THE IMPACTS OF CLIMATE CHANGE ON DESIGNING SUSTAINABLE URBAN LANDSCAPES

There is much evidence to indicate that the climate is changing. The aims of this study were to develop meadow-like communities of Continental, Mediterranean and Temperate grassland species as a new approach to designing sustainable urban landscapes under different climate change scenarios. To achieve this aim, a community of thirty-six species from Marine, Mediterranean and Continental temperate climates were chosen to represent a gradient from well-fitted to poorly-fitted to the current British climate. The species were chosen to share similar morphological characteristics, in terms of canopy size, texture and structure. They were also chosen to be attractive in terms of colourful flowers, from spring to autumn, which provides a strong design impact. Three series of the experiment were conducted to investigate the effects of different climate scenarios on the fitness and growth performance of native and non-native species in meadow-like communities. The plant species seedlings were grown in situ at Sheffield Botanical Gardens with three watering regime rates (50% increase in precipitation, 50% decrease in precipitation and ambient), two different temperature treatments (Ambient and Ambient plus 30C), two levels of CO2 concentration (Ambient and Ambient +450PPM) in the presence or absence of molluscs. The results indicate that water availability; CO2 concentration and temperature are three important factors to choose plant species for greenspace according to the future climate change scenarios. Although each of the environmental factors has specific effects on species fitness and adjustment, their interaction is more important. At the Ambient level of CO2, the intermediate-fitted group (Mediterranean climate species) shows the highest biomass production in future climate scenarios. The poorly-fitted species cannot tolerate high levels of moisture, when the moisture level reaches Ambient over 50% of the plants in this group will show negligible growth, but increasing temperature can decrease this effect excess water in different species at different levels. Increasing CO2 from the ambient level to 900PPM enhanced the biomass productivity in all groups. The continental temperate grassland species (poorly fitted species) at CO2:900PPM, Temperature: Ambient, Moisture: Ambient and the Ambient +50% condition, showed similar biomass productivity to Mediterranean climate species. Overall, a designed plant community of species from Marine and Mediterranean climates will present the best-fitted species to design naturalistic urban landscapes according the 2050 UK climate change scenarios. Mollusc grazing was affected by different climate scenarios (from dry and warm to wet and hot). Slugs showed different behaviours in dry, wet, warm and ambient temperature in terms of plant selection for feeding. There was no significant difference in biodiversity support between native and non-native species regarding mollusc grazing.