During the 20th century, woodland fragmentation and changes in composition have had an impact on the woodland ecology of lowland England. Government policy which initially focussed on softwood timber production, now aims to protect, enhance, restore and expand native deciduous woodland. These initiatives arguably will have the greatest ecological impact if they employ a landscape scale approach to ensure maximum woodland connectivity whilst retaining landscape character. This research investigated woodland change over the last 160 years in the Oxfordshire Chilterns. The Chilterns, characterised by beech woodland, is one of the most wooded areas in lowland England. Digital analysis of two types of historic maps, combined with historic documentary evidence, enabled a quantitative analysis of woodland composition alongside comparison of change over time. The research investigated hypothetical future scenarios for both woodland creation, based on historically wooded sites identified by the research, and restoration of non-native plantations to native species. These scenarios were shown to improve woodland connectivity and to increase patch size in comparison with BAP targets. These methods allowed the retention of the characteristic mosaic Chiltern landscape. Between 1840 and 1883, woodland extent reduced by only 4.6% but by 1883, 16.96% of native deciduous woodland had been converted to mixed woodland. In the 20th century, native woodland increased by 7.6%, still 12% less than in 1840, but mixed (26.13%) and coniferous woodlands (9.73%) increased markedly due to Government policy. These changes resulted in increased fragmentation of native deciduous woodland over time. Future restoration and creation scenarios improved woodland connectivity by increasing patch size and reducing near-neighbour distance; but to reach 30% woodland cover to create a habitat network, total woodland restoration combined with woodland creation is necessary, far exceeding BAP targets. In this research, historic information identifies regional native woodland type and past management which needs to be recognised in policy and information dissemination. More importantly, it provides the information necessary to retain the local cultural landscape pattern while enhancing ecological connectivity and is therefore a valuable method which could be applied elsewhere.
Webb, Mary
Year: 2010
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