Immediate effects of heather cutting over blanket bog on depth and microtopography of the moss layer

Abstract

The blanket bog ecosystems of the UK uplands fulfil important biodiversity and ecosystem services at multiple spatial scales. In response to perceived negative effects of burning to control heather growth on blanket bog, regulations on vegetation management now restrict this practice as part of the UK's wider commitment to reducing carbon emissions. Instead, there has been a significant shift towards cutting as an alternative heather management tool, despite a notable lack of research on its effects on blanket bog. A key component of blanket bog ecosystems in the UK uplands is the moss layer, in which Sphagnum mosses play a particularly significant role. To investigate the immediate effects of heather cutting on the structure and extent of the moss layer, measurements of moss depth and cover at the end of the cutting season were taken from cut and uncut areas of two managed blanket bog sites in northern England. Measurements of moss depth were used to generate an index of moss microtopography. Cutting resulted in significant reductions of moss depth, heterogeneity of moss hummock microtopography, and extent of pleurocarpous moss, but there was no change in cover of Sphagnum or acrocarpous mosses. Further research is needed to understand the effects of cutting, particularly in the longer term, in terms of cutting height, type of machinery used, whether brash is removed, and repeat cut interval. This research will inform evidence-based management of blanket bog habitats.