Impact Of Land Use Change On Canopy Ant Communities In Terms Of Species Diversity And Functional Diversity

Mojiang and Lüchun county belong to subtropical mountain monsoon climate,in Yunnan province.It makes economic crop cultivation become the main economic source of farmers because of suitable geographical conditions and climatic conditions.Plantations took place of primary plant,which affected the composition and structure of the biome and ecosystem function.Eucalyptus plantations,lac insect-corn agroforests,rubber plantations and lac insect plantations were typical man-made forest types and widely planted.Eucalyptus and rubber trees are exotic trees,and the secondary natural forest,lac insect plantations and lac insect-corn agroforests are mainly local plants.In order to reveal the responses of ant communites species diversity and functional diversity to land-use change.The canopy ants were investigated in secondary natural forest,eucalyptus plantations,lac insect-corn agroforests,rubber plantations and lac insect plantations by trap at Lüchun County,Yunnan Province in October 2012 and April 2013.Meanwhile,the plant diversity and environmental variables were investigated.The ant community foraging on Dalbergia obtusifolia canopy in lac-Fructus amomi agroforestry were investigated by trap in different plots at Yayi,Mojiang County,Yunnan Province in May and September,2015.The plot I never be used to cultivate Kerria yunnanensis,the plot II was used to cultivate lac insect three years ago but not cultivation in this experiment and the plot III is used to cultivate lac insect.The results were as folloes:(1)In total of 17998 ant individuals were collected,which belonging to 68 species,29 genera,and 6 subfamilies of Formicidae.The canopy ant abundance ranked as lac insect-corn agroforests > lac insect plantations > eucalyptus plantations > rubber plantations > secondary natural forests.The canopy ant richness ranked as lac insect-corn agroforests > lac insect plantations > secondary natural forests > eucalyptus plantations > rubber plantations.The canopy ACE index ranked as lac insect-corn agroforests > lac insect plantations > secondary natural forests > eucalyptus plantations >rubber plantations.There was significant and negative relationship between canopy foraging ant abundance,species richness and litter coverage,foliage density of the zone above 300 cm,and the tree crown density,but positive relationship between ant abundance,species richness and herbage coverage.Meanwhile,there was significant and negative relationship between ACE index and litter coverage,herbage coverage,and tree crown density,but a positive correlation between ACE index and foliage density of the zone from 175 cm to 199.9 cm.Plantation has a certain positive role to the ant diversity conversation,especially has a significantly effect by choosing native tree.Reasonable management of plantation is conducive to the conservation of biological diversity.(2)In total of 277 ant individuals were collected from the plot I,belongs to 14 species,11 genera,and 5 subfamilies of Formicidae;324 ant individuals were collected from the plot II,belonging to 16 species,12 genera,and 5 subfamilies of Formicidae;885 ant individuals were collected from the plot III,belonging to 22 species,17 genera,and 4 subfamilies of Formicidae.Ant species richness of plot II and plot III were significantly higher than plot I,but there was no significant differences between plot II and plot III.Ant relative abundance of three plots had significant difference with each other.And they all ranked as III >II >I.Ant community structures of plot II was similar to plot III,but community structures of these two plots were disfferent with plot I.Characteristic species presented in three plots were Dolichoderus thoracicus and Camponotus mitis,and their abundance ranked as III >II >I.Camponotus parius was characteristic species in plot II and plot III was,but its abundance in plot III was higher.And Pheidole sp.1 presented in plot I,Odontoponera transversa presented in plot II,Monomorium chinensis presented in plot III.The facultative mutualism had obviously positive effects on the ant species richness,relative abundance and community structures of ant communities,and its ecological consequences had certain temporal and spatial scale.(3)The functional richness FRic of lac insect plantations and lac insect-corn agroforests were the higest and eucalyptus plantations was the lowest.Seondary natural forests and rubber plantations were in the middle.The functional evenness FEve of seondary natural forests and lac insect plantations were the highest and the eucalyptus plantations was the lowest.The functional divergence FDiv of eucalyptus plantations was higher than other sites.Functional richness of canopy foraging ants were significantly and positively correlated with ant species richness.But there was no significant correlation between functional evenness of canopy foraging ants and ant species richness.And functional divergence of canopy foraging ants were significantly and negatively correlated with ant species richness.Environmental varibles,such as the leaf-litter coverage,leaf-litter thickness,trees abundance,herbage coverage,the and vertical density had significant effects on the functional diversity of ant communities.Therefore,reasonable management of artificial forest is beneficial to the realization and protection of ecosystem function.The leaf-litter also had positive effect on ant functional diversity,while the abundance of tree and shrubs and vertical density had negative effect.(4)The results of the characteristic species of the 5 types of sample plots were as follows.The ability of Crematogaster ferrarii and Crematogaster zoceensis were medium,which were characteristic species in eucalyptus plantations.Characteristic species in lac insect-corn agroforests was Dolichoderus thoracicus and Camponotus nicobarensis,the former was medium and the latter was high.Characteristic species in Seondary natural forests was Dolichoderus thoracicus,Camponotus parius,Camponotus lasiselene,Crematogaster millardi and Crematogaster ferrarii,in which medium ability was more and high ability also exist.The differentiation of ecological niche in rubber plantation was obvious,which characteristic species were Oecophylla smaragdina and Monomorium chinensis.The characteristic species of lac insect plantations were Technomyrmex albipes,Oecophylla smaragdina,Crematogaster ferrarii,Camponotus nicobarensis and Camponotus mitis,which the distribution of the function was uniform.Above all,species diversity and functional richness of ant communities were affected by land-use change.Secondary natural forests was beneficial to maintain stable ant community.And man-made forest was bebeficial to protect ant communities in term of species diversity and functional diversity by choosing native trees.Ant species diversity and functional diversity were decreased in eucalyptus and rubber plantations.In the same time,environmental factors such as leaf-litter,herbs and vertical density should be properly controlled in the planations management.Therefore,we should strengthen the protection of secondary natural forest.And if change the type of land-use,we should choose the plantation with several tree species or mixed agroforestry,which was more conducive to protect species diversity and functional diversity.