Current state of vegetation cover in the islands of Chivyrkuy bay (lake Baikal) under the influence of semiaquatic bird colonies

Semiaquatic bird colonies influence strongly the vegetation cover of the islands. There are not many islands occupied by altricial birds in Lake Baikal. We have studied the vegetation cover of three islands of Chivyrkuy Bay (Northern Baikal area): Goly Kyltygey, Pokoynitzkiy Kamen, Bely Kamen. The research results reflect the nature of vegetation cover transformation in these islands. In particular, we have noted the flora shrinkage, community mosaicity, die-off of separate trees and entire forest communities, and abundance of nitrophilous plant species. It is emphasized that there is an adventitization of plant communities due to the increased phytocenotic role of some alien species, but we havn’t revealed any growth of advent plants in the flora. The impact of bird colonies on the islands of Chivyrkuy Bay is quite similar to that on marine islands. Taking into account the normalcy of the high population size of cormorants, we have concluded that ornithogenic processes of vegetation cover transformation should not be assessed as negative process.