北京市门头沟区生态安全评估及预测

为研究和预测北京市门头沟地区生态安全形势,并在实践中为生态安全评价提供理论依据,在生态环境管理的方法论基础上,根据统计年鉴,采用压力状态响应模型建立生态安全指标体系,以不安全指数法对指标实际值归一化,运用层次分析法确定指标权重,采用加权指数法计算生态安全综合值,评价了门头沟区3年的生态安全状况。结果表明:门头沟地区2006-2008年3年期间,生态安全综合指数分别为:0.6192、0.639 3、0.6395。显示生态安全综合值缓慢上升,生态安全越来越好,但是仍然处于较不安全状态。指出其主要原因有经济欠发达、自然资源缺乏、人口众多等。建议该地区加快产业结构调整、改变增长方式、控制人口、提高土地利用率,保护环境并治理污染。     

A review of the protection of sources of drinking water in China

Water is a natural resource key to human and environmental health. China has suffered serious contamination of its water sources in the past decade, which has had severe consequences on the water supplies of millions of residents. Frequent polluting accidents and the amount of wastewater discharged have caused concern for the safety of drinking water. Fortunately, those at various levels of government have realized the importance of protecting the sources of drinking water and confirmed a list of 175 nationally important sources. Measures have also been adopted to control water pollution, including infrastructural, physical, chemical, ecological, administrative, and legal measures. While helpful, some areas in need of more attention are rural water, groundwater, agricultural pollution, and domestic sewage. Based on the lessons learned from experiences in developed countries, we offer some suggestions for improving, inter alia, funding, legal construction, management, and awareness‐raising, as well as present proposals for the future protection of our sources of drinking water. Future work should focus on water quality standards, quantitative research, high technology and legislation.     

不同林分土壤有机碳密度研究

在全球气候变化背景下,森林土壤有机碳作为土壤碳库的重要组成部分,已成为森林生态系统碳循环研究的重点之一;而森林土壤有机碳在剖面上具有明显的垂直分布差异,根据土壤发生层次特点,分别研究各层土壤有机碳含量分布规律,对于准确确定森林土壤碳储量具有重要意义。2008年7月在北京西山妙峰山林区侧柏（Platycladus orientalis）林、刺槐（Robinia pseudoacacia）林、栓皮栎（Quercus variabilis）林和侧柏、油松（Pinus tabulaeformis）混交林内,分别随机选取3个位置挖土壤剖面,然后根据土壤发生层次性特点,把各剖面划分为四个土层（0～10 cm,10～20 cm,20～40 cm和40～60 cm）,每层用环刀取样测定土壤容重,用土壤袋采集1 000 g的土壤样品,经除杂、风干、过筛等程序后,对土样的有机碳含量和碳密度进行了测定和初步研究。结果表明：4种林分下土壤有机碳平均含量和土壤有机碳密度不同,不同林分土壤0～10 cm有机碳含量和碳密度最高,并且均随土壤深度增加呈降低的趋势;其土壤有机碳密度的大小顺序为：栓皮栎林〉侧柏、油松林〉侧柏林〉刺槐林。4种林分类型0～20 cm土层单位面积有机碳储量占总有机碳储量分别为：栓皮栎林51.1%,刺槐林44.2%,侧柏林43.0%,侧柏、油松混交林37.7%,平均为44.0%。     

利益相关者视角下非政府组织参与环境治理的模式创新研究 —— 以绿色浙江"吾水共治"圆桌会为例

随着环境问题的日益复杂化,环境治理中多元体系的形成尤为重要,非政府组织(NGO)作为一种新的社会治理力量受到广泛关注。然而,治理过程中利益相关者之间很难达成共识,因此,探索各利益相关者共同参与环境治理的模式具有现实意义。基于利益相关者理论,以绿色浙江"吾水共治"圆桌会为例,对环境治理中的利益相关者角色及功能展开分析,研究NGO在协调多方利益、维护公众权益、促进民主协商、实现多元共治过程中的作用机制和模式创新。     

CO_2倍增和气候变化对北京山区栓皮栎林NPP影响研究

应用生物地球化学过程模型BIOME-BGC估算了1977—1992年北京妙峰山栓皮栎（Quercus variabilis）林的净第一性生产力（NPP）,并分析气候对NPP年际变化的影响以及未来气候变化情景下对NPP的影响。结果表明：1977—1992年15年间栓皮栎的NPP（以C计）平均值为340.17g·m-2·a-1,NPP（以C计）变化在143.56～431.56g·m-2·a-1之间,并无明显的整体变化趋势,但表现出明显的年际变化,年际变动率达18%。在这段时间内降水量成为控制栓皮栎林NPP年际变化的主要气候因子。通过设置18种不同未来气候方案进行栓皮栎林NPP模拟表明,CO2浓度加倍会降低栓皮栎林的NPP但降低幅度较小。在CO2浓度不变的情况下,温度升高2.0℃和降水的协同增加以及单个因子的增加都有利于NPP的积累,但协同增加不如单个因子的增加对NPP的积累效应明显;在CO2和气候同时改变的情况下,CO2浓度加倍、温度升高2.0℃和降水的协同增加有利于NPP的积累且协同增加比单个因子的增加对NPP的积累效应明显,但各因子之间交互作用较弱。     

北京地区不同季节PM2.5和PM10浓度对地面气象因素的响应

利用2013年1月—2014年12月北京地区PM_(2.5)和PM_(10)监测数据和同期近地面气象观测数据,采用非参数分析法(Spearman秩相关系数)研究了北京地区PM_(2.5)和PM_(10)的浓度对不同季节地面气象因素的响应。结果表明:北京地区大气颗粒物浓度水平具有明显的季节特征,冬季大气颗粒物污染最严重,夏季最轻。不同季节影响颗粒物浓度水平的气象因素各不相同,其中风速和日照时数为主要影响因素。PM_(2.5)和PM_(10)质量浓度对气象因素变化的响应程度也有较大区别,PM_(2.5)/PM_(10)比值冬季最高,PM_(2.5)影响最大,春季最低,PM_(10)影响最大。这些结论可对制订科学有效的大气污染控制策略提供参考。     

Spatiotemporal variation in rainfall erosivity on the Chinese Loess Plateau during the period 1956–2008

Water resources and soil erosion are the most important environmental concerns on the Chinese Loess Plateau, where soil erosion and sediment yield are closely related to rainfall erosivity. Daily rainfall data from 60 meteorological stations were used to investigate the spatiotemporal variations in annual rainfall, annual erosive rainfall and annual rainfall erosivity on the Chinese Loess Plateau during the period 1956–2008. The annual rainfall, erosive rainfall and rainfall erosivity decreased over the past five decades, as determined by the Mann–Kendall test. A comparison of the annual averaged rainfall, erosive rainfall and rainfall erosivity from 1980 to 2008 with that from 1956 to 1979 revealed a remarkable spatial difference in the rainfall trends on the Loess Plateau. Regions of the plateau with major decreases in rainfall were primarily in the Hekouzhen-Longmen section of the middle Yellow River, especially in the Wuding River basin, the Fenhe basin and the northern-central Shanxi province, where the annual rainfall and erosive rainfall decreased by more than 10% and the annual rainfall erosivity decreased by more than 15%. The rainfall erosivity also decreased more than the annual rainfall. Because the annual rainfall has decreased significantly on the Chinese Loess Plateau over the past 50 years, it is important to better understand the ecological and hydrological processes affected by this climate change.     

Relationship between types of urban forest and PM2.5 capture at three growth stages of leaves

Particulate matter diameter ≤ 2.5 μm (PM_2.5) causes direct harm to human health. Finding forms of urban forest systems that with the ability to reduce the amount of particulate matter in air effectively is the aim of this study. Five commonly cultivated kinds of urban forest types were studied in Beijing city at three stages of leaf growth. Results show that the urban forest system is capable of storing and capturing dust from the air. The types of shrubs and broadleaf trees that have the ability to capture PM_2.5 from the air are most effective when leaves have fully developed. In the leafless season, the conifer and mixed tree types are the most effective in removing dust from the air. For all kinds of forest types and stages of leaf growth, the PM_2.5 concentration is highest in the morning but lower in the afternoon and evening. Grassland cannot control particles suspended in the air, but can reduce dust pollution caused by dust from the ground blown by the wind back into the air.     

北京山区典型流域不同海拔椴树种群的空间点格局分析

采用点格局分析法对不同海拔的椴树(Tilia miqueliana Maxim.)种群进行分布格局及其种间关系进行了研究。结果表明:整体上群落内以中龄树个体数为最多,小树次之,成年树个体最少。随着海拔的增加可以看出:小树(d≤5 cm)随着海拔的增加而减少,中树(5 cm20 cm)的规律不明显;椴树种群的空间分布格局与空间尺度(25 m内)有密切关系,在较小的空间尺度上倾向于非随机分布,具有明显的空间相关性;在>15 m或25m的某临界尺度时却倾向于随机分布,同时空间关联变得微弱。随着海拔的增加,各物种聚集分布的尺度有逐渐减小的趋势。种间关系随着海拔的增加,物种间的正相关尺度有增加的趋势。