Impact of postfire management on forest regeneration in a managed hemiboreal forest, Estonia

Fire is a significant agent for the development of boreal and hemiboreal forests, altering soil and light conditions, affecting seedbanks, and removing seed trees. Burned areas should be managed with care, as inappropriate techniques prolong the regeneration period and reduce the diversity and resilience of stands to disturbances. To study the effects of fire and postfire management on the successional changes in regeneration abundance, species composition and tree height sample plots were established in sandy pine forests in northwestern Estonia on areas burned 2 or 22 years ago. Five types of sample plots were established: (i) areas without fire damage, (ii) burned uncleared areas, (iii) burned forest areas cleared after forest fire, (iv) burned uncleared areas with live trees, and (v) burned uncleared areas with dead trees. Three main tree species common to hemiboreal forests were analyzed: Betula spp., Pinus sylvestris L., and Populus tremula L. Results showed that clearing burned areas after wildfire significantly reduced the abundance of regeneration compared with burned uncleared areas but favored height growth of P. sylvestris in later development. To regenerate and maintain mixed stands after wildfire, retaining some residual trees can facilitate regeneration compared with complete clearing, although a dense stand with live trees or a large amount of deadwood can hinder regeneration.