Background

Wildfires have burned large areas of forest in Central Europe in recent years, and the risk of fires is predicted to increase. However, this region is still underrepresented in fire ecology research. To help to fill this knowledge gap, we investigated post-fire vegetation composition and mean Ellenberg indicator values (EIV) in two burned Scots pine forests in NE Germany with different levels of salvage logging (no, partial, complete) in the first 6 years after a severe fire.

Results

Vegetation composition of burned plots differed drastically from unburned control plots, resulting in enhanced species richness (mainly due to open land species) and increased EIV for light, reaction, and nitrogen. In the first year, species richness was generally lower on completely salvage logged plots, as was EIV for light, reaction, and nitrogen. On non-salvage- and partially salvage logged plots, total species richness and the number of open land species, as well as forb cover, increased in the first 3 years and decreased thereafter. The number of forest species, as well as the cover of grasses and bryophytes, increased continuously on all plots. EIV for moisture, reaction, and nitrogen showed a temporal decrease.

Conclusions

We were able to show that even in the short period of up to 6 years after fire, vegetation changed rapidly. Post-fire species composition shifted from early open land pioneer species towards late successional forest species. Decreasing EIVs for reaction and nutrients indicate that the temporary increase in nutrient availability quickly dissipates, probably due to nutrient leaching. Post-fire management has a strong influence on post-fire vegetation. Even if some successional patterns remained similar for all salvage logging groups, recolonization of completely salvage logged plots was slower, resulting in lower species richness and ground vegetation cover. In the next years, the shift from pioneer towards late successional climax species will probably continue in our study areas as site conditions are expected to change further.