Six Helianthemum soongoricum communities in Western Ordos area, namely Ass. Helianthemum soongoricum+Convolvulus tragacanthoides, H. Soongoricum+Oxytropis aciphylla, H. Soongoricum+Reaumuria trigyna, H. Soongoricum+Cara-gana roborovskyi, H. Soongoricum+Reaumuria soongorica, and H. Soongoricum+Tetraena mongolica, were surveyed with the random and contiguous quadrates (0.5m×0.5m). The pattern scales of the dominant species and the communities in the six Helianthemum associations were analyzed. Results show that different patch span numbers of H. Soongoricum population as constructive species exist in six Helianthemum associations. And the large patch spanning of H. Soongoricum population pattern in Ass. H. Soongoricum+C. Roborovskyi is smaller than that in the other associations. The patterns of the accompanying dominant species in the six associations are different. Detrended correspondence analysis (DCA) combined with two-term local variance ( TTLV) method can effectively reflect the community patterns of different Helianthemum associations. The community patterns of H. Soongoricum+R. Trigyna and H. Soongoricum+C. Roborovskyi are severely affected by their accompanying dominant species, but the other community patterns are the integrative reflection of the patterns of constructive species and accompanying dominant species.%针对西鄂尔多斯地区半日花分布区的半日花+刺旋花群丛、半日花+刺叶柄棘豆群丛、半日花+长叶红砂群丛、半日花+荒漠锦鸡儿群丛、半日花+红砂群丛和半日花+四合木群丛6种不同半日花群落,采用连续小样方(0.5 m×0.5 m)法调查植被,研究了各个群落中优势种和群落的格局规模.结果表明:在不同的半日花群落中,半日花建群种显示出不同数量的小、中、大斑块规模格局,而且在半日花+荒漠锦鸡儿群丛,半日花种群的较大规模的斑块比其它群丛要小.6种半日花群丛中的其它伴生种的格局各不相同.DCA排序与双项轨迹方差分析相结合的方法可以有效反映不同半日花群落的格局变化.半日花+长叶红砂群丛、半日花+荒漠锦鸡儿群丛的群落格局受伴生种的影响大,而其它群丛的群落格局则是半日花建群种与伴生优势种格局的综合反映.
展开▼
