Current warming and likely future impacts - Climate Change: Biological and Human Aspects - page 312

poaching). Coastal grazing marshes will be affected by sea-level rise and changes in
sea defences.
Acid grassland: there may be possible changes in competitive ability with other
grassland types and the potential for increased bracken invasion in the north (with a
possible reduction in the south). Soil-nutrient limitations may restrict adaptations to
changes in the TGS.
Dwarf shrub heath: a decrease in summer rainfall may change community types in
the south. There may also be an increase in insect damage.
Medium-to-highvulnerability
Coniferous woodland: there may be extreme weather events, encroachment by south-
erly species and limitation in altitudinal migration due to land-use change and spe-
cifically grazing.
Calcareous grassland: well-drained chalk soils increase the likelihood of drought
stress in dry summers. Species community change and/or structure alteration are
likely.
Bogs: there may be possible peat erosion and vulnerabilities due to changes in the
water table. Lowland bogs will be at risk from decreased summer rainfall, whereas
upland bogs will face erosion pressures from increased winter rainfall.
Highvulnerability
Rivers and streams: low summer and high winter flows, together with high summer
temperatures, are likely to have major impacts on species and the river environ-
ments.
Montane habitats: species migration is likely but some altitudinal limitations may
result in population declines/extinction. Less snow may affect snow buntings ( Plec-
trophenax nivalis ), which rely on insects in snow patches, and some bryophyte species
(a group of small, rootless, non-vascular plants), which rely on snow cover for insu-
lation and/or spring moisture. An increase in average climate of just 0.5 ◦ C would
eliminate many montane biomes in the UK.
Unknownvulnerability
The effects of climate change on the following biomes are unknown: inland rock,
built-up areas and gardens, maritime cliffs and coastal sand dunes.
Finally, the DETR report highlighted the need for climate impacts to be considered
proactively within UK conservation policy.
The second UK assessment was the UKCIP (2001) report on Climate Change
and Nature Conservation in Britain and Ireland , or MONARCH I. It was a suitable
follow-on from the 2000 departmental report. It linked established environmental
impact models to a national bioclimatic classification. As such, the report took on
board climatic changes but not impacts arising from elevated levels of carbon dioxide.
(You will recall that increased carbon dioxide levels have an effect separate to that