【作者】 刘云慧；

【导师】 宇振荣；

【作者基本信息】 中国农业大学 ， 生态学， 2004， 博士

【摘要】 土地利用及其环境效应是当前国际上诸多研究的热点和焦点。本文分别以北京东北旺乡生物多样性状况和曲周县土壤有机碳变化为例展开研究，以期对黄淮海地区集约化土地利用的环境效应获得初步的了解，并就相关问题提出合理建议。生物多样性研究中，动物多样性研究部分以步甲作为指示生物展开，方法为陷阱法；植物多样性研究部分采用田间试验以及遥感影像配合下的样方记录法；对区域土壤有机碳变化的研究采用遥感、地理信息系统和生物地球化学循环模型模拟相结合的方法。其中农业资源环境信息系统的建立为该部分研究提供了数据基础。研究得到如下结论： 1) 土地利用类型对步甲的生活规律影响不大，不同土地利用类型下，步甲群落的个体数量的季节性动态基本一致。但是不同物种活动的高峰期不同。 2) 土地利用类型对步甲物种的空间分布有显著的影响。不同的生境类型下步甲群落的个体数量差异很大，农田生境中步甲群落个体数量都较低，林地和农田边界地带较高；不同土地利用类型下，步甲群落的物种数量也有显著差异，农田边界处步甲群落的物种数量最多，其次为林地和与边界相邻的农田，而农田中出现的物种数量最少。总的来说在农业景观中，农田边界和林地更适合于步甲物种的生存，保护和建立这样的地带有利于农田生态系统生物多样性的保护。 3) 长期集约化的农业土地利用和城市化的快速发展使得东北旺地区植被类型单一，农作物是主要的植被覆盖类型；其次为人工种植的木本植物；自然植被所占比例很小，仅占整个调查区域面积的3.2％，并且主要出现在一些当前难于用作其它用途的地方(碎石地，废墟和土层薄的地方)。但是由于城市化的快速发展，农业用地快速地向建筑用地转化，研究区域植被多样性的状况仍然不容乐观。 4) 在整个植被调查的过程中，共发现295种自然生长的维管植物，其中在所有调查植被中存在度≥10％的物种有18个；试验地共记录物种64个，其中存在度≥10％的物种仅有11个。调查记录的植被与潜在植被具有巨大的差距。只有种子数量多，能够适应不同环境的植物能够在农业用地中得以生存。 5) 灌溉、施肥、秸秆还田这些农业管理措施对农田生境中步甲群落个体数量并没有显著的影响，但是在农田边界上，每年秋季的翻耕却能够显著地提高步甲群落的个体数量，这说明某些情况下适度的干扰有利于生物多样性的保护。而植物田间试验的结果也显示，即使在停止耕种后、创造良好定居条件的情况下，农业景观植被演替和恢复的状况也非常缓慢，这是由于长期的集约化种植使得研究区种植库贫乏，同时农业用地周围缺乏自然生境以及非种植作物的景观要素。因此，在这种长期受到人类强烈干扰的农田景观中，除了创造农田边界、林地等生境，合理的人为管理措施也是保护和提高生物多样性所必需的环节。 6) 农业资源环境信息系统构建过程中收集了基础地理、土壤、土地利用、农作管理、气象和社会经济方面的信息，并通过VB数据库技术和Mapobject技术构建系统管理界面，实现对上述数据的统一管理和调用。其中农业管理信息的获取和反映种植作物信息的土地利用分类对当前农业土地利用对土壤有机碳影响的研究具有重要的意义。对于农业管理信息的获取主要采用了农户调查、专家知识和统计数据三者相结合的方法；对于反映种植作物信息的土地利用信息的获取，则采用多时相高分辨率Aster遥感影像，通过监督分类和非监督分类相结合的方法。 7)比较曲周1980年和1999年区域调查的土壤有机质含量状况，结果显示，在过去的近二十年间，曲周地区土壤有机质的含量呈现增加的趋势。导致这种变化的主要农业管理措施有:①氮肥、磷肥用量的大幅上升;②秸秆还田比例的上升;③盐碱地的治理和开垦利用;④复种指数的持续上升;⑤主要种植作物的秸秆还田比例相对较高，并且土壤有机质处于正平衡状态。虽然土壤有机质含量有所增加，但还仅处于中等水平，并且由于过量氮肥施用引起了生态环境的污染。 8)在对DNoc模型进行验证和灵敏性分析的基础上，通过建立综合考虑土壤类型、土壤质地、反映种植作物信息和土地利用信息的模拟单元，根据土壤属性范围建立土壤属性的极大、极小方案，应用DNoc模型的点模式，对不同农作方案下县域土壤有机碳的状况进行了20年模拟。结果显示，与当前的典型施肥方案相比，减少当前化肥用量1/3对土壤有机碳的积累不会产生显著影响，相反可以极大地减少氮肥用量和减少NZO的排放量;而在减少当前氮肥用量1/3的同时提高秸秆还田量方案下，土壤有机碳的积累量显著高于当前的管理方案和减少当前氮肥用量1/3的方案下土壤有机碳的积累量。模拟中还发现，小麦/玉米轮作和单茬棉花的种植模式下，土壤有机碳的增量不同。这说明减少氮肥用量提高秸秆还田量，不仅可以减少过量施肥所带来的污染，还可以提高土壤碳库存储量;但是，未来土壤有机碳的时间变化除了受施肥的影响外，还可能受到种植结构调整的影响。更多还原

【Abstract】 Land use and its effects on the environment have become the hot points and focus of many international and multidisciplinary research projects. In this thesis, the impacts of land use and pattern on the eco-environmental systems in North China Plain were evaluated through two case studies, including biodiversity investigation in Dongbeiwang village, Beijing and soil organic carbon change in Quzhou county, Hebei province. Carabid beetle was selected as bioindicators and pitfall trapping was used as sampling method for animal biodiversity evaluation; for flora evaluation, both field experiment and releve approach were used with assistance of remote sensing image; for the evaluation of soil organic carbon change, a Regional Resources and environmental information system was established; and RS, GIS and biogeochemistry model were all used to evaluate the soil organic carbon change. The research results and conclusion were summarised as follows:1) Seasonal dynamics of carabid community were little effected by land use type that the seasonal trend of individuals number of carabid community were almost same in different land uses. However, species had the highest abundance in different seasons.2) The effect of land use type on the spatial distribution of Carabid community was obvious. Great differences of the individual number among habitats were observed that there were much more individuals in woodland and field margin than that in croplands. Significant differences of species numbers among habitats were found too: there were the highest species number in the field margin, higher in woodland and field that was adjacent to the field margin, and the lowest in the crop field. In general, it seems that the field margin and woodland were much fitter for carabid living than cropland; and it was beneficial to protect and establish such habitat for the biodiversity in agro-ecosystem.3) Because of the long-term intensively agricultural land using and rapid urbanization, the vegetation in the Dongbeiwang village was extremely homogeneous. Crop was the dominant cover in the area, and the planted woody vegetation was the second one. Little spontaneous vegetation was found with totalled 3.2% area of surveyed area in 2002; and their occurrence was restricted to sites that cannot be used for any other purposes in their current state (rubble heaps, ruins and area with thin-soil). However, due to the rapid urbanization, farmland were transform to buildings quickly, the state of vegetation diversity was still not optimistic.4) There were 295 spontaneously growing vascular plants identified during the survey at the Dongbeiwang village; Of these, 18 plants occurred with a degree of presence > 10% . 64 spontaneously growing vascular plants were identified at the experiment field; Of these, 11 plants occurred with a degree of presence >10% . There was great discrepancy between the taxa that would potentially be expected to occur in the study area and those that were actually found. Only plants with high seed production and wide tolerance range for different growing sites can grow in intensively disturbed agricultural land.5) The farm management measures, including irrigation, fertilization, straw return to filed, had no significant effect on the individual number of carabid community; However, plowing in autumn improved the individual number in the field margin greatly. It was indicated that the modest disturbance in some instance was beneficial to biodiversity conservation. Field experiment also showed that the colonisation and development of vegetation was slowly although open ground and favourable starting conditions offered, because there were the extremely limited range of species in the soil seed bank andno natural remnant biotopes or non-crop landscape elements in the immediate vicinity area. So, in the agro-landscape that was long-term strongly disturbed by human being, reasonable management measures were also essential for biodiversity conservation and improvement besides the establishing landscape更多还原