Biodiversity offsetting should not be used to compensate for the destruction of ancient woodlands, argues Robert Tregay, chair of consultancy LDA Design
Could new trees be planted to compensate when ancient woodland is paved over to make way for new developments? This question has been reignited after environment secretary Owen Paterson gave an interview to The Times, suggesting that such planting – at a ratio of 100 new trees to one ancient tree – is a good example of biodiversity offsetting.
As a consultancy that assists many house-builders to secure planning consent for new developments, we at LDA Design deal with infrastructure provision, biodiversity offsetting, and threats to ancient woodland every day, both nationally and internationally. These are the issues at the heart of sustainable development.
Often, the economic need for development and the UK government’s robust conservation policies do clash, and can give rise to genuinely difficult decisions. This can be the case with major infrastructure projects, such as roads and railways. It is, however, deeply unnecessary that ancient woodlands, or other top conservation sites, should be seen by the government as a constraint to our country’s need for new housing developments.
First and foremost, there are ample development sites on less environmentally sensitive land. Ancient woodland cannot be ‘offset’, as the value of the land lies primarily in its history. These woodlands store genetic material and are ecologically complex systems which, most crucially, include soil and soil organisms, as well as more visible species. Nor can they be measured by the number of trees, as this is a bad measure of their value.
Compulsory biodiversity offsetting, as trailed in the government’s green paper last September, may be a good idea, but it should not be applied to our most valuable and irreplaceable habitats, which include ancient woodlands. Offsetting could, however, be applied to lower value and more easily replaced habitats where a case can be made for sustainable development to meet housing need. As an example, this could apply to some wetland, scrub and grassland habitats, but it is dangerous to generalise as there are many sites where these habitats are high value and difficult, risky or impossible to replace.
Ancient woodlands are home to more than just trees
The government must apply biodiversity offsetting with great care, and ensure neither policy weaknesses nor over-simplified scoring systems for measuring value and impacts will result in a weakening of overall biodiversity. This is neither necessary for housing delivery nor good for the government’s environmental credentials. Biodiversity offsetting has already been described by some environment groups as a ‘licence to trash’. There is a real risk that the concept will become, unnecessarily, a ‘lose, lose’ for the government, especially if it fails to recognise the importance of the most valuable habitats.
This country is very much able to deliver the required housing provision on land with lower environmental value, and which does not require the loss of a single tree or clod of soil in our vitally important ancient woodlands.
