1 |
Calluna vulgaris regeneration on upland moorland post-wildfireGilbert, Jaqueline Anne January 2008 (has links)
Upland heather moorland is often subjected to wildfires, particularly in drought years, which destroy all vegetation, seed bank and surface peat. Post-fire management of liming, fertilising and seeding with grass species and Calluna vulgaris (ling heather), in addition to natural regeneration, often fails to fully re-vegetate the bare burnt peat, leading to erosion and degraded sites. Here, two sites were under investigation: Darwen Moor that suffered a severe fire in 1995, and a moor overlooking Stalybridge, Tameside, burnt in 1980. Both burnt areas received similar post-fire management. After a full vegetation survey of Darwen Moor, with data analysed using Two-way species indicator analysis (Twinspan), permanent quadrats were established within representative areas of identified vegetation sub-communities. Twice yearly surveys (spring and autumn) were undertaken within areas defined by these quadrats. Results of vegetation survey showed regeneration of C. vulgaris on burnt sections of Darwen moor had increased from 18% to 38%, (2000-2005), and had become the dominant species, with only 3% of the burnt moor remaining unvegetated. Vegetation succession was not advancing unidirectionally with increasing variation between samples of the same sub-community. This was in contrast to the Stalybridge site that remained unvegetated (77%) twenty-five years after wildfire. Survey data were collected using both digital photography and point quadrat survey. Pre-monitoring investigation showed no significant difference between data collected by these techniques. Experiments were undertaken to assess aspects of C. vulgaris seed dispersal and viability. Seed-trap experiments using transplanted C. vulgaris suggested that few seeds are being dispersed into degraded sites, whilst datalogger evidence showed poor germination opportunity for C. vulgaris seeds on moorland post-wildfire. C. vulgaris seeds were shown to germinate and grow on moorland peat in controlled conditions, although they rapidly became unviable when exposed to drought conditions. Use of a polyacrylamide gel to enhance environmental conditions for sown grass species showed early increased ground cover but failed to show any significant increase after 14 months. Accepted upland moorland revegetation management post-wildfire is reviewed and from experimental results, additional management techniques are suggested.
|
Page generated in 0.0169 seconds