| Abstrakt: |
This research was carried out in Kyiv Polissya geobotanical province, in one of most common woods type -- fresh and wet sudubravas. Its purpose is to determine ornithocenosis structure in diff erent age groups of this type of forest. To achieve that, forest bird species lists were composed, their population density and that of ecological groups of birds were calculated. In the course of the research in the breeding periods of 2013-2014, two-time surveys were carried out on 12 survey routes of total length 33 km. For further analysis, forests were divided into age groups: 0-20 years, 20-40 years, 40-60 years, 60-80 years, 80- 100 years and forests over 100 years. Altogether 53 bird species were found. Species lists were poorest in the forests of 0-20 years (18 species), and richest in the forests over 100 years (39 species). Minimal population density was 473 individuals per square kilometer in the youngest forest age group of 0-20 years, maximal -- 2155 individuals per square kilometer in pine forests aged over 100 years. Analysis of diff erent population densities of ecological groups reveals steadily growing numbers of hollow-nesting birds and tree-nesting birds in accordance with aging of the forests. In older forests hollow-nesting birds constitute an absolute majority. Population density of another ecological group shows no such direct tendency. [ABSTRACT FROM AUTHOR] |
