But the temporal and spatial characteristics of change of landscape are different among different types of beijing mountain area . in terms of different areas , the condition of vegetation cover in a whole has an increased trend in changping district , huairou county and miyun county 结果表明： ( 1 )就不同区域而言，昌平区、怀柔县以及密云县的植被覆盖状况整体表现为增加趋势；平谷县表现为减少的趋势，而门头沟区的植被覆盖率虽然较高，但其有转变为差的趋势。
But variation of the co ; concentration in the bottom soil show that sink effect of carbonate rock on the soil air co2 ( 2 ) the diurnal observation results of soil co2 dynamics in the different vegetation show that the soil co2 concentration in the bare land is sensitive to environment , but the soil co ; concentration in the other experimental site , which covered with vegetation , restrain the variation 在土壤?大气界面上，土壤表层可为大气提供游离co _ 2 ；而土壤深部co _ 2浓度的变化则显示下覆碳酸盐岩对co _ 2有吸收作用。 ( 2 )在不同植被系统中，土壤co _ 2昼夜动态变化进程不同。观测资料表明：裸地对外界环境的变化相当敏感，而有植被覆盖的竹林和草甸对土壤co _ 2浓度动态变化有平抑作用。
2 . the range of soil co2 concentration varied with soil temperature is not the same for the soil layer and its characters and different vegetation : the varied range of topsoil is higher than that of deep soil at testing woodland ; the varied range of soil layer ( - 20cm ) is the highest than that of the other soil layers ; the range of co2 concentration varied with air temperature begins to increase in turn from woodslay and shrublay to herbage 由于植被覆盖类型不一样和所处的层位以及本身性质，表层带岩溶生态系统各层的coz浓度随温度变化的幅度不一样，林地表层coz浓度变化的幅度比深部大，裸地土下e0 。 zcoz浓度变化的幅度比表层和底层大，林层、灌层和草层coz浓度变化的幅度依次变小。
Under the guide of pi dang ( professor dang anrong , from tsinghua university ) , during the project , we investigated many historic sites and local culture , measured and calculated vegetative cover extent in the local field , we also did effective surveys and interviews related to public health problem 在项目组负责人，来自清华大学的党安荣教授的指导下，项目实施期间，我们走访调查了很多名胜古迹，研究了当地文化，对当地植被覆盖情况进行了测量计算，我们也对有关公众健康问题进行了卓有成效的调查和采访。
In possible cost , overloading is in all the counties . 6 the research analyses the status and trend of human - land relationship in the zone . countermeasures to control the relationship conclude : family planning to control population ; consolidating education for population diathesis ; intensifying realize to generalize science and technology ; adding agriculture cost ; more vegetation to control desertification 6协调人地关系，提高区域人口承载力的主要对策是:实行计划生育，严格控制人口增长;大力发展教育，提高人口素质;强化科技意识，推广先进技术;增加投入，提高土地生产能力:提高植被覆盖度，控制土地荒漠化，改善生产环境。
