Effects of forest management on biodiversity in temperate deciduous forests: An overview based on Central European beech forests

Abstract

This overview of relationships between biodiversity and management focuses on Central European Fagus forests. Present management and conservation activities are embedded in the geographic and historic background of Central European forest flora, including endangered, protected, and plant species for which Germany has taken special responsibility to ensure their future survival. Managed and unmanaged forests are compared with respect to plants and other organisms. Based on the floristic background, management for climate change and consequences of conservation on a global ecological footprint will be discussed.The Central European tree flora contains only about 7% of the tree diversity of East Asia. Only a few genera re-migrated to Central Europe after the Pleistocene, while others were lost during the Pleistocene, e.g. the genus Pseudotsuga.In this study the forest flora is characterized by specialized plant species that only grow in forests. These forest specialists contribute only 10% of the plant species of the total German flora. This fraction is even less (4–5%) for Romania which is generally regarded as a region with close to “natural” forest conditions. Also, the forest flora of Germany and Romania contains fewer apomictic and hybrid plant species than the non-forest flora. No forest plant species have gone extinct in Germany in the past 250 years, which is the time since the first floristic documentation of a plant species that was lost in Thuringia, despite intense forest use including changes in dominant tree species.With respect to the Natura 2000 goals of maintaining species diversity of Europe, the deciduous forest, as managed by rotation forestry, contain more protected and endangered species, and species for which Germany has taken responsibility than protected forest. Forests managed with permanent forest cover (so-called “management close-to-nature”) contain fewer plant species than age-class (rotation) forestry. The abundance of dead wood-fungi and of soil bacteria is higher in rotation forest than in protected forests. For the initial phase of decay, a dead wood experiment identified two important tree species, Carpinus betulus and Picea abies, as the most preferred tree species for xylobionts. Carpinus has the most diverse fungal flora among all wood types and is a typical species for managed forests.The Natura 2000 habitat types were defined by plant species, but the assessment of ecosystem health is based on bird species in Central Europe. A time series extending from 1927 until 2015 indicates that most non-migratory forest bird species show an increasing abundance since 1970. Adding migrating and rare bird species populations resulted in constant average abundances since 1970. There is no evidence that sustainable forest management has led to decreased biodiversity in Central Europe. In view of climate change and increasing presence of tree diseases, Europe should avoid enlarging its ecological footprint by taking Central European forests out of management.