Quick target vegetation recovery after restorative shrub removal and mowing in a calcareous fen
This study is summarised as evidence for the following.
Use cutting to control problematic large trees/shrubsAction Link
Use cutting/mowing to control problematic herbaceous plantsAction Link
Use cutting to control problematic large trees/shrubs
A site comparison study in 1995–2001 in an overgrown rich fen in Sweden (Sundberg 2011) found that following shrub/tree removal, the plant community composition became more like a natural fen, and plant species richness and vegetation cover increased. Between one and six years after shrub removal, the overall plant community composition became more like an open fen (data reported as a graphical analysis). Where shrubs were removed, species richness increased for vascular plants (from 15 to 18 species/m2), mosses (from 7 to 9 species/m2) and fen-characteristic plants (from 8 to 10 species/m2). Cover of these groups also increased (vascular plants: from 18 to 24%; mosses: from 9 to 31%; fen-characteristic plants: from 7 to 15%), as did cover of common cottongrass Eriophorum angustifolium (from 0.3 to 0.6%) and three of eight Carex sedge species. Cover of five other sedge species, purple moor grass Molinia caerulea and common reed Phragmites australis did not change. In 1995, shrubs (mainly juniper Juniperus communis) and trees (conifers) were manually cut and removed from a 30 x 50 m area of overgrown fen. The fen was grazed by 7–12 cows every summer, both before and after shrub removal. Cover of every plant species was estimated in August 1996 and 2001: in nine 1 m2 quadrats across the managed area and three quadrats in another part of the fen that had not become overgrown.
Use cutting/mowing to control problematic herbaceous plants
A replicated, randomized, paired, controlled, before-and-after study in 1996–2001 in a degraded rich fen in Sweden (Sundberg 2011) found that mown and unmown plots maintained a similar overall plant community and vegetation cover, but that mown plots developed greater plant species richness. The overall plant community composition changed over five years, but in a similar way in mown and unmown plots (data reported as a graphical analysis). Likewise, vegetation cover increased by similar amounts, from similar initial values, in mown and unmown plots. This was true for vascular plants, fen-characteristic plants, bryophytes, six of eight Carex sedge species, common cottongrass Eriophorum angustifolium, purple moor grass Molinia arundinacea and common reed Phragmites australis. After five years, mown plots contained more vascular plant species than unmown plots (26 vs 18 species/m2) and more fen-characteristic plant species (14 vs 10 species/m2). Before mowing, species richness was similar in all plots (vascular: 15; fen-characteristic: 7–8). In 1996, nine pairs of 9 m2 plots were established in a degraded fen. Every August until 2001 vegetation was cut by hand (and cuttings removed) in one random plot/pair. The other plots were not cut. All plots had been cleared of trees and shrubs and were grazed every summer (approximately 50 cows/ha). In 1996 (before mowing) and 2001, cover of every plant species was estimated in one 1 m2 quadrat/plot.