ification was usually simple. The only ambiguity regarding the 1805 map was the borderline between mire meadows and meadows alongside creeks, because the latter were not included in this study. However, these issues could be solved through a careful consideration of the map’s descriptions and drawings.
The maps from 1785 (Figure 2a), 1805 (Figure 2b) and 1880 (Figure 2c) were scanned and then georeferenced using GIS software (ArcView 3.3 with Image Analysis) (the map from 1702 was excluded as it clearly did not include any mires in the study area). From the 1785 map, mire meadows and unused mires inside and adjacent to the study area were digitized, but when we saw that none of the mire meadows were located inside the study area, the data was not treated any further. The map from 1805 did not lend itself to georeferencing, because the mire meadows were rarely shown in their geographical locations. Regardless, all of the mire meadows on the 1805 map could be identified from their names and shapes, and the area of each meadow was given in the map tables, so the area of the mire meadows located inside the study area was simply summed from this information. From the georeferenced 1880 map, all mires—mire meadows, peat pits, and unused mires—were digitized manually into polygons, and the area of each one was calculated using GIS.
The detailed relative grading included in the map tables from 1880 was used to assess the proportion of mire meadows and unused mires of different productivity and to explore whether there was any difference between the two types of mire.
Furthermore, we tried to identify management efforts undertaken to increase the productivity of mire meadows through a comparison of the 25 meadows that were listed in both 1805 and 1880. Because the 1805 data consisted of absolute yield assessments whereas the gradings from 1880 were relative to each other, the two data sets could not be compared directly, so we created rankings. For 1805, a yield in kg/ha was calculated for each meadow, and we then ranked meadows relative to each other. For 1880, the ranking was produced directly from the relative grades. We then compared the two rankings and identified the meadows that had raised at least 10 rank positions between 1805 and 1880, assuming that such a large change might be an indication of increased productivity due to active management.
As artificial irrigation through flooding was a common way of increasing the productivity of mire meadows, the archives of the Timber Floating Association were searched for information on dams used for this purpose. We also looked for records or signs of catchwork irrigation systems in all available sources.
We searched available literature for information on the reclamation of mires, including the reports from the Swedish Roads and Waters Agency (Väg- och vattenbyggnadsstyrelsen, 1872–1910). In those reports, we found data concerning Abborrtjärn village in the reports from 1898–1903. Also, among the historical maps available from Abborrtjärn village (Lantmäteriet, 2020a) we found a cadastral map from 1912 (Figure 2d), established for the division of a property, which showed a portion of a mire that had been reclaimed as arable land. Furthermore, we searched the archives of the County Administrative Board of Västerbotten for ditching maps and plans, created for state-subsidized ditching projects for agricultural purposes, and evaluated the ones concerning mires in the study area, dating from 1915–1933 (Figure 2e).
As we did not know if the archival sources covered all reclaimed mires, we assessed what proportion of the total mire area had been converted to arable land using the existing data set on land cover in 1963 obtained from aerial photos (Figure 2f). Because the abandonment of arable land in the municipality began in the early 1950s (Bunte, Borgegård, and Gaunitz, 1982: 300), the land that was no longer used could be expected to be distinguishable on these aerial photographs. We selected all polygons classified as ‘arable and pasture land’, or found in another land class but