Research On The Species Diversity Of Compositae Along The Different Gradient In Henan Section Of The Yellow River Watershed

Diversity of community species, an important part of biodiversity, constitutes a key part in community ecology as well as the whole ecological studies. It not only reflects the abundance of species in a habitat or community, diversified temporal and spatial variation, and manifests the characteristics and the evolution regularity of a community and eco-system, but also reflects the interrelationship between geological conditions, human factors and the community.This study researched on the composite in different landscape types (mountain,hills,plain), with habitats formed by different disturbance types and intensity in the area in Henan section of the Yellow River Watershed. A field investigation was conducted in May 2010 to January 2011, investigating the distribution patterns and the abundance features of the species in different habitats, summarizing on two aspects, landscape and season, distribution pattern of the composite biodiversity and its environmental explanation. This study explored the influence of human and natural disturbance on the distribution patterns of species within the drainage area, and revealed the mechanism of the effects that natural ecological system the indirect effect of maintaining of agricultural ecological system high-efficient, harmonious and stable, healthy and sustainable development, thereby seek to a balance between the environmental response and maintaining stability, health, efficient and sustainable watershed landscape ecological system of human interference .After investigation, there are fifty-four composite in Henan section of the Yellow River Watershed, which belonging to 24 genera: Conyza canadensis, Aster subulatus, Artemisia capillaries, Artemisia capillariesetc. In the middle watershed, with the influence of community types replacement and natural, human disturbance, there is a certain change of species diversity index and evenness index, and still sticks to some rules in different seasons, and in the same season different habitat.Through finding the rules of changing of the diversity of species in different seasons, we know: in different seasons (spring, summer, fall, winter), either in the riparian land with less human disturbance or in the farmland of corn field with intense disturbance, species diversity index is apparent decline in turn trend; while in the habits of derelict land and woodland ,the change of species diversity index in spring, summer, fall, winter is not obvious, species diversity index in spring, summer, but markedly reduced in winter; The changing trends of Species evenness index in four seasons is the same of species diversity index.The results showed: In mountain area, hilly region, plain region, of the advantages are Conyza canadensis, Aster subulatus, they largely and widely distributed in the study area. Heteropappus altaicus, Artemisia annua, Artemisia eriopoda and so on are more common in mountain landscape type, which may relevant on the air humidity, temperature and other,such as Artemisia annua, Artemisia sacrorum are more In the hilly landscape types; And in plain landscape type the compositae is more, there are Bidens pilosa, Cirsium setosum, Xanthium sibiricum etc.With landscape types of change, species diversity index has increased and then a downward trend. In mountain area, due to the influence of by topography and geomorphology, moles narrower, bungeana affected is bigger, species diversity index is lower; Hilly landscape type is excessive type between hilly landscape types and plain landscape type, landform complex mountainous landscape, solar-thermal resource is rich, the interference by type more intensity and low, so in the hills landscape type species diversity index is higher; In plain landscape type, population density is bigger, human activity intensifies and the dangers of biological invasion, that diversity index has drastically reduced.Through the exploration of variation regularity of the biodiversity in different habitats, in the riparian land with less human disturbance ,species diversity index and evenness index are higher; in the farmland of corn field with the most intense disturbance, plant is strongly interfered in the whole growth period, the evenness and diversity index are the lowest in the downstream area; while in the habits of derelict land and woodland, the change of species diversity index and evenness index are not obvious, which concerned specific abandoned plantation habitat and planting time and the surrounding environment. This shows interference in not reach maximum resistance level of species circumstance, the compositae species are tend to distribution in the interference environment conditions, but when interference to achieve a certain degree, beyond the species, the compositae maximum tolerance level, the distribution of all kinds number and individual number can fall subsequently.