Local impacts of climate change
In the project region around the Wittenhams, there are a number of important habitats and they will be affected by climate change.
Habitats will be affected by climate change in different ways:
- Lowland mixed deciduous woodland - Trees could benefit from increased carbon dioxide levels and rising temperatures. However, on drier soils, species such as beech could decline, possibly to the point of total loss. Other more drought-resistant species, such as ash, are likely to increase. Many plants associated with woodland (e.g. dog’s mercury and bluebell) will continue to thrive. Wind damage is likely to become more of a problem and possibly fire.
- Lowland calcareous grassland – the response of species could vary, depending partly on their rooting depth and other habitat requirements. Species such as turtle dove and blackwort may show little change, while butterflies, such as Adonis blue and silver-spotted skipper, could increase their climate space. Meadow oat grass is likely to experience large losses. Future species’ distributions will also depend on land use and land management responses to climate change and other pressures.
- Wetlands - many wetland species are at risk due to greater seasonal variation in rainfall and increasing summer droughts, but suitable climate space should remain for the important Great Crested Newt. Lowland raised bogs, and fens could be adversely affected by decreasing water availability, directly through climate change and indirectly through human water demands.
- Climate regions may shift at a rate of several km per year. Some species (trees and plants in particular) may not be able to disperse fast enough to follow these shifts, especially where habitat barriers such as urban areas intervene.
- Insects and birds can migrate faster. eg Speckled Wood Butterfly has moved steadily northwards in UK over past 100 years. Species formerly occupying the same climatic range may end up moving to different areas and will no longer be associated in the same habitats. Thus the species composition of some habitats may change, together with their landscapes.
- Wildlife in the past has adapted to the impacts of human activity and climate change. There have been extinctions and introductions. The landscape of the future will look different, but if we want to maintain a diverse and attractive environment we must try to enhance the adaptability of habitats and wildlife to rapid and inevitable change.
- Protected reserves are needed, allowing a variety of habitats and rare species to flourish with limited human impact.
Links (dispersal corridors) are needed between fragmented habitats to encourage dispersal of wildlife, allowing species to follow the shifting climate regions. Such links include hedgerows, river banks or crossing points allowing animals to traverse barriers such as motorways.
