基于盐分梯度的荒漠植物多样性与群落、种间联接响应

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于盐分梯度的荒漠植物多样性与群落、种间联接响应 DOI: 10.5846/stxb201306071403 作者: 作者单位: 新疆大学资源与环境科学学院,新疆大学资源与环境科学学院,华东师范大学环境科学系,新疆大学资源与环境科学学院,新疆大学资源与环境科学学院,新疆大学资源与环境科学学院,新疆大学资源与环境科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学重点基金项目(41130531) Responses of desert plant diversity, community and interspecific association to soil salinity gradient Author: Affiliation: College of Resources and Environment Science,Xinjiang University,College of Resources and Environment Science,Xinjiang University,Department of Environment Science,East China Normal University Shanghai,College of Resources and Environment Science,Xinjiang University,College of Resources and Environment Science,Xinjiang University,College of Resources and Environment Science,Xinjiang University,College of Resources and Environment Science,Xinjiang University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤盐分是影响干旱区荒漠植物群落动态的决定因素之一。基于样方调查和不同土壤盐分梯度下植物多样性指数及群落与种间关联的计算结果,分析干旱区荒漠群落植物多样性、群落联接性和种间关联对土壤盐分梯度的响应动态。结果表明,在土壤盐含量为0.03%-0.55% (S1)、0.61%-1.24% (S2)和1.41%-1.79% (S3)的盐分梯度上,(1)随土壤盐含量升高,群落生活型结构改变,草本比例减少,乔木比例增加;(2)植物多样性指数随土壤盐分增加而下降,低盐分梯度下,二者极显著正相关(P<0.01),中盐梯度下二者间呈部分显著负相关(P<0.05),高盐梯度下则转为以正相关为主(P>0.05);(3)群落联接性随土壤盐分梯度转变,在0.61%-1.24%的中度盐含量时正联接性最强(VR=1.89),高盐度含量下群落转为不显著的负联接,稳定性降低;(4)沿盐分升高梯度,种间的负相关种对数增加,正相关种对数减少,种间关联(相关)强度提高,正负相关种对比(PNR)与多样性指数呈显著正相关(P<0.05)。综上可知,干旱区荒漠植物多样性在土壤盐含量达到1.41%-1.79%水平时总体显著降低;土壤盐分水平显著影响植物群落和种间联接性,种间互利性随盐分梯度增加下降,物种趋于独立分布,并最终导致荒漠植物多样性降低。 Abstract:Dynamic response of plant diversity, community and interspecific association along environmental gradients is one of the basic issues in community ecology and biodiversity science. Soil salinity is one of the most decisive factors that govern desert plant community dynamics. The Ebinur Lake wetland national nature reserve is located in typical arid desert area. Previous related studies about the reserve had point out that soil salinity influences the desert plant community characteristic significantly, but the specific role of soil salinity in plant community dynamics is still unknown. Based on this, the objective of this study is focused on the responses of desert plant diversity, community overall association and interspecific association to soil salinity gradient.In this study, altogether 74 sampling plots were investigated; including 22 plots for trees (10 m×10 m), 35 plots for shrubs (5 m×5 m) and 17 plots for herbs (1 m×1 m). At each plot, abundance, height and diameter at breast height of trees, abundance of shrubs and herbs were surveyed. According to soil salinity of the corresponding plot, all plots were classified to 3 salinity gradients by cluster analysis, with the salt contents of low (S1), middle (S2) and high (S3) defined as 0.03%-0.55% (S1), 0.61%-1.24% (S2) and 1.41%-1.79% (S3) respectively. A range of different diversity indices including Shannon-Wiener, Simpson, Pielou, Fisher-α of logarithmic series distribution and Margalef were calculated to examine the plant diversity under each salinity gradient. Variance ratio (VR), χ2 test and Spearman rank correlation were employed to quantitatively analyze the community overall association and interspecific association under different salinity gradient. VR value, proportion of species pairs with positive and negative correlation, Dice index and Spearman rank correlation coefficient were used in exploring response of overall association and interspecific association to different soil salinity. The results indicated that: 42 species (which belong to 39 Genus of 18 Family) were identified in the Ebinur Lake wetland national nature reserve. Along the soil salinity gradient (S1-S3), (1) Life form structure in community was changed, more specifically, proportion of herbaceous decreased while tree proportion increased as salinity increases, and shrubs proportion decreased slightly. (2) Plant diversity indices decreased with increased soil salinity, and showed a very significant positive correlation in low salinity (P<0.01), then the correlation turned into partially significant negative (P<0.05) in middle salinity and showed positive mainly in high salinity gradient (P>0.05). (3) Community overall associations was significant positive in low (VR=1.42) and middle (VR=1.89) salinity, but converted to negative (VR=0.62) in high salinity, which means that high soil salinity lead to the decrease of community stability. (4) Along rising gradient of soil salinity, number of species pairs with a negative correlation increased, while number of species pairs with a positive correlation decreased; both of positive and negative correlation strength (coefficients) was enhanced as soil salinity increases; ratio of positive species pairs to negative species pairs showed a significantly positive correlation with diversity (P<0.05). In conclusion, reduced desert plant diversity and shifted community and interspecific association under high salinity threatened plant community stability of arid area, and may lead to retrogressive succession of community. Results of the present study provide a scientific basis for arid area in vegetation management, vegetation restoration and soil salinization prevention. 参考文献 相似文献 引证文献