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НАУКОВІ ЗАПИСКИ ДЕРЖАВНОГО ПРИ РОДОЗНАВЧОГО МУЗЕЮ
              Випуск 33                        Львів, 2017                      С. 23-32

            УДК 591.5:598.244]:911.5(477.41/.42)

            Bokotey A., Strus Iu., Dzubenko N.

            NESTING HABITATS OF BLACK STORK (CICONIA NIGRA L.) IN UKRAINIAN
            FOREST ZONE (POLISSIA) REVEALED BY AN OVERLAY ANALYSIS IN GIS

                  The study was based on an overlay analysis in GIS. Exact locations of 108 nest and layers
               representing forest types, prevailing tree species, forest age and productivity (bonitet class)
               were used. 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%).
                  Keywords: Black Stork, Ciconia nigra, habitats, GIS.

                                            Introduction

               Conservation  of  any  species  is  usually  impossible  without  protection  of  habitats
            important  for  their  breeding,  foraging,  resting  etc.  Black  Stork  is  one  of  most  habitat-
            dependent species of birds in Europe, because it is strongly dependent on the availability of
            mature forests and trees with a low level of disturbance. There is a large number of papers
            devoted to Black Stork habitat preferences in Europe. Most of them are based on the studies
            made in Central and East European countries [1, 4, 7, 11, 12 etc.], mostly Baltic countries,
            which is reasonable, taking into account the species distribution in Europe and the sizes of
            national populations [2, 10].
               Ukraine possesses a significant part of the European Black Stork population [2, 10] and
            is interesting as a territory of breeding range margin, where European Forest zone borders
            with steppes. The Ukrainian population may be underestimated and might actually be much
            bigger.  No  detailed  studies  of  Black  Stork  breeding  habitats  in  Ukraine  have  been
            conducted so far. Some generic works [5, 17, 17, 20 etc.] with the topic-related information
            have been published, yet there is a lack of specialized studies. One study [14] was related to
            habitats and their changes but was mostly analytical and based on expert opinions without
            appropriate raw numerical data. Current publication aims to fill some of gaps in this area of
            Black Stork studies using GIS approach.

                                         Materials and Methods

               The analysis of Black Stork spatial distribution in relation to forest habitat types was
            performed  in  the  territories  of  eight  forestry  companies  (table  1)  in  the  Rivne  region  of
            Ukraine, which overlap with the Polissya nature zone and with the kernel of Black Storks
            highest  population  density,  as  well  as  with  the  main  part  of  the  breeding  range  of  this
            species in Ukraine (fig. 1). The territories of other forestry companies in the region and
            known nesting locations from other parts of Ukrainian Polissya have not been covered by
            the analysis, because it was not possible to obtain databases of their forest structure so far.
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