兰州鲇资源量的影响因素及自然种群恢复措施探讨

兰州鲇(Silurus lanzhouensis)属于中国特有世界濒危鱼类,仅分布在黄河中上游水域,由于黄河水域生态环境的破坏,兰州鲇资源量急剧下降。本文对该物种栖息水域环境质量状况、肌体受重金属污染状况及影响兰州鲇资源量的主要环境因素和种质因素进行了深入分析,提出了控制COD排放,治理Hg、Zn和Pb污染,加强渭河、沣河等黄河主要支流水域环境的综合治理,划定禁渔期和禁渔区,建立兰州鲇种质资源保护区和原种场,开展人工增殖放流等兰州鲇自然种群恢复的具体措施,以期为有效保护黄河濒危鱼类资源提供技术支撑。     

Deriving efficient frontiers for effort allocation in the management of invasive species*

Invasive species cause significant losses through their effect on agriculture, human health and the environment. Their importance has increased with time owing to globalisation, as the spread of invasive species is facilitated by the increased movement of people, cargo and genetic material around the world. There is a vast literature on the economics of invasive species and their management. Here, we contribute to this literature by applying a spatio‐temporal model to the allocation of surveillance resources. We focus on three questions regarding resource allocation to control a newly discovered invasion: the budget, which determines the amount of search effort available; the duration of the control program; and the allocation of surveillance and control in time and space. We also explore the complementary role of passive surveillance by members of the public. We derive efficient frontiers for effort allocation that represent the trade‐off between cost and probability of eradication after inefficient strategies have been eliminated. We use the results to illustrate how to evaluate whether introduction of passive surveillance is desirable based on cost and eradication probability. We conclude by discussing the implications of our findings in the design of control programs.     

Public Preferences and Willingness to Pay for Forest Disease Control in the UK

Invasive pests and diseases in trees impose a range of costs on society related to reductions in timber values, impacts on recreational opportunities and effects on forest biodiversity. These costs need to be considered when assessing control options and developing public policy. We investigate the preferences and willingness to pay of the UK general public for a range of forest disease control measures using a choice experiment with a sample of 605 people. Respondents were relatively well informed about general tree disease‐related issues, such as causes and general measures to minimise the risk of disease spread. They were less knowledgeable about specific tree diseases, with Dutch elm disease and chalara ash dieback being the most well known. We find that disease control programmes in publicly‐owned forests and forests owned by charitable trusts are more likely to be supported by the public than equivalent control programmes in privately‐owned and/or commercial forests. The nature of scientific uncertainty about diseases does not affect peoples’ preferences for disease control measures significantly. Higher respondent income, greater ex‐ante knowledge about tree diseases, and more frequent visits to forests are correlated with greater willingness to support publicly‐funded tree disease control programmes in forests. Better knowledge about tree diseases also improves the clarity of respondents’ choices. We find a negative sentiment against some disease control measures, such as clear felling of a forest, and chemical or biocide spraying. We conclude that there is significant public support for part‐financing forest disease control policies in the UK, but that this is conditional on forest ownership and the type of control measures used.     

如何发挥财务管理在科研单位管理中的核心作用

文章结合国土资源系统和环境保护系统审计及财务管理实践,就如何发挥财务管理在科研单位管理中的核心作用进行了探讨,明确了基层单位管理中财务管理的重点和地位,提出设计内部管理模式和目标考核指标等观点,以期建立和完善适应单位管理的内部控制制度,从而强化资金管理,提高资金使用效益,达到提高单位社会效益和经济效益的目的.