title: The direct vs. indirect effect of fire on the distribution of some steppe origin plant species in boreal coniferous forests
reg no: ETF6229
project type: Estonian Science Foundation research grant
status: accepted
institution: University of Tartu
head of project: Rein Kalamees
duration: 01.01.2005 - 31.12.2008
description: Little is known about the actual role of forest wildfire in the maintenance and recruitment of steppe origin herbaceous species in boreal forests. In the past fire was the main factor causing large-scale disturbances, responsible for variation in forest age structure, soil environment and light climate. Due to the present-day intensive forestry practice forest fires are rare and this can be one of the reasons behind the decline of several potentially fire related plant species, e.g. Geranium bohemicum, Arenaria procera, Dracocephalum ruyschiana, Astragalus arenarius and Pulsatilla patens. In the total impact of burning, direct and indirect effects of fire should be distinguished. The former include those connected with heat and chemical changes in the environment (e.g. accumulation of charcoal leads to a decrease of poisonous phenolic compounds in ericaceous litter). The indirect effects operate through the improved light availability under burned canopies. The pilot study for this project shows that in the case of one species - Pulsatilla patens - the direct and indirect effects of burning can be contrasting. Burning generally enhances, but locally high radiation level retards the establishment of the seeds. The main aim of this study is to elucidate the role of fire in the distribution of a set of presumably fire-related rare species. The hypothesis about the diametrically opposite nature of direct vs. indirect effects of burning will be tested. The fire-dependence of the selected species will be studied in a series of garden and field experiments. In the garden experiments the presence of phenol-rich ericaceous litter, the presence of (highly absorbent) charcoal, and light availability will be experimentally manipulated in a factorial design. Field experiments will be established in Estonian forest wildfire areas and in the prescribed burning experimental sites in Evo, Finland. The results will provide optimal management instructions for the studied rare and protected species.

project group
no name institution position  
1.Rein KalameesUniversity of Tarturesearcher 
2.Mari LepikUniversity of Tartudoctoral student 
3.Kersti PüssaUniversity of Tartudoctoral student