Abstract

The aims of this study were to (i) calculate the coverage and location of drained peatlands which from an environmental perspective are the most suitable for peat harvesting in Sweden, and (ii) to calculate the volumes of peat on drained and un-drained peatlands as a basis for an analysis of the potential for sustainable future peat harvesting in the country. Data were selected from the Swedish National Forest Inventory of Forests, more specifically from the National Forest Inventory 1993-1997 and 1998-2002, and from the Swedish Forest Soil Inventory 2003-2004. The area of productive forest land covered with peat thicker than 1 m comprises about 700,000 ha, half on drained and half on un-drained sites (Fig. 1, Appendix 1). Deep peat lay-ers are especially common in the provinces of Småland and Västerbotten (southern and coastal parts, respectively), cf. Fig 2. The area of non-productive mires with thick (> 1 m) peat cover encompasses ca 2.6 million ha. About 200,000 of these mires are drained (Fig. 3, Fig. 4, Appendix 2). Half of the drained forest land with thick peat, about 180,000 ha, belongs to peatland sites greater than 10 ha which can be regarded as the minimum size for profitable peat harvesting (Fig 5a). As for the drained non-productive mires, less than a quarter of the area has to be rejected as potential sites for harvesting because of being too small size (Fig 5b). In total, about 180,000 ha of drained forest land and 165,000 ha of drained non-productive mires with thick peat can be regarded as the country’s potential for peat harvesting. The emission of greenhouse gases is greater from highly productive than from low-productive drained peatlands. The dominant part of the drained forest land belongs to the three most pro-ductive site types (Fig. 6, Appendix 5). A change in the ongoing land use, from forestry to peat harvesting, should be least expensive immediately after final felling of a mature forest (and before the establishment of a new generation of trees). The stands on the drained produc-tive forest land are fairly evenly distributed across on maturity classes. Areas where final fell-ing has recently has been carried out, and stands ready for final felling in near future, consti-tute the largest proportion of the drained productive forest land (Fig. 7, Appendix 6). The total volume of peat on drained peatlands was assessed as 18 billion m3. Two thirds of this volume is on productive forest land and one third on non-productive mires (Table 2a). After eliminating sites smaller than 10 ha and sites with peat layers shallower than 1 m, about 5.3 billion m3 on drained productive forest land and ca 3.9 billion m3 on drained non-productive mires, i.e. a total of 9.2 billion m3, remains as having as the potential area for peat harvesting. Based on the present harvesting pace, about 12 million m3 per year, the peat with a potential for harvesting will last for 440 years on the forest land and for 325 years on the mires for a total of more than 750 years (Table 4a). The total peat volume on all drained and un-drained peatlands in the country is approximately 95 billion m3. An alternative, more conservative, calculation where some area figures in the (smaller) data set from the Forest Soil Inventory were changed to correspond to the (greater and more reliable) area data set in the National Forest Inventory, resulted in a total peat vol-ume of 7.4 billion m3 that would last for about 600 years of harvesting (Table 4b)

Keywords

torvmarksresurs; torvutvinning; dikad mark; djup torv; torvmarksareal; myrmarksareal

Published in

Journal name missing
2006, number: 5
Publisher: Stiftelsen TorvForsk

SLU Authors

• Hånell, Björn

  • Department of Silviculture, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Renewable Bioenergy Research
Environmental Sciences related to Agriculture and Land-use
Forest Science


Permanent link to this page (URI)

https://res.slu.se/id/publ/8590