Last summer it was hailed as a climate change solution with ‘mind-blowing potential’: tree planting has been making national headlines as government, NGOs, national and local organisations have launched initiatives to increase UK tree cover. Thousands of trees were planted in Oxford during National Tree Week in November, with support from Oxford Direct Services, Oxfordshire Trees for the Future and the International Tree Foundation. We were delighted to be joined by over 100 enthusiastic volunteers to plant 500 new trees in Sunnymead Park.
Increasingly, however, this focus on tree planting is being questioned. Journalist George Monbiot, in particular, has argued that public resources should be directed towards “rewilding” – allowing trees to seed and spread themselves – instead of tree planting. According to Monbiot, rewilding “is much faster and more effective, and tends to produce far richer habitats”. Monbiot draws on work by Simon Lewis and others which suggests that “[commercial] plantations are much poorer at storing carbon than are natural forests, which develop with little or no disturbance from humans”.
What do we make of this view? One answer is that we are looking at a false dichotomy – this is not about tree planting vs rewilding but – as Dr Cecile Girardin, Science Lead of Oxford University’s Biodiversity Network puts it – about “the right ecosystem, in the right place”. So, for example, rewilding or “natural regeneration” may make sense in many places to ensure resilience to disease, benefits for native biodiversity, and carbon sequestration in the long term. In some places, however, there may be a case for managed tree planting, for example to sequester carbon sooner and/ or produce more timber (particularly if this can support the decarbonisation of the construction industry).
Friends of the Earth have published a helpful article summarising “some of the more complex issues surrounding how best to increase tree cover.” The article explains that both rewilding and tree planting are needed to protect our climate and environment. Tree planting has a role “where rewilding simply isn’t likely to occur, such as in urban parks, or on land remote from natural seed sources”. Or on farms, where incorporating more trees – fruit and nut trees, wood pasture and shelter belts, for example – can play a role as part of a “systemic change” in land use. And, of course, “tree planting” does not have to equal “commercial monocultures”. Here in Oxford, Oxford Direct Services’ Julian Cooper takes the view that it’s “all about the species mix”. In planning Oxford’s “urban forest“, he and his team choose mixes of species that will maintain and enhance local biodiversity.
But even if we take the view that both tree planting and rewilding have their place, there is another issue: whilst the restoration and development of ecosystems – including tree planting – can contribute to climate mitigation, the idea that they can “offset” carbon emissions risks distracting from the more radical changes needed to decarbonise our economies: “When the President of the USA denies the urgency of climate change at Davos yet talks up planting a trillion trees in the same breath, we have reason to be cautious or even alarmed” (Yadvinder Mali and Janet Franklin writing in the introduction to a recently published Royal Society special journal on “Climate change and ecosystems”). Moreover, many offsetting schemes operate to incentivise fast tree growth, including monocultures, at the expense of longer term resilience and biodiversity – undermining the whole idea of “the right ecosystem, in the right place”.
So does this mean our enthusiasm for tree planting is misplaced? The answer seems to be no – as long as we are alert to the issues and go about it in the right way. We need the right species mixes, in the right places. And whilst trees can contribute to the transition to net zero carbon emissions, they can’t be a substitute for the more radical changes needed to reduce emissions at source.
At LCON, we look forward to helping extend North Oxford’s urban forest further where it makes sense, and contributing to the maintenance of the existing woodland. We hope many of you will join us.