According to the soil particle distribution theory and the fractal theory , this paper studied soil structural property of seven different forest types and grassland 摘要运用土壤粒径质量分布原理与分形理论，对淄川峨庄流域内7种林分和对照荒草地的土壤结构特徵进行研究。
It was showed that the drought resistance among three trees were different , p . orientalis was strongest , then wes p . tabulaeformis , the thi rd was r . pseudoacacia 试验表明，各树种忍耐长期干旱的能力不同，侧柏最强，油松次之，刺槐最差，表明了各树种林分抗旱稳定性的不同。
The tong - term tune bests of pinus yunnanensis management lead to bio - diversity decrease , diseases and insect pests damage , genetic degradation , and productivity decline 摘要长期以来，云南松的纯林经营使得生物多样性降低、林分稳定性变差、遗传品质退化、林分生产力下降，从而导致生态系统功能衰退。
The results showed that plant height , crown breadth , leaf number , leaf breadth and sporophyll number of dryopteris crassirhizoma populations were influenced by forest crown density and light condition 结果表明：林分郁闭度和光照条件显著影响粗茎鳞毛蕨种群的株高、冠幅、叶片数量、叶片宽度、孢子叶数等形态指标。
The results show that the water consumption of transpiration can be reckoned through standard specific conductivity of standard tree and the relative model between breast height diameter of tree and sapwood area 结果表明，通过标准木的标准比导率和树木胸径和边材面积的相关模型，可以比较准确地推算出林分的蒸腾耗水量。
This paper summarized the studies on biomass production , biomass growth models , biomass measurement , biomass and forest density , as well as carbon storage of poplars in china in recent 20 years 摘要本文总结了中国近20年来有关杨树生物量产量、生物量增长模型、生物量测定、生物量与林分密度，以及杨树碳储量方面的研究进展。
As for western mountainous area of beijing , the key factor of survival lies in whether it can stand the drought environment factors , such as less rainfall , higher air temperature , lower humidity and less soil water , etc 就北京西部山区而言，林分存活与否的关键在于其是否能够经受住春季降雨少、气温高、湿度低、土壤残留水分少等干旱环境的考验。
It was showed that forest with good structure could improve the soil noncapillary porosity and water conversation function , and it was implied that forest with rational structure stored rainfall and surface runoff quickly 表明具有良好结构的林分，可有效改善土壤非毛管孔隙度和滞留贮水功能，从而有效地提高对降雨的快速贮存以及蓄洪与涵养水源作用。
Thinning stands with the thinning intensity of about 20 % and 30 % had no significant effects on species diversity , biomass of shrub and herb , and physical properties of soil 各林分的树种组成在12年间基本没有发生变化，即间伐没有显著地改变林分的树种组成，目前的树种组成即落叶松、其他针叶树（云杉、冷杉和红松）和阔叶树组成比约为6 : 3 : 1可能是相对稳定的群落。
