Skip to main content
Dryad

Diversification of Molinia-dominated blanket bogs using Sphagnum propagules

Data files

Nov 15, 2021 version files 219.25 KB

Abstract

This dataset contains vegetation and water table data from a trial described in the paper "Pilkington, M.G., Walker, J., Fry, C., Eades, P., Meade, R., Pollett, N., Rogers, T., Helliwell, T., Chandler, D., Fawcett, E. and Keatley T. (2021). Diversification of Molinia-dominated blanket bogs using Sphagnum propagules. Ecological Solutions and Evidence. Article DOI: 10.1002/2688-8319.12113

The trial investigates the establishment and growth of Sphagnum colonies arsing from planting Sphagnum propagules ("plugs") amongst purple moor grass, Molinia caerulea (‘Molinia’), a vascular plant which can dominate upland blanket bog of the UK. Increasing dominance by Molinia on these globally rare and protected bogs is a growing threat to diversity and carbon storage, as well as increasing the risk of wildfire.

Establishment and growth of plug-derived Sphagnum was measured by collecting visually-assessed data on cover (%) within 2 m x 2 m quadrats. The cover of blanket bog "indicator species" was calculated according to the definition of this group as stated in Common Standards Monitoring and the concept of Favourable Condition. Water table data were collected manually from monthly campaigns.

The following key results were found:

There was an initial rapid increase in cover of plug-derived Sphagnum (PDS) which suggested an advantage over that of naturally-occurring Sphagnum colonies, the latter remaining below 1% cover throughout; subsequent plateauing of PDS cover in areas of moderate Molinia cover (< 80%) was linked with drought stress, whereas declining cover in Molinia-dense areas (> 80%) suggested additional competition for light. The cover of Molinia was only weakly reduced by, and then completely recovered from, a baseline flailing treatment. Increasing cover of PDS in all of the treatments had no clear effect on the cover of Molinia. The cover of naturally-occurring indicator species was strongly reduced by a baseline flailing treatment; subsequent recovery was not complete, even with contributions by PDS. There was a negative linear relationship between Molinia cover and indicator species cover, over all ranges of Molinia cover. Water table depths were lowered by PDS during the first three years of the trial, likely due to facilitated capillary conduction of water though the buried plug tissues.