首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3篇
  免费   0篇
水产渔业   2篇
植物保护   1篇
  2023年   1篇
  2019年   1篇
  2014年   1篇
排序方式: 共有3条查询结果,搜索用时 15 毫秒
1
1.
In the years 2013 and 2014 the presence and the infestation level of Plasmodiophora brassicae in six federal states of Germany were assessed using a bioassay method. Soils were sampled from 237 oilseed rape fields and the farmers provided information about the soil type, the soil pH values and the last year of oilseed rape cultivation. Clubroot was detected in 66 % of the fields investigated with a mean disease severity (BI) of 0.34. Between and within the federal states differences in presence and infestation level of P. brassicae were detected. In Schleswig-Holstein significantly more fields were infected by P. brassicae (90 %) and BI was relatively high (0.49) compared to Lower Saxony, Mecklenburg-Western Pomerania and North Rhine-Westphalia with 50 % infected fields and a mean BI of 0.27. Highly infested fields (BI > 0.8) were prevalent on 15 and 25 % of fields investigated in every federal state. Within the federal states the soil climate regions (BKR) differed significantly from each other. In BKR with light and sandy soils P. brassicae was less widespread compared to neighboring BKR with loamy soils. In addition, BKR with high infestation levels on fields investigated revealed a high presence of clubroot infested fields within this BKR. The infestation level in our study was significantly influenced by soil type, content of sand and soil pH value: soil types with a sand content of 30–35 % and a pH values lower than 5.6 showed high clubroot severity and disease incidences.  相似文献   
2.
Despite regular reforms, problems under the EU's Common Fisheries Policy (CFP) persist. In order to identify priorities for future reforms of the policy, we developed an analytical framework consisting of 17 criteria and specifying indicators, derived from scientific, wider fisheries, and common resources literature. We applied the framework to the CFP governance system, its regulations, institutions, and processes at EU as well as member state level. The results show that the CFP does not fully meet any of the 17 criteria for an effective resource policy. Its performance was assessed as “neutral” regarding 10 criteria and “negative” regarding seven criteria. Trend analysis shows that there is a slightly positive trend regarding the CFP's performance, with five criteria trending positively, 11 showing a neutral trend and only one criterion trending negatively (simplicity of rules). The analysis identified five criteria which are performing badly and have not improved over time: simplicity of rules, user‐pays principle, resource efficiency, accountability, and compliance mechanisms. Future reforms of the CFP should first and foremost address these criteria while continuing efforts to improve the CFP's performance regarding other criteria. The evaluation of the CFP demonstrates the applicability of the analytical framework which can also be applied to other multilevel fisheries governance systems. Moreover, the results can inform reforms of Regional Fisheries Management Organisations. Like the CFP, these institutions manage transboundary fisheries and have not effectively addressed the issues of resource rent capture and resource efficiency.  相似文献   
3.
Recreational fishing (RF) is a large yet undervalued component of fisheries globally. While progress has been made in monitoring, assessing, and managing the sector in isolation, integration of RF into the management of multi-sector fisheries has been limited, particularly relative to the commercial sector. This marginalises recreational fishers and reduces the likelihood of achieving the sector's objectives and, more broadly, achieving fisheries sustainability. We examined the nature and extent of RF inclusion in harvest strategies (HSs) for marine fisheries across 15 regions in 11 nations to define the gap in inclusion that has developed between sectors. We focused on high-income nations with a high level of RF governance and used a questionnaire to elicit expert knowledge on HSs due to the paucity of published documents. In total, 339 HSs were considered. We found that RF inclusion in HSs was more similar to the small-scale sector (i.e., artisanal, cultural, or subsistence) than the commercial sector, with explicit operational objectives, data collection, performance indicators, reference points, and management controls lacking in many regions. Where specified, RF objectives focused on sustainability, economic value and catch allocation rather than directly relating to the recreational fishing experience. Conflicts with other sectors included competition with the commercial sector for limited resources, highlighting the importance of equitable resource allocation policies alongside HSs. We propose that RF be explicitly incorporated into HSs to ensure fisheries are ecologically, economically, and socially sustainable, and we recommend that fisheries organisations urgently review HSs for marine fisheries with a recreational component to close the harvest strategy gap among sectors.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号