 (Elveland, 1983). The yearly production of graminoids on the acidic mires that are common in northern Sweden may amount to around 50 g/m2, whereas less acidic mires and those influenced by spring water may produce up to 250 g/m2 (Moen, 1976). In the coastal part of northern Sweden, practically all mires suitable for hay production were in use already in the beginning of the Middle Ages (Zackrisson, 1976a), and by the late 1800s, this was the case also in the interior (Bylund, 1956; Zackrisson, 1976b).
Because haymaking implies a substantial removal of biomass, it is believed to cause nutrient depletion (Frödin, 1952). In addition, the disturbance caused by mowing may induce a reduction in biomass (Moen, Lyngstad, and Øien, 2015). Therefore, it was common practice to harvest mire meadows only every second year (Frödin, 1952; Moen, Lyngstad, and Øien, 2015). By contrast, periodically flooded littoral meadows could be harvested every year. Inspired by this natural productivity boost, many farmers turned to artificial flooding of mires through either seasonal damming or installation of catchwork irrigation systems (Campbell, 1982 ; Elveland, 1979). In Västerbotten County in northern Sweden, at least 10,000 ha of irrigated meadows were reportedly created between 1834 and 1860 (Frödin, 1952: 171).
More radical measures were both widely discussed and attempted in Sweden during the 1700s and 1800s (Strandin Pers, 2012). The population was growing, more arable land was desperately needed, and reclamation of mires seemed to be the obvious solution (Arrhenius, 1884). Despite the skepticism of some authors, influential scholars asserted that virtually all mires were potentially arable, if only they were ditched and fertilized (Hellström, 1917: 204; Osvald, 1937: 233; Strandin Pers, 2012: 128–132). In northern Sweden, mires were considered to be particularly suitable for the production of animal fodder such as oat, turnips, and hay, enabling the keeping of even more livestock and thus the production of more manure to fertilize fields on mineral soils (Bosin, 1901). Ditching of mires was also believed to prevent frost damage on nearby arable land (Hellström, 1917: 36–41). In the 1840s, the Swedish government therefore introduced subsidies for ditching projects (Hellström, 1917: 222). Between 1841 and 1914, subsidies funded more than 1,500 such projects in Västerbotten County, leading to the creation of more than 138,000 ha of drained land (Hellström, 1917: 223). Similar payments continued well into the 1930s (Bunte, Borgegård, and Gaunitz, 1982: 199).
During the 1800s, forestry became a growing industry, and some large landowners believed that trees could be produced on almost any mire if only it was properly ditched (Kempe, 1909). Forest ditching became a common practice during the first half of the 1900s, periodically subsidized by the state to mitigate unemployment (Eliasson, 2008). According to the Swedish Wetland Survey, between 25% and 90% of the larger wetlands in Västerbotten County (depending on municipality) have been subjected to ditching for either agricultural or silvicultural purposes (Forslund, Löfroth, and Rundlöf Forslund, 1994). Ditching to increase tree growth was much more common and also continued longer, because marginal arable lands began to be abandoned around 1920 (Hånell, 1990). In 1986, new legislation introduced permitting requirements for drainage of new wetlands for silvicultural purposes, leading to an almost complete abandonment of this activity (Hånell, 1990).
Finally, mires have been used for extraction of peat. During the late 1800s, it became common practice in northern Sweden to use dried peat as beddings in stalls (Hellström, 1917). Later, the peat extraction industry developed for both energy production and soil amendment in parts of Sweden. This type of industrial-scale extraction is totally destructive for mires. Only relatively small areas have been exploited, however. In 2002, there were about 20 permits for peat extraction in Västerbotten County, covering about 5,000 ha, but only one active