恢复黄土高原林草植被及盖度的前景

Perspective of Recovering the Vegetation and Cover Percentage of Forest and Grass on the Loess Plateau

通过分析黄土高原古代自然植被景观和现代植被带的划分及目前人工林草生长情况,认为大于550mm降雨量地带易成林,乔木生长较好,可划为人工乔木带;在400～550mm降雨量地带乔木明显矮化,可划为矮化乔木、灌木带。黄土高原绝大部分地区可建立良好的植被。笔者根据目前保护较好的天然植被及已推广的人工植被盖度,并结合日人筑后(Chikugo)的方法和实地调查资料得出的回归方程推算,提出在自然条件下(无人为破坏)黄土高原森林地带植被盖度可达90%～100%,森林草原地带(400～500mm)可达80%以上。

Based on the analysis of ancient natural vegetation landscape and present-dayvegetation zonifications as well as artifieial vegetation growing situations, it is con-sidered that the zones with rainfall of over 550 mm are suitable for forests to grow sothat forests are growing much better and these zones can be classified as theartificial tree belts,while the zones with rainfall of 400-550 mm where trees are evi-dently dwarfed can be classified as the dwarfed trees and shrub belts. The bettervegetation can be constructed over most of places on the Loess Plateau. Meanwhile,based on the well-preserved natural vegetation cover and extension of artificial vege-tation cover percentage in close combination with Chikugo method and the estima-tion from the regression equation with field surveying data, it is suggested that thevegetation percentage in forest belt on the Loess Plateau reach 90%-100% under thenatural conditions (without any damagss caused by human activities)while that coverthe forest and grassland belts (with rainfall of 400-500 mm) reach over 80%.