%0 Research note
%T Forest habitat loss and fragmentation in Central Poland during the last 100 years
%A Mazgajski, Tomasz D.
%A Zmihorski, Michal
%A Abramowicz, Katarzyna
%D 2010
%J Silva Fennica
%V 44
%N 4
%R doi:10.14214/sf.136
%U https://silvafennica.fi/article/136
%X The process of habitat fragmentation consists of two components –  habitat loss and fragmentation per se. Both are thought to be among the  most important threats to biodiversity. However, the biological  consequences of this process such as species occurrence, abundance, or  genetic structure of population are driven by current, as well as  previous, landscape configurations. Therefore, historical analyses of  habitat distribution are of great importance in explaining the current  species distribution. In our analysis, we describe the forest  fragmentation process for an area of 178 km<sup>2</sup> in the northern  part of Mazowsze region of central Poland. Topographical maps from the  years 1890, 1957 and 1989 were used. Over the 100-year period, forest  coverage in this area changed from 17% to 5.6%, the number of patches  increased from 19 to 42, while the area of the forest interior decreased  from 1933 ha to 371 ha. The two components of fragmentation were  clearly separated in time. Habitat loss occurred mainly during the first  period (1890–1957) and fragmentation per se in the second (1957–1989).  Moreover, we recorded that only 47.7% of all the currently (in 1989)  afforested areas constitute sites where forests previously occurred (in  1890 and 1957). For forest dwelling organisms characterized by low  dispersal abilities, the effective forest coverage seems to be a half of  the real forest area in the studied landscape. New afforestations  should be planned especially to increase those patches which contain  ancient forest, where various plants and animals sensitive to  fragmentation may have survived.