乔木林

当地下水埋深超过8m，地下2m处土壤含水率达到12%以下，大部分乔木林枯梢率达到90%以上，而灌木林枯梢率也达到50%以上。

When the depth of groundwater was deeper than 8m and soil water content was less than 12 % , the die-back rate of tree was morn than 90 % , and that of shrub was more than 50 % .

青海主要乔木林生态系统公益的评估

Estimation of Ecosystem Commonweal of Main Arboreal Forest in Qinghai

森林，包括乔木林和竹林。

Forest includes arbor forest and bamboo forest .

得出结果：不同乔木林类型的土壤含水量在不同时期各不相同。

Through the regular positioned monitoring of the different artificial arbor forests by soil drilling method in the northwest Liaoning , the changes in soil moisture were analyzed .

三种植被群落在植物多样性方面差异并不大，草原群落的物种多样性和群落均匀度要略小于乔木林和灌木林群落。

Differences of the plant diversity of these three vegetation communities are little , and the species diversity and evenness of steppe community are less than those of arbor and shrub communities .

青海省的灌木林大多生长在“三江源”区和乔木林难以生存的高位山体间等生态系统极其脆弱的特殊地区。

Most shrub forests in Qinghai are mainly growing at the Three Rivers ' headwater area , and in the alpine valleys where the eco-system is so fragile that arbor species are hardly survive .

贫乏的土壤水分状况与区内的光热资源匹配不协调，限制了天然乔木林的正常生存，制约了农业的不稳定，但却适宜耐旱灌木和耐旱禾草植物生长。

The growing of the natural tree forest is limited by the inferior soil moisture condition and the incoordination of the light and heat resources , but arid tolerant shrubs and grasses grow well under the condition .

格局分析还表明，研究区植被景观为典型的人工生态、天然草原和耕地植被的高度镶嵌体，人工乔木林是各景观类型中面积最大的一类。

Analysis for vegetation pattern reveals that vegetation landscape through the study site is a highly mosaic structure of artificial ecological , natural steppe and agrarian vegetation . The arboreal plantation is the largest type among all landscape types .

乔木林、人工灌木林、天然草地分别占到流域总面积的5%、19%、38%，农田为22%，裸地为10%。

The proportions of the area of arboreal forest , artificial shrub , natural grass land , cropland and bare land are 5 % , 19 % , 38 % , 22 % , 10 % respectively in the entire watershed .

通过对三峡库区不同退耕还林阶段的植物群落调查，结果表明退耕还林后植物群落演替基本沿着：农田杂草→草地→灌木林地→天然次生乔木林的方向而发展。

Investigations on plant community of different stage in conversion of cropland to forest in Three Gorges Reservoir area , it indicated that the plant community succession is along : cropland weed → pasture → shrub woodland → natural secondary arbor .

影响人工乔木林和灌木林群落林下草本层物种多样性和均匀度指数变化的主要因素有植物物种种源、植物自身因素（初植密度）和人为因素（破坏、放牧时间）。

The main factors influencing indexes of the diversity and the evenness of herb layer under the artificial arbor and herb are species source , plants ' own factor ( plant density ) and human factor ( destroying , grazing and time ) .

根据山东省植被特点，将植被分为农作物、乔木林、灌丛、草地、沼泽湿生植物五种主要类型，研究了不同植被类型的土壤重金属环境容量。

According to the characteristics of vegetation in Shandong Province , Vegetation are divided into five main types : crops , forest trees , shrubs , grassland , meadow and marsh plants , and environmental capacity of heavy metals in soil of different vegetative types were studied .

研究结果表明，天然灌木林群落物种多样性和均匀度指数最大，天然草本群落与人工乔木林群落接近，人工灌木林群落最小；

The results showed that as to the indexes of diversity and evenness , natural bush community has the highest ones , and artificial arbor community has no significant difference with the natural herb community , and artificial bush community has the lowest indexes of diversity and evenness .

在城市环境下，不同林分结构类型的乔木片林对空气负离子水平以及空气质量指数（CI）的影响差异不显著；（4）天气条件对绿地的空气负离子水平存在显著影响；

Under the different tree environment , the aero-anion horizontal difference is remarkable ; ( 3 ) In the city ecology environment , the concentration of air anions and CI had no significant differences when the stand structure of arbores were different ;

同时，研究区的生态环境建设措施应以恢复退化草场和改造乔木纯林为乔灌结合林为主。

At last the proposal was put forward that eco-environment construction of research area should primarily restore the degenerated pasture and change the pure arbor forest as to mixed forest with shrubs .

研究了西双版纳热带季节雨林6种乔木幼树在林窗中的叶生长与叶虫食动态。

Leaf growth and herbivory dynamics of six tree species saplings were measured in tropical seasonal rainforest gaps in Xishuangbanna , SW China .

研究结果如下：（1）群落的生物量测定采用回归生物量模型，将林分结构划分为乔木层、林下植物和枯枝落叶层，对各层的生物量进行研究。

The results were as follows : 1 . Structure of community stand was divided into arbor layer , understory layer and litter layer for researching the community biomass , also , regression of biomass model was used .

两种趋势作用于泰山所得到的综合结果是泰山乔木不管是针叶林还是阔叶林的分布重心都有所上移，证明在泰山地区气温上升比降水减少对植被分布影响更大。

Based on the two trends , the coniferous trees or broadleaf forests in Taishan area all show an upward movement in distribution center , proving that temperature rise in Taishan area has greater impact on vegetation distribution than the decreased precipitation .