Investigation Of Sandification Influences On The Wetland Function In Xianghai And Management Measures

Wetland usually occurred at interface of terrestrial ecosystems and aquatic ecosystems, and formed by the interaction of them. As a physical synthesis composed of water, soil and vegetation, wetland is an important landscape and ecosystem, dominated by the water in the surface layer of the earth. The filtration of wetlands is the core of ecological process and function in wetland, that is defined as the movement, transference, redistribution and effects of water, nutrients and contaminants in multi-interface through terrestrial and aquatic interaction in wetland, including water process and effects, cycling process and effects of nutrients and contaminants, wetland productivity and biodiversity and so on. Wetlands have huge environmental functions in maintaining ecological balance and regional stability due to their particulates characteristics in hydrology, soil, and plant, then emphasized by scientists and governments over the whole world, and became a Hotpoint paid a close attention by many scientists in different fields. Wetland abounds in living things resources, peat resources and water resources and important land resources as well. Wetland is one of ecosystems with important environmental functions and habitats for various biotas on the earth. Wetlands are generally acknowledged as highly productive ecosystem, which provide much service to economic system and hold many important economic values. The economic values of wetland come from the interaction among the biological, physical and chemical components of an ecosystem. It is composed of hydrology, biogeochemical cycling and adaptation and improvement of biota for it, the interaction among those factors cerates the entire function of wetlands. It plays an essential role in adjusting environment, maintaining stable microclimate, regional ecological balance and sustainable economic development. Wetland resources have obviously decreased because of the general public and government lack a comprehensive understanding of the importance of wetland benefits. Wetland ecological system is week, with the development of economy, unreasoning large-scale reclamation of wetland, excessive exploitation of resources, strictness of wetland pollution damage of wetland induced the decrease of capability of natural disaster, effect of carbon conservation and environment purification, industrial waste water pollution, and species decrease of rare animals and plants. The decrease of wetland quality has led to decrease of wetland functions on flood control, runoff mitigation, floodwater storage to combat drought, so it is necessary for protection of wetland, and policies that should be formulated for future rational and sustainable utilization of wetland resource. We should establish an integrated, standardized and scientific system for the protection and management of wetland, which enables the restoration of regressive wetland, furthest exerts the functions and benefits of wetland ecological system, and guarantees sustainable utilization of national wetland resources. Wetland is multi-functional, it provide services-such as water storage, flood mitigation, storm abatement, aquifer recharge water quality improvement, storm protection, sedimentation and stabilization of local climatic conditions, these functions depend on the type of wetland, soil and water characteristics and associated biotic influences. In this paper, it introduces some kinds of functions of wetland,analyzes progress on the wetland assessment of functions, and discusses the potential trend of future studies. In these years, because of irrational use and various disturbances, sandification has emerged in Xianghai wetland; the ecological environment is deteriorating gradually, which has become the main obstacle factor for agriculture and economical sustainable development in this region. Soil sandification refers to the process that non-aeolian sandy soils degraded into aeolian sandy soils in arid area. Genetic conditions of soil sandification may be summarized into four aspects as follows: first, soil drought is the key factor of soil sandification; second, vegetation degradation reduces the sand-control and check-wind capacities; third, light texture of soil forms the material basis of soil sandification; fourth, gale and winds blow out sand grains are the dynamic factor of soil sandification. Soil sandification makes grain size coarse, soil fertility poor and total salt content reductive. This paper has studied the affection level of the sandification, reasons of sandification, and the factors affecting the functions of wetland in Xianghai. Resulted information indicates that sandification causes the losses of wetland function and enormous value, about 51.04millionRMB/a. Study shows outdated mode of production and irrational way of land use are the main factors causing seaward sandification. The absence and irrational exploitation of water resources is the key factor causing the sandification of wetland in Xianghai. Due to insufficient water supply, parts of wetland dried up, posing a threat to various aquatic organisms. It induced degradation of ground flora, decrease of biology yield, soil coursing, and degeneration of ecological function and intensified desertification. In addition, wetland desertification are also caused by blind reclamation and...