多草地的

The influence of environmental variables on distribution of PAHs(1) The concentrations of PAHs were higher in warm temperate zone and subtropical zonethan in low temperature zone;(2) The concentration in plain, hilly land and Ya\'an mountainousregion were higher than in other places;(3) The concentration in paddy fields, dry land andforests were higher than in artificial land and grass;(4) There was positive correlation betweenthe concentration of PAHs and TOC. The correlation was more obvious for 4-rings PAHs thanfor 5-, 6-rings PAHs;(5) The concentration of PAHs in acid soils was higher than in alkali andneutral soils;(6) The concentrations in conifer and spinney forest were higher than inbroad-leaved forest.Part two: The temporal and spatial distribution characteristics of POPs at Basin-MountainTransect.

环境因素对多环芳烃分布的影响(1)温带和亚热带地区土壤多环芳烃含量高于低温地区土壤中多环芳烃含量；(2)在平原、匠陵和雅安市附近的山区多环芳烃含量高于其他地区含量：(3)水田、旱地和林地多环芳烃含量高于建筑用地和草地中含量；(4)多环芳烃含量和土壤总有机碳含量成正比，四环多环芳烃与总有机碳的相关性高于其他多环芳烃的相关性；(5)酸性土壤中多环芳烃含量高于碱性和中性土壤中含量；(6)针叶林和灌木林多环芳烃含量高于阔叶林中的含量。

Barely two blocks back from the water, on either side of the bayou, the town abruptly stops, giving way to an endless maze of marsh grass and open water and more marsh grass adorned with statuesque snowy egrets fishing stone-still in a pose straight out of an Audubon painting.

向左或向走两条街﹐小镇就突然不见了﹐再过去就是一望无际的沼泽草地和空旷的水域﹐再远是更多的沼泽草地﹐其间点缀着雪点般的白鹭﹐它们寂静不动的捕鱼形象﹐有如出自奥特朋的油画。

On the other side, the relations among community classification, structure, diversity and distribution pattern were also investigated through the study of species composition, diversity and interspecific relation of Medicago falcata in Inner Mongolia.

另一方面，本文又以松嫩平原天然草地中的五脉山黎豆、多茎野豌豆、花苜蓿以及内蒙古的黄花苜蓿为研究对象，从植物群落的物种组成、多样性、种间关联等几方面探讨了我国天然草地中豆科牧草的群落类型、结构、群落多样性与分布格局之间的关系。

Flooding,as a kind of disturbance events,occurred with higher and higherfrequency over the world.To investigate the effects of flooding disturbance ongrassland vegetation and the soil,a comparatively thorough study was conducted onAneurolepidium chinense grassland in Songnen plain,Northeast China.The studysite was located in Sanjiadian National Rangeland in the territory of Da'an city,Jilirprovince,which was partly flooded in 1998.On the study site,Several transectssubjected to different flooding durations and intensities were designed for thecomparative study among them on such aspects as vegetation characteristics,seedbanks,vegetative propagation of rhizomatous plants,distribution patterns ofpopulations,interspecific relations,and physio-chemical properties of soil.Theresults were as follows:(1)Of the functional group composition of the vegetation,with the elongation of the flooding duration or the increase of flooding severity,theratio of hygric and hygro-mesic plants increase,while that of mesic and mesoxericplants decrease,of Therophytes changed unimodally,of Geophytes increased,whileof Hemicryptophytes decreased.

为弄清草地植被及其土壤环境对水淹干扰的响应，在松嫩平原羊草草地1998年部分遭受水淹的吉林省大安市三家甸子草场内设置了经历不同水淹干扰持续时间和不同水淹强度的样带，并在这些样带之间从植被特征、种子库特征、根茎植物的营养繁殖性能、种群分布格局、种间关系及土壤的理化性质等多个方面展开对比研究，主要结果如下：(1)在植被的功能群组成中，随干扰强度的增加和水淹干扰持续时间的延长，湿生、湿中生类植物功能群的优势度比例基本上是逐渐增加的，中生、中旱生类植物功能群的优势度比例则逐渐减小，而一年生植物的优势度比例呈单峰型变化，地下芽植物比例增加，地面芽植物比例减小。

The 0-40cm soil layer soil mean value looked that mixes by the interlacing broadcasts the lawn soil ulmin, the alkaline hydrolysis nitrogen content to be highest; The fast-acting phosphorus, the fast-acting potassium are highest by the unicast awnless brome lawn content; The colleague mixes broadcasts lawn pH to be biggest.

无芒雀麦对土壤要求不严，耐贫瘠、严寒，耐碱性也较强，需氮较多，适宜与紫花苜蓿、沙打旺、野豌豆、百脉根、红三叶等豆科牧草混播，借助豆科牧草固氮作用，促进无芒雀麦良好生长[4]。本实验就是无芒雀麦单播草地和与紫花苜蓿混播草地对土壤理化性质的影响进行比较。

In fact, current condition is mainly caused by artificial factors. Among the artificial factors, overgrazing is considered to be the foremost one.

在导致草地退化的诸多人为因素中，过度放牧被认为是造成草地退化的主要因素。

Within a few years, there was not enough grass for all the cattle, especially along the trails.

在短短几年内，已经没有足够多的草地来养这些牛了，特别是前往火车站沿路的草地就更少了。

However, research on the relationship between herdman's production behavior and grassland degradation is not very much.Peasant problem is the core of"Three Agricultural Problems"in China.

大多相关研究集中在区域内草地退化的表现和原因，而将牧民作为研究对象，从牧民的生产生活出发探究草地退化之间成因、寻求抑制草地退化措施的研究尚不多见。

The introduction adaptation of Kentucky bluegrass varieties in Beijing is summarized. Indices including growing habit, turf quality, turf duration, winter and summer survival, disease resistance were analyzed.

该文根据3a多的试验，分析了草地早熟禾的生长特征和特性，以及形成草坪的质量、持续年限、越冬越夏性和抗病性等结果表明，草地早熟禾各品种差异十分明显，大多数品种比较适宜北京种植。

Before the show, there were cars which were sent to pick up the exhibitioners and during the show period, there have drinks and fruits offered for free, BBQs, all these details reflected the organizers' eagerness and carefulness.

对于场地，主审Rita女士说像这样的草地赛在美国非常多，对于草地质量，Rita也补充说虽然离顶级赛事的要求还有一些差距，不过在美国，这样的草地足以胜任非常多的全犬种赛事。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。