Climate change and conservation policy : developing adaptation strategies to minimise climate change impacts to the conservation interest of Scotland's standing freshwaters

There is little doubt that anthropogenic climate change will have long lasting, unavoidable, large scale and cross sector effects. Having a clear understanding of the scale and rate of projected future changes, and the potential impacts of those changes at multiple spatial and temporal scales, will be important to allow environmental managers the best chance of adapting to changing conditions. There are particular concerns about impacts on freshwater systems due to the coupling of direct impacts to both hydrology and ecology. Expected changes can be grouped into three functional categories: those affecting physico-chemical (broadly water quality), hydromorphological (physical structure and habitat) and biological elements of the lake system. The Lake-Landscape Context framework provides a way of approaching the sensitivity or resilience of an individual lake to change by exploring the complex and multi-layered relations between water, land and human activity. However, the exact combination of strategies and actions available to environmental managers is yet to be comprehensively documented beyond broad principles. To reach this goal, to manage our ecosystems in the most comprehensive and responsible way, we need to have a clear understanding of what and where that resource is, what the conservation priorities currently are and where threats to these priorities are likely to emerge. Therefore, the overall aim of this thesis was to develop adaptation strategies to minimise climate change impacts on the conservation interests of Scotland’s standing freshwater. This was approached through the adoption of the ESVRA conceptual framework, intended to assist policymakers and practitioners in adaptation planning. Practical actions can be guided by working through the framework’s four key stages: understanding exposure to the pressure (external drivers); considering the sensitivity and resilience of the system at multiple scales (internal functions); exploring areas of vulnerability (a measure of sensitivity plus exposure); and consideration of multiple possible responses across spatial and temporal scales. Chapter 2 explores the lake resource making use of the latest geospatial data and GIS techniques to investigate Scottish standing freshwaters in depth. 5,165 Scottish lakes exhibit an outstanding myriad of forms and sizes ranging across the country. This variety of form, density and distribution contribute to habitats of international importance for numerous species. Perhaps because of this diversity, no natural grouping of lakes were found based on simple hydromorphological categorisations. The use of landscape and wildness ‘scoring’ is a novel geographic approach, which may be an important factor in how landscapes are valued in the future. Chapter 3 investigates the direct exposure to global climate change facing Scotland. Projected changes to global climate were downscaled to illustrate impact on the UK and Scotland using both the UKCP09 and HadGEM2-ES climate models. Climate change by the 2050s will impact the UK in the range 1.1°C to 2.7°C with a clear South-East/North-West gradient. Precipitation too is projected to change in the UK in this time, with annual precipitation varying from -65 to +116 mm/yr. By incorporating the climate model data into a GIS it was possible to further interrogate the results for specific locations, with a detailed water balance model created for all 5165 lakes. This model suggests that during the summer months there will be sustained periods of water scarcity and deficit. Finally, in this chapter, a climate change spatial risk assessment was undertaken, identifying 200 lakes in the area of greatest projected change. Leading on from these findings, Chapter 4 explores the vulnerability of Scotland’s standing freshwaters. A vulnerability framework attempts to place resilience as a key part of the model, which has to date been missing from similar assessments. The expert weighted scoring mechanism highlights 851 of Scotland’s standing freshwaters, geographically spread across the country, as being highly vulnerable to projected climate changes. The results were mapped to show the vulnerability across Scotland and a display system for individual lakes proposed that allows a transparent and coherent structure that can shed light on distinct components of vulnerability, so that each can be evaluated individually, and in combination. Finally, in Chapter 5, a multipart online survey with key stakeholder experts actively involved in freshwater environmental management was produced to approach adaptation strategies and actions themselves. Over 80 adaptation actions specifically applicable to Scotland’s standing freshwaters were collated and grouped into 12 adaptation strategies. All 12 strategies were considered desirable with six strategies considered ‘Definitely feasible’, a further four considered ‘Likely feasible’. This provides a framework of potential actions that could help to reduce system sensitivity by increasing adaptive capacity or system resilience. In conclusion, while there are undoubtedly challenges ahead for Scotland’s standing freshwaters and for those who manage them, there is clear opportunity to make proactive and engaged decisions to minimise the impact of climate changes on the conservation interest of these important habitats.