London scoping - ukcip

Final Report
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beech tree, however. An alternative would be Sweet Chestnut, which would perform equally
well under hot and dry conditions, and supports a wider range of other species than Plane
(Richards, pers.com.).
6.15.5 Socio-Economic Scenario Differences
Under GM, land use would be determined by the market, and there would be fewer restrictions
of land for biodiversity and for amenity value than currently. High climate change impacts
upon green spaces and its biodiversity would therefore be attenuated by the reduction in
statutory protection and spatial extent of such land. By contrast, under RS there would be
greater protection of land and more emphasis placed on enhancing and managing biodiversity.
Under RS, the lower level of climate change plus greater protection of green spaces would be
more favourable.
6.15.6 Case Study and Comparison with Other Cities
Case study of impacts on ‘green spaces’ - The Royal Botanic Gardens at Kew
The Botanic Gardens at Kew are famous as both a tourist attraction and a valuable centre for
monitoring and conservation of flora and fauna. A former royal possession granted to the nation
by Queen Victoria, it is now run as a non-departmental government body overseen by DEFRA.
One of its statutory purposes is to conserve native flora and fauna, including species which
come to live in the UK as a result of environmental change and conservation practice. Records
at Kew have shown that some species (e.g. crocus, bluebells, laburnum and certain cherries)
have been blooming earlier over recent years – roughly 1 to 2 weeks earlier since 1952. In 2002
the Crown Imperial Fritillary opened earlier than ever before. No records are kept of autumn
leaf fall/turning.
Species such as Marbled White and Gatekeeper butterflies and certain types of rare dragonflies
appear to be moving their range northwards, and more of these species are being noted at Kew.
It is not clear if any species have yet been lost due to changing climate, but in the future drier
summers may cause some plants to disappear. Species such as the meadow saxifrage (spring
flowering in damp meadow habitat) and the wild camomile may be most at risk. However, even
in the hot dry summers such as that of 1995 species reappeared after prolonged drought.
A warming climate would widen the range of species present, but lower summer rainfall with
more evaporation would reduce the numbers. Emergency plans such as using river water or
Kew lake water for irrigation are being considered, but there are health and environmental
implications arising from such uses. For example, the Kew lakes and ponds are themselves
important habitats and river water might need treating before it could be used. The satellite
garden at Wakehurst Place, West Sussex (currently wetter and cooler) may be used as a backup.
Kew is on thin poor soil over gravel, with a high water table resulting in shallow root structures.
Any raising of the water table from increased winter rain would cause even shallower rooting,
paradoxically making plants more vulnerable to dry-out in drier summers. Direct flooding from
the river has not been a problem yet, nor is salination of groundwater, but this may occur in the
future with more overland flooding.
More visitors in a warmer climate would be welcome – in fact there are currently several
initiatives to encourage more visitors such as seasonal festivals. Kew could accommodate a
substantially larger number of visitors before it reached capacity. However, it is noted that in