西藏雅鲁藏布江中游下段沙地植被研究

STUDY ON SAND VEGETATION IN BOTTOM OF MIDDLE REACHES OF YALUZANGBU RIVER IN TIBEAT

沙地植被主要有沙地高山松林、巨柏疏林、砂生槐群系和固沙草群系。砂生槐＋多花亚菊群落是本区沙地植被演替的顶极群落，高山松林疏林可能会成为本区人为演替顶极群落，风沙活动是影响本区植被演替的主导因子，半固定沙区仅生长砂生槐灌丛阶段是沙地植被正逆向演替的临界状态。砂生槐和高山松在沙地具有天然更新能力和生长快的特点。

The types of Sand vegetation in this area are(1)Sandy land pinus densata forest,(2)Sand land cuppressus gigantea sparse forest,(3)Sophora morcrot From.,(4) Orinus thoroldiiFrom.Sophora morcrot and Ajania myriantha community is the topiccommunity and Pinus densatawill be the anthropenic climax in sandy land. Wind- sand activity is the dominant factor that affectsand vegetation succession.The status which only grow sophora morcrot in semi-stabiized sand dune iscritical status of sand vegetation succession,Pinus densata and Sophora morcrot grow well and canreproduce in sandy land.