Guidance

Woodland creation and mitigating the impacts of deer

Published 3 December 2020

Applies to England

• Publication for Northern Ireland
• Publication for Scotland
• Publication for Wales

1. Background

Wild deer are a part of our biodiversity. They provide pleasure for visitors to the countryside and are a source of healthy meat. But in the absence of predators and due to increased woodland cover, deer have increased to unsustainable densities in some areas.

At moderate to high densities, wild deer can have negative impacts on the natural environment as well as wider impacts on forestry and have negative effects on agriculture. Deer can simplify woodland structure by:

• preferentially browsing seedlings or regrowth of certain palatable tree and plant species
• impacting upon diversity
• impacting resilience of woodlands to factors such as climate change, as heavily impacted woodlands are less able to sequester carbon or intercept water flow, and processes such as natural colonisation can be prevented

Significant effort is required by those responsible for creating and managing woodlands to manage deer across the country. There is a need to develop stronger mechanisms to build increased capacity and focus on reducing current and future impacts, and collaboration is required at a national, landscape and local level to achieve this.

This guidance provides practical advice to anybody with a responsibility for the creation and management of woodlands and the mitigation of deer impacts within them. It supports the guidelines for sustainable forest management set out in the UK Forestry Standard. It provides an overview of the considerations required during the planning and assessment of woodland proposals, including surveys, which may be required to establish current baseline status of deer in a particular area.

2. Negative effects of deer on habitats

Deer, sometimes of more than one species, are present in every county of England and deer ranges are expanding. Each of the 6 wild species has a slightly different effect on the habitat in which they live. In some cases they can be beneficial, such as by helping to maintain open habitats. But where new woodlands are being created or regenerated, whether by planting or through natural processes , deer can have a negative effects (impacts), which can worsen as deer population density or number of species in an area increases. Find out more about the negative effects of deer.

Deer can rapidly colonise newly created woodlands and can inflict varying levels of impact on young seedlings or transplants as well as the developing ground flora.

3. Mitigating deer impacts

There is a risk that in some cases that impacts of deer may be unacceptable if mitigation measures are not put in place. The precise measures used may depend on the stage of woodland development. For example, at the planning and establishment stages, there are important opportunities to build in mitigation measures to safeguard the woodland’s future success. It is much easier to design these measures into a new woodland at its inception than to do it retrospectively once it is established. Similarly integrating deer management infrastructure at the felling or restocking stage is less costly than during a crop rotation.

3.1 Management objectives

Establish clear management objectives. These will have a bearing on the level of risk.

Use one of the standardised methods to assess current deer activity/impact on the site.

Be aware that the objectives and tolerance of impacts for woodlands in one ownership may differ from those of others within the landscape, and that responsible and effective management(particularly of the herding species of deer) should be carried out at a landscape scale.

3.2 Establishing risk

The location (for example, the proximity to other woodland, or barriers to deer movement) and types of planting intended will affect the degree of risk from deer.

Assess the potential risks that creating new deer habitat may pose to adjacent sites in terms of impacts to agriculture, protected sites or highways (Deer Vehicle Collisions).

The scale, the size and shape of a site affect how vulnerable it might be, how easy it is to protect, and which protection methods are most appropriate.

Although tree species vary in their palatability to deer, all planted trees (or those establishing through natural colonisation) are vulnerable to browsing and should be protected if deer are present. The length of the establishment phase (and susceptibility to damage) will be species and site dependent, and will be affected by the species of deer present. Deer will also present a threat for future management, affecting restocking and natural regeneration, woodland structure and the viability of other species reliant on that woodland to live and breed.

Identify where and which individual tree protection or fencing will be required and for how long.

3.3 Basic principles

Establish the level of ’deer risk’ as early as possible. The perceived risk will depend on a clear understanding of the objectives for the woodland and the surrounding landscape. Deer impact at some level is likely. Whether that impact will be tolerable may depend upon whether the woodland is intended for timber production, conservation, recreation, carbon sink, water management or soil protection, or a combination of these.

Accumulate knowledge of deer status, species present, impact and activity through undertaking surveys, as well as of any active management on land adjacent to and within 5-10 miles of the site. Local collaboration and information sharing will help. The resulting data will form baseline evidence for assisting with future woodland management.

If, in rare cases, deer are absent on the site and highly unlikely to arrive then it may be possible to establish the woodland without taking deer into account. It is nonetheless recommended that you watch out for deer arriving, whether by natural or other means, and that the woodland design accommodates future management infrastructure (such as adequate, appropriately located open space).

If deer are currently not present but are within 5-10 miles of the site, or if it is likely that deer will arrive within 5-10 years, then the site should be treated as if deer were already there.

Risks may be higher if the species of deer include one of the larger, herding species (such as Red, Fallow or Sika) or if deer of more than one species are present or close by.

3.4 Mitigating impacts

Silvicultural decisions such as species choice, ground preparation, planting patterns and woodland design (woodland shape and open space) will influence vulnerability and ease of mitigating impacts. When re-stocking, in order to make impact mitigation easier or more possible, carefully consider the shape of any area already felled or likely to be felled in the future, and maintaining open areas. Also consider using existing landforms.

Protect (and maintain) the most vulnerable areas during critical periods.

Continue or initiate culling deer in conjunction with physical protection (tree tubes of fencing) to safeguard sites and habitats. On sites where localised deer impacts are already significant, consider pre-emptive culling prior to planting or commencing woodland management.

Monitor to strengthen the evidence base, then feed back/review/repeat (Adaptive Management).

If tree protection is used then it should usually be in conjunction with well-planned deer population control (find out more about planning deer population control). This reduces the overall risk from deer and is important to prevent impacts to non-protected habitat. Conversely, even where deer are efficiently culled, some (minimal or short term) protection may be necessary for vulnerable species or areas. Deer culling will usually be a condition of grant-supported schemes of any scale. On most sites, deer will already be culled, either on site or locally. This may make establishing a practical and efficient culling programme easier. If not, it may be necessary to establish one. It is likely that deer population control will become necessary at some point, even if physical tree protection is in place. In some cases, pre-emptive cull planning and control should be undertaken prior to planting or woodland management occurring. Culling while population density is lower may be more effective than waiting until impacts have become intolerable.

Physical protection must be appropriate to existing and future deer species, and will require maintenance and inspection. Note that as deer fenced areas increase in size, they become more vulnerable to deer ingress, especially where tree and understorey growth has reached thicket stage. This may result in a captive deer population that is difficult to control, resulting in unacceptable impacts and a potential deer welfare issue. Extensive use of fencing may also deny deer access to parts of their former range, thereby increasing pressure on the remaining unfenced areas or causing them to cross areas where they are vulnerable, such as roads. Using badger gates may help prevent early breaches by deer. Tree protection needs to be of a more robust standard if feral or wild boar are present. Find out more about tree protection when feral or wild boar are present.

Where woodlands are to be created near to urban areas or where there is community involvement, you are advised to discuss the need for deer impact mitigation with stakeholders at the early stages of planning and include deer in the wider management planning process Deer fences may be more vulnerable to vandalism or neglect (such as breaches or open gates) in these areas.

Reliance upon fencing and individual tree protection alone in areas with moderate to high deer impacts is not advisable. Some level of lethal control is generally required in most cases, not only to protect newly planted trees but also to reduce impacts to adjacent areas, particularly when fencing has been used to exclude them from areas of their former range.

Identify opportunities for deer control areas, high seat positions or culling vantage points, sightlines, and access within the design plan. Within grant limitations, leave 15-20% space on anything other than small sites. If possible, avoid long (300m+) straight lines or putting all the space in one area. Plenty of ‘edge’ is good, not only for deer control but also for conservation and visual interest.

Establish and activate a deer management plan (DMP) that includes a deer cull plan and that links to and complements any existing Woodland Management Plan (WMP). If herding species are present, collaborative, landscape scale deer management is more effective than relying on management only at a holding or woodland level .

Collecting data to inform the DMP, such as impact surveys and deer cull information, can be invaluable for informing future management and justifying lethal control where necessary. Recording deer management effort is as important as the number of deer culled .

Establish a means of monitoring and recording at an early stage to establish baselines and begin to build evidence. Where possible, use a standardised method of assessing deer activity and impact, and install exclosures and fixed-point photography points. The data gained is used to establish baselines and measure progress towards DMP/WMP objectives. Regular reviews increase the chance of mitigation measures remaining efficient through the life of the woodland (Adaptive Management)

Initiate or build on deer discussions with neighbours to establish the potential for collaboration across boundaries and landscapes. This is particularly important where wide ranging, herding species of deer are present.

4. Further Advice

Your local Forestry Commission Woodland Officer can help with:

• information and support about grants
• expert advice on woodlands

Your local Forestry Commission Deer Officer can help with:

• general Deer advice
• deer advice in grant schemes (through the Woodland Officer)

For more information, visit the Create woodland: overview page.

You can also find useful information in Deer Best Practice Guidance including Deer Biology and Ecology, Management Information, DMP template and Woodland Impact method.