Parro, K., Köster, K., Jõgiste, K. and Vodde, F. 2009. Vegetation Dynamics in a Fire Damaged Forest Area: the Response of Major Ground Vegetation Species. Baltic Forestry, 15 (2): 206-215
As fire is inherent to boreal forest, sustainable forest management should consider emulating this disturbance type, taking into account the natural fire regime and the historical impact of humans. Fire often removes the dominant species and reveals mineral soil, which allows new species to spread on burned areas. Variable conditions provide habitat for many different species. Fire is sometimes necessary for the retention of species, which do not regenerate in the absence of fire. Fire-damaged forest stands are often salvage logged. The necessity of this procedure can be disputed, as the cleaning may decrease biodiversity, favour pioneer herbs and shrubs, which are highly competitive with tree regeneration, and disturb the ecosystem’s nutrient cycle. The effect of burning and post-fire cleaning was studied. Ground vegetation was investigated during three subsequent years, 2004–2006, in fire-damaged pine forest areas in North-western and South-eastern Estonia, both dry and wet site types. Fire occurred 10–12 years prior to the inventories in the first and 2–4 years in the latter. The vegetation survey took place on 2×2m squares undergoing three different treatments: Burnt and Cleaned (BC), Burnt and Uncleaned (BU) and Control (CO). Floral composition differed significantly between treatments. Biodiversity was higher on burnt plots than in control plots in humid areas and lower in dry areas. On dry sites, Molinea caerulea and Calluna vulgaris benefit from cleaning, which may hamper pine regeneration. Prescribed burning on such sites can reduce the fire risk. On wet sites, there was no significant difference between pioneer and shade-tolerant species between cleaned and uncleaned areas. Whether cleaning after fire should be maintained as a management action therefore depends greatly on the forest site type and other circumstances, such as management objectives and surrounding stands.
Key words: boreal forest, ground vegetation, succession, prescribed fire, post-fire management, salvage logging