艾比湖地区植被和土壤在南-北区段上的差异性分析

South-north differences of vegetations and soils in the Aibi Lake area

从艾比湖两岸大致沿同一经度分别向南北山前地带,对39个样地进行野外调查和样品采集。通过研究植被结构和土壤性质的变化特征,探讨了植被-土壤在南北两断面上的差异。结果表明:两地植被存在群落中优势种群类型、数量、长势及其空间分布的差异,而多样性指数及植被盖度的统计学差异并不显著;土壤的粒度平均水平明显不同,而粒度的离散性及对正态的偏离度仅在表层差异显著;多种养分含量差异均显著;土壤表层、次表层含水量、含盐量(包括盐分主要离子含量)和pH的平均水平及变化程度,南北差异的显著性不一致,但整体上看,仍属于比较明显的范畴。这些差异是艾比湖南北地形、水文、气象、物源明显不同的结果,也是植被和土壤耦合作用的结果。

In the previous studies, due to a large randomicity of sampling, selected sampling sites were limited, and then the comparison study of vegetation and soil between the south and north transects is lacking. For this shortage, in this study the investigation of terrain and landform was conducted, observing of vegetation parameters and sam- piing of soils in 39 sites, ranging from 82°52′14″E-83°1 ′45″E and 44°23′36.6″N-44°59′28″N in the south and north areas of Aibi Lake, Bortala Prefecture, Xinjiang, China. Using the method of descriptive comparison and the analysis of significant level for statistic differences, the paper discussed the distribution characteristics of vegetation structure and soil physical-chemical properties and explored the differences between the south and north transect areas of Ai- bi Lake. The results show that there are the differences in population type, quantity, growth regime and their changes for dominant species between south and north areas＇ vegetation. This is, the fluctuant forms of diversity of plant com- munities and the mean indices of vegetation parameters with the varying sampling sites are different, however, the statistic differences in the diversity, evenness and cover indices are not significant. In terms of soil physical-chemical properties, comparing with the south transect area the grain size of soil in north transect area is coarser, the sorting is more poor, the source of material and dynamic of movement are more complex. However, in the south transect area the peak values of the grain size fraction which is sensitive to environments more occur near 60 μm, representing that there are some of aeolian sands. Because the impact of wind force on soil was limited, the significant differences in dispersing from soil grain size and in departure from normality in two transect areas only occurred in the topsoil layer. However, the differences in concentrations for organic matter, total N, total P and total K are signifi- cant. In terms of the mean levels for soil moisture, soil salt （including main soil soluble salt ions） and pH, the signif- icance of differences between the every soil layer of south-north areas is not consistent, and as a whole, the differ- ence is in a marked range. These differences are the results from remarkable distinctness of terrain, hydrology, weather, vegetation, soil source and properties in the south and north transect areas, and then the heterogeneity and coupling relationship of vegetation pattern and soil physical-chemical properties strengthened the differences of the south and north transect areas.