Effects of controlled fire on the biodiversity of heath communities
Background and objectives
Muirburn is the practise of using controlled fire on heather moorland with the purpose of bringing mature or old heather from its degenerated phase to a re-growing pioneering phase. When this practice is applied to small strips of heather on a rotational basis, it creates a mosaic in the heather structure that it is believed to be beneficial for the productivity of insect communities, grouse, waders, pipits, small mammals and for grazing areas for mountain hares, deer and sheep. On the other hand an associated negative effect is the release of carbon into the atmosphere, especially when the fire affects deep deposits of peat.
Little is known about how different management practises affect the successional stages of heather recovery, for example, what is the contribution of sheep and deer grazing (as single- or mixed-species groups) on the vegetation and fauna. Grazing can delay the recovery of the vegetation, especially at high stocking densities, but at moderate densities selective grazing and faecal deposition help to produce a fine scale mosaic within the recovering burnt patches. Faecal deposition increases the spatial heterogeneity of soil nutrients at fine scale and might also attract colonising insects. The activity of small mammals (mobilisation of biomass and burrowing) increase the complexity of the structure of the vegetation.
The objectives of this study are to investigate the effect of fire, edge effect and grazing regime by deer and sheep (mixed species, single species) on the biodiversity of blanket bog and dry heath.
Study area
We will use 11 plots of 100 x 100m placed on wet and dry heath at The James Hutton Institute Glensaugh Research Farm (see figure to the right). Block A (south block) will have sheep and deer (all our GPS collars will be deployed on these animals) and block B (north block) will have only deer.
Measurements
We will record before fire base-line measurements of abundance and composition of plants, insects and small mammals and the sucessional recovery of these communities after the fire.
For further details of this work, please contact Javier Perez-Barberia.