The recent EFI Scientific Seminar in Aberdeen was an opportunity to remind ourselves of the important role plantation forests play. The area of planted forests is increasing, both in the UK and worldwide, led by two main drivers:
Offsetting carbon is the obvious one for countries like the UK that want to meet their goals for the Paris Agreement. In the UK’s case, it aims to plant about 15000 ha per year. A recent paper estimated the global reforestation potential at 0.9 billion hectares, demonstrating that so far land availability is not an issue, even in EU. The challenge is then to plant the right tree in the right place with the appropriate technique.
Increasing bioeconomy demand – more population, more substitution – is another strong driver. Even though global plantation area increases while forest areas decrease, the annual increase of 1.2% observed over the last decade is lower than the 2.4% needed to meet demand, which will double by 2050.
A third driver of plantation expansion is climate change itself; with more disasters and diseases affecting forests, the replacement of large areas will require appropriate afforestation plans, but with high resilience. Genetic resources are key to success and will have to be characterised by much more than provenance tracking. Sustainability for all intensification measures such as fertilisation, mechanisation, and breeding will have to be assessed more precisely.
Using non-native tree species
Worldwide, 81 – 82% planted forests consist of native trees, but in Europe some large areas were planted with exotic species. About 150 Non Native Tree species (NNT) are present in Europe, but only a few (7 species) are widely used. Their productivity is on average 30% higher than native species in the same situation. Our current limited knowledge of the genetics of some NNT needs to be improved, so we can evaluate better their potential and eventual risk. In most cases, soils are improved by the introduction of NNT, but biodiversity is often lower in these stands – this together with a fear of invasiveness is leading to legal restriction of NNT in some European countries.
Forestry is about people
Polarisation around plantation topics is a (re?) emerging strong trend. Part of this comes from the feeling of companies or private owners making money – which is not an ecosystem service – from a common good without re-examining all the benefits and investments associated with this. Policy makers have a role to play as they can feed the polarisation or explore creative non-binary solutions based on scientific knowledge through policy tools such as regulation, financial incentives, and information/advice. A good example of politically driven depolarisation was the example of Scotland’s forest strategy design, which used participatory processes.
Are foresters prepared enough for this dialogue, being so convinced that growing trees is good for the planet? Should we dedicate capacity building to developing know-how on conflict management related to plantations, or do we assume that explaining the least bad options will be enough?
A landscape mosaic
Historically plantations had a strong focus on restoration, or protection against erosion, flooding etc. Now they are used in more combined objectives (for example in Italy, where wood production runs alongside carbon sequestration and substitution roles). The diversity of actors and private (short-term high income) or public (long-term, maximum externalities) expectations are complementary from a societal perspective. Land use sharing with large range of intensification level is the best option.
Today 7% of world forests provide 35-40% of timber. Plantations have their role in the landscape, reducing pressure on protected lands. Depending on how you design plantations (composition, structure) you can provide all types of ecosystem services, and it is important to use financial, regulatory and certification tools adequately to get the perfect mosaic. Plantations in the landscape can serve farming thanks to agroforestry, but also have a role in cities with peri-urban plantations or hydrology by saving watershades or support water recharging.
In a context of global change there is a need for more guidance, standards, regulation, good practices, payment for actions… but also for real territory governance to make landscapes more resilient and make the most of plantations.
Take home messages
- The land use impact of plantation forests is always much lower than agricultural land use. Science-informed decisions should guide integrated land use and resilient landscape design rather than polarised opinion.
- In Europe plantation forestry already plays a significant role in meeting environmental, economic and climate policies; going forward investments associated to good practices could enhance these contributions further.
- More data collection, better gene pool characterisations, more long term field trials and more research coordination, knowledge sharing and policy measures are needed to support the establishment, management and utilisation (markets) of planted forests.
- Social demand and climate Change are drivers for intensification and more flexible, complex and diverse plantation systems producing a larger set of ecosystem goods & services
- Adaptation/resilience is essential to secure mitigation, leading to high expectations for genetic resources.
- Even plantations with non-native species bring lots of colours to the forestry (and science) palette!
Photo: Stephen Bird/AdobeStock
Hi, thank you, now corrected to billion. For the source see “The global tree restoration potential”, Science, 05 Jul 2019, Vol. 365, Issue 6448, pp. 76-79 (https://science.sciencemag.org/content/365/6448/76).