Fifty years of landscape transformation in managed forests of Southern Finland

Intensive forest management has changed both local and regional characteris tics of Fennoscandian forest. However, quantitative documentation of landsc ape transformations is rare. In this study, five forest landscapes were exa mined in order to define and quantify forest landscape transformation in so uthern Finland from the 1940s to the 1970s and 19905. These areas of 140-20 0 km(2) contained both private and state-owned forests. Digital aerial phot ographs of each area were classified into no-canopy forest (clear-cut and s eedling stands, open mires) and closed-canopy forest (young and mature stan ds). Patch density, mean patch size, largest patch index and edge density c alculated for closed-canopy patches indicated fragmentation from the 1940s to the 1970s and recovery from the 1970s to the 1990s. Trends were very sim ilar in both ownership groups. Thus, fragmentation of closed-canopy forests has not progressed continuously in southern Finland, but shows different p atterns depending on the period. However. the recovery observed between the 1970s and 1990s does not necessarily mean an increased abundance of the na tural old-growth areas that are needed to host many of the currently threat ened species.