The Study Of Community Ecology On Helianthemum Son-Garicvm Schrenk

Helianthemum songaricum is a dwarf shrub of genus Helianthemum and family Cistaceae. As a tertiary relic plant and a single species of genus Helianthemum in Asia desert region, the species is listed as secondary rare and endangered plant of China and plays important roles in the maintenance of the stability of desert ecosystem and researches for environmental evolution, flora, biological evolution and biodiversity. In recent years, the distribution area of H. songaricum diminished and fragmented gradually under the influences of environmental change and human activities, so its survival and development were subjected to serious threat. This study analyzed the distribution area, community flora, community structure and process and community biodiversity of H. songaricum with methods of community ecology to understand the current living situation and maintaining mechanism of its population and community. Our results showed that:1. The amount of H. songaricum individuals in age class I and III were less, and most of individuals were in age class II, indicated that H. songaricum population was relatively stable. The spatial pattern and spatial associations between different age class individuals of H. songaricum population were affected by habitat environment and depended on spatial scale strongly.2. H. songaricum formation was classified into2association groups and8associations, in which Association Hellanthemum songaricum-Ajania achilleoides and Association Hellanthemum songaricum-Oxytropis aciphylla were the major community types. The distribution of H. songaricum communities correlated with slop, slop aspect and soil moisture closely.3. The pattern of species abundance in H. songaricum community was in line with the neutral theoretical model, and therefore, was the neutral pattern.4. H. songaricum and its community were distributed presently in the ancient Mediterranean region, and the ancient Mediterranean flora showed high proportion. In west Ordos, in spite of a narrow distribution area, the potential distribution area of H. songaricum extended to west and east.