Recent (post-1950s) climate change impacts on society and ecosystems have been recognised globally. However these global impacts are not uniform at regional or local scales. Despite research progress on such scales there are still gaps in the knowledge as to 'what' is happening and 'where'? The goal of this study addresses some of these gaps by analysing climate variability and vegetation response at the furthest south westerly peninsula of the United Kingdom. This research is focused on West Cornwall (South West England) - an area dominated by a strong maritime influence. The first part of this PhD research analysed archive and contemporary instrumental data in order to detect any trends in climate variability. The weather data was retrieved from the Met Office archive for Camborne 1957-2010 and Culdrose 1985-2011 stations; Trengwainton Garden (1940-2010), and from the Royal Cornwall Polytechnic Society, for Falmouth (1880-1952) and Helston (1843-1888). The data showed positive trends in mean annual and maximum temperature with the largest trend magnitude in the 20th and 21st century. Seasonal temperature change varies locally with the highest increase in autumn spring and summer. Precipitation trends were only positive for the 19th century for Helston. Correlation between precipitation data and North Atlantic Oscillation (NAO index) was negative, however the opposite result was detected when the NAO index was correlated with temperatures. Surprisingly, return period analysis showed a decrease in the frequency and intensity of extreme precipitation events post 1975 for Camborne and Trengwainton Garden stations. The second part of this study analysed changes in vegetation distribution in West Cornwall using historical and contemporary vegetation records. Historical vegetation records were used from the Flora of Cornwall collection of herbarium records and contemporary vegetation records which were available online, containing mainly the 'New Atlas of British and Irish flora'. Data sets were geo-referenced using ArcGIS in order to analyse changes in species geographical distribution pre and post-1900. Analysis showed that historical vegetation records can be used to assess any changes in geographic distributions of vegetation. Analysis for the area of West Cornwall showed a loss of range for 18 species, for 6 species this loss was larger than 50% of the area, and there was no change in overall range area for 10 species. Ellenberg values and environmental indicator values showed that they can be used as an indicator of environmental change, showing a decrease in species with lower January temperatures. Analysis also showed an increase in moderate wetter species, where species with extreme low and high precipitation environmental indicator values showed a greater loss. Furthermore species with a higher requirement for light showed a loss as well as species with lower nitrogen values. To analyse the loss of species at the local scale, West Cornwall was divided into three areas (North Border Cells, Central West Cornwall Cells and South Border Cells). The highest loss of 11 species was detected for South Border Cells, where the loss for Central West Cornwall Cells was 6 and for North Border Cells 8 species. It was found that 17 species were experiencing loss on different local sites. For 9 of these 17 species, change at the local scale was different to the national scale change at the individual species level, group level and habitat level. Furthermore, the whole area of West Cornwall lost two species post-1900, with a different loss locally. This showed that species could be protected locally in appropriate microclimate refugia, which will be of benefit for the preservation of regional identity ecosystem services and overall genetic pool of the species.

Climate change is no longer debated in the context of whether or not it is occurring, but rather in the context of how rapid and extensive that change will be. This is the global situation to which the biomes of national parks in Canada and the United States must adapt. Through the use of the MC1 Dynamic Global Vegetation Model (DGVM) this thesis constructs projections of possible vegetation response of ten biome classifications to the impacts of continental-scale climate change in seven regions: Atlantic, Great Lakes, Mountain, Northern, Pacific, Prairie, and Southern. It then analyzes the potential ways in which DGVMs can be utilized by park management schemes in accommodating for future climate change in the selection, creation, and maintenance of national parks. As the latest generation of vegetation modelling systems, the advantages of Dynamic Global Vegetation Models over pre-existing equilibrium biogeography models are examined in this thesis. DGVMs highlight the degree to which ecosystems are interconnected, and are able to provide continental-scale data necessary in coordinating an integrated planning approach for national parks in North America. They are utilized in this study for generating projections of future biome distribution, based on climate information from three General Circulation Models: CGCM2, CSIRO Mk2, and HadCM3. Following the generation of possible climate scenarios, the impact of changes to biome distribution within national parks is discussed. The thesis findings provide valuable modelling analysis and scenarios for use in future planning by the US National Park System and Parks Canada. Utilization of DGVMs will help in creating flexible, coordinated management strategies that take into account projected vegetation responses to climate shifts that lie ahead.

Climate change is no longer debated in the context of whether or not it is occurring, but rather in the context of how rapid and extensive that change will be. This is the global situation to which the biomes of national parks in Canada and the United States must adapt. Through the use of the MC1 Dynamic Global Vegetation Model (DGVM) this thesis constructs projections of possible vegetation response of ten biome classifications to the impacts of continental-scale climate change in seven regions: Atlantic, Great Lakes, Mountain, Northern, Pacific, Prairie, and Southern. It then analyzes the potential ways in which DGVMs can be utilized by park management schemes in accommodating for future climate change in the selection, creation, and maintenance of national parks. As the latest generation of vegetation modelling systems, the advantages of Dynamic Global Vegetation Models over pre-existing equilibrium biogeography models are examined in this thesis. DGVMs highlight the degree to which ecosystems are interconnected, and are able to provide continental-scale data necessary in coordinating an integrated planning approach for national parks in North America. They are utilized in this study for generating projections of future biome distribution, based on climate information from three General Circulation Models: CGCM2, CSIRO Mk2, and HadCM3. Following the generation of possible climate scenarios, the impact of changes to biome distribution within national parks is discussed. The thesis findings provide valuable modelling analysis and scenarios for use in future planning by the US National Park System and Parks Canada. Utilization of DGVMs will help in creating flexible, coordinated management strategies that take into account projected vegetation responses to climate shifts that lie ahead.

Terrestrial ecosystems in the southeastern United States have evolved with fire as a common disturbance and as a result many natural communities require the presence of fire to persist over time. Human development precludes natural fires from occurring within these communities; however, prescribed fire is considered to be a critical tool in the effort to restore fire-dependent ecosystems after decades of fire exclusion. Direct effects of fire on individual floral and faunal species as well as benefits to biodiversity at the landscape (gamma diversity) level have largely been supported in previous research. However, information on the effects of natural and prescribed fire on plant diversity at the local level (alpha diversity) is limited, particularly for southeastern forests. The applicability of the Intermediate Disturbance Hypothesis (IDH), which suggests that the highest levels of biodiversity are found at intermediate levels of disturbance, is also untested for North Florida upland plant communities. This study compared the effects of fire on local scale mean plant species diversity by examining burned and unburned portions of three fire-dependent communities to determine if there is an effect of prescribed fire on in alpha biodiversity. Alpha biodiversity was not significantly different (p=0.433) between burned and unburned fire-dependent plant communities in northern Florida, suggesting that prescribed fire does not affect plant species diversity in these communities and/or the IDH for plant communities is not supported at the time scale tested. However, the application of prescribed fire did result in changes in abundance of species, particularly with species such as Dicanthelium acuminatum, Quercus myrtifolia, and Vaccinium myrsinites, that respond positively to fire, which may have implications for associated faunal diversity.