查询词典 selection forest

However remarkable impacts were observed in the plantation in terms of community physiognomy,community structure,species composition,species richness,and biomass accumulation.1 Planting trees made community structure simple.Betula alnoidis plantation had three layers including a dominant arbor layer,a complex and well developed shrub layer and a poorly developed vine layer.The arbor layer contained few species and had a single layer.The mountain rain forest had 4 layers including the dominant arbor layer,shrub layer,grass layer and vine layer.The vine layer was well developed and very rich in species composition,and the arbor layer contained as many as 38 species that could be grouped into 3 layers.2 Sequenced by the important value,main species for the plantation and the nature forest were totally different,and the plantation had one dominant species while the nature forest contained many dominant species.3 Planting trees changed the community physiognomy.

但是人工种植西南桦林对群落的季相外貌、群落的结构、物种组成、物种丰富度以及生物量等方面有较大的影响。1人工造林使得群落结构简化，西南桦人工林的层次结构有3层，以乔木层占优势，并且有种类多而发达的灌木层，同时，藤本植物欠发达，但是乔木层树种单一，明显仅有一层；山地雨林的层次结构有4层，以乔木层占优势，还有灌木层、草本层和藤本植物，藤本植物种类多，十分发达；乔木层树种丰富，可达38种，乔木层还可分为3层。2人工造林较大程度地改变了群落的物种组成，根据重要值的大小排列，人工林和天然林的主要物种组成已经完全不同；并且人工林单优树种明显，而天然林就含有较多的优势树种。3人工造林改变了群落的外貌。

The diversity index of broadleaved forest and bush, the evenness index of conifer forest and broadleaved forest,the dominance index of bare rock and farmland were higher than that in the other habitat types.

对5种不同生境类型的蝶类多样性进行分析，物种多样性指数最高的为落叶阔叶林和灌丛，均匀度指数最高的为针叶林和落叶阔叶林，优势度最高的为裸岩和农田。

According to regulations of the government, in addition to afforested land, the area of bush forest, the area of forest land inside farm land and the area of trees planted by the side of farm houses and along the roads, rivers and fields should also be included in the area of afforested land in the calculation of the forest coverage-rate.

在计算森林覆盖率时，森林面积包括郁闭度0.2以上的乔木林地面积和竹林地面积，国家特别规定的灌木林地面积、农田林网以及四旁（村旁、路旁、水旁、宅旁）林木的覆盖面积。

In this treatise, the Huangfengqiao forest farm in Youxian county is taken as the research object. The applications of artificial neural network in forest management decision-making are discussed, including forest resources prediction and site quality evaluation.

本论文以攸县黄丰桥林场作为研究对象，初步探讨了人工神经网络方法在森林经营决策中的应用，包括在森林资源预测以及立地质量评价中的应用。

The soil and water losses are very light and its difference is not notable in woodland of different tillage mode of economic forest, relatively the soil and water losses is lighter hi protecting slope model than in clearing model in low crown density benching economic forest such as Chinese chestnut, but the soil and water losses is lighter in clearing model than in protecting slope in high crown density benching economic forest such as bayberry.

不同耕作模式成年经济林地水土流失情况都较轻微，差异性不显著。相对而言郁闭度小的经济林如板栗林地台地护梯方式要比台地清耕方式好，郁闭度大的经济林如杨梅林地台地清耕方式要比台地护梯方式好。

Annual supply, demand, profit and loss of EF (1995-2005) for Tianjin were calculated based on MEFM. Per capita Ecological Footprint of arable land, pastureland, forest land, water area and fossil-energy land were 0.0009,-0.3224,-0.1991, 0.0255,-1.9600 hm^2cap^(-1) respectively. The deficit of PEF for pastureland, forest land and fossil-energy land increased annually except that the PEF for forest land and water area increased a little. During the period of 1995-2005, higher energy consumption of per unit production, accretions of population and built-up area were the main factors to the increasing of PEF deficit for Tianjin.

利用改进后的生态足迹模型计算天津市1995-2005年的生态足迹及其动态变化值，天津市耕地、牧草地、林地、水域和化石能源用地人均生态足迹盈亏分别为0.0009，-0.3224，-0.1991，0.0255，-1.9600hm^2人^(-1)，除耕地和水域略有盈余外，牧草地、林地和化石能源用地人均生态赤字均呈递增趋势。1995-2005年间天津市单位产值能耗居高不下、人口规模增长与建筑用地扩张是导致人均生态赤字扩大的根本原因。

In this study, we take severely soil eroded land, ban forest (as the control I ecosystem after planting Pinus massoniana and baned) and a mixed forest of Cunninghamia Lanceolata plantation and Pinus massoniana (as the control II ecosystem after planting a mixed forest of Cunninghamia Lanceolata plantation and Pinus massoniana and taking engineering restoration measurement)for study.

本文以未治理的侵蚀地作为对照，以在侵蚀地上营造马尾松并封禁管理以及通过工程措施后种植杉木—马尾松混交林为研究对象，通过野外观测和实验室分析，研究了不同恢复措施对土壤结构、土壤化学性质、群落生物量、植物养分、生物多样性的影响。

The forest parks on the Qinling Mountain′s north slope are the mainly area for forest recreation industry in Shaanxi province. Forest recreation value is one of non-market products, a new method for value estating need to be exploied.

根据秦岭北坡森林公园为陕西省森林生态旅游活动的主体，而森林公园游憩价值又是非市场性的，这就需要探索新的方法来进行计量测评。

The results indicate that:(1)Compare with the comparion, the soil physics character are improved after vegetation restortion , the soil unit weight in cyclobalanopsis glauca, Pinus elliottii, Robinia pseudoacacia , mixed forest and fire slash shrub separatly are 1.525g/cm~3, 1.426 g/cm~3, 1.625 g/cm~3, 1.482 g/cm~3, 1.423 g/cm~3. We can find the soil unit weight in other forest all bigger than the comparion (1.580 g/cm~3) except Robinia pseudoacacia .All these mean forest soil is looser and better capacity for aerated and dank.

结果表明：(1)植被恢复后林地土壤物理性质有良好的改进，青冈、湿地松、刺槐、混交林、火烧迹地灌丛容重分别为：1.525g/cm~3、1.426g/cm~3、1.625g/cm~3、1.482g/cm~3、1.423g/cm~3，除刺槐外其他林地均低于对照(1.580g/cm~3)，上述几种林分的孔隙度分别为：45.872%、51.956%、44.093%、50.485%、55.648%、47.228%，说明林地内土壤较对照更为疏松、通气透水能力更强，更有利于土壤微生物的活动，为研究区土壤肥力的提高奠定了基础。

The quality and composition of the pine forest and oak forest were highly similar while the relationship between the composition of light and the canopy characters varied with forest types.

3光资源的数量及其组成在油松林和辽东栎林下的变化非常相似，但光资源的组成与林冠特徵的关系在两种森林间存在差异。

If you were not , and OS X just booted normally, have no fear.

如果你没有，和OS X刚刚启动通常，没有恐惧。

I only want to preserve our all .

我只想保存好我们的一切