Impact of groundwater level rise on vegetation in Melnais Lake Mire Nature Reserve: first results

Published source details Auniņa L. (2013) Impact of groundwater level rise on vegetation in Melnais Lake Mire Nature Reserve: first results. Pages 197-203 in: Raised Bog Management for Biological Diversity Conservation in Latvia. University of Latvia, Riga.
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This study is summarised as evidence for the following.

	Action	Category
	Rewet peatland (raise water table) Action Link

Rewet peatland (raise water table)

A replicated, before-and-after, site comparison study in 2011–2013 in a degraded raised bog in Latvia (Auniņa 2013) reported that rewetting had no effect on plant species richness, increased cover of sheathed cottongrass Eriophorum vaginatum, white beak sedge Rhynchospora alba and Sphagnum moss, and reduced cover of heather Calluna vulgaris (but not other trees/shrubs). Most of these results were not tested for statistical significance. Over six months, rewetting had no significant effect on plant species richness on three of four transects (before: 13.6–15.2 species/20 m²; after: 13.6–15.8 species/20 m²) but increased cover of sheathed cottongrass in 19 of 21 quadrats (by 1–5%). Over 18 months, rewetting increased cover of white beak sedge (before: 1%; after: 4%) and Sphagnum moss (before: 53%; after: 72%), but reduced heather cover (before: 84%; after: 68%) and had no effect on other tree/shrub cover (before: 20%; after: 22%). When vegetation cover changed, it became more like a pristine bog (with 80% Sphagnum, 18% sedge and 9% heather cover). In early 2012, drainage ditches were blocked in a bog remnant. In summer 2012 and 2013, cover of every plant species was estimated in the rewetted bog (in twenty-one 4 m² quadrats) and in a nearby undisturbed bog (details not reported).

(Summarised by: Nigel Taylor)