Element release in beech (Fagus sylvatica L.) forest gaps

Nutrient cycling in forest gaps has received little attention until now, although gap regeneration is important to natural dynamics and forest management practices in temperate forests. Four gaps of 30 m diameter were cut in a mature beech forest (Fagus sylvatica L.) in the Selling Kills in 1989. Two gaps were limed. Atmospheric deposition, plant nutrient uptake, nitrogen mineralization, seepage water chemistry and element losses were compared between gaps and the surrounding mature stand. The most obvious changes in element cycles in gaps occured in the ecosystem losses of nitrate, cations and nitrous oxcide. The major difference in seepage water concentrations of nutrients among gaps was caused by the development of the herbaceous vegetation in the limed gaps. The concentrations of nitrate in the seepage water from the unlimed gaps exceeded drinking water standards. The results stress the importance of effective and early coupling of decomposition and nutrient uptake by new vegetation after tree removal. If soil acidity limits rapid revegetation, liming may be considered as a vegetation management practice.