摘要
通过对天山南北坡25个样地的物种-面积关系的研究,结果发现:①所有样地种-面积关系斜率的平均值为0.21±0.02,低于全球平均水平;②草甸、草原和荒漠的种-面积关系的斜率分别为0.14±0.02,0.13±0.01和0.28±0.02。草甸和草原的种-面积关系斜率无显著差别,但两者显著低于荒漠的种-面积关系斜率;③天山南北坡种-面积关系斜率与水分和能量因素均存在显著相关关系,全气候模型解释率为80.42%,其中水分因子的影响最大,为负相关,解释率为69.88%;与物种丰富度对数呈显著负相关关系;④天山南北坡种-面积关系截距与能量因子、水分因子和气候稳定性因子均显著相关,全气候模型解释率为91.9%,水分影响最大,为66.22%,正相关;与物种丰富度也呈显著正相关关系。表明水分因子是影响天山南北坡植物种-面积关系的主要因子,物种丰富度也对其存在显著影响。
Species-area relationships （SARs） were discussed in the past decades,and they were supposed to be one of the few ＂genuine law＂ in ecology. Xinjiang is located in the hinterland of the Eurasia,where there is a high radiation but a low precipitation. In this study,the patterns and mechanisms of SARs in different arid vegetation types in the Tianshan Mountains were explored by investigating sample plots. The species-area curves of steppe,meadow and desert were charted based on 26 nested sample plots,the minimum area of each nested sample plot was 0.25 m2,and the maximum one was 400 m2. All species in each sub-plot were recorded to develop SARs. The logarithmic form power curve （S = c·Az） was applied to fit SARs,and then SARs from different areas were compared with climatic variables by plotting the slope （z value） and intercept （c value） to explore the main factors affecting the patterns of SARs in Xinjiang. The power-law model was used to explain 0.90 ± 0.01 of variance of species richness at different scales. The average value of overall slope was 0.20±0.02,lower than the mean of the world. The slopes of steppe and meadow were 0.13±0.01 and 0.14±0.02 respectively. There was no significant difference between the two vegetation types. However,these two figures were significantly lower than that of desert （0.28±0.02）. The climatic variables were classified into three groups：energy,water and climatic stability. In the full climatic models,all the factors were used to explain 80.42% of z value and 91.90% of c value respectively. In all the three factors,water factor was the most important for SARs,and the R2 values of z and c were 69.88% and 66.22% respectively. However,the effects of water factor on z value and c value were quite different,and z value was decreased but c value was increased with the increase of water factor. Similarly,z value was decreased but c value was increased with the increase of species richness. The results reveal that water was the main factor affecting the species-area relationship in this area,and the species richness also played an important role.
出处
《干旱区研究》
CSCD
北大核心
2011年第1期54-59,共6页
Arid Zone Research
基金
国家自然科学基金重点项目(40638039)
关键词
草甸
草原
荒漠
生物多样性
水分
物种丰富度
天山
新疆
steppe
meadow
desert
biodiversity
moisture cointent
species richness
Tianshan Mountains
Xinjiang
