Non-anthropogenic dynamic factors and regeneration of (hemi)boreal urban woodlands – synthesising urban and rural ecological knowledge

The natural dynamics of urban woodlands are seldom discussed despite the general acknowledgement that understanding of natural processes is a prerequisite for successful management of ecosystems. This paper reviews the non-anthropogenic dynamic factors, and anthropogenic changes in them, in urban woodlands. Several gaps in the knowledge are identified: (1) amount of tree regeneration and factors affecting it, (2) seedbed availability for poor competitors, (3) wind as a dynamic factor, (4) insect outbreak severity, (5) effect of urban climate on tree regeneration, (6) pollination and dispersal and (7) effect of herbivory on tree regeneration. It is concluded that natural dynamics drive regeneration in urban woodlands, but the disturbance regime and successional pathways may be altered. Natural colonisation of derelict land and natural dynamics in existing woodlands are beneficial because of decreased management costs, and the biodiversity, educational, recreational and psychological values they provide.