---

作 者 ：李慧勇³;李慧卿^1,2;李清河^1,2;刘建锋^1,2;江泽平^1,2

期 刊 ：应用生态学报 2008年 19卷 04期 页码：741-746

关键词：种群；

摘 要 ：以乌兰布和沙漠东北缘黄灌区绿洲边缘早期营造的人工固沙花棒林、沙拐枣林和梭梭林为主要研究对象，并以附近天然植被为对照，采用连续小样方组成的样带法调查，分析了已进入衰老期的3种人工固沙林的多种群多尺度格局特点及种间关联.结果表明：对照区的天然植被中, 74.29%以油蒿单种群格局出现，24.99%以白刺单种群格局出现；人工固沙林逐渐演替成为近天然植被.与对照区天然植被相比，人工固沙林格局强度较高，在防风固沙，促进天然固沙植物恢复、演替方面发挥了重要作用.但随着演替进程，人工种植灌木将衰退减少，天然植物种逐渐成为林分的优势种.在环境条件差异较小情况下,植被的格局尺度受斑块内优势植物种特征及其相互关系的影响较大.种间关联与斑块的大小、植物种组成及不同植物种对斑块的贡献率有关.

Abstract:Taking three sandfixing plantations Hedysarum scoparium and Calligonum mongolicum, Haloxylon ammodendron- on the oasis verges in northeast Ulanbuhe desert irrigated by Huanghe River as test objects, the multi-species and multi-scale patterns and the species associations of the plantations were investigated by contiguous quadrats transects method, with the natural vegetation nearby as the control. The results showed that 74.29% of the natural vegetation was dominated by single species pattern of Artemisia ordosica, and 24.99% was dominated by single species pattern of Nitraria tangutorum. The sand-fixing plantations gradually became-
close-to-natural vegetation. Compared with natural vegetation, the sandfixing plantations had higher pattern intensity, and played important role in sand-fixing and in accelerating the regeneration and succession of natural sand-fixing plants. However, with the succession, artificially planted shrubs would decline, while natural plants would be dominant. Therefore, it should be better to make use of the native dominated species in sand-fixing engineering. Under the almost same conditions, pattern scale was highly correlated with the characters and the associations of dominated species. The species association was correlated with the patch scale and species composition, as well as the species contribution to the patch.

---