London scoping - ukcip

Final Report
83
(Marchant et al., 1998), the number of cases of Lyme disease spread by ticks has approximately
doubled in the UK since 1986 (Subak, 1999). Higher year-round temperatures in the future are
likely to increase the risk of recreational exposure to Lyme disease, changes in tick numbers and
activity.
Finally, London is home to numerous flora and fauna introduced from warmer parts of the
world but now flourishing in the City. Many exotic species have been inadvertently introduced
via imported materials such as foodstuffs, timber, minerals and birdseed. Others have ‘escaped’
from gardens to be naturalised (e.g., butterfly bush, michaelmas daisy, Japanese knotweed) or
have formed spontaneous hybrids with their native relatives (e.g., Highclere holly, Spanish
bluebell). The rich cultural botany that has developed around areas such as Deptford has
become part of the local heritage. Part of this success has been attributed to the favourable
climate of London’s heat island (see Sections 3.2 and 5.2). Longer growing seasons, reduced
incidence of night frosts and higher maximum temperatures in summer have allowed plants
such as London rocket, Guernsey fleabane, hoary mustard and Chinese mugwort to thrive (see:
http://www.lbp.org.uk/action/statements/ssexoticflora.htm). Projected increases in regional
temperatures under the UKCIP02 scenarios together with possible intensification of the heat
island will allow such flora, along with naturalised bird species (e.g., collared dove and ringnecked
parakeet) to thrive in the future. However, the same conditions could also favour a
small minority of introduced plants that cause significant problems in London’s ponds and
canals (e.g., New Zealand pigmyweed, parrot’s-feather, floating pennywort), and terrestrial
habitats (e.g., Japanese knotweed, giant hogweed).
5.6.5 Stakeholder Concerns
In addition to the issues raised above, stakeholder engagement highlighted further potential
biodiversity impacts related to climate change (Table 5.8).
Table 5.8 Potential biodiversity impacts and adaptations identified by stakeholders
Associated Impacts
Increased tourism and leisure pressure at conservation sites
Increased soil erosion associated with more intense winter rainfall
Increased expenditure on pest control
Air quality impacts from incinerators, water quality impacts from landfill
Use of building roofs for green space and water storage
Restricted access to sensitive sites and habits (e.g., foreshore)
Use of green spaces and river corridors to allow species to move to new climate space(s)
Greater public education and involvement in ‘biodiversity networks’ (phonology)
Greater recognition of dynamic ecosystems in site designation and management