排序方式: 共有4条查询结果,搜索用时 0 毫秒
1
1.
Comparative Studies on the Usefulness of Seven Ecological Indices for the Marine Coastal Monitoring Close to the Shore on the Swedish East Coast 总被引:1,自引:0,他引:1
The simultaneous behaviour of seven ecological indices(Hurlberts, Margalefs, Menhinicks, Shannons,species number, Jaccards and saprobic index) wasstudied based on phytoplankton data close to the shoreon the East coast of Sweden during the summer 1998.The sampling stations had a similar eutrophicationlevel and were located in bays. Standard phytoplanktondatabases were used in calculating the indices, whichwere later compared using cluster analysis.Hurlberts, Margalefs, Menhinicks, Shannons andspecies number indices, as measure of communitydiversity, produced similar trends which oftendiffered from those based on Jaccards index ofsimilarity. However, the simultaneous use of theseindices was found meaningful as a possible part of themonitoring close to the shore. The application of asaprobic index lead to erroneous conclusions in thestudied case. 相似文献
2.
During a historically observable period, profound and often irreversible changes in the faunal composition, distribution,
and abundance of game animals were taking place throughout the territory of northern Europe. These changes were especially
conspicuous in case of large mammals because of their large body size and roles in biocenoses and human economic activities.
This paper deals with the results of monitoring the range and abundance of the wild boar and some ecological observations
on this species at the northern limit of its distribution in European Russia. 相似文献
3.
4.
The dispersal, population dynamics, and ecological features of the European roe deer at the northern limit of species distribution and also their visits, wintering, and breeding outside the range boundary are discussed. A significant increase in the abundance of roe deer in the northern part of the range and their largescale expansion beyond the historical distribution limit have taken place during the past decade. However, their spread in Karelia and Arkhangelsk oblast is strictly limited, depending primarily on snow depth and duration. Hunting the roe deer as a game species in the region is possible only in the south of Pskov oblast, where habitat conditions are most favorable for it. 相似文献
1