Research of the spatial distribution of black stork (Ciconia nigra L.) nests in Ukrainian forest zone (Рolissia) revealed by an overlay analysis in GIS. Features distribution of Black Stork nests in the forests with different prevailing tree species.
Аннотация к работе
The analysis was performed on the level of individual nests (spatial join to point layer), and on the level of buffers with 500m radius around nests. To find the most preferable forest types for Black Stork we compared the frequency of distribution of forest types on the nesting territories with the frequency of distribution of those types in the study area and in 500m buffers around 108 random points. According to the results of our research, the spatial distribution of Black Stork nests to a great extant follows the general structure of forests in the region. We found some selectivity in case of wet forest types with prevalence of oak with pine, as well as with black alder, but the result is not statistically significant. The only statistically significant relation was found in case of forest age. Black Storks prefer old and mature forests. The most important trees for nesting were oak (53,3%) and pine (29,9%). Of course, many of those nests are used by the same pairs, but we cannot distinctly separate them. Moreover, in Ukraine 500 m buffers are proposed as a zone of strict protection of the species, so it seemed reasonable for us to use such a distance for the analysis. Fig. 2. Example of a forest structure analysis in 500 m buffers around nests (in this particular case - the comparison of areas of different forest types; the areas were calculated in GIS and stored in the attributive table) In total, in the analysis we have used location information from 100-108 nests and attributive information about the forest age, type, productivity, main tree species and vegetation-humidity types from 148000 forest plots (so-called vydil - the smallest forest unit in Ukraine).