Preference of plant species for woodlands with differing habitat continuities

In north-eastern Germany, the presence of 243 vascular plant species in 304 ancient woodlands (continuous existence > 200 years), 71 old woodlands (continuous existence since 150-100 years) and 103 recent woodlands was observed. The association of 75 species with ancient, old, and recent woodlands was tested by statistical methods. Twelve tree species, nine shrub species and 36 herb species are significantly associated with ancient woodland. Only one tree species and 12 herb species show a clear preference for recent woodlands. No species was predominantly or exclusively found in old woodlands. Besides the importance of habitat continuity, site factors and various life history traits of the plants explained the preferences for the different woodland types. Ancient woodland indicators reach significantly lower mean values for light, moisture, soil reaction and nitrogen. Moreover, most of them are stress-tolerant and adapted to low-level disturbances by man. Several species have an exclusive potential for short-distance dispersal. Nearly all recent woodland indicators are not typical woodland plants but competitive species with a relatively high tolerance towards human disturbance, being able to cover short and long distances. Species common to ancient and old woodland reflect both the impacts of forest management and a development towards a more or less typical wood, whereas species common to ancient and recent woodland mainly reflect the ability of some woodland plants to survive outside forests. The data show that it is very important to distinguish between ancient, old, and recent woodlands. This differentiation allows a clear interpretation of the actual distribution pattern regarding species diversity in the past, the present and the future.