白梭梭人工林林下植被恢复的演替规律研究

Study on Succession Pattern of Undergrowth Plants during the Recovery Process of Vegetation in the Haloxylonpersicum Plantation

人工林防护体系的建设能够促进退化沙漠生境的恢复,进而影响人工林林下植被的空间分布和演替。本研究以古尔班通古特沙漠中不同年代种植的白梭梭人工林林下植被为研究对象,探讨了其生态特征,并以相邻地区的天然植被为对照,采用时空替代法,分析了林下植被恢复的演替规律。结果表明:(1)林下植被中短命植物和一年生草本显著增加,截止到调查时为止,植物种数达到了35种,达到相邻自然沙垄植物种数的92%。(2)群落优势种逐渐由单一物种占绝对优势的结构向多物种同时占优的方向演替,物种丰富度达到了较高的水平,生活型组成结构逐渐多样化,但目前的群落结构仍不稳定,应对环境变化的能力很差。(3)林下植被恢复的空间异质性逐渐减弱,与相邻自然沙垄原有植被特征的差异逐渐减小。综上所述,古尔班通古特沙漠白梭梭人工林的建植促进了林下植被向自然沙垄原有的群落结构恢复,建植时间越长恢复效果越好,即植被群落结构向着有利的方向发展。但目前的群落结构仍不稳定,因此在古尔班通古特沙漠遭受人为扰动的区域进行长期封育十分必要。

The construction of the artificial forest protection system can promote the recovery of the degraded desert habitat,and then affect the spatial distribution and succession of the vegetation under the artificial forest.The objective of this project isto study the Haloxylonpersicum planted in different ages in the Gurbantünggüt Desert,and explore its ecological features and compare it with the natural vegetation in adjacent areas,and finally to analyze the succession law of vegetation recovery under the forest by using the space-time substitution method.The results indicated that:(1) ephemeral plants and annual herbaceous plants in underforest vegetation increased significantly,and as of the survey,the number of 35 plants reached 92% of the adjacent natural dune.(2) Community dominant species were gradually replaced by the structure from absolutely dominant single species to multiple species simultaneously,species richnessreached a quite high leveland the lifestyle composition structure was gradually diversified,but the current community structure was still unstable and the ability to cope with environmental changes was very poor.(3)In addition,vegetation reconstruction was decided on thedistance from provenance to plantation,spatial heterogeneity of species composition and community structure declinedgradually along with succession,the composition of undergrowth vegetation tended to be the same ortended to be the vegetation in natural dune nearby plantation.In summary,plantation was good for the undergrowth vegetation restoration under natural condition,the plant diversity increased with plantation growth,but the community structure was still unstable,so enclosing for a long time is necessaryforthe natural recovery in this area.