Impact Of Flaveria Bidentis (L.) Kuntze Litters On Community Structure Of Soil Invertebrates

An investigation was conducted during fall 2014 through 2015 to study the impacts of non-native plant species Flaveria bidentis invasion on ground-dwelling soil invertebrates’ community structure by using the tool with nylon mesh bag and cutting ring. The survey was implemented in four different habitats, forestland, cultivated field, uncultivated land and ditch, all invaded by F. bidentis. And the control plants were Populus X hopeiensis Hu& Chow, Artemisia annua Linn., Phragmites australis(Cav.) Trin. ex Steud, Lonicera japonica Thunb., all originated in China.The collection yielded a total number of 17466 individuals belonging to 1 phylum 8 classes 18 orders dominated by Arachnoidea and Psocidae and the relative abundance of other species were smaller. In all habitats, F. bidentis litter decomposed faster than litter of control plants. The result also shows that the numbers of ground-dwelling soil invertebrates individuals collected from F. bidentis treatments are noticeable more than those from control plants as control(by 11%-53%). Through the survey season, species richness and diversity index of the ground-dwelling soil invertebrates are usually higher in the F. bidentis litter than in control, and reach significant level at the peak of F. bidentis growth. The reason maybe the humid environment from July to September accelerate the litter decomposition to provide source of food for the ground-dwelling soil invertebrates communities. Other results also suggests that the effect of F. bidentis litter on the ground-dwelling soil invertebrates may be associated with the extent of human disturbance, indicating that the habitats rarely visited by human, such as uncultivated land and ditch, may be affected more than forestland and cultivated field, which involving more human activities. The cluster analysis showed that the ground-dwelling soil invertebrates community represented high similarity degree between cultivated field and forestland habitats, but inversely in ditch habitat.Another investigation was conducted to explore the impacts of F. bidentis litter on the communities of soil invertebrates in three different habitats including forestland, wasteland, and ditch habitats. A total of 54315 individuals were captured in three habitats on October 23 rd by cutting ring, which is divided into three sampling layers in this study. All of the individuals belong to 2 phyla 10 classes 17 orders, among which Arachnoidea and Collembola were the dominant orders in three habitats, and the relative abundance of other species were smaller. The canonical correspondence analysis showed that the content of nitrogen, phosphorus, potassium and organic matter of F. bidentis litter and surface humus soil was significantly different from control, which cause the increasing of diversity of soil invertebrates and also it trends to increase for the diversity of soil invertebrates in litter from top to bottom. F. bidentis litter could provide the better habitats and food sources for the dominant orders of soil invertebrates, thereby affecting their community structure of soil invertebrates which mainly related to growth conditions of F. bidentis, control plants and companion plants, which was characterized by its weaker growth conditions in forestland but stronger growth in wasteland land and ditches.