected by other ants includes foraging on the ground.In addition to Ponerinae,there is niche differentiation in other subfamilies.In the Formicinae and Myrmicinae,ants of the same genus have different diversity in the selection of niche.6.The four dominant species of ants in Huoditang forest region had similar food composition and feeding habits.Four species of ants mainly feed on small insect corpses.Among them,the proportion of Hymenoptera insects was relatively high.Stable isotopes method was used to analyze their feeding habits.The results showed that the span of the?¹³C?-26.488^-25.622‰?and?¹⁵N?3.874⁴.700‰?values of the four species of ants were all less than 1‰,the food compositions were similar and had similar food sources.On the basic of the?¹⁵N value,it was found that the trophic level of them was near the third trophic level.The feeding habits of Formica japonica was carnivorous,while the feeding habits of F.sanguinea?F.gagatoides and M.luteolawere were omnivorous partial carnivorous.