%0 Research Notes %T The effect of regular collection of Drosera rotundifolia in natural peatlands in Finland: plant density, yield and regeneration %A Galambosi, Bertalan %A Takkunen, Niilo %A Repcák, Miroslav %D 2000 %J Suo - Mires and peat %V 51 %N 2 %U http://suo.fi/article/9788 %X Yield potential and the effect of strict collection on the regeneration of natural populations of Drosera rotundifolia were studied in Finland during 1993-1999. Flowering plants were collected in July from 37 sample plots 1 m2 in size. Plant number, height of flowering plants, fresh weight as well as 7-methyljuglone, quercetin and kaempferol contents were determined. The average plant density was 45-56 plants m-2, and the average fresh weight was 6.3-6.7 g m-2 in the first and second years of collection. Regular and strict collection decreased significantly the population density. The average plant number in the third and seventh years ranged between 21 and 29 plants m-2. The collected fresh weight decreased respectively from 6.7g m-2 to 2.7g m-2. At the end of the vegetation periods the number of new seedlings averaged 188 m-2 on the observation plots, implying that the population may easily regenerate from the seed bank stock of the peat. According to the results of these experiments, the 4H organization elaborated a new, environmentally friendly collection programme for young collectors. The collectors were obliged to leave 5-10 flowering plants to spread seed and to assure natural regeneration of sundew populations.