RESTORATION EVIDENCE

Individual study: Shrub removal facilitates recovery of wetland species in a rewetted fen

Published source details

Kotowski W., Dzierża P., Czerwiński M., Kozub Ł. & Śnieg S. (2013) Shrub removal facilitates recovery of wetland species in a rewetted fen. Journal for Nature Conservation, 21, 294-308


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Cut large trees/shrubs to maintain or restore disturbance Peatland Conservation

A before-and-after, site comparison study in 2004–2009 in a degraded fen in Poland (Kotowski et al. 2013) found that in an area cleared of shrubs (then rewetted and mown), the plant community composition changed in favour of fen meadow and wet meadow species. Over five years, the overall plant community composition in the managed area became more similar to a target fen meadow vegetation (data reported as a graphical analysis; change not tested for statistical significance). The abundance of fen meadow and wet meadow species, including sedges Carex spp., increased in the managed area but did not change in the target area (data reported as an abundance index). In 2004, willow Salix cinerea shrubs were cleared from 0.7 ha of drained, overgrown fen. The area was then mown annually and rewetted. The study does not distinguish between the effects of these interventions. The managed area was compared to 0.9 ha of target, shrub-free, fen meadow vegetation (retained in depressions during the drained period, but also affected by the rewetting and mown every other year). Annually between 2004 (before shrub clearance) and 2009, cover of every plant species was estimated in 18–22 plots/area. Plots were 20 x 20 m.

(Summarised by Nigel Taylor)

Cut/mow herbaceous plants to maintain or restore disturbance Peatland Conservation

A before-and-after, site comparison study in 2004–2009 in a degraded fen in Poland (Kotowski et al. 2013) found that in an area where mowing was resumed (also cleared of shrubs and rewetted), the plant community composition changed in favour of fen meadow and wet meadow species. Over five years, the overall community composition became more similar to target fen meadow vegetation (data reported as a graphical analysis; change not tested for statistical significance). The abundance of fen meadow and wet meadow plant species, including sedges Carex spp., significantly increased in the managed area but did not change in the target area (data reported abundance indices). In 2004, annual late summer mowing was resumed in 0.7 ha of drained, overgrown fen. The area had been prepared by removing willow Salix cinerea shrubs, and was later rewetted. The study does not distinguish between the effects of these interventions. The managed area was compared to 0.9 ha of target, shrub-free, fen meadow vegetation (retained in depressions during the drained period, but also affected by the rewetting and mown every other year). Annually between 2004 (before intervention) and 2009, vegetation cover was estimated in 18–22 plots/area. Plots were 20 x 20 m.

(Summarised by Nigel Taylor)

Rewet peatland (raise water table) Peatland Conservation

A before-and-after, site comparison study in 2004–2009 in a degraded fen in Poland (Kotowski et al. 2013) found that in a rewetted area (also cleared of shrubs and mown), the plant community composition changed in favour of fen and wet meadow species. Over five years, the overall plant community composition in a managed area became more like target fen meadow vegetation (data reported as a graphical analysis; change not tested for statistical significance). The abundance of fen and wet meadow plant species, including sedges Carex spp., increased in the managed area but did not change in the target area (data reported as abundance indices). In 2004, 0.7 ha of drained, overgrown fen was rewetted by blocking its connection to a drainage ditch. After rewetting, the water table was 0–16 cm below the peat surface (during summer). The fen was also cleared of willow Salix cinerea shrubs, then mown annually. The study does not distinguish between the effects of these interventions. The managed area was compared to 0.9 ha of target, shrub-free, fen meadow vegetation (retained in depressions during the drained period, but also affected by the rewetting and mown every other year). Each year between 2004 (before intervention) and 2009, vegetation cover was estimated in 18–22 plots/area. Plots were 20 x 20 m.

(Summarised by Nigel Taylor)