天山北麓中段拟南芥生存群落主要种群种间联结性

Interspecific associations among main plant populations in communities with Arabidopsis thaliana occurrence in middle part of northern Tianshan Mountains.

运用种间联结测定方法研究了天山北麓中段拟南芥(Arabidopsis thaliana)生存群落24个主要种群的种间联结特征。结果表明:群落内物种总体联结方差比率(VR)为1.55,表现为显著正联结。24个物种组成的276个种对中,有123对表现出正关联(V>0),150对为负关联,3对无关联。χ2检验有61对表现显著或极显著正关联,有24对表现显著或极显著负关联。有232个种对0<OI<0.6,仅有12个种对OI>0.6,另有32个种对OI=0,表明多数物种间联结性较弱或无联结。DCA分析显示,排序图中的种间距离较好地表示了种间联结的强弱。拟南芥与新疆绢蒿(Seriphidium kaschgaricum)、猪毛菜(Salsola collina)等耐旱植物关系密切,对它们依赖性较强,表明拟南芥具有较强的抗旱特性。拟南芥与邻近种庭芥(Alyssum desertorum)呈极显著正关联,与丝叶芥(Leptaleum filifolium)和舟果芥(Tauscheria lasiocarpa)显著正关联,表明它们生态需求相似,生境趋同。拟南芥与邻近种小拟南芥(A.pumila)等联结性较弱,生境趋异。多数十字花科短命植物之间以及它们与群落优势物种之间具有较强的关联性,体现了该科物种在干旱区分布的特点。

By using interspecific association determination methods, this paper analyzed the characteristics of interspecific associations among the 24 main plant populations in the communities with Arabidopsis thaliana occurrence in middle part of northern Tianshan Mountains. The variance ratio （VR） of the overall associations among the 24 populations was 1.55, showing a significant positive association. Among the 276 species pairs of the populations, there were 123 pairs showing positive correlation, 150 pairs negative correlation, and 3 pairs with no correlation. The Х^2 test indicated that there were 61 species pairs showing significant or very significant positive correlation, and 24 species pairs showing significant or very significant negative correlation. 232 species pairs had the Ochiai values 〉0 and 〈0. 6, 12 species pairs had the Ochiai values 〉0. 6, and 32 species pairs had their Ochiai values = 0, suggesting that most of the species pairs had weak or no interspecific association. The detrended correspondence analysis （DCA） indicated that the distances between species on the ordination diagram better reflected the strength of interspecific association. A. thaliana had close relations with and high dependency on drought-resistant species Seriphidium kaschgaricum and Salsola collina, indicating its stronger drought-resistance, and had significant positive associations with its adjacent species Alyssum desertorum, and with Leptaleumfilifolium and Tauscheria lasiocarpa, indicating that these species had similar ecological requirements and habitats. However, the association between A, thaliana and A. pumila was weak, showing a divergence of their habitats. Most of ephemeral cruciferous species had stronger associations among them and with the dominant species in the communities, reflecting the distribution characters of cruciferous species in arid area.