Environmental Management最新文献

Effective control measures for small-bodied invasive alien species (IAS) in lotic environments are essential for preserving native biodiversity and ecosystem health. This study integrates modeling and field-based removal data to assess the efficacy of electrofishing in controlling populations of the globally invasive Eastern mosquitofish Gambusia holbrooki across four lowland headwater streams in southern Greece over a one-year period. Results indicated significant reductions in mosquitofish post-removal abundance, although natural recruitment persisted, leading to population suppression rather than eradication. Indeed, our pre-removal population viability analysis suggested a temporary suppression of mosquitofish populations, influenced by factors such as the species' life history and reproductive traits. Furthermore, our study suggests modifications of physical control methods expected to enhance effectiveness. Specifically, the narrow implementation timeframe of the removal actions highlights the need for multiple removal campaigns in consecutive years and for long-term population monitoring, thus aligning with past research. The timing of removal efforts is also critical as it must exploit seasonal variability in fish eradication susceptibility, by its implementation within the best "window of opportunity". Finally, addressing knowledge gaps in the ecological impacts of IAS control methods as well as exploration of novel control and monitoring technologies, are also vital for informed management strategies. This study, by proposing modifications to fish removal planning and methodology, contributes to ongoing efforts for optimal IAS control, particularly in regions where such management approaches are underutilized.

This paper examines the Multistakeholder initiative (MSI) "German Initiative on Sustainable Cocoa (GISCO)". MSIs represent arenas in which heterogeneous actors from governments, businesses and civil society come together to achieve sustainability goals that they cannot achieve otherwise. The self-defined goals of GISCO are first, to improve the living conditions of cocoa farmers and their families; second, to conserve and protect natural resources and biodiversity; and third, to increase the share of sustainably produced cocoa. Although all stakeholder groups share these goals, they have different agendas and conflicting interests. Despite numerous case studies, no theoretical basis has been established on the functioning and success of negotiations in MSIs. Therefore, the question arises as to how the governance of an MSI can be captured empirically to explain (un)achieved outcomes of the collaboration. The contribution of this paper is the development of a theoretical framework and its application to the case study. Minutes of 84 meetings and 18 qualitative expert interviews were analyzed by social network analysis and qualitative content analysis using MaxQDA to identify (a) influential actors, (b) collaboration structures and (c) processes as well as (d) topics discussed to explain (not) achieved outcomes regarding the self-defined goals. The results provide detailed insight into the governance of an MSI. The MSI helps members to extend their individual networks and to learn from each other, but quickly reaches its limits in achieving the self-imposed common goals. One reason for this is the lack of representation of actors from the Global South, despite addressing environmental and living conditions there in two out of the three GISCO goals. Furthermore, it is shown that the structures and processes of decision-making within the MSI are designed in such a way that a lack of hierarchical directives, sanctions and other decision-making mechanisms makes negotiation-based compromises difficult. Consequently, the power of each stakeholder group to use their veto right to delay or prevent the changes required to achieve common goals cannot be overcome.

Dense beds of water plants can be perceived as nuisance, but this perception, however, may not be similar for different user categories, and this may affect their willingness-to-pay (WTP) for plant removal. A questionnaire survey was used to test this for residents and visitors and find underlying socio-cultural or economic drivers. We studied five cases where nuisance water plant growth is managed: the rivers Otra (Norway) and Spree (Germany), and the lakes Kemnade (Germany), Grand-Lieu (France), and Hartbeespoort Dam (South Africa). We used a different payment vehicle for residents (annual household tax) and visitors (tourist tax). The survey included questions on days spent on specific types of activity per year, the importance attached to different functions and activities, overall environmental attitude, perception of the plants, socio-demographic respondent characteristics and WTP for increased plant removal. We observed no increase in WTP for increased removal in most sites. The two most important drivers of variation in current WTP were income, and whether respondents were engaged in boating and angling and thus perceived the plants negatively. Variation in WTP among sites was considerable, and mainly related to the mixture of activities among respondents. Differences between residents and visitors were less important than those among sites. Our observations bear importance for water management: information on differences in experienced nuisance among user categories and the frequency of use by these categories is useful as guidance for the design and implementation of any plant removal plan.

Plastic waste poses a significant challenge to achieving sustainable production and consumption of resources, particularly in sub-Saharan Africa where effective governance and waste management systems are lacking. In this paper, we develop an empirical understanding of the influence of public governance system on promoting circular economy (CE) for plastic actions among individuals. Through a survey of 1475 participants across five sub-Saharan African countries, we tested five hypotheses drawing on New Governance Theory and CE Action Recipe to explore the relationship between governance and individual’s actions supporting CE for plastic. We found that a governance system that supports CE practices and exhibits governance efficiency is positively associated with individuals’ actions supporting CE for plastic. The awareness of government policies, laws and regulations, institutions, processes, and programmes have a significant impact on individuals’ engagement in plastic circularity practices. The paper’s theoretical and governance implications highlight the relevance of public governance in shaping action towards a CE for plastic at the individual level.

Scientists and managers seek to implement more inclusive and effective conservation strategies by incorporating plural valuations of nature and nature’s contributions to people (NCP) into research and decision-making. For Argentina’s threatened Espinal ecoregion, this need is particularly acute. In Entre Ríos province, practically all of these forests are devoted to production, and the expanding agricultural frontier increases their conversion to crops. We surveyed family ranchers and agricultural/environmental specialists, two key stakeholders for managing Espinal forests used for cattle grazing. Employing a sociocultural valuation, we determined i) stakeholder recognition of the Espinal’s NCP and its support for quality of life, ii) similarity between stakeholder valuations (importance: 0 = none; 4 = very) of NCP and dimensions of well-being derived from the Espinal, and iii) relationship between ecological (e.g., forest degradation) and social (e.g., place of residence) factors and perceptions of the forest. Ranchers recognized more NCP and quality-of-life aspects, and the importance to their well-being tended to be greater than specialists. Both groups valued regulating and non-material NCP above material contributions and considered that forests are very important for physical and mental health. Finally, only rancher perceptions varied with tested variables, depending on degradation levels of forests with which they have the most contact and/or carry out their activities, the number of uses and recreational activities they carry out in forests, their knowledge of forests, and their place of residence. This study illustrates common ground upon which to promote synergies between production and conservation in Espinal-cattle agroecosystems.