“No trees in the wrong place” defining multifunctional priorities for woodland expansion strategy to meet national climate targets in the Cairngorms National Park

Forests are the repository of much of the world's biodiversity, and therefore foresters must assume a degree of responsibility for its management and conservation. (Kapos and Iremonger, 1998). Maintaining such biological diversity it is now one of the most important goals of managing forests in a sustainable way and to address this need, biodiversity conservation organizations have proposed nine templates of global priorities over the past decade. (Brooks et al., 2006). However, if forest conservation priorities are well recognised globally, the process for understanding the distribution of species and ecosystems locally is scale-dependent (Lindborg et al., 2017). On the other hand, data that are available at a global scale are still typically sparse and of varying quality, while locally choices are still driven by detailed data. Managers and policy makers need to be cognizant of the biological significance of the forests they manage in a broad context, avoiding to compromise global biodiversity goals by managing their forests inappropriately. Therefore, to achieve this important management target it is crucial that managers be fully informed (Noss, 1999) on the status, condition, conservation value of each forest, and change in forest conditions over time. This thesis addresses these questions by examining a range of data-driven spatially explicit approaches with the purpose of supporting the assessment of potential impacts of different policy and climate scenarios on the Scottish forest- based sector. The specific forest types characterization and potentialities are guided by information at two levels: bottom-up models based on local characteristics of each site; and an overarching, top-down, national-level national policy for net carbon sequestration. In the forest Scottish context detailed local scale case studies are still lacking in incorporating the policy context and the ecosystem service approach, introduced in Chapter 2, to meet national strategic targets. Beside, human activities within and nearby the protected areas boundaries have increased the pressure on forest and the services they deliver, exacerbating the concept that management and land-climate systems need to coexist, and pursue the same sustainable development. The Cairngorms National Park represent an example, that may possibly encourage dialogue between different actors for the mutual advantage of using tools that facilitate the visualisation of constraints and opportunities for the forestry sector. In Chapter 3, the specific bio-physical assessment in the area and socio- economic drivers and barriers to change in Cairngorms is presented. Forests as carbon sinks, therefore, are required to play a multifunctional role that includes, but is not limited to, biodiversity conservation and maintenance of ecosystem functions; yield of goods and services to the society; enhancing the carbon storage in trees, woody vegetation and soils; and providing social and economic well-being of people (Pandey, 2002). Evaluating how climate mitigation measures (e.g. woodland expansion) may have unconsidered effect on other ecosystems and forest functions has become increasingly important in the study of long-term maintenance of biodiversity (Peters and Darling, 1985, Van der Plas et al., 2018, Minang et al., 2014). However, works dealing with modelling of the impacts of climate change on woodland species dynamics in Scotland to address carbon sequestration, one of the pillars in global mitigation, are limited. An attempt to model the future distribution of broadleaved and conifer species at Scotland scale, and investigate the potential impact on soil carbon is described in Chapter 4. Natural protected areas provide valuable services to society, including the supply and purification of fresh water (Postel et al., 2005, García-Nieto et al., 2013., Birch et al., 2014). Ecosystem services modelling tools has been widely compared (Dennedy-Frank et al., 2016, Rosenzweig et al., 2014, Cheaib et al., 2012, Vigerstol and Aukema, 2011), with a quite relevant concern in validation and accurancy, however successfully attempt in hydrological ecosystem (Redhead eta la., 2016) have recently raised the attention around InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs, Sharp et al., 2015). In Chapter 5, a methodological approach to nutrient and sediment retention taking account of modelling response to options of woodland expansion is established, through the integration of ideas developed in the Interim report for the Scottish Government (Gimona et al., 2019). Adaptation and resilience cannot be achieved without credible and robust information on climate change and its variability is needed to inform decision-making. UKCP18 is the most up to date national climate projections for the United Kingdom and will provide users with the most recent scientific evidence on projected climate changes with which to plan. The UKCP18 trends can drive future fluvial flooding which, already increasingly nowadays, can heavily threats the hydraulic and biological process of the flood plains. Engineering solutions seem insufficient to maintain low flood risk without affecting biota components (Talbot at al., 2018, Nedkov et al., 2012), hence natural catchment-based adaptation measures (e.g. Natural Flood Management, NFM) are likely required (Wilkinson et al., 2019, Iacob et al., 2016, Nisbet at al., 2011). Afforestation is one of the measures that can increase infiltration rates associated with improved soil structure and macropore formation (Eldridge and Freudenberger 2005). Target areas for spatial decision support and NFM approaches can be implemented through the use of Geographical Information Systems (GIS) providing an excellent opportunity for integrating with multi-criterion evaluation results (Jankowski et al., 2001). A suitability model of the occurrence of flooding risk and opportunity for afforestation in the Cairngorms National Park has been developed. This work is described in Chapter 6. The persistence of native species in fragmented landscapes is dependent on dispersal or foraging movements between habitat patches, which may be limited. Although corridors have been heralded as solutions, their effectiveness depends on species’ movement behaviour, which has rarely been studied (Doerr et al., 2011). Chapter 7 brings together results of potential dispersal connectivity for generic species in broadleaved woodland and specialized birds for native conifer. The connectivity paradigm here is defined by a prediction of movement patters in complex landscape based on circuit theory software. Such models identified the spatial opportunities for new trees that can act as stepping stones, increasing connectivity and facilitating range expansion (Rossi et al., 2016). Additional spatial data, not obtained by modelling methods, and the creation of the baseline land cover map to use for generation land use change scenarios is discusses in details in chapter 8; while results of four woodland expansion scenarios in the Cairngorms to meet the rate of national strategic target are presented in chapter 9. The outcomes are the simulation of forest land managers that can benefits from tools (e.g. spatial Multi Criteria Analysis, sMCA) to identify win-win functions and avoid unintented negative effects. Chapter 10 draws conclusions regarding this work. The management of all natural resources must now meet both national and local targets and guidelines. To achieve this stakeholders such as policy makers, managers, ecologists, foresters, and field rangers must have access to both spatial data and tools. Combining, GIS, statistical spatial models, specific ecological software and open- source frameworks and integrating data in a computer-based platform to let decisions managers explore options is therefore crucial to simulate and define multiple benefits. The main task of this research was to find a means to implement and integrate all the specific outcomes in the Cairngorms National Park area and outline the implication, described in chapter 11, of such effort. The specific objectives of this work therefore were: 1. To define areas for net positive soil carbon sequestration through woodland expansion in Scotland accounting for climate changes (2050-2070). 2. To parametrize and use model in water purification service in Scotland assessing some of the consequences of scenarios of broadleaved land use change. 3. To outline priority areas for implement Natural Flood Management in Scotland with the use of spatial analysis. 4. Defining the potential dispersal pathways addressing native conifer and broadleaved species to enhance connectivity in the Cairngorms National Park. 5. To discuss the usability and usefulness of MCDM methods from the viewpoint of supporting forestry decision making, identifying priority areas in the National Park for native woodland creation. 6. To map the options of woodland expansion in the Cairngorms National Park to meet national climate target. 7. To examine differences in the results of simulating different stakeholders opinions in defining priorities to the four chosen criteria. 8. To review the current Cairngorms National Park Forestry Strategy 2018.