Finland: Restoration of Semi-natural Meadows using Sheep

Project Stage:
Completed

Start Date:
1996-01-01

End Date:
2000-12-31

Primary Causes of Degradation

Degradation Description

The threat to species richness in these ecosystems is the rapid decline of semi-natural meadows which has taken place during recent decades in many European countries. In Finland, the area of these meadows reached a maximum of 1.6 million hectares in the 1880s, but had declined to only 18,690 hectares in the 1990s. The meadow’s composition differs from other previously described vegetation, partly because of eutrophication, shrub encroachment, and the decline of traditional management methods that are all cited as reasons for the decline. The plowing and sowing of commercial forage plants and the use of chemical fertilizers and pesticides have impoverished the flora and fauna in these specific habitats. The plots used in the project were established in 1996 in a former pasture that had been used until 1969 and then only occasionally in the 1980s.

Reference Ecosystem Description

Traditional, low intensity management of semi-natural grasslands has enriched the flora and fauna in many European countries. Many species are dependent on these man-made environments, in Finland 28% of the threatened plant and animal species live on semi-natural grasslands.

Project Goals

This project sought to examine whether the responses of different functional plant groups to grazing could be used in evaluating the success of restoration of the species richness and composition in an overgrown mesic meadow. These groups represent different successional stages and thus their reactions to grazing indicate the direction and speed of change during restoration. When the responses of different species are understood, then management practices can be optimized.

Monitoring

The project does not have a monitoring plan.

Stakeholders

The project was critical to understand the many changes that had taken place in the Finnish semi-natural meadows over the last century. Because of the precipitous decline in the acreage of semi-natural meadows in Finland it was seen as critical that due to land abandonment, to changes in the agricultural system, and to the continuing outright decline in the type’s coverage; all were cited as reasons for intervention and restoration.

Description of Project Activities:
The experimental plots where the project were conducted were at two meadow patches, ca. 50 m apart. At both sites, seven 1-sq m permanent plots were located in a 10 m x 10 m grid. Seven of these plots were selected by stratified random sampling to be grazed and seven were protected from grazing by fencing (controls). The east site (E) had three grazed and four control plots and there were four grazed and three controls on the west site (W). In the first year of the survey, grazing started in early August and continued until the beginning of October. In 1997-1999, the grazing period was 1 July to 30 Sept. (in two periods of 2-3 weeks). The stocking rate was 15 sheep to an area of ca. 1.5 ha, grazed to low height. Percentage cover of all vascular plant species and litter was visually estimated for each square meter plot in mid-June each year recognized set cover values. The same person estimated cover throughout the project. The change in vegetation was studied by looking at the reactions of different functional plant groups: herbs vs. grasses, tall vs. short species, species differing in flowering time, species representing different Grime's CSR strategies, and species that were indicative of rich vs. poor soil. Using all of these functional traits and classifications, species were classified into seven ecological groups. Soil analysis was done at the beginning of the experiment in 1996, with samples taken just outside the corner of each plot and all the data was pooled.

Ecological Outcomes Achieved

Eliminate existing threats to the ecosystem:
At the beginning of the experiment, the mean number of vascular plant species per plot was ca. 14 in both grazed and ungrazed plots. After three years of grazing, the number of species started to increase in the grazed plots, but remained constant in the exclosures. By year 5 (2000), the mean number of species in the grazed plots had increased by 4.1 ± 0.9 (mean ± 1 s.e.) species. Most species that invaded grazed plots were already present in the community. Their cover increased when grazing removed the accumulated litter and suppressed the dominant species. Some small herbs, indicating the success of management invaded the grazed plots: Rhinanthus minor (invaded two plots), Cerastium fontanum (3), Stellaria graminea (3), Trifolium pratense (3) and Taraxacum spec. (four plots). Litter cover decreased in the grazed plots compared to the controls and at the end of the study in grazed plots litter was minimal when cover in the control plots was 31%. Grazing had little effect on the early flowering tall herbs Anthriscus sylvestris and Geranium sylvaticum as they had already flowered and started to reallocate resources to their roots when grazing started in July. In contrast, Epilobium angustifolium and Filipendula ulmaria are tall herbs, flowering at the end of July which explains their decrease in the grazed plots results indicate that the abundance of these tall herbs (C strategists) can be decreased if grazing occurs just before flowering. Small herbs increased in cover when grazing suppressed the cover of competitively superior tall herbs and decreased the litter cover. Many of these herbs are general strategists and grow in various habitats. Grazing favored some small and creeping herbs, such as Cerastium fontanum, Stellaria graminea and Trifolium pratense. Ranunculus acris and Trollius europaeus are poisonous species and are avoided by grazers. Two C-strategy tall grasses, Alopecurus pratensis and Elymus repens, decreased in response to grazing. These grasses are nitrophilous to some extent, and are therefore expected to decrease in the long-term when grazing removes nutrients via consumed biomass. In contrast, smaller grasses that favour intermediate rich soil conditions, i.e. Agrostis capillaris (CSR-strategist), Anthoxanthum odoratum and Festuca ovina (S-stress tolerators), increased due to grazing. The results suggest that it is useful to study the responses of different functional plant groups to grazing. Individual species may be too scarce for changes in their abundances to be seen but by following reasonable species groups much valuable data could be acquired. By using this information grassland managers can optimize the method and timing of management practices to succeed in restoration.

Factors limiting recovery of the ecosystem:
Mere low intensity sheep grazing has been successful in managing low productive hill pastures. In more productive habitats, however, a surplus of soil nutrients may retard the change of vegetation, and hence grazing along may be insufficient to achieve quick results. In this project, a combination of early mowing followed by grazing would probably have given better results. Early mowing combined with grazing would effectively suppress the dominance of early flowering tall herbs. Another possibility is to start grazing earlier in summer. Spring grazing has been shown to increase species richness in low land meadows, but in long used upland meadows some of these strategies had no effect on species richness.

Socio-Economic & Community Outcomes Achieved

Economic vitality and local livelihoods:
Grazing increased the mean number of species per plot by 29.5% with this project, but the increase was largely due to the spread of species already present in the community. The slow increase in the number of species might result from the lack of old managed meadows in close proximity to the restoration site. This indicates that no artificial input of diasporas is needed where there is a sufficiently rich, local species pool. Sometimes the presence of a seed bank my help, but most grassland species disappear from the seed bank after some years of abandonment. Grazing is preferred to mowing because animals are able to spread plant propagules.

Long-Term Management

The target community in this area will be a low productive meadow with many small herbs and grasses. Ordination of the data showed that the community moved towards the desired state with many small growing herbs, following grazing. Small herbs that are currently absent, but those which could be imported into and spread in the area include Antennaria dioica, Erigeron acer, Fragaria vesca, Leucanthemum vulgare, and Veronica officinalis. One point for further monitoring is to evaluate if these species do have time to migrate in from nearby remnant meadows. The time frame of this study may not have allowed for that to have happened. One final note is that the development of such a species-rich meadow may take decades to restore.

Sources and Amounts of Funding

The project was financially supported by The Academy of Finland (projects 35558 and 40951) and the Kone Foundation. The land on which the project was conducted was offered for study by the landowner and the project utilized a local farmer’s sheep during the four years of the project 1996-1999.

Primary Contact

Organizational Contact