大渡河上游林区森林资源退化及其恢复与重建

Rehabilitation and Degradation for Subalpine Coniferous Forest on the Upper Reaches of Dadu River of Eastern Tibetan Plateau

虽然森林采伐后的恢复重建一直是青藏高原东部地区森林经营管理的主要实践活动之一 ,但有关该区大规模森林恢复重建实践及其存在的问题还不清楚。本文选择大渡河上游林区 ,分析了该区目前森林资源现状、森林退化及其恢复重建及特点 ,阐明了该区目前资源管理与恢复重建存在的主要问题 ,并提出了相应的技术对策。结果表明 ,该区林地资源丰富 ,但森林资源量小 ,覆盖率不足 2 3% ,长期采伐导致森林生态系统结构和功能严重恶化 ;现有恢复重建技术体系不健全 ,人工成林成功率在高山同峡谷区不足 30 % ,高丘区不足 15 % ;造林树种单一 ,造林密度过大 ,抚育管理不力 ,人工林质量低下 ;强化对迹地退化过程的深入研究和监测 ,充分认识迹地环境的制约作用 ,强化抚育管理 ,改进和完善现有的森林重建技术体系 ,增加造林树种 。

Coniferous forests distributing extensively in hte Thbetan Plateau have provided the large number of economic value for national and local development and also have been existed as an ecological safeguard for whole Changjiang River.Large-scale logging coniferous forest resources had resulted in serious environmentet of the whole Changjiang river basin in the past decades.Foresrt logging ban carrying out it is absolutely necessary that the actively artificial rehabilitation are implemented on large number of serious degraded clearcut with accordingly secondary vegetation types.Forest recovery and rehabilitation after logging has been one of major experiences of forest management on the Eastern Tibetan Plateau.Many researches have done in monitoring micro-environmental change of degraded clearcut,suitable tree screening,site preparation,afforestation experiences,etc,Artificial plantation has been identified as the most effective rehabilitation pathway.But few attentions from research were put on large-scale practice in afforestation implemented by local and national forestry institutions and the existing problems remain unclear to date.The present work inspected past practices of forest degradation and artificial rehabilitation in athe upper reaches of the Dadu River on eastern Tibetan Plateau.Many people including experts,technicians,foresters,policy-makers,and forest managers,were visited,inquiring timber logging and production process,artiricial plantation and forest management.Relevant historical data and information were collected.The plot method was employed to investigate the status of forest generation.We systematically analyzed the forest degradation and rehabilitation in the fragile region.The situationof forest resources were expounded,features of forest degradation and artificial rehabilitation were revealed and the existing major problems were proposed.The countermeasures for promoting forest recovery and rehabilitation also were suggested in the paper.