The changing structure and tree composition in the traditionally grazed forests in the parish of Stenbrohult, southern Sweden
Author
Summary, in English
The formerly grazed forest (utmark) was the dominant land use on most farms in southern Sweden until about 100 years ago. Here I describe the changed structure and tree species composition over time of the utmark on three farms owned by the church in the central part of Stenbrohult. In this area Carl Linnaeus spent his first 20 summers until 1728. The study is based on old forest management plans, other old documents, published and unpublished pollen analyses from 3 small bogs, tree ages on a clearcut in 1974, own measurements of vegetation and other observations during the last 50 years.
Slash-and-burn cultivation (each treated plot usually 1600 – 2100 m2) occurred annually on all three farms in the 1790ies, but it is unknown when this land use ceased on these farms. The first detailed forest management plan is from 1878, but pollen analyses reveal a decrease of deciduous trees and an opening up of the forest until about 1850. The utmark was about 67 % of the farms total area around 1880. At this time the grazed forest was very heterogeneous with many small and a few larger open mires. Total proportion of mire (open fen and bog) was 15 – 36 % of the utmark on the three farms. There were many other openings in the forests, including a few due to forest cuttings (about 0.1–0.5 ha each year on a farm). The old forest planned for cutting at that time was dominated by pine Pinus and spruce Picea, but sometimes with much birches Betula (Table 2). However, most of the utmark was an open birch-dominated forest (tree volumes usually 20 – 80 cubic meter per ha). Later these birch trees were cut, to be used as firewood on the farms, which transformed the older forest to a dense coniferous forest dominated by spruce. This old forest was recently cut (mainly in the 1980ies), the small mires were drained and spruce was planted. The dense regeneration of birches, oaks, aspen and beeches on the clearcuts have been cleared around the planted spruces. Thus, during the last 150 years there has been a drastic transformation due to man from an open mixed birch-dominated forest grazed mainly by cattle to a dense spruce-dominated forest without domestic animals. The documented forest management on these farms refute the climate and spruce immigration hypotheses as explanations for the recent changing tree species composition in southern Sweden. Spruce has been actively promoted by man and his domestic animals more than 100 years in this area and I suggest that this is a general pattern in large regions.
Slash-and-burn cultivation (each treated plot usually 1600 – 2100 m2) occurred annually on all three farms in the 1790ies, but it is unknown when this land use ceased on these farms. The first detailed forest management plan is from 1878, but pollen analyses reveal a decrease of deciduous trees and an opening up of the forest until about 1850. The utmark was about 67 % of the farms total area around 1880. At this time the grazed forest was very heterogeneous with many small and a few larger open mires. Total proportion of mire (open fen and bog) was 15 – 36 % of the utmark on the three farms. There were many other openings in the forests, including a few due to forest cuttings (about 0.1–0.5 ha each year on a farm). The old forest planned for cutting at that time was dominated by pine Pinus and spruce Picea, but sometimes with much birches Betula (Table 2). However, most of the utmark was an open birch-dominated forest (tree volumes usually 20 – 80 cubic meter per ha). Later these birch trees were cut, to be used as firewood on the farms, which transformed the older forest to a dense coniferous forest dominated by spruce. This old forest was recently cut (mainly in the 1980ies), the small mires were drained and spruce was planted. The dense regeneration of birches, oaks, aspen and beeches on the clearcuts have been cleared around the planted spruces. Thus, during the last 150 years there has been a drastic transformation due to man from an open mixed birch-dominated forest grazed mainly by cattle to a dense spruce-dominated forest without domestic animals. The documented forest management on these farms refute the climate and spruce immigration hypotheses as explanations for the recent changing tree species composition in southern Sweden. Spruce has been actively promoted by man and his domestic animals more than 100 years in this area and I suggest that this is a general pattern in large regions.
Department/s
Publishing year
2006
Language
Swedish
Pages
393-412
Publication/Series
Svensk Botanisk Tidskrift
Volume
100
Issue
6
Full text
Document type
Journal article
Publisher
Svenska Botaniska Föreningen
Topic
- Ecology
Keywords
- Linnaeus
- Betula
- history
- grazing
- land use
- Stenbrohult
- forest
- Picea
Status
Published
ISBN/ISSN/Other
- ISSN: 0039-646X