Suo - Mires and peat vol. 51 no. 2 | 2000

Cultivation experiments on D. rotundifolia and D. anglica were carried out in peat beds in Mikkeli, South Finland (61°44’ N, 27°18’ E) in 1992-1997. Plants were propagated by direct sowing and transplanting of small seedlings in peat beds (size 3 m2, depth 0.7 m) filled with non-fertilized peat (pH 4.0). Seed germination, growth, flowering cycle as well as fresh herb and seed yields were measured. To increase the growth, plants were regularly fed milk powder. The 7-methyljuglone, quercetin and kaempferol contents of the flowers, leaves and stems were determined from sown and transplanted, fed and non-fed Drosera plants. Both Drosera species were successfully cultivated in peat beds. Direct sowing in autumn followed by natural winter stratification seemed to be the best propagation method. Flowering started after the second and third growing years. Feeding the plants milk powder increased growth by 27-113%. The fresh yield during the third, fourth and fifth years ranged between 0.05 and 0.9 kg m-2, being highest in the first and second harvest years. Plant density decides the yield of small-sized species. The average yield was about 50 times higher in peat beds than in the nature. Feeding milk powder did not affect the secondary metabolite contents. The 7-methyljuglone content was 13-81% higher in the fed Drosera rotundifolia plants than in the non-fed ones. The quercetin and kaempferol contents were lower in the fed plant, 10-30% and 1-10% lower in D. rotundifolia and 30-60% and 1-15% lower in D. anglica, respectively. According to the results, it seems to be possible to grow Drosera rotundifolia and D. anglica under controlled conditions outside the natural ecosystem. The results also suggest that higher yields can be expected by cultivation of these species.

• Galambosi, Ecological Production, Resource Management, Agricultural Research Centre of Finland, FIN-50600 Mikkeli, Finland Sähköposti: ei.tietoa@nn.oo
• Galambosi, Sähköposti: ei.tietoa@nn.oo
• Repcák, Sähköposti: ei.tietoa@nn.oo

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.

• Galambosi, Ecological Production, Resource Management, Agricultural Research Centre of Finland, FIN-50600 Mikkeli, Finland Sähköposti: ei.tietoa@nn.oo
• Takkunen, Sähköposti: ei.tietoa@nn.oo
• Repcák, Sähköposti: ei.tietoa@nn.oo

Summary: The habitats of particular significance referred to in the forest act 10 § include following mire site types: herb-rich spruce swamp woods, eutrophic fens (south of the Province of Lapland) and scrubland and wasteland sparsely treed mires. Lounais-Suomi forestry centre has invented those habitats of particular significance 1997-99. This matter was also studied by the 9th National Forestry Inventory (1998). The detailed directions concerning mire site types of habitats of the forest act are performed by quide Meriluoto & Soininen (1998). Also Lounais-Suomi forestry centre has observed mainly this quide. There is however a problem with some site types for ex. herb-rich sedge hardwood-spruce fens and herb-rich sedge birch-pine fens of scrubland and wasteland, which are not classified for habitats of the forest act. Because they are rare and there is no clear legal obstacle, those mire site types are also classified habitats of the forest act by Lounais-Suomi forestry centre. Only 25 % of the mires are in Southwest Finland are in virgin state and about 15 % of these mires are located in nature preserve areas. The inventory result of the forestry centre states, that there are 863 hectacres of mire habitats of particular significance referred to in the forest act in Southwest Finland mires, which is only 1.4 % of virgin mires outside nature preserve areas. NFI 9 found three times more habitats of the forest act than the inventory of the forestry centre, because NFI 9 cannot take into account territorial frequency of habitats and demand of small size of objective. However the distribution of mire site types is similar in both inventories. The inventory result of Lounais-Suomi forestry centre proves that there is a relatively small number of herb-rich level mire site types. Especially herb-rich sedge hardwood-spruce fen (RhSK) is very rare. It is important to classify all herb-rich level mires (taking into account the restrictions of the forest act) for habitats of the forest act in the future and also in natural state which is not wholly perfect. Nutrient-poor bogs are mainly consisted of virgin mire site types. They are often large mire complexes and in that sense not suitable habitats of the forest act. In this inventory nutrient-poor bogs represent one fourth of the total number. In the future it is sensible to choose only the most representative nutrient-poor bogs for habitats of the forest act.

• Silver, Sähköposti: ei.tietoa@nn.oo
• Kajava, Sähköposti: ei.tietoa@nn.oo