An Integrated Approach to Enhancing Ecological Connectivity and Accessibility in Urban Areas: a Case Study of Sheffield, UK
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An Integrated Approach to Enhancing Ecological Connectivity and Accessibility in Urban Areas: a case study of Sheffield, UK Ebru Ersoy Department of Landscape The University of Sheffield Sheffield, UK 2 Volumes Volume I A thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy June 2015 Abstract Recently, increasing environmental threats to the functioning of landscape and biodiversity have heightened the need for developing new approaches to nature conservation. Green and ecological networks have been developed as an attempt to maintain the functioning of landscapes, promote the sustainable use and conservation of nature, support the movement of species and increase people's use and enjoyment of the nature (Bennett and Wit, 2001; Bennett and Mulongoy, 2006; Lawton et al., 2010). These can be achieved by the identification and selection of the main features of ecological and green networks based on ecological and / or social functions we intend them to fulfil as well as the determination of objective conservation measures. The main purpose of this research is to focus on critically examining different ways of defining green and ecological networks and their functionality for biodiversity and people in the case of Sheffield, which were derived from different theoretical and professional perspectives (planning and ecology), and to explore the potential for different approaches to define ecological / green networks. Due to its multidisciplinary nature, this thesis uses a mixed research methodology, based on different methods of data collection and analysis. This research commences with the analysis of existing green and ecological network approaches, namely the Green Network (Sheffield City Council) and the Living Don (Sheffield and Rotherham Wildlife Trust). In order to analyse these approaches, policy document analysis, semi-structured interviews and ArcGIS spatial analyses were conducted to understand the rationale, aims and the spatial structure of current networks in the case of Sheffield. For the identification of criteria to develop alternative routes of connectivity, ArcGIS and FRAGSTATS were used. After generating land cover and land use maps at a very fine scale (2m raster resolution) and with different levels of detail, the alternative connectivity routes, for both biodiversity and people, were identified on the basis of two connectivity measures. The first set of spatial analyses took into account structural connectivity of landscape components as the main criteria, to develop potential routes using ArcGIS and FRAGSTATS in combination. On the i other hand, based on functional connectivity, the second set of alternative connectivity routes were developed using a least-cost corridor approach in ArcGIS. For the delineation of alternative connectivity routes for biodiversity, 10 species were selected from 3 different taxon groups (birds, mammals and reptiles); and for people, the alternative routes from residential buildings to (a) green and open spaces, (b) public buildings and (c) industrial / commercial units were used considering the effects of physical / legal accessibility and slope. Then, existing approaches and derived alternative routes of connectivity were compared and contrasted to each other in ArcGIS, to analyse the relationship between their structural properties and the urban morphologies in which they occur, with a view to predicting the implications for ecological connectivity and use by members of the public. The Sheffield City Council and the Sheffield and Rotherham Wildlife Trust aim at maintaining and enhancing ecological connectivity for the benefit of wildlife as well as supporting public enjoyment and movement, and both of their network approaches benefit from the linear connectivity formed around the main rivers, streams and valleys. However, it was found that there are significant differences in the representation, spatial coverage and arrangement of the Green Network and the Living Don based on the methods and the site selection criteria used for developing green and ecological networks. Regarding the structural connectivity routes for biodiversity and people, significant differences were found in the spatial extent and arrangement of alternative routes. On the other hand, functional connectivity routes for biodiversity showed both similarities and differences in their spatial extents and arrangements according to selected species' habitat requirements and movement behaviours across the landscape. Similarly, functional connectivity routes for people changed as I used different destinations and parameters. The overall results of this research provide further support for the conceptual premise that the definition of green and ecological networks is highly dependent on the methodology, ecological and / or social functions that are considered, and also criteria for the inclusion of different habitats or land uses within the network. ii Acknowledgements The completion of my PhD has been a long journey. I could not have succeeded without the invaluable support of a great number of the kind people around me. First and foremost, I specially would like to thank my enthusiastic supervisors, Dr Anna Jorgensen in the Department of Landscape and Prof Philip H. Warren in the Department of Animal and Plant Sciences, for their help, support and patience during my research which have been invaluable on both my academic and personal life. They have been actively interested in my work and have always been available to advise me. It would not be possible to undertake this extensive research and write this thesis without their help and support, for which I am extremely grateful. I would also like to thank the Turkish Government and Ministry of National Education for their financial support during my PhD in the United Kingdom. Without this support, it would not have been possible for me to study a PhD in the United Kingdom. There are two people I want to mention specially, my better half Ceyhun Tonyaloglu and my dear sister Esra Ersoy, for their support, great patience, understanding, and large heartedness at all times which encouraged me to work hard and continue my research. Without them, this thesis would never have been written. I fell short of words in expressing my gratitude to my family. This thesis would not have been possible without the unconditional love, support and care of my mummy Ayse Ersoy, daddy Ilhami Ersoy and brother E. Yalcin Ersoy. They have always been inspirational and supportive in my decision to take up this challenge. I would like to express my special gratitude to the colours of my life; Huseyin Kaygun, David Alger, Fatih Ileri, Birsen Kesgin Atak and Nurdan Caner Erdogan. They used to take all the tensions away, fill me with new energy and helped me to continue my research. Thanks a lot for being in my life and making it so special. iii All of staff at the Department of Landscape administration office has been great and supportive during my PhD. Special thanks to Ms Helen Morris, Ms Emma Payne, Mr Paul Buck, Ms Denise Hall and Ms Janet Richardson. I also thank the staff of the Ecology Unit in Sheffield City Sheffield City Council and Sheffield Wildlife Trust, as they have contributed immensely to my research project. This was very helpful throughout my research. The value of knowledge I gained from them cannot be overstated. Last but not the least; I would like to thank all my friends and colleagues who made my expedition of PhD in the University of Sheffield so cheerful. I am particularly thankful to Melih Bozkurt, Elisa Olivares, Laura Silva Alvarado, Helen Hoyle, Gulsah Bilge, Israel Legwaila and Hae Joon Jung. iv Table of Contents Abstract ......................................................................................................................... i Acknowledgements ..................................................................................................... iii Table of Contents ......................................................................................................... v List of Tables.............................................................................................................. xii Table of Figures ........................................................................................................ xiv Table of Boxes ......................................................................................................... xvii Table of Maps ......................................................................................................... xviii Acronyms and Glossary ............................................................................................. xx Chapter 1 General Introduction .................................................................................... 1 1.1 Study Background .............................................................................................. 1 1.2 Study Area .......................................................................................................... 3 1.3 Aim and Objectives of the Research .................................................................. 3 1.4 Thesis Structure .................................................................................................. 4 Chapter 2 Literature Review ........................................................................................ 7 2.1 Introduction .......................................................................................................