干旱区生态环境知识资源中心

In ecotone between oasis and desert of Qira, we choose different positions on bald dune, where vegetation was cut off completely. Then we observe and analyze microclimate, soil, plants, microorganism and water. In extreme and zone, water is always the most important factor in restoring vegetation. Therefore, the possible positions for restoration are mainly in such places as oasis verges and old rivers with high water level. There, floods overflow easily. That is in the region with good ecological environment. It can not only supply enough water for the seeds' sprouting, but can offer the basic conditions for the young plants' extending, growing gradually and developing downwards deeply depending on ground water. hi other else vast deserts, there's almost no environment fit for the vegetation's growing and restoring. After closing and rearing desert where all vegetation was cut, the essences of vegetation' restoration on dune is the van plants' initial condition-on bald ground. Whether or not this restoration can go on is initially more dominated by physical environment than by biological environment of community. Terrain's important function lies in changing the distribution and composition of factors. This is active and important for restoring and widening the plants in desert. In the valley of dune, the configuration of water, heat and temperature is proper. Here, plants can easily touchdown and restore most quickly and the quantity of microorganism is most. The environmental condition on the top of dune is worse-high temperature, quick change and small vertical grads. The middle part is between them. Once the coverage degree gets to some extent, plants in turn. affect the habitat. They prick up the variation of microhabitat at different positions. The features of plants per se must match the habitat. And only when they take advantage of the occasional opportunity then develop quickly, can they make an opportunity for ecesis.