干旱影响下人工林的天然更新进程  

Natural Regeneration of Plantation Forests under Drought

作　　者：王晗生[1,2] 

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《干旱区研究》2012年第5期743-750,共8页Arid Zone Research

基　　金：国家科技支撑计划(2006BAD09B09);中国科学院知识创新工程重要方向(KZCX2-YW-441;KZCX2-YW-149)项目

摘　　要：通过植被状况调查、气象条件分析以及地面处理试验,在分析人工林天然更新因子的同时,对更新幼苗的发生进行了探讨。结果表明:落种的萌发成苗过程是干旱影响下人工林天然更新的关键环节,其间水分因子起着显著的作用。更新幼苗与降水特点密切相关,冬季积雪、春季或旱季出现连续数日的降水过程或连阴雨天气,都是更新幼苗发生的有利条件。冬、春季缺少持续降水,干燥的地表使得更新幼苗难以发生。地面处理产生的覆土效果可改善落种的水分环境,克服降水条件的制约,从而促进更新幼苗的发生。为使成苗状况稳定和完成天然更新,进一步讨论了人工促进更新的一些措施。Based on the investigation of some typical plantation forests and peripheral natural grasslands in a drought-prone semihumid area on the Loess Plateau, the analyses on meteorological conditions and the trial of shal-low scarification of plantation land with fallen seeds and seedlings for regeneration were mainly regarded the factors affecting the natural regeneration of plantation forests. The results indicated that the germination of fallen seeds on land surface and seedling formation would be the key links for the natural regeneration of plantation forests under drought, in which water factor might be a dominant factor. Closely related to rainfall, the favorable aspects to en-sure seedling occurrence for regeneration is snow cover accumulated in winter without thawing until early spring, and also precipitation lasting for a number of days or continuous rainy overcast appearing in spring or droughty sea-son. Owing to successive scarcity of precipitation in winter and spring, it is difficult to emerge seedlings for regen- eration in dry land. Nevertheless, to earth up may improve soil moisture conditions in dry land for fallen seeds and overcome the restriction of precipitation scarcity, thus the emergence of seedlings for regeneration may be im-proved. In order to stabilize the survival and growth of seedlings and achieve the natural regeneration of plantation forests, it is suggested to take some artificial measures.

关 键 词：人工林 天然更新 幼苗建立 土壤水分 黄土高原 

分 类 号：S754[农业科学—森林经理学]