The UK government plans to increase woodland cover as part of its plans to store more carbon, to mitigate climate change. However, many of the UK's trees are threatened by climate change and a range of pests and diseases, which might limit their ability to contribute to carbon storage and the wide range of other benefits delivered by woodlands. We therefore need to make our woodlands resilient to these future threats. Resilience is the ability of a system, such as a woodland, to recover from a disturbance. One commonly proposed approach to increase the resilience of woods is to increase their tree diversity. Thus, spreading the risk amongst many different trees, as we don't know exactly how each tree species will respond to climate change, nor what threats from pests and diseases they may face decades into the future. However, woodland managers have different perceptions of diversity, and how management may best deliver it, and we know that different tree species will support the woodland ecosystem in different ways. Therefore, it is important to combine stakeholders' knowledge with ecological knowledge to identify which tree species and management approaches best deliver diversification that increases resilience. DiversiTree focuses on woods dominated by two conifer species, Scots Pine and Sitka Spruce, as in the year to March 2021 54% of all new woodland was coniferous. Scots Pine is the UK's only native conifer of economic significance. It is planted for timber production but is also the dominant species in the culturally iconic native Caledonian pinewoods. Scots Pine is at risk from the tree disease Dothistroma. Sitka Spruce is not native to Britain but is our most economically valuable tree species and is at risk from invasive bark beetles and climate change. This project addresses four knowledge gaps related to the diversification of woodlands: 1) How do stakeholders understand forest diversity, their diversification strategies, and their visions and ambitions for diverse future forests? 2) Are the microbes found on the leaves of trees more diverse in woodlands with mixed tree species and does this help trees to better defend themselves against diseases? 3) How may diversification of tree species within a wood allow the continued support of woodland biodiversity? 4) How do we implement and communicate management strategies to increase woodland resilience? To address these knowledge gaps, we work across disciplines bringing together ecologists, microbiologists, social scientists, and woodland managers. The Woodland Trust is embedded at the heart of our project to enable us to co-develop and check the feasibility of our results with practitioners. Results from interviews with woodland managers, focus groups and analyses of policy documents, will be used to improve knowledge of the options for woodland diversification, and both the enthusiasm for, and capacity to, implement diversification strategies. The microbes on leaves are important for plant health. Utilizing existing long-term experiments, we will examine the microbes on the leaves of Scots Pine grown in monocultures and in mixed woods. We will assess if the diversity of microbes on a leaf increases as the diversity of tree species increases, and whether this enables the trees to resist existing diseases. Surprising we don't have lists of which species use which trees. This information is required if we are to plant trees that will continue to support woodland biodiversity. We will collate data on the biodiversity hosted by Scots Pine and Sitka Spruce and assess which other tree species could also support the same biodiversity. Finally, we bring the results together to co-develop with practitioners, management strategies for diversification and case studies illustrating how the results can be implemented. The results will be shared via videos, podcasts, social media, and practitioner notes in addition to publications in the scientific literature.

Tree planting has been the most common woodland expansion strategy in the UK for many decades. Despite its many benefits, this approach is increasingly being questioned following overestimates of benefits, poor targeting and challenges in scaling-up tree planting at the level required to meet ambitious woodland expansion targets. Consequently, there is growing interest in incorporating 'natural colonisation' (allowing trees to colonise new areas naturally) into woodland expansion strategies, partly because it is assumed that naturally created woodlands will be more structurally diverse, ecologically complex and resilient than planted sites. Embracing natural colonisation as a complementary approach to tree planting has the potential to radically transform UK treescapes and unlock woodland expansion at scale. Tree planting and natural colonisation may be used in complementary and blended combinations across a landscape, depending on the local conditions and the benefits expected. However, we know very little about the socio-ecological consequences of creating woodlands through approaches incorporating natural colonisation. We also have a poor understanding of land managers' attitudes towards woodland creation approaches other than tree planting, and it is not clear which kinds of land managers do, or would, engage with woodland creation through alternative approaches incorporating natural colonisation, and why. Using an inter-disciplinary approach, we will explore agricultural land managers' attitudes towards woodland creation strategies spanning the planting to natural colonisation continuum. We will also quantify the differing ecological and social consequences of these approaches, and identify factors associated with woodland resilience. Finally, we will integrate socio-ecological evidence to demonstrate how tree planting and natural colonisation can be used in combination to scale-up woodland expansion for a range of objectives on agricultural land. We will focus on broadleaf, and mixed broadleaf and conifer, woodlands created in agricultural landscapes with varying degrees of land-use intensity (from intensive arable lowland to marginal grassland on the upland fringe) and surrounding woodland cover, as these factors are likely to influence stakeholder perceptions and socio-ecological outcomes of woodland creation methods. These landscapes represent a major portion of UK land area with potential for woodland expansion. We will exploit two unique and complementary networks of woodland sites across the UK to create a novel platform from which to assess stakeholders' perceptions and socio-ecological consequences of woodland creation approaches spanning the planting to natural colonisation continuum. These sites provide a rich data resource and access to a diverse range of land-mangers. TreE_PlaNat will provide the evidence base to inform how, where, and for whom different strategies along the 'planting' to 'natural colonisation' continuum can be used to meet Government woodland expansion targets. Stakeholder organisations, including NGOs, statutory agencies and industry, are embedded in this proposal as co-applicants and project partners, demonstrating the co-development of this project and facilitating implementation of our findings.

Conservation organisations are concerned with the protection of natural habitats and species, for their intrinsic value, the services they provide humanity and for their amenity value. Under international and local statutes, conservation organisations are obliged to prevent wild habitats from becoming degraded and halt or reverse the decline of species of conservation concern. This job is increasingly difficult given the extent of degradation and fragmentation of habitats and the threat of global changes, such as climate change. Until now, conservationists have been mainly concerned with habitats and species, and have neglected to consider a third strand of biodiversity called 'genetic diversity'. Genetic diversity can be found in all species. It is variation among individuals in DNA sequences that cause differences in their physical attributes, and is responsible for the familial resemblance among relatives. Genetic diversity is relevant to conservation in a number of ways. Firstly, many populations of endangered species are isolated and consist of small numbers of individuals. These populations often have little genetic variation, and this can hamper their ability to adapt to changing environmental conditions through natural selection. Adaptation is key to success in conservation, because without it, species will be prone to extinction under environmental changes such as climate change. Secondly, small or isolated populations often consist of closely related individuals, and mating among these close-relatives can lead to inbred offspring that suffer immediate health problems. This can act as an additional burden on endangered species, making their populations more difficult to conserve. Thirdly, similar problems can occur due to inter-mating between very divergent populations. This may occur if human-aided movement of species brings previously separated populations into contact. Although these types of genetic problems are relatively well understood, there is no generic framework for assessing which species are at risk of which genetic problems, or decision-making tools to guide management actions. In addition, conservationists may be disinclined to incorporate these genetics problems into their action plans, because jargon and terminology in genetics can make the field inaccessible to conservationists without a genetics background. Our aim in this project is to enhance dialogue and the exchange of knowledge between researchers interested in genetic biodiversity, and wildlife conservationists. In doing this we will facilitate improved strategies to conserve species and enable the best use of genetic data in conservation programmes. Firstly we will develop a working group consisting of geneticists and conservationists to provide a forum for the exchange of ideas, ensuring that geneticists are aware of the key conservation challenges, and conservationists are aware of when genetic information is likely to be useful. Secondly, we will evaluate previously published genetic information to fill gaps in understanding, and to determine when genetic problems are most likely. Thirdly we will develop a mechanism to assess the risk of genetic problems faced by any individual species, and link this to a framework recommending the best course to alleviate these problems. We will then test and refine this approach using species of conservation importance in the UK. Our fourth objective will provide standard protocols for choosing the sources of individuals for human-aided movement of plants or animals from one place to another. We will develop a system for recording the success and failure of these translocations to better inform future guidelines. Finally, our key goal is to make all of this information accessible. We will produce user-friendly handbooks aimed at explaining genetic issues in conservation, and will produce web-pages to assist conservation managers develop management strategies that incorporate genetic approaches.

The 2007 floods prompted the UK Government's "Pitt review", which came up with the idea that we need to start to deal with the causes of flooding upstream of the affected communities, rather than rely solely on the downstream engineering solutions. This stimulated a range of organisations to introduce "natural" features into the landscape that may have benefits in terms of reducing flooding (so called "Natural Flood Management, NFM"). Having introduced features these organisations, and local stakeholders working with them, are increasingly asking "Are these features working?" This has highlighted to funders, those implementing the features and scientists alike that there are gaps in the evidence of how individual features (e.g. a single farm pond or a small area of tree planting) work and what are potential downstream benefits for communities at risk of flooding. Stakeholders want both questions answered at the same time, making this one of the most important academic challenges for hydrological scientists in recent years. The only way to quantify the effects of many individual features at larger scales is to use computer models. To be credible, these models also need to produce believable results at individual feature scales. Meeting this challenge is the focus of this research project. Consequently, our primary objective is to quantify the likely effectiveness of these NFM features for mitigating flood risk at large catchment scales in the most credible way. In this context, credibility means being transparent and rigorous in the way that we deal with what we do know and what we don't know when addressing this problem using models. In doing this we need to address particular scientific challenges in the following ways: * We need to show that our models are capable of reproducing downstream floods while at the same time matching observed local hydrological phenomena, such as patterns of soil saturation. Integral to our methodology are observations of these local phenomena to further strengthen the credibility of the modelling. * We use the same models to predict NFM effects by changing key model components. These changes to the components are made in a rigorous way, initially based upon the current evidence. * As evidence of change is so critical, our project necessarily includes targeted experimental work to address some of the serious evidence gaps, to significantly improve the confidence in the model results. * This rigorous strategy provides us with a platform for quantifying the magnitude of benefit that can be offered by different spatial extents of NFM implementation across large areas. By addressing these scientific goals we believe that we can deliver a step change in the confidence of our quantification of the likely effectiveness of NFM measure for mitigating flood risk at large catchment scales.

It has been reported that the time-of-year of many typical indicators of spring, such as egg laying in birds and flowering in plants, has been changing in recent decades. Many of these recurring biological events now happen earlier in the year than they did just a few decades ago. This is believed to be one of the most conspicuous biological impacts of climate change. Far from trivial, these changes could disrupt seasonal relationships between species. This is because different species have changed their seasonal timing to different extents. For example, predators such as some woodland birds may now need to feed their chicks at a time of year at which peaks in their insect food no longer occur, whereas these events may once have coincided. Such changes in the seasonal synchronisation of different species have the potential affect numbers of offspring produced and the survival of populations. A few studies on a small number of species suggest that predators and prey may become de-synchronised because they have different responses to a warming climate but we do not currently know whether this is a general pattern that holds across a large number of species. We also do not currently know how much the observed changes in the timing of spring events has been affected by human-induced climate change, rather than climate change brought about by natural causes. The current project aims to address these gaps in our knowledge by analysing thousands of long-term studies on hundreds of UK plant and animal species and showing whether predatory species have, on average, different responses to climate change compared to their prey and whether these changes are likely to be effects of the human-induced component of climate change. We also aim to establish the regions of the UK, and habitats, in which possible de-synchronisation between predators and prey is most likely by focussing on birds and the insects on which they feed their chicks. This is the first time that so many species from marine, freshwater and dry-land environments have been analysed in a way that allows meaningful comparisons to be made between them, and that allows a statement to be made about the likely significance of human-induced warming for the functioning of a wide range of UK ecosystems.