草地

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。

Total bacteria and filamentous microbial biomass in 0～10cm were more than that in the other soil layers.

在内蒙古伊盟准格尔旗皇甫川流域，对退化草地和恢复草地土壤微生物生物量进行了研究。

The soil under grassed elleyways had higher NH4+,and K,but lower NO3- than the soil under herbicide strip,with exception that the soil in the layer of 0～10 cm under herbicide strip had higher content of K.

施肥增加土壤速效N的含量。土壤NO3-的季节性变化表明5至6月份土壤中NO3-的含量高，而花前和7月份土壤中NO3-含量低。P、K在清耕带10 cm以下土壤的含量低于生草地土壤，但在0～10cm土层中K的含量高于生草地。P的含量不受影响。

In Anxi County, food production service values in prohibited grazing region in lowland halophytic meadows and desert grassland increased 16.25 yuan/hm^2 and 7.75 yuan/hm^2, and total values increased by 176.5 yuan/hm^2 and 170.5 yuan/hm^2, respectively.

安西县低地盐生草甸草地禁牧区较非工程区食物生产价值增加了16.25元/hm^2，总价值增加了176.5元/hm^2；温性荒漠类草地禁牧区较非工程区食物生产价值增加了7.75元/hm^2，总价值增加了170.5元/hm^2。

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。

In this paper,the effect of the compound stress of Cu,Cd,Pb,Zn and As on the growth and the accumulation and the distribution of heavy metals in Juncus Effuses is researched by using soil cultures method.

盆栽试验结果表明：Cd、Pb、Cu、Zn、As 5种重金属复合胁迫对灯心草地上部生长有一定程度的抑制作用，在土壤环境质量二级标准上限值处灯心草地上部生物量减产9。

Results showed that biomass of the ground part of Juncus Effuses was inhabited to a certain degree. When the dosages of the heavy metals added to the soils were close to Grade II Criteria of the State Soil Environmental Quality Standard (GB15618-95), Juncus Effuses could still grow normally in appearance though its yield decreased by 10%, however biomass of the underground part was not much affected.

实验结果表明：5种重金属复合污染对灯心草地上部生长有一定程度的抑制作用，在土壤环境质量二级标准上限值处灯心草地上部生物量减产9.15%，0%，但地下部生物量减产趋势不明显。

When initial NO3--N was leached, the correlation coefficients between soil initial NO3--N and mineral N extracted by CaCl2 before aerobic incubation with raygrass nitrogen uptake were decreased to 0.613 and 0.607, respectively, and both reached 5% significantly level. However, the correlation coefficients between mineralizable N extracted by aerobic incubation, soil initial mineral N and mineralizable N extracted by aerobic incubation, N0 and soil initial mineral N and N0 with raygrass nitrogen uptake were raised obviously, and all reached 5% and 1% significant level.

以不包括土壤起始NO3--N盆栽试验植物吸氮量为参比，通气培养前CaCl2淋洗起始NO3--N和起始矿质氮与五期黑麦草地上部氮素累积量间的相关性尽管有所降低，但相关性仍达5%显著水平，相关系数分别为0.613和0.607；而通气培养30周矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、N0及N0+起始矿质氮与五期黑麦草地上部吸氮量的相关系数却明显提高，相关系数分别为0.718，0.782，0.688 和0.640，均达5%或1%显著水平。

The results indicated that when initial NO3--N was not leached, soil initial NO3--N and mineral N extracted by CaCl2 before aerobic incubation were closely related with raygrass nitrogen uptake, the correlation coefficients were 0.856 and 0.862, respectively, both reached at 1% significant level. When initial NO3--N was leached, it was no good relationship between mineralizable N extracted by aerobic incubation, soil initial mineral N and mineralizable N extracted by aerobic incubation, N0 and soil initial mineral N and N0 with raygrass nitrogrn uptake, the correlation coefficients were 0.410, 0.553, 0.492 and 0.419, respectively, indicating that the poor effects of mineralizable N on reflecting soil N capacity were influenced and disturbed by initial nitrate.

以包括土壤起始NO3--N盆栽试验植物吸氮量为参比，通气培养前CaCl2所淋洗起始NO3--N和起始矿质氮与5期黑麦草地上部氮素累积量密切相关，相关系数分别为0.856和0.862，达1%显著水平；与此相反，通气培养30周所矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、氮素矿化势(N0)及N0+起始矿质氮与5期黑麦草地上部氮素累积量间无显著相关关系，相关系数分别仅为0.410、0.553、0.492和0.419。

Using the Landsat Thematic Mapper data and the measured grass yield data,the monadic linear regression models and the non\|linear regression models were established,to express the relations between grassland biomass and the different vegetation indices.

通过陆地卫星TM遥感影像数据和同期野外调查数据，分析了植被指数与草地植被生物量之间的相关关系，建立了不同植被指数与草地生物量之间的一元线性回归模型和非线性回归模型。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。