Tundra disturbance and ecosystem production: Implications for impact assessment

Environmental regulations governing industrial activities in tundra environments stem largely from the expected ecological effects of the activities. One of the major ecological effects of industrial activities is the surface subsidence associated with thermokarst, which can result in changes in primary and secondary production. The primary production changes associated with thermokarst are strongly governed by three ecosystem properties—soil temperature, water regime, and nutrient availability. Most disturbances set in motion a more-or-less predictable sequence of landscape change related to these properties: soil warming, thermokarst, surface flooding, accelerated organic matter decomposition, and increased nutrient availability. The warmed soil and the enhanced nutrient availability typically lead to increased annual primary production, increased dominance by graminoids, and reduced plant species diversity. These vegetational changes may in turn potentially enhance secondary production, but in general these second-level responses have yet to be quantified. More information is needed about the food-chain effects of tundra landscape disturbances before regulators can make well-informed predictions of impacts or plan useful habitat rehabilitation.     

转变观念,面向市场,提高农业综合开发整体水平

在计划经济体制下.农业不是也不可能成为一个独立产业,其结果只能是社会效益可观、经济效益甚微甚至倒贴,吃苦的是农民。社会主义市场经济体制的逐步确立,为农业走向市场带来了希望,首要的是确立市场经济观念。丘陵地区大搞农业资源的综合开发是使农业走向市场的重要途径,综合开发上了水平,实现“三高”农业就大有希望。搞农业综合开发的途径很多,但都必须以市场为导向、科技为先导、经济效益为中心,大搞农业产加销一条龙、贸工农一体化是提高农业综合开发整体水平、实现“三高”农业的必要途径。     

全面提高成人高校学报质量的思考

针对全国报刊治理整顿后多数学报由内部发行转为正式学报类期刊的新情况,本文从学报业务工作的几个方面对全面提高成人高校学报(以下简称“成高学报”)办刊质量进行了较详细的论述,旨在对成高学报的办刊工作起到一些促进作用。     

“白色农业”与“三色农业”兴起及中国农业产业化方向

本文从白色农业与三色农业概念入手,阐述了白色农业的创新意义,提出了我国农业产业化的战略构想。     

Sustainable Agriculture: New Paradigms and Old Practices? Increased Production with Management of Organic Inputs in Senegal

Farmers in Sahelian countries are confronted with a variety of soil fertility and management problems. During the last two decades, NGOs have worked with farmers and research institutions to develop and test practices that will increase food production, while at the same time enhance the natural resource base.Since 1987, The Rodale Institute (RI) has worked closely with farmers' associations and government institutions to promote regenerative agriculture-farming systems that prioritize the use of local resources while improving them as they are used to grow food, using agro-ecological methods. The Senegalese Agricultural Research Institute has collaborated in this program as a partner of RI. The Senegal Regenerative Agriculture Resource Center model has been applied as a new and viable approach that builds on traditional knowledge and farmer-to-farmer exchange.Research results on soil conservation and improvement have shown that fields spread with amended animal manure or compost yield greater harvests than fields farmed with traditional methods.     

Applying Agroecology to Enhance the Productivity of Peasant Farming Systems in Latin America

The great majority of farmers in Latin America are peasants who still farm small plots of land, usually in marginal environments utilizing traditional and subsistence methods. The contribution of the 16 million peasant units to regional food security is, however, substantial. Research has shown that peasant systems, which mostly rely on local resources and complex cropping patterns, are reasonably productive despite their land endowments and low use of external inputs. Moreover analysis of NGO-led agroecological initiatives show that traditional crop and animal systems can be adapted to increase productivity by biologically re-structuring peasant farms which in turn leads to optimization of key agroecosystem processes (nutrient cycling, organic matter accumulation, biological pest regulation, etc.) and efficient use of labor and local resources. Examples of such grassroots projects are herein described to show that agroecological approaches can offer opportunities to substantially increase food production while preserving the natural resource base and empowering rural communities.     

碳中和愿景下电力部门低碳转型路径研究

碳中和愿景一方面加速了全社会电气化发展,致使电力需求持续增加,另一方面对尽早实现零碳电力提出要求,电力部门低碳转型进程更加紧迫而复杂。本文首先定性分析碳中和背景下电力部门的总体转型思路和技术不确定性影响,其次采用电力部门与终端部门耦合的C~3IAM/NET模型对电力需求进行预测,同时根据关键低碳技术发展的保守预期和积极预期设计多种情景,以开展电力低碳转型路径优化和成本效益研究。结果显示,发电碳排放量峰值可能出现在40亿～42亿吨,在2049—2060年有望实现零碳电力,电力部门低碳转型速度和效果因技术不确定性而存在明显差异。2021—2060年电力低碳转型累计投入为171万亿～180万亿元,CCS技术累计减排贡献超过250亿吨,可再生能源电力占比需达到68%以上,风电和光电将成为主要电力。     

小城镇环境保护规划存在的问题与对策

根据全国生态环境保护“十五”计划要求,在计划期间力争60％的小城镇完成环境保护规划,广西小城镇由于经济发展不平衡,部分小城镇还比较落后,且存在较多的环境问题,目前小城镇的环境保护规划尚未得到有效的开展,因此应及时找出问题和差距,并根据存在的问题作出相应的对策,在计划期内是可以完成小城镇环境保护规划的目标,为广西小城镇的可待续发展提供环境保障。     

Air Pollution Effects on Forest Trees in Balikesir,Turkey

Air pollution has become an actual problem in Balikesir because of rapid urbanisation and increasing of the polluting sources. Air pollutionproblems occur under the unfavorable meteorological conditions which increase in frequency of occurrence in winter due to use of low quality lignite coals for heating. The `Protection of Air Quality' in Turkey dated 1986 is based on the human health criteria. But the critical limit values are lethal for the forest trees as far as SO₂ is concerned. The field observations showed that leaves of the trees have yellow spots indicating acid burns in Balikesir. This study aims at determining the relationships between the SO₂ concentrationsin the air under selected climatic conditions, and the effects of air pollution on forest trees in Balikesir. Samples of leaves were collected from the City Parks in Balikesir, Deirmenboaz forested area located 10 km far fromBalikesiron the Balikesir-Bursa highway, and from the forestation areas near the Balikesir-Edremit highway. Sulfur contents of the leaves were very high especially in the city (2650–5300 g m^-3).Samples from other areas had values lower than this range but above the usual values (850–3612 g m^-3). The diameter increments of the trees were found to be lower and these results clearly showed the adverse impacts. Negative correlations were found between these sulfur concentrations and the daily mean temperatures and wind speeds. Positive correlation was seen between these concentrations and pressures, humidities. Emission sources must be controlled in order to safeguard the forests which protects the soil, facilitate water production, assimilate carbon dioxide in air and produce oxygen. It must be considered that the problems are not only regional but have a global identity.     

Utilization of Photographs for Determining Impact Indicators for Trail Management

Indicators are a key component of resource management, but selecting them can be difficult and controversial. This study explores different methods for selecting impact indicators for management of trail conditions by comparing photo survey methods (PSM) with written survey methods (WSM). A total of 661 subjects participated in interviews conducted within Mudeung- Mountain Provincial Park in Kwang-ju, Korea. PSM explained variation in acceptability better than WSM. Six major photo components (in order of importance: area of large rocks on trail, area of wood steps, area of bare roots, area of bare soil, area of small stones, and area of stone steps) explained 84.7% of the variation in acceptability of trail management conditions. This study suggests that PSM can be a useful tool for selecting impact indicators. Supported by the grant of Post-Doctoral Program, Chonbuk National University (2001)