Resilience and tree health: a basis for implementation in sustainable forest management

Resilience is rapidly becoming a prominent concept in research, policy and practice. However, it is apparent that there is no consistent meaning of resilience being used by those involved in governing and managing forests and tree health. We aimed to (1) identify how the concept of resilience is defined in a range of decision-making contexts, (2) develop an understanding of resilience, which will be useful in the context of tree health and forestry and (3) suggest how managers could use this understanding more broadly as a framework for decision-making on resilience within the forestry sector. Implementation of resilience for tree health needs to encompass a range of functions and services, management objectives and threats, all present at a variety of scales. We conclude that, due to the complexity of the resilience concept and forest systems, no single definition of resilience can be sufficient and it is more appropriate to explicitly consider four resilience components: resistance, recovery, transformation and adaptation. We propose a set of decision steps which stakeholders can use to develop a Resilience Implementation Framework to guide management for their system of interest

Martens in the matrix: the importance of nonforested habitats for forest carnivores in fragmented landscapes

The intervening landscape between patches of forest (i.e., matrix) has enormous potential to mitigate the negative effects of forest fragmentation. However, to release this potential requires understanding of how individual species perceive matrix. Here we investigated use of matrix by pine martens (Martes martes) in a region with low forest cover (Scotland). We radiotracked 11 martens to determine their habitat preferences, then combined our data with those published from 5 additional Scottish landscapes to examine how home-range size (i.e., population density) and diet of martens varied with forest edge density (i.e., fragmentation). Our tracking showed that although mature forest was the most preferred habitat, certain matrix habitats (scrub and tussock grassland) also were consistently selected. These 2 habitats provided martens with fundamental resources that are of limited availability within intensively managed plantation forests: den sites and primary prey (Microtus agrestis). Our synthesis of data across landscapes indicated martens benefit from supplemental resources in matrix habitats; consumption of small mammals increased with fragmentation and coincided with an initial increase in marten population densities. However, population densities of martens decreased once fragmentation passed a threshold level. Our results demonstrate that habitat complementation at the landscape-scale is essential for some forest-associated species. Resource supplementation from matrix habitats may be particularly important in regions with a long history of low-forest cover or where forest cover is now dominated by afforested plantations, which may lack essential resources

Ash dieback and other tree pests and pathogens:dispersed risk events and the Social Amplification of Risk Framework

It is widely acknowledged within the risk literature that the mass media play a pivotal role in shaping information about risk events for audiences. Whilst some risk events reflect occurrences specific to particular times and locations, other risk events are more difficult to temporally and spatially situate as they are dispersed across years or months and are not constrained to particular geographic locations. Studies examining the relationship between the social amplification or attenuation of risks and their framing in the media have tended to focus on the former type of event. In this paper we explore the social amplification of risk in relation to ash dieback disease (Hymenoscyphus fraxineus), a tree health issue that attracted intense media attention in the UK in 2012, and characterise what we designate as a dispersed risk event. Drawing on the influential Social Amplification of Risk Framework (SARF), we present a frame analysis of UK national newspaper articles to assess the connection between media coverage of dieback and risk amplification, and the extent to which dieback coverage drew on other tree health issues and objects of media attention. Focusing particularly on the blame frame around dieback, the paper considers the implications of conceptualising dispersed risk events for the SARF and its amplification metaphor. Moreover, given that risk events such as dieback are often associated with policy shifts, we suggest that there is value for risk communicators and policy makers in broadening their focus to incorporate more of the ‘history’ of risk events in order to anticipate likely anchors of public and media attention

Diversionary feeding: an effective management strategy for conservation conflict?

Human population growth has led to increased contact between people and wildlife, with adverse impacts for both, such as damage to economic crops and wildlife persecution. Diversionary feeding, where food is used to draw animals away from problem activities or locations, is sometimes proposed as a socially acceptable conservation action, but little information exists on its success or what influences its efficacy. Here, we review literature on diversionary feeding and evaluate factors contributing to its success or failure. Success varied greatly among studies and successful uptake of diversionary food did not consistently produce outcomes that met stakeholder objectives. Studies often failed to report results in sufficient detail to allow a quantitative evaluation of efficiency. Of 30 trials presented in 21 studies, 13 enabled assessment of outcomes related to the ultimate objective of reducing conflict (related to threatened prey density, crop yield or nuisance reports) and only five of these were considered successful by the researchers conducting the study. A grand mean increase of 15% in respective measures of success at the outcome stage was found across all studies. Although diversionary feeding is considered expensive, cost-effectiveness analyses were rarely conducted. Only a third of studies reported information on costs and benefits that could be used to inform future management actions. We propose a decision-making framework that incorporates ecological knowledge, financial costs and evidence from previous studies to aid the planning and implementation of diversionary feeding in an adaptive format. Future studies of diversionary feeding should clearly report objectives, results, costsand effort to allow the return-on-investment to be calculated for different levels of management effort

Fur and faeces: an experimental assessment of non-invasive DNA sampling for the European pine marten

Non-invasive genetic sampling using materials such as faeces or hair can be used to monitor wildlife populations, although DNA quality is often poor. Improving sampling efficiency and minimising factors that reduce DNA quality are therefore critical. After a severe decline, the European pine marten, Martes martes, has reclaimed much of its former range in Scotland, UK. Recording this rapid range expansion requires developing techniques for accurate monitoring, but this is hampered by the species' elusive behaviour. We tested two sampling methods, hair collected from hair tubes and faeces (scat) collected along tracks, to assess the effects of key environmental and sampling variables on DNA quality and sampling efficiency. For hair, we tested the influence of hair tube location (distance from forest tracks) on collection rate and sex ratio of animals successfully sampled. For scats, we assessed the effect of time since defecation (1 to 16days) on genotyping error rates and success under two contrasting environmental conditions (exposed to rainfall or sheltered). We found no bias in the collection rate or sex ratio of animals detected by hair samples with differing proximity to forest tracks. DNA amplification failure for scats exposed to rainfall increased from 28 to 65% over the 16-day experimental period. During periods of low rainfall, the length of collection sessions could therefore be extended to increase sample number without risk of DNA degradation. Lack of bias in hair collection rates with proximity to forest tracks provides justification for tube placement close to tracks, as this reduces survey effort. These findings provide guidance for the development of efficient and cost-effective non-invasive sampling of Scottish pine martens

Niches for Species, a multi-species model to guide woodland management: An example based on Scotland's native woodlands

Designating and managing areas with the aim of protecting biodiversity requires information on species distributions and habitat associations, but a lack of reliable occurrence records for rare and threatened species precludes robust empirical modelling. Managers of Scotland’s native woodlands are obliged to consider 208 protected species, which each have their own, narrow niche requirements. To support decision-making, we developed Niches for Species (N4S), a model that uses expert knowledge to predict the potential occurrence of 179 woodland protected species representing a range of taxa: mammals, birds, invertebrates, fungi, bryophytes, lichens and vascular plants. Few existing knowledge-based models have attempted to include so many species. We collated knowledge to define each species’ suitable habitat according to a hierarchical habitat classification: woodland type, stand structure and microhabitat. Various spatial environmental datasets were used singly or in combination to classify and map Scotland’s native woodlands accordingly, thus allowing predictive mapping of each species’ potential niche. We illustrate how the outputs can inform individual species management, or can be summarised across species and regions to provide an indicator of woodland biodiversity potential for landscape scale decisions. We tested the model for ten species using available occurrence records. Although concordance between predicted and observed distributions was indicated for nine of these species, this relationship was statistically significant in only five cases. We discuss the difficulties in reliably testing predictions when the records available for rare species are typically low in number, patchy and biased, and suggest future model improvements. Finally, we demonstrate how using N4S to synthesise complex, multi-species information into an easily digestible format can help policy makers and practitioners consider large numbers of species and their conservation needs

Non-invasive genotyping and spatial mark-recapture methods to estimate European pine marten density in forested landscapes

Accurate population density estimates are important for conservation but can be difficult to obtain where species are elusive or rare. Non-invasive genotyping from hair or faeces has provided a promising solution and allowed individual identification from genotypes to inform population assessment models. We use individual genotypes derived from hair samples and Spatially Explicit Capture Recapture (SECR) models to estimate the population density of European pine marten (Martes martes) in three Scottish forests, then examine the effects of forest fragmentation on population size. Relative trends in pine marten abundance can be observed via changes in the number of scats in an area through time, but the link between this measure and population density remains unclear. We provide the first calibration of scat counts to enable population density estimation without the need for genetic analysis. Population density estimates ranged from 0.07 km-2 (95% CI 0.03 – 0.16) to 0.38 km-2 (95% CI 0.11 – 1.07), which were mid to low compared to other estimates from the Scottish population. An unequal sex ratio was found in one of the three forests. We found support for the previous finding that pine marten density in Scotland increases with forest fragmentation up to a threshold level (20 – 35% forest cover), beyond which it decreases. Our calibration suggests a non-linear relationship between scat counts and population density, although relatively small changes in population density result in marked changes in scat number. Following the recent re-introduction of pine martens to Wales, non-invasive genetic sampling for population estimation may provide an effective way of monitoring their progress

Working with decision-makers for resilient forests: a case study from the UK

Improving resilience in forests relies on an understanding of the values, knowledge and practices associated with forests. In this paper, based on a case study from the UK, we present qualitative data on how the concept of resilience is understood by decision-makers, the effectiveness of existing policy tools to promote resilient forests and the current boundaries and social acceptability of different management options. Our research reveals that the articulation of actual, possible and needed policy responses reflects the challenge that resilience is a multifaceted concept with an array of potential implications, connected with a diverse set of forest ecosystems. Our research suggests that the collaborative development and promotion of an overarching vision for resilience, which recognises the needs and contexts of different owners and managers in the sector, might begin to overcome the current challenge of fragmented policy and lack of policy tools. This will necessarily involve discussion and coordination across different areas of government and involve those agencies and organisations responsible for the science behind resilience approaches and applications. In particular, there is a need to contextualise and communicate resilience in line with stakeholder needs, and to articulate the uncertainty associated with resilience measures in a range of situations so public agencies, forest owners and managers can make informed choices

Expert risk perceptions and the social amplification of risk: A case study in invasive tree pests and diseases

The Social Amplification of Risk Framework (SARF) is often used as a conceptual tool for studying diverse risk perceptions associated with environmental hazards. While widely applied, it has been criticised for implying that it is possible to define a benchmark ‘real’ risk that is determined by experts and around which public risk perceptions can subsequently become amplified. It has been argued that this objectification of risk is particularly problematic when there are high levels of scientific uncertainty and a lack of expert consensus about the nature of a risk and its impacts. In order to explore this further, this paper examines how ‘experts’ – defined in this case as scientists, policy makers, outbreak managers and key stakeholders – construct and assemble their understanding of the risks associated with two invasive tree pest and disease outbreaks in the UK, ash dieback and oak processionary moth. Through semi-structured interviews with experts in each of the case study outbreaks, the paper aims to better understand the nature of information sources drawn on to construct perceptions of tree health risks, especially when uncertainty is prevalent. A key conclusion is that risk assessment is a socially-mediated, relational and incremental process with experts drawing on a range of official, anecdotal and experiential sources of information, as well as reference to past events in order to assemble the risk case. Aligned with this, experts make attributions about public concern, especially when the evidence base is incomplete and there is a need to justify policy and management actions and safeguard reputation