Predicting success in restored bogs shortly after restoration works

Background/Question/Methods

Bog exploitation for horticultural purposes leaves large surfaces of residual peat that remain devoid of vegetation for decades. Restoration of those bogs is necessary to mitigate the loss of local biodiversity. However, tools to assess the success of restoration works have not been rigorously defined yet. We used vacuum-milled peat extracted bogs restored by the moss transfer technique in Eastern Canada as a model system to test an approach for assessing restoration success, based on plant composition. A total of 188 plots in 12 restored bogs that had been restored from 4 to 11 years ago and continuously monitored were clustered in three success categories, according to their characteristic vegetation composition. Then, vegetation composition in the plots was analyzed retrospectively at the third year since restoration to obtain the combination of indicator species that best discriminated between the success categories using linear discriminant analysis (LDA).

Results/Conclusions

LDA classified correctly 86% of the cases into three success categories: a first one representing Successful restoration, with dominance of Sphagnum, a typical bog genus that is able to initiate self-regulatory mechanisms leading back to bog ecosystems (restoration goal); a second one representing Failure, with dominance of bare peat; and a third category, interpreted as a dead-ended successional pathway, dominated by Polytrichum strictum, a pioneer moss that usually facilitates Sphagnum colonization. Recently restored bogs were finally used to illustrate the use of our predictive tool and suggest different management strategies.