生态环境保护与可持续发展

简述了可持续发展提出的历史背景及其内涵,以及生态环境保护在实行可持续发展战略中的地位和作用,指出我国生态环境中存在的问题及其原因,就我国生态环境存在的问题及解决途径作了阐述。     

关于中国西部“山川秀美”再造的思考——兼论西部生态安全建设中的防灾减灾

再造一个“山川秀美”的大西北 ,展现出一幅理想的人与自然依存的场景。笔者为此给出独特的思考和科学的见解 :要实现这一目标 ,必须研讨“山川秀美”的科学内涵 ,以恢复大西北自然生态安全环境为基础 ,以防灾减灾 ,保护人与自然为手段 ,依靠科技进步 ,坚持可持续发展战略 ,从长远利益并结合地区实际 ,才能真正实现人与自然和谐共存的“山川秀美”     

Sperm precedence and sperm storage in multiply mated red flour beetles

In insects, the last male to mate with a female often gains access to a disproportionate number of subsequent fertilizations. This study examined last-male sperm precedence patterns in doubly and triply mated Tribolium castaneum females. Sperm storage processes were investigated by measuring the quantity of sperm stored within the female spermatheca following single, double, and triple matings. Both doubly mated and triply mated females exhibited high last-male sperm precedence for progeny produced during the first 48 h following the last mating, with females in both groups exhibiting parallel declines in sperm precedence 1 and 2 weeks later. The number of sperm stored by females increased by 33% between singly mated and doubly mated females, indicating that the spermatheca is filled to only two-thirds capacity following insemination by the first male. Based on the proportion of stored sperm from first and second matings, we tested predictions about sperm precedence values based on models of random sperm mixing. High initial last-male sperm precedence strongly supports stratification of last-male sperm. By 1–2 weeks after double matings, sperm precedence declined to levels indistinguishable from values expected under random mixing. These results provide insight into mechanisms of sperm storage and utilization in this species. Received: 20 August 1997 / Accepted after revision: 24 May 1998     

Investigating the embryo/larval toxic and genotoxic effects of γ irradiation on zebrafish eggs

Eggs/larval of freshwater fish (Danio rerio) were exposed to low dose rates of external gamma radiation (from 1 to 1000 mGy d⁻¹) over a 20-day period, with the objective of testing the appropriateness of the 10 mGy d⁻¹ guideline suggested by the IAEA. The present study examines different endpoints, mortality and hatching time and success of embryos as well as the genotoxicity of γ-irradiations (after 48 h). The 20-day embryo-larval bioassay showed an enhanced larval resistance to starvation after chronic exposure to γ irradiation (from low 1 mGy d⁻¹ to high dose rate 1000 mGy d⁻¹) and an acceleration in hatching time. Gamma irradiation led to increased genotoxic damage Ito zebrafish egg (40-50% DNA in tail in Comet assay) from the lowest dose rate (1 mGy d⁻¹). Possible mechanisms of γ radiotoxicity and implications for radioprotection are discussed.     

三峡工程对长江中游湖泊生态影响及监测因子优选

分析了三峡工程的兴建对长江中游湖泊生态环境的影响,为保护长江中游湖泊生态环境,优选出了８类指标的监测因子,以期通过这些因子的监测,可以较全面,准确地反映了三峡工程对长少中游湖泊生态环境状况的影响及其动态变化趋势,为保持长江中游湖泊生态系统的良性特环境提供科学依据。     

生态建筑在我国西部小城镇规划中的应用研究——以安仁镇为例

本文从全球生态环境危机和我国西部小城镇的特征上分析了生态建筑应用的重要性与发展前景,并且从生态建筑设计的手法、布局等方面阐述了其在我国西部小城镇规划中应用的方法,提出了小城镇规划以人为核心,以构建可持续发展的和谐人居环境为其重要目的的观点。     

Interdependence with the environment: Commitment,interconnectedness, and environmental behavior

Do individuals’ perceptions of their interdependence with the natural environment affect their environmental behaviors? From the perspective of interdependence theory, we introduce a scale to measure commitment to the natural environment. In Study 1, higher levels of commitment to the environment and greater inclusion of nature in the self separately predicted higher levels of pro-environmental behavior, even when controlling for social desirability and ecological worldview. In Study 2, participants primed to experience high commitment to the environment reported greater levels of pro-environmental behavioral intentions as well as pro-environmental behavior relative to participants primed to experience low commitment to the environment. Commitment to the natural environment is a new theoretical construct that predicts environmental behavior.     

Adaptation as a Political Process: Adjusting to Drought and Conflict in Kenya’s Drylands

In this article, we argue that people’s adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies.     

Monitoring and assessment of radionuclide discharges from Temelín Nuclear Power Plant into the Vltava River (Czech Republic)

The paper summarizes impacts of the Temelín Nuclear Power Plant (NPP) on the Vltava and Labe River basins. The study is based on the results of long-term monitoring carried out before the plant operation (1989–2000), and subsequently during the plant operation (2001–2005). In the first period, the main objective was to determine background radionuclide levels remaining in the environment after global fallout and due to the Chernobyl accident. A decrease in the concentrations of ⁹⁰Sr, ¹³⁴Cs and ¹³⁷Cs, which was observed before the plant operation, continued also during the subsequent period. Apart from tritium, the results of the observation did not indicate any impacts of the plant on the concentrations of activation and fission products in the hydrosphere. The annual average tritium concentrations in the Vltava River were in agreement with predicted values. The maximum annual average tritium concentration (13.5 Bq L⁻¹) was observed in 2004 downstream from the wastewater discharge in the Vltava River at Solenice. Estimated radiation doses for adults due to intakes of river water as drinking water contaminated by tritium are below 0.1 μSv y⁻¹.