Current warming and likely future impacts - Climate Change: Biological and Human Aspects - page 311

The DETR report based its assessment on the UK's Biodiversity Action Plan (or
BAP), which the UK Government developed as part of the nation's commitment to
the 1992 UN Conference on Environment and Development (held in Rio de Janeiro)
and its Convention on Biological Diversity, but not its Framework Convention on
Climate Change (which in the USA prompted that country's Climate Action Report
[Department of State, 2002]; see the previous case study).
The UK departmental report (DETR, 2000) addresses many of the points regarding
species impact covered in this and the preceding chapter. However, it also notes that
the UK, being comprised of islands, has restricted population pools and that the
sea inhibits species migration (unlike the USA, which has Canada to the north and
Mexico to the south). The report also comments on human-imported species, currently
residing in parks and gardens, noting that some of these may find future conditions
favourable for expansion.
Landscape fragmentation is also an issue highlighted by the report. It noted that
some species, which otherwise might benefit from a warmer climate, such as the
dormouse ( Muscardinus spp.), may have their expansion hindered by landscape frag-
mentation.
The report's consideration as to the vulnerability of UK biomes to climate change
is summarised below.
Lowvulnerability
Arable and horticulture: the change of species will need to be managed and a man-
agement regime for existing species in existing locales established.
Low-to-mediumvulnerability
Mixed broad-leaved and yew woodland: damage will occur due to extreme weather
events. Climatic effects may become manifest in 100-150 years. There is a particular
risk to lowland woodland in southern England due to dry summers.
Fen, marsh and swamp: there will be a change in species composition and a risk of
soligenous (communities relying on water that has drained through geological strata)
fens drying out in summer. Drought may exacerbate air-pollution impacts. Coastal
fens will be affected by sea-level rise and a sea-defence response to sea-level rise will
be necessary.
Standing water and canals: isolated high-altitude lakes are vulnerable to temper-
ature increase. High-summer temperatures could restrict cold-water species. There
could be changes in the frequency of algal blooms in eutrophic (nutrient-rich) waters.
Warmer winters could increase populations of overwintering plankton.
Mediumvulnerability
Improved grassland: there may be changes in the thermal growing season (TGS).
Risks include an increase in moisture-loving species (such as rushes; Juncus spp.)
and surface damage to soil and vegetation due to hoof action on wetter ground (called