基于MSO方法的2个油蒿群落格局对比研究

Analysis on Pattern Characters of the Two Artemisia ordosica Communities by MSO

应用多尺度排序法(multiscale ordination,简称为MSO),对乌兰布和沙漠东北缘黄河水与井水2种灌溉模式绿洲外围的半固定油蒿群落进行多种群格局对比研究。结果表明:在黄灌区,油蒿不仅是群落的优势种(重要值为45.26%),而且对植被格局的贡献率也最高;83.84%的植被形成了油蒿单种群格局,且油蒿贡献率高达0.889 6。在井灌区,植物种对格局的贡献率与其在群落中的重要值明显不一致:油蒿是群落的优势种(重要值为47.41%),但在植被格局中的贡献率明显下降,只有15.54%的植被形成了以油蒿为主的格局;沙冬青、白刺却相反,它们在植被格局中的贡献率远远高于其在群落中的重要值。对比2区段的其它格局特点还发现:井灌区油蒿群落植被的斑块化现象更严重一些,并且油蒿斑块内的格局强度低于黄灌区。

The patterns of two semi-fixed Artemisia ordosica communities outside the oasis on the northeast of Ulanbuhe desert irrigated by Yellow River and well water were analyzed with the method of Multiscale Ordination（MSO）.The results showed that： in the communities outside the oasis irrigated by Yellow River,A.ordosica was not only the dominated species in the communities（the importance value was 45.26%） but also the greatest contributor to the pattern.It occupied a proportion of 83.84% of the vegetation with the contribution rate as high as 0.889 6.In the communities outside the oasis irrigated by well water,the contribution of species to the pattern was different from the importance value to community.A.ordosica was the dominated species in the communities（the importance value was 47.41%）,but its contribution to the pattern decreased very much.It was inversely for Ammopiptanthus mongolicus and Nitraria tangutorum whose contribution to the pattern was much higher than the importance value to community.Comparing with other pattern characters of the two communities,it showed that the pattern number outside the oasis irrigated by well water was more and the pattern intensity of A.ordosica was lower.