古尔班通古特沙漠南缘优势物种的种间关联特征

Interspecific associations characteristics of dominant species in the southern Gurbantunggut Desert

基于古尔班通古特沙漠南缘植物多样性的调查,对22个优势物种间的关联性进行了分析。结果表明:231个种对中,正关联种对数(141对)多于负关联种对(90对),且前者达到显著关联的种对数(89对)也多于后者(27对)。乔灌木对草本植物分布具有显著影响,形成种对中正关联种对数(44对)多于负关联种对(28对),且前者达到显著关联的种对数(22对)也多于后者(10对)。其中白梭梭、白茎绢蒿和淡枝沙拐枣分别与18个优势草本中的11个、13个和13个呈正关联,且多为显著关联;但梭梭与这些草本均不存在显著正关联,表现出明显的生境趋异性。绝大部分(211对)种对的OI<0.6,处于中等偏弱联结强度,表明干旱环境胁迫使部分物种在资源利用趋同同时,而不同物种集团之间发生了空间分布的分离。DCA排序图的种间距离和分布位置在一定程度上印证了上述结果。研究认为本沙漠白梭梭、白茎绢蒿和淡枝沙拐枣等灌木不仅具有防风固沙效应,而且对草本具有重要的看护效应,需要重点保护。在人工植被恢复过程中,应重视不同乔灌木与草本植物间的合理搭配,以构成灌木-草本群落,形成立体防风固沙体系,更好地发挥生态效应。

Based on the survey of plants diversity in the southern Gurbantunggut desert, we analyzed the interspe- cific associations among 22 dominant species. The result showed that 141 species pairs showed positive correla- tion in a total of 231 species pairs among 22 species, while the other 90 species pairs showed negative correla- tion. The 89 specfes pahs in the 141 species pairs showed significantly positive correlations, and 27 species pairs in the 90 species pairs showed significantly negative correlations. The distribution of herbaceous plant was signifi- cantly impacted by shrubs, there were 44 species pairs showed positive correlation, while more than 28 species pairs showed negative correlation, and the 22 species pairs in the former showed significantly positive correc- tions, and more than 10 species pairs in the latter showed significantly negative correlations. Haloxylon persicum, Seriphidium terraealbae and Calligonum leucocladum were positive correlation with the 11, 13 and 13 of 18 domi- nant herbs and most had significantly positive correlation, respectively, but there were no significant positive cor- relation between Haloxylon ammodendron and these herbs, showing obvious the habitat divergence. The interspe- cific associations of 211 species pairs in the 231 species pairs were medium weak （ OI 〈 0.6 ）, indicating that while drought stress let some species convergence in resource utilization, the spatial distribution occurred separa- tion between the different species groups. The distance between the species and the species location in the DCA figure partly confirmed the relationships between the species. This study suggests that Haloxylon persicum, Se- riphidium terrae - albae and Alligonum leucocladum not only has the functions of wind prevention and sand fixa- tion, but also has important nursing effect of herbs, which need to highlight protect. In order to constitute shrub - herbs community, form the three - dimensional system for windbreak and sand - fixation, we should pay atten- tion to the reasonable collocation between different shrubs with herbs in the process of artificial vegetation restora- tion, and play better in the ecological effect.