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   48篇
  免费   0篇
林业   2篇
  19篇
综合类   23篇
农作物   1篇
园艺   2篇
植物保护   1篇
  2018年   1篇
  2016年   4篇
  2014年   1篇
  2012年   2篇
  2011年   12篇
  2010年   3篇
  2009年   2篇
  2007年   3篇
  2006年   1篇
  2005年   7篇
  2004年   1篇
  2003年   1篇
  2002年   5篇
  1999年   1篇
  1997年   4篇
排序方式: 共有48条查询结果,搜索用时 46 毫秒
1.
由于蝴蝶对环境变化反应比较灵敏,常被作为检测环境质量变化的指示生物。对宁夏云雾山国家级自然保护区蝶类群落的结构组成与多样性做了初步调查。结果表明:云雾山蝴蝶共有29种,隶属于6科26属。其中,眼蝶科的属和物种数量最多,为8属8种;凤蝶科最少,仅1属1种。通过Margalef物种丰富度指数、Shannon-Wiener多样性指数、Pielou均匀度指数和Berger-Parker优势度指数对蝶类的多样性进行分析,眼蝶科的多样性指数最高,但均匀度指数和优势度指数均最低,分别为1.57、0.76和0.28;弄蝶科的丰富度指数最高,达到1.31;蛱蝶科的优势度指数最高,达到0.44;灰蝶科的均匀度指数最高,但多样性指数最低,分别为0.96和1.34;粉蝶科的丰富度指数最低,为0.82。眼蝶科在云雾山保护区是优势科,物种丰富,但物种相对集中,群落结构不稳定,而凤蝶科物种较为贫乏,需要对其加以保护。  相似文献   
2.
Calcareous grasslands, as extraordinarily species-rich and diverse habitats of northern and central Europe, need some management for their long-term conservation. Traditionally, they have been used as pastures, mainly with sheep, but goats are important, because they mainly browse and climb rocks. This study presents a comprehensive approach to the conservation of these sites, including the requirements of shepherds, which were obtained by a questionnaire, together with autecological information on the habitat requirements of species. Grazing is a central option, which has to be regulated in timing, intensity and spatial distribution, to gain optimum results. Nevertheless, local regulations must consider the requirements of the shepherds regarding infrastructure and social conditions, so that grazing remains practicable. Additionally, sheep-farming on conservation sites is presently unprofitable and therefore needs financial support. This support is supplied by state subsidies in Bavaria (Vertragsnaturschutzprogramm), and in the study area by a lamb-meat sales premium, which allows the shepherds to charge higher prices for lamb-meat produced under the premium regulations. The success of the overall strategy is only possible given a well adjusted interplay of influencing factors.  相似文献   
3.
Butterfly assemblages were used to characterize and evaluate the conservation value of the main habitat types in the Aiguamolls de l’Empordà Natural Park (north-eastern Spain), an important protected wetland area on the Mediterranean coast. Butterfly data were obtained from a number of transects walked as part of the Catalan Butterfly Monitoring Scheme, which uses a standardized methodology for monitoring butterflies. A Mantel test indicated a strong association between habitat types and the composition of butterfly assemblages and a principal component analysis ordinated individual butterfly species along a gradient from woodland to open areas, thereby indicating various degrees of shade tolerance. In addition, cluster analysis distinguished two main groups of habitats based on the similarities of their butterfly fauna: woodland and bramble clumps and a group of three different kinds of grasslands (traditionally hay meadows, pastures, and alfalfa fields). Hay meadows flooded in winter (the so-called closes) appeared always as the highest ranked habitat in terms of conservation evaluation: they have more butterflies and a slight tendency to harbor more and generally rarer species. This conclusion coincides with that of previous investigations that have indicated that the most diverse and rare plant communities in the whole Natural Park are present in the closes, and highlights the importance of traditionally managed hay meadows for wildlife. However, these hay meadows - one of the rarest habitats in the Mediterranean region - are in alarming decline and have become the most threatened habitat in this protected area: no longer profitable, we believe that the future of the closes will depend ultimately on the existence of agri-environmental schemes.  相似文献   
4.
南岭国家自然保护区鳞翅目蝶类考察初报   总被引:10,自引:0,他引:10  
陈锡昌 《昆虫天敌》1997,19(1):26-40
本文报道南岭国家自然保护区鳞翅目蝶类本底调查的结果,共11科,150多属,300多种。近百蝶种为广东省分布的新记录。其中1个蝶种属于国家一级保护的珍稀蝶种,另有10多种属较稀有的种类。并就蝶蝶资源发发利用,以及珍稀蝶种的保护提出了几种建议。  相似文献   
5.
小陇山林区的蝶类资源(五)   总被引:2,自引:2,他引:0  
记述了近年来在小陇山林区采集到的蝶类昆虫71种,其中弄蝶科52种,斑蝶科3种,蚬蝶科5种,喙蝶科1种.补充记述了凤蝶科1种,粉蝶科9种.  相似文献   
6.
甘肃小陇山林区的蝶类资源(四)   总被引:4,自引:3,他引:1  
记述了采自小陇山林区的灰蝶科昆虫48属、95种.  相似文献   
7.
佳木斯地区蝶类资源开发与利用   总被引:2,自引:0,他引:2  
通过对佳木斯地区蝶类资源进行调查研究,鉴定出蝶类共7科92属196种,掌握了佳木斯蝶类资源分布情况。文章对佳木斯蝶类资源进行阐述,并提出了蝶类开发利用的方法措施。  相似文献   
8.
湖南省及自然保护区蝶类资源记述及保护利用研究   总被引:7,自引:0,他引:7  
对湖南省及自然保护区蝶类8 000 余号标本的鉴定,确定湖南省及各自然保护区蝶类284 种,隶属于11 科132 属,其中凤蝶科13 属32 种、粉蝶科9 属24 种、斑蝶科4 属7 种、环蝶科3属3 种、眼蝶科14 属51 种、蛱蝶科37 属82 种、珍蝶科1 属1 种、喙蝶科1 属2 种、蚬蝶科2 属4种、灰蝶科23 属35 种、弄蝶科25 属43 种。对已鉴定的标本抽取有详细分布资料的240 种进行区系分析,得出湖南省蝶类在世界动物地理区划中,以东洋区种为主,占38.33% ,中国特有种占26.67% ,古北区种占15.42% ,古北- 东洋共有种占13.32% ,其他组合比例较低;湖南蝶类在中国地理区划中,以华中- 华南共有种、华中-华南- 西南共有种为主,分别占17.50% 和16.25% ,其次华中- 华南- 青藏共有种占12.08% ,其他组合比例较低;对湖南省240 种蝶类在湖南4 个农业区的归属进行分析,得出其在湘西农业区所占比重为25.83% ,四区共有种20.83% ,其它农业区及组合所占比重较低。并提出了蝶类资源保护与利用措施。  相似文献   
9.
甘肃麦积山景区的蝶类资源(二)   总被引:1,自引:1,他引:0  
记述了麦积山景区的蝴蝶类昆虫50种,其中眼蝶科47种,斑蝶科1种,蚬蝶科1种,喙蝶科1种。  相似文献   
10.
记述了近年来在麦积山景区采集的蛱蝶科昆虫39属82种。  相似文献   
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