THE POTENTIAL EFFECTS OF GLOBAL WARMING ON THE PRIMARY PRODUCTIVITY OF A SUBALPINE LAKE1

ABSTRACT Atmospheric scientists have predicted that large-scale climatic changes will result from increasing levels of tropospheric CO₂ We have investigated the potential effects of climate change on the primary productivity of Castle Lake, a mountain lake in Northern California. Annual algal productivity was modeled empirically using 25 years of limnological data in order to establish predictive relationships between productivity and the climatic variables of accumulated snow depth and precipitation. The outputs of monthly temperature and precipitation from three general circulation models (GCMs) of doubled atmospheric CO₂ were then used in the regression model to predict annual algal productivity. In all cases, the GCM scenarios predicted increased algal productivity for Castle Lake under cenditions of doubled atmospheric CO₂The primary cause of enhanced productivity was the increased length of the growing season resulting from earlier spring ice-out.     

大跨度公路隧道洞口段爆破对高边坡安全影响研究

为研究大断面公路隧道洞口段爆破开挖对边坡稳定性的影响,以某公路隧道洞口段工程为研究背景,基于Abaqus有限元软件,建立隧道—边坡三维数值计算模型,研究隧道洞口段爆破开挖对两侧高边坡安全性的影响,并分析砂浆锚杆对边坡的加固效果。结果表明:隧道洞口段爆破开挖施工时边坡坡脚处围岩振速最大,爆破对边坡水平振速影响较竖向振速及轴向振速更为显著,爆破时应控制坡脚及坡肩的水平振速;边坡坡面最大振速出现在洞口边坡坡面与仰坡坡面交线位置,边坡坡面与仰坡坡面交线上顶点为坡肩振速最危险的特征点,下端点为坡面振速最危险的特征点;增加锚杆长度对边坡水平位移的控制效果较竖向位移更为显著,锚杆长度宜取14 m。研究结果可为类似工程提供理论借鉴。     

Who should manage protected areas in the Swedish mountain region? A survey approach to co-management

This article investigates attitudes towards co-management of protected areas in Sweden, at the national, county and local level. In Sweden, protected areas are still primarily designated and managed hierarchically-a practice increasingly contested by people living close to them, including indigenous Sámi reindeer herders whose economic activities are located within protected areas. The general view could, on the contrary, be anticipated to be pro-state since protected areas are considered to be of national interest. For democratic reasons, however, the opinions of the whole population should be considered. In order to measure both local and general views, this study is based on a two-sample survey of 8868 respondents. The objectives are to map and explain attitudes regarding who should manage protected areas in Sweden, and to test the usefulness of a multi-level quantitative method. Such an approach is unusual in co-management literature that is empirically mainly based on local case studies. The explanatory ambition sets out to test three hypotheses drawn from common-pool resource theory; resource dependency, common understanding, and trust. Perhaps surprisingly, the results show that a considerable majority of the respondents (at all levels) wish to see self- or co-management. All three hypotheses are important to understand attitudes toward the management of protected areas, but not always in the way that the theory anticipates.     

广州帽峰山林区空气负离子动态及与环境因子的关系

采用定位连续观测方法,研究了广州帽峰山森林公园负离子含量近5年的年、季、月变化及不同天气的变化规律,并以此对帽峰山森林公园的空气质量进行了计量评价.分析了空气负离子含量与环境因子的相关关系.结果表明:林区不同观测区的负离子含量差异较大,山下瀑布空间负离子含量最高.平均水平达达2l 729 ions.cm-3;林内负离子含量年间及月间变化不大,沟谷小溪和山中部瀑布空间由于人为干扰,负离子含量年动态呈现降低趋势,山下瀑布空间年负离子含量维持在20000 iotis·cm-3左右;负离子含量的季节差异显著,春夏季大于冬秋季,夏季最高、冬季最低.空气质量评价系数CI的最低在2月份、最高在8月份.不同天气条件下负离子含量大小顺序为下雨>晴天>阴天.负离子含量与空气温度呈正相关,与空气湿度呈正相关.与空气气压呈负相关.     

Study on the Circular Agriculture Development in Beijing’s Mountain Areas

Abstract

Circular agriculture is an essential way to realize the positive recycling of ecology and harmonious development of the country construction. The sustainable development of Beijing’s mountain areas depends on the background and orientation of ecological economy. Beijing’s mountain areas bear the responsibility of protecting the ecological safety of the whole Beijing district and also the exploration of circular agriculture in mountain areas is very important to promote the sustainable use of agriculture resources. Beijing’s mountain areas have possessed some practical experience in recycling agriculture development. Through summarizing the development mode and analyzing the development practice, the article puts forward three key segments of promoting Beijing circular agriculture development: strengthen propagate, develop superiority and built management mechanism.     

秦岭大巴山地区山地灾害及减灾对策

本文在论述秦岭大巴山地区山地灾害类型特征、分布规律及综合分析致灾成因的基础上,提出了五条具体的减灾对策。     

黄山风景景观的地貌条件研究

黄山风景景观是多种因素共同作用的结果，本文着重探讨了地貌条件在黄山风景景观形成中的特殊作用，以便为进一步开发利用黄山，保护生态环境提供科学参考。     

生态系统管理理论在山地生态旅游开发中的应用

生态系统管理是一种可持续的系统的自然资源和环境管理理念,综合了生态、经济和社会的发展要求。以大别山区岳西县为例,探讨了山地生态旅游开发的生态系统管理,提出从整体上综合分析旅游流对山地自然生态环境的影响,研究具有关键性影响的生态要素和生态过程,采取适应性管理,确保旅游客流、当地民众和自然生态环境之间的和谐。     

广东山区反季节蔬菜栽培研究──以信宜县山区为例

本文在对信宜县山区农业气候资源进行深入研究分析的基础上，根据各种蔬菜的生物学特性，提出了信宜县山区露地种植反季节蔬菜的适宜海拔高度和栽培措施，为广东省山区合理利用垂直气候资源，发展反季节蔬菜生产提供了科学依据。     

粤东山区土壤环境与蔬菜反夏栽培研究

以粤东丰顺县下八乡山区为例,根据其土壤、气候与环境特点,对蔬菜反夏栽培的适宜品种、播种期、轮作形式及各种配套技术措施进行了多年的试验研究。试验及推广的结果表明,种植反季节蔬菜及实行稻菜轮作的经济效益都比种植水稻高;新植茶园间套种蔬菜也有较高的经济效益。