The conversation about how nature can help us tackle climate change has become dominated by trees.  Today, the RSPB publishes a report reviewing the evidence about how different approaches to woodland expansion can help or indeed hinder our attempts to address the climate and ecological emergency.  This (slightly longer than usual) blog gives outlines the key messages from the report.

Conifer plantation alongside fridd habitat, RSPB Lake Vyrnwy Nature Reserve (Nicholas Rudd,

In January the Committee on Climate Change published their advice to the UK Government and devolved administrations on how to reach net zero by 2050, and the role that tree planting could play in this.

The need for more trees and woodlands is obvious, for climate change, wildlife and perhaps most pressingly given recent events, natural flood risk management.  With the plight of our woodland species highlighted in last year’s State of Nature Report, woodland wildlife is in pressing need of assistance.  Research published this week from the RSPB highlights that new native woodland can lead to net benefits for birds.

But with the landscape still scarred by the mistakes of previous woodland planting drives (think about non-native trees on blanket bog or on heathlands), and with open habitat species such as curlew on the brink, getting it right this time is crucial.  We must not simplistically focus on tackling the climate crisis at the expense of biodiversity.   In many ways this is similar to the debate we have had for the past twenty years about renewable energy.  We have always argued that that we need a revolution to help us tackle climate change, but we have also argued that the revolution must take place in harmony with nature.

That’s why we are publishing a new report looking at the role different approaches to woodland expansion can play in delivering both climate and biodiversity goals.  It is possible to play fast and loose with the extent to which new trees and woodland are a silver bullet for climate change.  As with most things in life, scratch a little deeper and it gets much, much more complicated.

Considering the role of woodland expansion, many previous studies have considered either carbon, or biodiversity but we felt there was a need for these issues to be considered together. So, we commissioned a consultant, Ellie Crane, to examine the evidence around different approaches to woodland creation – going beyond just tree planting – together with peatland habitat restoration from plantation forestry and the fate of carbon stored in harvested wood.  The report looks at carbon and biodiversity implications, whilst acknowledging that many of the questions remain hard to answer definitively.  As with many of these reports, the need for more research is a key conclusion.

Bog pools and conifer plantation, Forsinard RSPB reserve (Norman Russell,

What the report does highlight though is the many shades of grey around woodland creation and climate change.  In particular, it highlights that…

…there may be a choice between rapid carbon sequestration and long-term carbon stores. Whilst claims from forest industry groups that fast-growing non-native conifers sequester carbon more quickly than slower growing native broadleaves are true in some cases, harvesting these species limits the scope for the woodland to develop as a permanent carbon store.  Looking long-term, native woodland will generally store more carbon, provide for a more secure carbon store and does not depend upon technological unicorns like carbon capture and storage (CCS).

soil is all. Carbon gains from woodland expansion on mineral soils can be significant, noting lots of caveats about type of tree species, establishment methods and post-creation management. Ensuring new woodland does not cut across other priority habitats will be the key challenge here.  Woodland creation on deep peat however is a no-no, and this report highlights increasingly compelling evidence that restoration of deep peat habitats after forestry is the surest way of securing carbon stores and sequestering more carbon in the long term.  Shallow peats, or organo-mineral soils are a much greyer area, and the carbon and biodiversity impacts of any woodland creation will be site specific. Given the prevalence of these soils, especially in Scotland where more than 80% of recent planting has occurred, getting to grips with carbon fluxes of woodland creation on these shallow peaty soils is a critical short-term priority.

…we need to protect existing native woodlands, and expanding this resource will be the best starting point for both biodiversity and tackling climate change. Woodland is under pressure everywhere, but especially in the context of a nascent infrastructure boom (which is why we urged a rethink about HS2). Protecting these woodlands, expanding them and connecting them up is a no brainer for the climate and wildlife.

the fate of harvested wood products is critical.  Industry claims about the climate benefits of commercial forestry are for nought if it ends up as toilet paper.  While recent events have highlighted that domestic supply can be important (!), it’s no good pretending that it constitutes a long-term carbon store.  Our report identifies that over half of all UK grown timber ends up as fuel, paper or a short term use such as fencing.  Ensuring that the carbon life-cycle of new planting is fully accounted for, including within offsetting systems, is therefore a crucial early step if new woodlands are to play a genuine role in the fight against climate breakdown.

trade-offs are inevitable. More should be done to protect existing species and habitats from inappropriate woodland, and the recent experience with a flower rich meadow in Cumbria has highlighted some of the pitfalls of our current system for nature. This report though does highlight that some trade-offs are inevitable.  For example, woodland birds, butterflies and plants need management to open up the canopy, but this will often mean reducing the total biomass of the woodland at least in the short term, with subsequent impacts for carbon.  Work like this to understand the evidence on these issues is critical, and timeframes are also key – again, management can, in the long run, increase carbon stores.

There are the headlines but for more detail, I would recommend reading the executive summary of the report or the briefing attached below.

What the report really reveals is that it is not simply a case of more trees = good news for a safe climate.  The way in which woodland interacts with peatlands, grasslands and other habitats – nature-based solutions in their own right – is critical, and in all the public debate about more trees, we must also ensure that peatland restoration and other habitat creation and restoration also accelerates.  That’s why we were so supportive of the Scottish Government’s recent announcement about funding for peatland restoration.  For the RSPB, making sure the drive for more woodlands doesn’t have a negative impact on key priority species such as the curlew is also a major focus.

As with food, understanding how to achieve our timber needs is undoubtedly a factor we cannot ignore.  This thread from my colleague Tom Finch, land use scenario guru, is pertinent here.  A more ecological approach to commercial forestry, that incorporates more diversity of species and structure, and takes better account of existing land uses, is a key finding of the report too.  The ONS revealed that in 2017 timber made up just £225m of the £5.3 billion value of the ecosystem services from woodland, so the case for a multi-functional approach to future woodland creation is undeniable.

What is clear to us is that, across all four countries of the UK, we need a much more strategic and proactive approach to planning woodland expansion, that takes account of the climate and biodiversity impacts, with a focus on native woodland creation.  This will take investment in habitat inventories and the capacity of the statutory nature conservation agencies, as well as leadership from all four governments.

Time will tell if our politicians are willing to take the plunge and move beyond the headline grabbing targets into the (valuable) weeds of what those numbers really mean.  

7356.3582.Woodland & climate report briefing FINAL Mar 20.docx

  • This is a very bad report. It reflects the problem across the sector that conservation is stuck in the 1990s - and your photos make the point very clearly. The material on carbon is an unselective mish mash of material from across the world, from different forest types and management histories that may have a completely different context to the UK. The report completely fails to recognise both history and future of afforestation - in particular, that it was post-war agriculture policy that pushed forestry onto the poorest land, and ultimately the Flow country, nor that with barely a murmur from conservation, agriculture has pushed intensification up the hill with re-seeding and fertilising to the extent that cause celebre from the 1990s like Llanbrymair are now completely surrounded by improved farmland of negligble conservation value - virtually wiping out a range of open upland species in Wales in the proccess. Your comments - as are the report's - on the carbon cycle and products like toilet paper and woodfuel are fundamentally flawed because they are based on assertions that it takes years to replace the carbon lost from the forest - whereas in a mature UK forest carbon is re-captured almost at once as trees are felled and replaced . It is increasingly frustrating for forest planners that the breadth of thinking - from biodiversity through timber and carbon to recreation, landscape and quality of life- seems too wide for people focussed in on their particular interest. I think RSPB is in danger of creating a silly  'climate change vs biodiversity'  clash which won't necessarily end well for the birds. With our exit from the CAP we have completely different opportunities which it is time we all got our heads round, to the benefit of land managers, biodiversity and the population at large.