影响阜康荒漠-绿洲过渡带荒漠植物数量特征的土壤驱动力分析

荒漠-绿洲过渡带是绿洲向沙漠系统的过渡地带,荒漠植物是绿洲扩展或荒漠化加速的缓冲器,土壤环境是影响植物演变的重要影响因素,土壤环境因素是整个过渡带演化的重要驱动力。通过对阜康荒漠-绿洲过渡带荒漠植物群落实地调查,利用通用植物数量分析软件CANOCO 5.0中冗余度分析(RDA),探讨过渡带影响荒漠植物群落数量特征指标的土壤驱动因子。结果表明:(1)土壤含水量、全N、全P和有机质是影响荒漠植物群落数量特征的主要驱动力因子,环境解释量累计达到69%,而总盐、p H和全K对荒漠植物群落数量特征影响较弱;(2)4个土壤主要驱动力对荒漠植物群落数量特征重要性大小顺序:土壤含水量有机质全N全P;(3)荒漠植物群落数量特征与土壤含水量、有机质和全P呈正相关,但与全N为负相关关系,揭示了土壤含水量、有机质和全P是利于荒漠植物群落稳定的正驱动力,而全N为抑制荒漠植物生长的负驱动力。综上所述,土壤各因子的驱动力作用不尽相同,存在正、负差异,协同维护荒漠植物群落数量特征的稳定和发展。

Driving forces of desert plant characteristics in a desert oasis transitional zone in FuKang, Xinjiang, China

The desert-oasis ecotone is a transition zone between oasis and desert. Desert plants are the buffers against oasis expansion or acceleration of desertification. The soil environment is not only an important factor affecting plant evolution, but also it is an important driving force for the evolution of the whole transition zone. In the desert-oasis ecotone of FuKang, a total of 50 plots in three north-south quadrats were selected, and the quantitative characteristics of the desert plants including coverage, abundance, fresh weight and dry weight were measured. Then, we collected soil samples from the different depths of 0-5 cm, 5-10 cm, 10-20 cm, 20-30 cm, and 30-50 cm to analyze its soil moisture content, total salt, pH, total N, total P, total K, and organic matter. Finally, we used redundancy analysis (RDA) to determine the relationships between desert vegetation characteristics and soil environmental factors. By conducting a field investigation of the Gurbantunggut Desert-Oasis ecotone desert plants, this paper tries to discuss the soil factors that drive characteristics of desert plant quantities, using redundancy analysis (RDA) with the application of commonly used plant quantity analysis software Canoco 5.0. The results show that soil moisture content, total N, total P, and organic matter were the main driving forces which affect the characteristics of desert plant quantities. These environmental factors accounted for up to 69% of the variation, whereas the total salt, pH, total K, and the number of desert plants had smaller effects. The order of importance of the four soil factors that drove plant characteristics is:soil moisture > organic matter > total N > total P. The quantitative characteristics of desert plants were positively correlated with soil water content, organic matter, and total P content, but negatively correlated with total N, which reveals that soil water content, organic matter, and total P are all positive driving forces which are favorable to the stability of desert plant communities, while N is a negative driving force that inhibits desert plant growth. In summary, the soil factors that drive desert plant characteristics do not have the same effects; there are differences between positive and negative effects and synergistic maintenance of desert plant community quantitative characteristics, including stability and development.