​

Protecting the trees we have

 

Key recommendations: 

• Update the grey squirrel action plan to provide clearer incentives for land managers to effectively manage grey squirrel populations, in line with new methods and technologies.

• Support more pine marten reintroductions in appropriate areas of the UK.

• Update the deer management strategy to include support for venison processing along the supply chain and issue new guidance within the Government Buying Standard for Food to include venison in the food offering of public institutions. 

• Introduce clear labelling for all plants that, if not carefully managed, can be invasive.

 

We may consider trees to be strong, hardy, and resilient, but in reality they are almost constantly at risk from pests, disease, and human interference. When one thinks of such risks to trees, the Dutch elm disease crisis is the go-to example. Having first arrived in the UK from Canada in the 1960s, the disease has since wiped out millions of our elm trees. This has been joined in more recent years by the ash dieback disease and the spruce bark beetle. But the danger does not stop there: while the particular pest or disease may change, the risk remains.

 

Grey squirrels were first introduced to the UK from North America in the 19th century and have proved detrimental to our native red squirrel population ever since, most notably because of their ability to pass on the deadly squirrelpox virus with no harm to themselves. As a result, red squirrel numbers have dwindled to a mere 160,000 or so in the UK, often found in remote corners of Scotland and Wales. 

 

But it is less well known that grey squirrels are also a serious pest to trees. They strip bark from tree trunks and branches in order to access the nutritious sap beneath. This can severely damage, or even kill, trees, and also creates entry points for pests and disease. The economic cost of damage from grey squirrels to our woodlands, not including costs to UK biodiversity, has been estimated at £37 million per year in England and Wales. 

 

The government’s decision to update its grey squirrel action plan is therefore a welcome one. The original plan, published a decade ago, went some way to tackle this pest, but time has revealed that action has not been sufficient with grey squirrels continuing to proliferate. 

 

One notable gap in the existing plan was the lack of clear incentives for land managers to manage the grey squirrel population in concert with their neighbours. In order to tackle this pest head-on, the government has embedded some grey squirrel management incentives, such as traps and culling, into its new SFI payments within the broader ELM schemes. This should be extended to other management strategies, such as contraception, in line with findings from Defra-funded research and trials. 

 

Another element of this strategy should be to introduce another native, charismatic creature back into our landscapes: the pine marten. Due to being heavily hunted for its fur throughout the 19th century and the rapid decline of its natural, arboreal habitat, the pine marten quickly became one of Britain’s rarest predators and was considered functionally extinct in England by the early 20th century. The passage of the Wildlife and Countryside Act 1981 during the premiership of Margaret Thatcher afforded the remaining population protection and pine marten numbers have crept up ever since, but remain pitifully low. 

 

Despite being near to extinction, the species hung on in remote corners of Britain. In the north of Scotland, red squirrels coexist with pine martens in woodlands and mixed plantations. Grey squirrel numbers, on the other hand, have been shown to be controlled in areas where pine martens are present. However, the exact process of how pine martens control grey squirrel populations is not fully understood. 

 

Developing a better understanding of this relationship through research and pilot reintroduction projects, as the government is already enabling, will create the necessary evidence base to approve pine marten reintroduction projects across the UK. In line with existing proposals, where appropriate, more pine marten reintroduction pilots should take place in the short term to help build and strengthen this evidence base in the long term.

 

Another plan the government is seeking to update is its deer management strategy. There must be positive encouragement to land managers from the government to tackle deer numbers, to alleviate the sense of risk currently felt by rural communities wanting to act. The deer population in the UK is at its highest level in 1000 years, with numbers thought to exceed 2 million. The grazing habits of this booming population presents problems for the natural regeneration of woodlands and to farmers' livelihoods as their crops are eaten, not to mention issues with road safety as collisions between deers and vehicles continue to rise. Fortunately, the need for deer management is a delicious problem to solve. 

 

Supporting the wild venison industry through grants to establish more venison processing and refrigeration facilities could encourage better deer management and thereby reduce deer numbers. Currently the limited facilities are blocking the ability to harvest this protein at the scale required. Greater wild venison processing would support efforts to boost domestic food production levels and bolster rural economies. A lower deer population would remove a barrier to natural woodland regeneration. 

 

Just as there are stipulations about the frequency of serving fish in the public sector, caterers should also be encouraged through new guidance in the Government Buying Standard for Food to use more venison, which is a low-cost, nutritious form of protein.

 

As grey squirrels, deer, and Dutch elm disease have long reminded us, human interference, in the form of importing goods from overseas, is often to blame for environmental harms. The same is true of many plant species, most notably being rhododendron ponticum and Japanese knotweed, which suffocate other plant growth and dominate their habitats.

 

The government has previously forbidden the sale of nuisance plants, through multiple pieces of legislation. But all too easily one invasive plant can be substituted by another non-native plant that has the potential to become invasive. Plants that are demonstrably harmful to the environment should be banned. But to do so requires a scientific, evidence-based case, which is often lacking. As an interim step, the government should introduce a labelling requirement for all plants that risk becoming invasive to inform amateur and expert gardeners and horticulturalists alike of the potential dangers of their purchase.

​