Managing Trees Species of High Social and Cultural Value: Forest Manager Attitudes towards Pest and Disease Risks to Oak in Britain

Abstract

The values of forests have been extensively researched by focusing on general public perspectives with different frameworks used to categorise them. Studies have also explored forest manager values; however, there is limited evidence on the values they associate with specific tree species. Understanding more about managers’ values regarding a particular species is important when considering how they make decisions and might respond to tree pests and disease threats. In this study, we explored forest managers’ values regarding oak trees and the effects of a particular pest and disease risk known as Acute Oak Decline on these. This paper outlines the results from interviews with forest managers in England and a survey of private forest managers in Britain to capture the ways in which they value the oak trees they own, manage, or influence. Forest manager types included private owners of single or multiple properties, forestry professionals, businesses, and tenants. The results show that oaks were highly valued by forest managers as an iconic cultural species in the landscape and for their timber. Veteran and ancient oak trees were considered very important, and managers were more likely to spend time and resources attempting to conserve these oaks due to their perceived cultural value. Those who had trees that were suffering from Acute Oak Decline were also more likely to spend resources on them to save the trees or try to reduce the impact of the disease. Gaining a better understanding of forest managers’ attitudes towards protecting species they value is important as it has implications for their decision-making and management behaviours. It can also help to provide relevant bodies with information on how best to develop and communicate guidance and advice on monitoring and reporting disease symptoms, as well as managing oak tree health.

1. Introduction

In the United Kingdom (UK), the majority of trees, woods and forests are owned privately, 74%, according to official statistics [1]. The remaining 26% is owned by government bodies and agencies. Forests in Britain are managed to meet a wide range of objectives, from timber production, conservation, and amenity to multiple objectives [2,3]. There is currently a strong focus in Britain on enabling and encouraging more tree planting to increase forest cover [4]. Various studies have segmented forest managers in Britain into different groups, often based on their values, motivations, and attitudes, to better understand how they can be supported and incentivised to manage and/or create more forests. For example, studies in Britain have identified managers with wide-ranging objectives, from those focused on multi-functional objectives to those who focus on economics, in particular timber production, or who are interested in conservation and amenity [2,5,6]. The British Woodlands Surveys of forest managers in 2020 and 2021 [7] found the three most important aims and motives for managing forests were as follows: (1) protect/improve nature, biological diversity, and wildlife habitat; (2) personal pleasure; and (3) protect/improve the landscape. The 2020 survey of forest managers and professionals also found that respondents were becoming more aware of climate change, and 79% said they were more aware of the increasing threats from tree pests and pathogens and the damage they have caused in the previous five years. Therefore, in this paper, we focus on Acute Oak Decline as a disease that is threatening oak trees in Britain.

The values that different stakeholders have regarding trees and forests have been researched and debated through a range of differing disciplinary perspectives. This research also drew from a variety of frameworks to understand those values. A focus on ecosystem services is one of the approaches used; it focuses on the provisioning, supporting, regulating, and cultural services provided by forests [8,9]. Specific tree species can be valued in different ways by stakeholders such as forest managers. Oak trees are valued across many countries for high-quality timber and biodiversity [10]. For example, the cork oak (Quercus suber) savannah-type landscapes of Portugal are considered important as they provide multiple ecosystem services, including cultural values related to nature-based tourism, links to traditional songs, and traditional agricultural practices [11]. Soares et al. [12] outline the value of holm oak (Q. ilex), as it provides important ecosystem services, and a study in Spain of holm oak parklands found private land-holding respondents valued having these oaks on their land for income as well as aspects related to natural beauty, their importance to wildlife, and shade [13].

In Britain, two native species are highly valued: Q. robur, which is mostly found in the south and east of England, and Q. petraea, found more in the north and west of England, as well as in Scotland and Wales [14,15,16]. Oak is the second-most common broadleaf tree species in Britain [17]. In England specifically, there are possibly more ancient native oaks than in all other European countries combined [18], with more than 65,000 veteran, ancient, and notable oaks recorded in the Ancient Tree Inventory [19]. Ancient trees are those that have reached a great age compared to others of their species. Veteran trees have developed some of the features found in ancient trees, such as deadwood or hollows in the trunk; however, they are not old enough to be ancient [16]. Oaks are celebrated in prose and poetry [20], and they occur both in forests and outside of forests and can be particularly prominent in the landscape when in wood pasture, including ancient wood pasture in Scotland, and in large parkland estates such as Windsor Great Park in London [21,22]. Oaks appear in stories and folklore: the ‘Oak at the Gate of the Dead’ in Wrexham is associated with a great 12th-century battle between Wales and England [23], and the ‘Major Oak’ in Sherwood Forest is associated with stories of Robin Hood (a figure from English folklore). The Department for Environment, Food and Rural Affairs in Britain estimated that the social and environmental value of oak was GBP 280 million per year, including recreation, landscape, carbon sequestration, elements of biodiversity value, and air pollution absorption [24].

1.1. Values of Oak (Quercus robur and Quercus petraea) Explored through a Cultural Lens

Understanding forest manager values is important [3], as the ways in which forest managers value tree species, such as oaks, can have an impact on their behaviours, decision-making, and management actions. Private forest managers focus on their individual values, while public forest managers work on organisational objectives. Values can be looked at in different ways. They can be defined as the principles that guide people’s attitudes and can motivate them to take action [25,26,27]. Shared values are those that are held collectively by society, groups, or communities and can be important to understand. Values are rooted in culture and linked to people’s preferences, attitudes, and motivations [3,28,29]. Chan et al. [30,31] talk about relational values that move beyond a focus on intrinsic and instrumental values to focus on values that are preferences and principles about human/nature relationships. These relational values concern the deep-seated relationships people have with nature, whereas intrinsic value relates to something that is of value in and of itself. Meanwhile, instrumental value is associated with the value of something as a means to an end—for example, the value of oak trees for their timber. However, Luque-lore [32] strongly critiques this distinction, outlining that intrinsic and instrumental values can also be thought of as relational. The majority of studies focus on people’s individual values; however, exploring values that are shared or common across a group of people or stakeholders can be important when trying to understand issues at a landscape scale and where people consider the importance of particular issues for their community or for wider society (see, for example, reference [28]). Work by the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) has led to a values assessment that provides a typology and guidelines for ‘reconciling a good quality of life with that of life on earth’ [33]. There is also some evidence that private forest managers, in particular, are influenced by the ways in which they perceive forests to be valued by wider society. This can lead them to make certain assumptions about the social acceptability of forest management practices. This can sometimes make them concerned or reluctant to undertake particular management practices such as pre-emptive felling because of potential community-scale objections [3].

1.2. Oak Health and Pests and Pathogens Affecting Oaks

Trees and forests are facing a range of threats due to climate change and the movement of plant species across the world through globalisation, which in turn is resulting in increased movement of pests and pathogens [34]. There are a range of pathogens affecting oak trees in the UK, including powdery mildew of oak, which attacks young leaves and shoots and pathogens in the genera Armillaria and Gymnopus, which affect the roots of oak. Pests affecting oak include the Oak Processionary Moth, which is a hazard to human and animal health, and large numbers of the caterpillar feeding on the leaves of oak can leave the trees vulnerable to other stresses [35,36]. The oak pinhole borer Playtpus cylindrus infests and breeds in stressed trees such as windblown trees, cut trees, and dying trees [37]. Recent research has shown that forest managers with oak trees are very much aware of these increasing threats, and while the majority consider their oaks to currently be in good health, there is great concern that Quercus spp. is increasingly at risk in the future.

In this study, we specifically focus on a condition known as Acute Oak Decline (AOD), which has multiple causes, including bacterial pathogens. In one-third of cases, D-shaped exit holes are found in oak stems created by the bark beetle Agrilus biguttatus, which is native to Britain. At one time, the beetle was rare enough to be classed as vulnerable [38]. The beetle’s role in AOD has been somewhat controversial as it has been hard to prove whether this species only favours stressed oak trees or whether it has a more active role in spreading the pathogens [34]. Recent research has shown that AOD symptoms are caused by both bacteria and the A. biguttatus beetle [39]. AOD is a complex decline syndrome that can cause the death of oak trees, and it is mostly found in England, Southeast Wales, and the Welsh borders at present. The disease mainly affects the two native oaks in the UK (Quercus robur, Q. petraea), and symptoms include stem bleeds and weeping fissures on the trunk [40].

Encouraging and supporting active forest management in dealing with tree pests and diseases are the key aims of the British government [41]. The values that forest managers hold influence the objectives they have for the forests they are responsible for. This will affect their decision-making and management behaviours. Therefore, understanding these values is important so that support, guidance, and communications can be developed to promote and encourage oak health. Along with raising awareness about AOD. Consequently, in this research, we aimed to address the following research questions:

• What are the ways in which forest managers value oak trees?
• Do these values differ, or are they stronger, depending on whether the forest manager manages oak trees in different settings, from parklands to forests, or whether the forest has AOD?
• How do forest managers’ actions and use of resources differ when responsible for veteran/ancient oaks and oaks with AOD?

Addressing these research questions can provide evidence that could inform future guidance and support for AOD management and potentially other pest and diseases.

2. Materials and Methods

A mixed-methods approach was undertaken, including semi-structured interviews with a range of forest managers—primarily in England, where the majority of AOD is found at present—and an online survey of forest managers across Britain. We carried out the survey across Britain because although AOD is currently mainly confined to England and some areas of Wales, it is continuing to spread across Britain. The interviews added depth and detail about forest managers’ values and why they may act to support oak health, while the survey responses gave us quantitative data on what values are the most important across a broad number of private managers.

2.1. Survey Method

An online survey of private forest managers was conducted by Sylva Foundation using its network of forest managers, owners, and forestry professionals, which it drew upon to undertake the regular British Woodlands Survey (BWS) [42]. A small number of questions in the survey focused on the cultural values of oak. The survey was completed by 606 respondents in total. However, the number included in this study (n = 256) involved those respondents who confirmed that they managed or owned oaks and who stated their forest manager type as professional agent, woodland owner (private owner of single or multiple properties, forestry professional, or business), or tenant. Respondents who were owners also stated whether their ownership was personal non-agricultural; personal agricultural; or agricultural business, charity, or private trust (Appendix A). Different types of forest manager can have a variety of aims and motivations that can influence their decision making and behaviours. For example, a professional agent may act to deliver against the objectives of a large forest owner who may be interested in timber production. Meanwhile, a smaller woodland owner may manage for conservation or personal pleasure. The list of aims/motives for forest management is a standard question asked in each BWS and is sometimes used to explore if management priorities are changing over time [42]. We asked whether participants thought any of the oak trees they managed had AOD. The questions also covered the extent to which they perceived oak trees as culturally significant because they are part of country identity; part of shared history; or part of folklore and legend, literature, and poetry. Finally, respondents were asked whether their values regarding oaks might affect their management decisions. Of the 256 sample, 134 tree managers had oaks that were not veteran or did not have AOD, 90 managed veteran oaks, and 29 managed veteran oaks and had AOD. Four others who managed oaks reported that these were not veteran trees, but they did have AOD (

Table 1. Survey respondents—simplified owner type (see [5] for full typology) and those with oak and with or without AOD or veteran specimens. Note: one null response was identified.

Type of Respondent	Oak	Oak and AOD	Oak and Veteran/ Ancient Trees	Oak and AOD and Veteran/ Ancient Trees
Agent	13	1	17	13
Business	5		3	1
Professional: own forest	7		5
Professional: personal	6		7	3
Forest owner multiple	24		17	2
Forest owner single	79	3	40	10
Total	134	4	89	29

). The introduction to the survey outlined who was funding the research, how the data would be used, and that the study would follow the General Data Protection Regulation. Consent from participants was sought by outlining that if they clicked a ‘next’ button and started to complete the survey, they were giving their consent for their anonymised data to be used as outlined in the survey introduction.

2.2. Survey Data Analyses

Previous evidence suggests that type of owner and forest area can be key variables when exploring the perceptions of forest managers [42]. We also wanted to explore whether the type of oak (veteran/ancient) or whether managers had trees with AOD might also influence perceptions. Therefore, we include these factors in our models when analysing the survey data. The aims and motives of land managers (respondents scored each option on a scale of 0–10, with 10 being the most important aim or objective) were analysed using generalised linear mixed-effects models with binomial errors and logit link function [43]. In the analysis, scores of seven and above were assigned a value of 1, and scores of 6 and below were assigned a value of zero. Question options, owner type, forest area owned/managed, and oak types owned/managed, plus the interaction of question options and each of the other predictors, were used as fixed effects in the model, with individual respondents used as random effects. The analysis of deviance (Chi-sq tests, [44]) was used to determine significance of fixed effects, with post hoc tests [45] used to predict proportions (Appendix B,

Table A1. Aims/motives for managing forests—inferential statistics: global tests.

Predictor	Chi-Square	Degrees of Freedom	p-Value
Aim/motive Options	377.9513706	26	0.0000000
Owner Type	16.6982144	17	0.4749867
Woodland Area Owned/Managed	0.6488274	1	0.4205322
Oak Types Owned/Managed	5.6029659	4	0.2308259
Sub-Question: Owner Type	63.8730069	69	0.6519515
SQ: Woodland Area Owned/Man	11.1858448	14	0.6713786
SQ: Oak Types Owned/Managed	39.4011857	56	0.9547339

).

The significance of oak by setting (which respondents scored on a scale of 1–5, strongly disagree to agree) was analysed using cumulative link models with random effects via the Laplace approximation. Responses were ordered factors from strongly disagree to strongly agree. Question options, owner types, forest area owned/managed, and oak types owned/managed, plus interaction of question option and each of the other predictors, were used as fixed effects in the model, with individual respondents used as random effects. nalysis of deviance (Likelihood Ratio Chi-sq tests, [44]) was used to determine significance of fixed effects, with post hoc tests [45] used to predict proportions (Appendix B,

Table A2. Cultural significance of oak—inferential statistics.

Oak Types Owned/Managed	Probability	Lower CI	Upper CI
Ancient and veteran oaks hold more cultural significance than other oaks	0.8542158	0.8047219	0.9037098
Oak trees hold greater cultural significance than other native British trees	0.7354012	0.6624747	0.8083277
Parkland oaks hold greater cultural significance than other oaks	0.4510504	0.3582536	0.5438472
Oaks in hedgerows hold greater cultural significance than other oaks	0.3004660	0.2182634	0.3826687
All oak trees hold equal cultural significance	0.2259915	0.1525087	0.2994744
Owner type	Probability	Lower CI	Upper CI
Agent	0.5720706	0.4851136	0.6590277
Professional: Own Woodland	0.5620004	0.4238583	0.7001424
Woodland owner: Single	0.5385936	0.4768533	0.6003339
Woodland owner: Multiple	0.5157382	0.4265237	0.6049526
Professional: Professional/Personal	0.4946503	0.4946503	0.5999072
Business	0.3974969	0.2531050	0.5418888
Oak Type Owned/Managed	Probability	Lower_CI	Upper_CI
Oak + AOD	0.5830446	0.3658664	0.8002228
None	0.5256020	0.4363391	0.6148650
Oak + Veteran + AOD	0.5243991	0.4313692	0.6174291
Oak + Veteran	0.4871479	0.4309394	0.5433565
Oak	0.4469313	0.3861330	0.5077296

).

To identify the cultural significance of oak, data were analysed using a generalised linear mixed model with binomial errors. In the analysis, scores of 4 and above were assigned a value 1, and scores below 4 were assigned a value of zero. Question options, owner type, woodland area owned/managed, and oak types owned/managed, plus the interaction of question options and each of the other predictors, were used as fixed effects in the model, with individual respondents used as random effects. An analysis of deviance (Likelihood Ratio (LR) Chi-sq tests, [44]) was used to determine significance of fixed effects, with post hoc tests [45] used to predict proportions (Appendix B,

Table A3. Personal cultural significance of oak trees to forest manager questions—inferential statistics.

Predictor	Chi-Square	Degrees of Freedom	p-Value
Cultural sign items	101.4730	9	0.0000
Owner type simplified	1.4646	5	0.9171
Scale (total area)	0.0029	1	0.9571
Oak AOD type	4.4200	4	0.3521
Sub-question owner type simp	28.0293	45	0.9777
SQ: Total area	4.2449	9	0.8946
SQ: Oak and AOD type	36.2771	36	0.4557

).

To determine how the management of oak trees is affected by cultural significance, the data were analysed using generalised linear models with binomial errors and logit link function [46]. Those who answered yes scored 1; those who answered no scored 0. Owner type, forest area owned/managed, and oak types owned/managed were used as predictors in the model. Analysis of deviance (LR Chi-sq tests, [44]) was used to determine significance of fixed effects with post hoc tests [45] used to predict proportions (Appendix B,

Table A4. Management of oaks affected by their cultural significance by oak type owned or managed—inferential statistics.

Predictor	Chi-Square	Degrees of Freedom	p-Value
Owner Type	5.2387927	5	0.3874382
Woodland Area Owned/Managed	0.0539274	1	0.8163650
Oak Types Owned/Managed	17.5230971	3	0.0005516

).

2.3. Interview Method and Analysis

Specific sampling criteria were developed in order to identify and target the qualitative interview sample. These included identifying the following for interview:

• Those managing oak-dominated forests and/or parkland, as well as mixed forests with oak.
• Primary focus is on England, as this is where the majority of AOD is found at present.
• Managers in a variety of roles, from forest owners or managers to external consultants and advisors.
• Managers with and without Acute Oak Decline.

In total, 21 managers were interviewed, the majority of which were private forest managers, ranging from those who owned forests to those who managed forests or estates on behalf of forest owners. At the same time, others had a key role as advisors to forest owners, such as tree officers and forestry or arboricultural consultants. We use the overall term ‘forest manager’ to encompass this range of management activities, recognising that they can be quite different but also highlighting that all interviewees were involved in decision making concerning forests and oaks. We found interviewees by using a snowballing sampling strategy and by contacting key stakeholders who knew of or worked with forest managers.

Table 2. Interview respondents (n = 21).

Main Category	Sub-Category	Number
Sex	Male	19
	Female	2
Role of interviewee	Forest owner or manager	11
	Tree Officer	4
	Forester	2
	Other (consultant, agent)	4
Tree context	Oak forest (broadleaf)	4
	Parkland	2
	Mixed forest (broadleaf and conifer)	8
	Mixed forest with parkland/nature reserve	7
Management objectives	Mixed—production, recreation, conservation	9
	Conservation and recreation	9
	Commercial production	3

provides some details of the interview sample.

The interviews covered a range of topics, including whether the interviewee was a forest owner or manager and the type of forest (managing broadleaf/conifer/mixed/parkland and size of forest have implications for decision making) they managed or advised on. We also explored to what extent they valued oak, their knowledge of threats to oak from pests and diseases, awareness and understanding of AOD, and where they go for information and advice on pests and diseases. We also discussed what they thought about the acceptability of different potential and hypothetical management options, as well as potential new approaches to dealing with AOD (see Appendix A for interview questions). Out of the interviewees, nine stated that the forests they were involved in had AOD, three were unsure, and five said they did not have it. We asked interviewees what they thought was important or of worth about oaks; this was as far as we went in defining their perception of value.

All of the interviews were undertaken via telephone or Microsoft Teams and recorded and transcribed verbatim. Written consent was sought from interviewees, and interviews lasted up to 1 h. All transcripts were read in order for us to become familiar with the data. A deductive and inductive approach was taken for the analysis of the interview data. Broad initial codes were developed from the text that focused on key aspects such as values regarding oak, drivers of AOD, and monitoring and management approaches. These deductive codes were used to organise the data in the first round of analysis. These were then reviewed. Further codes and sub-codes were then developed inductively from the data itself. These codes were labels for concepts in the data that linked to the research objectives [47]. Nvivo 12 was used to code the sentences and segments into sub-codes and then themes. Notes were taken based on reflections on reading and coding the data [48]. Ethical guidelines and principles were followed, as outlined in [49].

3. Results

We sought to understand the broad range of values that forest managers hold regarding oaks and then explore the impact of AOD to identify whether the held values would affect the management decision making of forest managers in relation to this disease. First, we outline the results from the survey before reporting on the results of the interviews.

3.1. Survey Results

The top three overall management aims and objectives for the forest managers in our survey, specifically in relation to their management of oak, included: (1) protect/improve nature, biological diversity, and wildlife habitat; (2) personal pleasure; and (3) protect/improve the landscape. The lower-scoring objectives were non-timber forest products and hunting/shooting (Figure 1). The analysis of deviance showed that only the aims/motives question options were significant predictors of difference (p < 0.001) (Appendix B, Table A1).

The majority of forest managers in the survey identified ancient and veteran oaks as particularly culturally significant (82% strongly agree/agree) and oaks as generally of greater cultural importance than other native British trees (74%) (Figure 2). Fewer forest managers thought oaks in parklands (38%) and hedgerows (21%) were as culturally significant, while 27% (strongly agree/agree) thought all oaks held equal cultural significance. The analysis of deviance showed that the question options, owner types, and oak types owned/managed were significant predictors of difference (p < 0.001) (see Appendix B, Table A2). Agents and forest owners tended to be more positive in their responses to the cultural significance of oak than businesses (57% and 56%). Those who managed forests with AOD were more positive about their cultural significance than those without AOD (58% vs. 53%).

In the survey, different aspects of the cultural significance of oaks were scored by forest managers from their personal perspectives (Figure 3). The categories of cultural significance were developed from the literature [15]. Over 20% to 75% of respondents scored the items in Figure 3 as very significant. Oaks providing iconic beauty in the landscape, followed by how they were valued and appreciated as a building material and their symbolic qualities of strength and stability were the top three items in terms of cultural significance. In our model (see Section 2 and Appendix B, Table A3), only the cultural significance question options were significant predictors of difference (p < 0.001).

We also explored whether the perceived cultural value of oaks impacted forest managers’ decisions. In the survey, there was an even split between those who said they would be influenced (51%) and those who would not (49%). However, there was a statistically significant difference in the response to the question between those who owned or managed oaks with AOD and those who managed veteran and ancient trees. We found that 75% of forest managers with AOD and 68% with veteran and ancient trees and AOD were more likely to be influenced in their forest management practices than those who managed oaks that were not veteran or ancient and did not have AOD (Figure 4).

Forty-three per cent of respondents from the survey said they were likely to spend more resources on oaks due to their cultural significance. Again, there was a statistically significant difference in response by the type of oaks managed. Those who managed oaks with AOD and/or veteran or ancient trees were inclined to spend more resources on oak due to their perceived cultural significance (p < 0.01) (see Appendix B, Table A4). Given the numerous threats to oak tree health, we also asked whether survey respondents thought that oak would remain an arboreal icon even if oaks in Britain went into terminal decline, and a majority of 89% said that it would remain an icon.

3.2. Interview Results

3.2.1. What Are the Ways in Which Forest Managers Value Oak Trees?

Our research found that there were many ways in which forest managers value oaks, related to symbolism, ecological value, historical, and aesthetic value, as well as the value of oaks as a material.

• Symbolic identity and cultural significance

In the interviews, some managers talked about oaks being associated with Englishness, while for others, they were a symbol more broadly of Britishness. Oaks were considered iconic and linked to ideas of national identity and their historical and ecological importance, highlighting the overlap between different categories of value. Oaks were felt to be a symbol of strength and longevity but were also talked about in terms of emotions, as they were viewed with affection and love. Two of the quotes below mention mature and veteran oaks in parkland settings, emphasising the significant cultural value of old and large oaks that often stand alone within these settings. They are therefore often prominent and very visible in the landscape.

‘It’s culturally significant as the nation’s go-to tree. I manage a landscaped park, which wouldn’t look the way it did if it didn’t have these massive veteran oaks within it’ (ID11, charity manager).

‘They’re definitely an iconic British tree in many ways and a mature oak tree supports a vast amount of other ecologically associated species. So, it’s an integral part of the English countryside and it has enormous value and then when you get the mature and the veteran oaks in the parklands, they’re absolutely magnificent’ (ID2, private consultant/advisor).

Oaks were also highlighted as being an important part of folklore, with stories of Sherwood Forest and Robin Hood, a heroic outlaw in British myths and legends. This was mentioned by a few interviewees, who felt that these tales still resonated with the public. Interviewees clearly stated from their own experience that oaks were also highly valued by the public. Some felt the public was more aware of what oak trees looked like than other tree species and therefore would think they should be protected. This made any felling of oaks sometimes quite difficult to deal with in terms of the response from the concerned public.

‘Oaks are highly valued by the public, full stop. I’d say there is a strong cultural attachment to them, and we’ll get objections if we fell any, regardless of the age’ (ID1, public manager).

2.

‘Native’ ecological value

Interviewees, regardless of the type of manager they were or their motivations, all highlighted the critical role of oaks ecologically. This was particularly the case for native oaks, as they talked about their importance for insects and birds as well as how they increase in biodiversity value as they mature. Again, veteran and ancient oaks were viewed as particularly important for biodiversity. Interviewees also talked about invertebrates and fungi and associated species such as birds and bats.

‘From a biodiversity point of view, oaks are massively significant’ (D8, charity manager).

‘Certainly, from a biodiversity point of view and a conservation point of view, a habitat point of view and again particularly the veteran trees are very high habitat, biodiversity value’ (ID18, charity manager).

‘Well, the ecosystem services that they provide, when you list other tree species, they just can’t home that many invertebrates as oak do and associated species being birds and bats that kind of feed off of that. Plus, fungi, there are some fungi that are only associated with oak’ (ID15, consultant/advisor).

‘…obviously from a conservation, biodiversity value, they’re incredibly high value, especially veteran and ancient trees.’ (ID6, public manager).

3.

Historical and Aesthetic value

Oaks were also noted for their landscape and aesthetic value; in fact, particular specimens were sometimes called ‘magnificent’. The part that oaks play in history was raised, as they can live for many hundreds of years. This was linked to them being viewed as an iconic species that symbolises resilience, longevity, and stability. The use of the name ‘Royal Oak’ for many pub names (venues that serve alcohol) and the use of oak by the Royal Navy in shipbuilding were all highlighted by interviewees as important and historical reasons why oak is important and embedded within British/English culture.

‘We all love our Oak trees, we’re all very fond of them and of course it’s the symbol of English history in all its associations with history, etc.’ (ID18, charity manager).

‘Charles I was around and probably when Henry VIII was around, that sort of historic connotation, which is quite rare and quite extraordinary really, and I think people do appreciate that sort of historic link and cultural links’ (ID18, charity manager).

Interviewees talked about ancient oaks and their sculptural shapes, which they suggested made them very charismatic trees. When they become large in terms of girth, height, and the reach of their branches, they can be dominant in a landscape. These specimens were viewed as rugged, dependable, and solid. Reinstating historical management of pollarding (this is a method of pruning trees by removing branches to keep dense growth at the top of the tree but to keep the tree from getting too large) was important to one interviewee. Another noted the longevity of oaks and the role they can play in the landscape and in people’s lives by lasting several human generations.

‘I like to see an oak, I think in my mind, it’s a quintessentially British landscape tree and should be valued as that, not just as a biodiverse product but also as an aesthetic product too, culturally also’ (ID4, private consultant/advisor).

‘Obviously, you’ve got the historical value, so we’ve just started reinstating and initiating new oak pollards because obviously you’ve got the issue that you’ve got a lot of old lapsed pollards all around the country and for us, …. down the road and a lot of ancient and veterans and you’ve got no, what we call future veteran and ancient trees. So, we’ve been reinstating that, so that’s been really important for us and linking that to ecology, historical and cultural importance’ (ID6, public manager).

‘An ancient oak tree to our ancestors would have been something that had just always been there, always doing its thing, as far back as living memory went, …’ (ID14, consultant/advisor).

4.

Material Value

Oaks were also viewed as important for their material properties used for building and furniture, as well as for their commercial viability. Oak was seen as a durable, good-quality, and attractive wood. The following quote encompasses a range of values but highlights the importance of oak timber across generations, and many of the interviewees talked about the importance of oak in previous centuries for shipbuilding.

‘Oak has a place of affection in British society, hearts of Oak and the Navy and all that kind of stuff. So, I think people do value Oak in that respect. I think people revere oak timber. So, I think in this country, in Britain and Scotland and wherever you are, oak has a special place I think in peoples’ affection and their appreciation of timber and all that kind of stuff’ (ID3, private manager).

One person talked about how woodworking with oak helped him appreciate the characteristics of oak as a material. Another talked about the satisfaction of establishing oak stands in his forest but also highlighted some of the challenges of management.

‘There’s something quite satisfying about, for me, good oak silviculture and getting oak stands established. The only thing that taints it slightly is things like squirrel damage and it’s quite heart-breaking at times when you get a lovely woodland established and then they come in and completely devastate it’ (ID7, private manager).

Interviewees talked about the durability of oak and emphasised its use in furniture in terms of its aesthetics and toughness. The final quote below also touches on the importance of oak in construction.

‘Oak timber is good stuff. It’s durable and it looks nice and it’s quite interesting that we supply a couple of furniture makers with our hardwoods’ (ID3, private owner).

‘Whereas Oak is valued probably more, going back to the previous question, as a resource for furniture and finer things.’ (ID13, public manager).

‘As a timber tree, it’s really important. So, we use any by-product of Oak that we can for any construction that we’re doing on the Common or anything like that, whether big or small’ (ID6, public manager).

3.2.2. Management and Resources

In the interviews, a similar distinction arose from the survey results, with respondents who managed veteran or ancient oaks stating they would try to do whatever was necessary to save their oaks. Interviewees talked about a range of actions they might undertake to protect their valuable oaks from AOD. This included haloing or thinning around the trees to give them space and reduce competition and stress. Another interviewee talked about reducing mowing around parkland oak trees and keeping cattle and people from compacting the ground near to them. One interviewee outlined that parkland trees get different treatment due to their historical and cultural value, as well as health and safety concerns, as these spaces are often open to the public. They also have more prominence in the landscape and are noticeable to the public. The more commercial timber production-focused interviewees talked about felling oaks in order to realise the value of their timber before they might become affected by AOD and then restocking. Those who value and manage oak forests without veteran or ancient trees and without AOD were more likely to say they would consider any advice to improve oak health but would see what the cost of any intervention might be or wait until there was concrete advice on what to do. Others talked about balancing the pros and cons of any potential options to reduce the threat of AOD. In looking to the future, if oaks were lost, some interviewees said they would restock. Others talked about natural regeneration, and some would consider planting different species or more mixed species.

‘how very quickly natural regen still is, that’s still going, our argument is we don’t really need to do any planting because actually it’s all happening. We turn our backs, and we turn round two or three years later and all the trees, they’re all coming up under completely their own steam and of course they’re fine examples, they grow much better than anything we ever plant. They grow with all those associated micro lives of species, planted by Jays probably. Nature doing its thing, as usual’ (ID5, private manager).

There were concerns expressed by a small number of forest managers that a focus on planting native oaks or any native species was not accounting for changes that would occur due to climate change. The range of particular species, such as oak, has the potential to change due to a warming climate. One interviewee was particularly concerned about this issue and how it is communicated to the public.

‘there are some in that organisation that are a bit more forward thinking, but an awful lot of them are still all about native species, local provenances and just keeping what was there and it’s not helpful at all, with the increasing risks that we’ve got with the climate and pests and diseases. All they’re doing is creating vulnerable stands that are going to be squirrel damaged anyway and leading the public up the garden path, that they’re doing wonderful things and they’re not’ (ID1, public manager).

Felling trees was also viewed by some interviewees as an emotive issue for the general public, who they felt would be concerned about the felling of any trees, even if they were impacted by a pest or disease. The role of the Agrilus biguttatus beetle in AOD was an issue many of the interviewees raised, particularly the uncertainty of not knowing whether the beetle was spreading the pathogens from tree to tree or whether it was just associated with AOD, as it favoured stressed trees. Because the beetle is native and was previously identified as vulnerable, it led interviewees to be reluctant to manage or reduce the beetle population until they were sure about its impact.

4. Discussion

In this study, we draw on our quantitative survey and qualitative interview data and outline the many ways in which forest managers value native oaks in England and wider Britain. The survey provides data on what values forest managers in Britain associate with oaks and whether this might influence their actions. The qualitative data provide rich detail and emotionally driven insights into why oaks are important to managers in England, where most of the current AOD impacts are found. Combining these methods provides more holistic forest manager perspectives. We focused on a specific threat to oaks, that of Acute Oak Decline, and explored whether the values forest managers associate with oaks would lead to an emphasis on trying to conserve them. The key findings from our research show the following:

(1)

Forest managers highly value native oak trees, often more than other species.

(2)

There is concern that oaks are under threat from AOD and other pests and diseases.

(3)

Forest managers’ values regarding oak have implications on their behaviours, particularly those who manage veteran and ancient oaks or have trees with AOD. These managers are more willing to spend time and resources in conserving these trees and reducing the impact of the disease.

4.1. Values for Native Oak Trees

Forest managers in this study, regardless of the type of manager or their management objectives, all valued oaks in multiple ways. They identified their cultural, historical, aesthetic, ecological, and material importance. The focus of these values, however, differed—for example, those concerned with productive management objectives valued oak for its material timber more strongly than others. Those with veteran and/or ancient trees talked about the cultural and historical significance of their oaks. However, all interviewees recognised the ecological value of oak as outlined by Broome et al. [16]. This is similar to another study that explored the evolution of the oak tree alongside human history [50]. That study identified the historical and cultural symbolism of oaks and how the trees’ status related to longevity, cohesiveness, and robustness [50]. A review of private forest owners found they had strong personal connections to their forests, which we also found in this study with forest managers talking about their emotional connections to oak trees [3].

In this study, both interviewees and survey respondents with oaks in parkland settings, which could include veteran and ancient trees, felt these specimens were particularly important for many historical, cultural, ecological, and aesthetic reasons. Mitchell et al. [51] state that half of the ancient trees in the UK, registered via the UK ancient tree forum, are outside of forests. Our qualitative and quantitative evidence suggests that those who manage these oaks and those with AOD would try to do whatever is necessary to protect and conserve them. This emphasises the emotional attachment and high value expressed for these trees, as well as for trees under threat of disease [14]. This also links to the main aims survey respondents had for managing their trees, which included protecting nature, personal pleasure, and protecting the landscape. Smalley and White [52] highlight that nature can facilitate awe-inspiring experiences, and these can be triggered by scenes that create wonder and amazement. Several of our interviewees talked about having a strong affection and love for the oaks they managed. Native oaks within British culture have a status [15], and this was identified as well by our forest managers, particularly in the interviews, because of oaks’ longevity and resilience. The values forest managers identified could be considered relational due to the strong relationships that managers have with the oaks they manage [30,31]. Because of the importance of oak, an initiative has started in the past few years called ‘Action Oak’, which aims to protect oak trees through a range of communication and knowledge-exchange approaches. It also aims to work with various stakeholders to emphasise how to grow healthy oaks [53]. The founding partners of ‘Action Oak’ include government bodies, charities, research agencies, and botanic gardens, illustrating the desire at a national level in Britain to conserve oaks.

There was also some evidence of forest managers being influenced by the views of the public and how they perceived the public would react to the felling of oaks, even if these were affected by a pest and disease. Tree felling can have low levels of social acceptability, even when managers are dealing with tree pest outbreaks [54]. This can lead to concerns being raised by the public [3,54].

4.2. Implications of the Values of Oak in Terms of Forest Management

Marzano et al. [55] have noted that there are gaps in our understanding of how forest managers value trees and react to tree pests and disease risks. Our research starts to address this gap, as we explore forest managers’ values of oak in the context of AOD. We found that forest managers have differing ideas of how to deal with and manage the disease [55]. Another project focused on oak, called PuRpOsE (Protect Oak Ecosystems), highlighted the challenges of managing oak with regard to multiple values, whether that was cultural, social, or biodiversity [56]. AOD is a complex syndrome with limited advice provided to forest managers on actions they can take to reduce the likelihood of their trees being affected. A 2010 practice note [57] suggests that managers should survey and monitor oaks, leave infected trees in place, prune infected trees, disinfect any felling or pruning equipment, be cautious about using timber from infected trees, and restock if oaks die. Trying to reduce the stress oak trees are facing was also mentioned as important in an update on AOD [34]. Our interview and survey evidence highlight forest managers’ desire to reduce oak stress through approaches such as reducing competition from other trees, decreasing compaction, and watering trees. Our results suggest forest managers of veteran and ancient oaks and those with AOD would do all that they could to conserve these trees and follow any management guidance that would support their conservation and survival. The cultural values they hold for these trees influence the amount of resources and care they said they would deploy to protect them, and they would prioritise the care of these oaks. They were also conscious of these trees’ historical significance and their importance within the wider cultural landscape for the whole of British society. However, those who did manage oaks that were not ancient or did not have AOD talked about striking a balance between taking action and considering the costs and capacity that might be needed to undertake any actions recommended. These forest managers wanted to take a more pragmatic approach and consider the various options that might be available to them. It is important to note that very recent evidence has now found that AOD symptoms are caused by bacteria and the Agrilus biguttatus beetle together [39]; however, our interviews were undertaken before these results were published.

4.3. Values in Forestry Policy and Forest Culture

The Independent Panel on Forestry, created after the government consulted the public on the sell-off of the public forests managed by the Forestry Commission [58], identified the need to create a new woodland culture. This could then recognise the full value of trees and woods. A variety of research has highlighted the importance of trees and forests to the public in recent years, covering a wide range of benefits, as reviewed by Binner et al. and Bateman et al. [59,60,61]. However, there is less research covering the value forest managers hold regarding their trees, particularly regarding a single species. Some progress has been made in incorporating and recognising some of the values of trees in policy making, particularly if there is a monetary value attached to these values (see, for example, [59]). However, if the values identified are not quantified or monetised, then policy-makers and practitioners find it more of a challenge to take them into account in their decision making [62]. Protests can arise when, for example, trees are felled without considering people’s values of them (see, for example, the Sheffield Street tree issue outlined in [63]). The current focus for planting more trees in Britain to mitigate climate change, if performed in collaboration with different publics and other stakeholders, could help to foster engagement with forests if public access is provided and communities are engaged. Effective communication with forest managers focused on their values regarding oak could support more managers to monitor and report AOD symptoms and follow current guidance on managing oak health.

4.4. Limitations and Research Gaps

In terms of the quantitative data, we were limited to adding a small number of questions to an existing forest manager survey. However, we may have reached more respondents by taking this approach due to the survey being delivered by the Sylva Foundation, which organises the regular British Woodlands Survey. This organisation has a large database of contacts to help promote its surveys. The usual limitations of online surveys are a factor, although there is a trend for the ever-greater use of online approaches. Therefore, this is less of a barrier to participation than in former times when in-person surveys were the preferred method of engagement because of potential biases in the use of the Internet. We aimed to interview 25 land managers; however, it was very difficult to reach those managing oak and encourage them to be part of our study and be interviewed. However, the 21 interviewees who were involved had a wide range of experience and provided in-depth evidence of how they thought through their oak management. Forest managers are often managing mixtures of species, so it can be difficult for them to focus on only one species. However, we found that managers had a lot to say about the oaks they were managing or responsible for. Further research could usefully explore longitudinal case studies of managers with and without AOD. This could be used to gather evidence on perspectives and management actions and how these change over time as the disease invades a site, is managed on-site, or as the tree potentially recovers from AOD or dies.

5. Conclusions

This research has filled an evidence gap concerning how forest managers value oaks in terms of their cultural significance. It illustrates the broad range of cultural values that they hold for this species. The research covers oaks in different contexts, such as forests and parklands. For the first time, it also incorporates a focus on those who manage veteran or ancient oaks and those with AOD. This work also provides a better understanding of how managers are trying to reduce the stresses on their oak trees to make them more resilient to pests and diseases such as AOD. We found that those managing ancient and veteran trees and those with AOD were prepared to spend more time and resources in conserving them due to the trees’ cultural and historical importance. This was also due to the concerns they had about their oak’s health. This research provides a better understanding of the ways forest managers value oak. Therefore, guidance and advice could be specifically targeted at managers with veteran trees and/or AOD with detailed information about how they might conserve their oaks or deal with AOD. More general guidance on maintaining oak health could be provided for other managers, along with information about how they might identify AOD and how to report it if they do suspect they have the disease. This approach would help to raise awareness and support a stronger focus on oak health.