Norwegian Journal of Agricultural Sciences : above- and below-groundbiomassof boreal outlying hay-lands at the Solendet nature reserve, Central Norway

Abstract

Studies of the above- and below-ground biomass of the field-layer species were carried out in permanent plots in two communities of rich fen and two communities of wooded grassland at the Slendet nature reserve in the years 1992-94. The method used is based on the numbers of individuals of the species and their mean individual weights. The results show an overall tendency for biomass to decrease, both above and below ground, and for both the number of shoots and the ratio of above-ground/below-ground biomass to increase with increasing scything frequency. The highest biomass values were recorded in the tall-herb birch woodland, with total biomasses of about 4000, 9000 and 12,000 kg-ha·' for plots scythed annually, biennially, or not scythed for more than 40 years, respectively. The lowest biomass values were found in the rich fen margin community, with total biomasses of about 1700, 2000 and 5300 kg-ha', respectively. The number of individuals was highest in the open rich fen community (more than 6000 per m2), and lowest in the overgrown, tall-herb community (1000 per m^2). There were also considerable differences in biomass values and in the numbers of shoots between years. It is postulated that this may partly be due to fluctuations in the climatic conditions, but the effect of some methodological bias is also stressed.