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  • Writer's pictureAlistair

Planting trees vs natural regeneration

Hundreds of Aspen suckers sprouting up at Cefn Garthenor without permission or a grant!

How do the thousands of self-seeded and sucker trees sprouting up over Cefn Garthenor fit with the government’s well publicised plans to plant our way to net zero by 2050? Well, those plans (from both the Welsh government and the UK government in Westminster) don’t seem to consider this most natural of ways to expand tree cover.

All we hear about is planting trees and I suppose it seems an obvious thing to do. Capture lots of carbon and provide a good environment for nature, right? A nice, simple solution that allows for easily understood targets?

In March 2022, the UK’s Department for Environment, Food & Rural Affairs (DEFRA) together with the National Audit Office (NAO) laid out government plans to get on with it as part of the country’s ambition to hit net zero by 2050. Across the whole of the UK this would involve planting between 90 and 120 million trees a year by 2025, covering 30,000 hectares per year. That is the equivalent of just over 300 Cefn Garthenor sized plots per year, each with over 300,000, trees across the UK (source: Planting trees in England ( ). The Welsh government’s contribution is to be at least 5,000 hectares a year (source: Natural Resources Wales / Get help to plant trees and create woodland ). Since 1975, in Wales, it has never exceeded 2,000 hectares per annum, and in 2020 it was just 290 hectares, so only 3 Cefn Garthenor sized plots (source: Written Statement: Trees and Timber (12 July 2021) | GOV.WALES ).

So, a huge increase in tree planting is required to hit these targets. Some worry that this will dent UK food production. This is unlikely as around 13% of the UK is wooded at the moment and even if we hit these targets it will not tip the needle by more than a few percent to 15% or 16%, leaving us well behind admittedly less densely populated France (32%), Germany (33%) and Spain (37%) (source: Planting trees in England ( ). Wales is a little higher than the UK average at 15% (source: Woodlands for Wales ( ). Historically, as I’ll discuss later, trees have been planted on the least “productive” land, so if repeated that relatively small reduction in farmland would have a negligible impact on food production. I’d argue we should actually plant on slightly “better” farming land (which is more nature depleted) and that we should think more carefully about what and how we farm to provide food security. That is another subject altogether, so back to planting more trees …

The bigger concern for me is the way in which it is done. What are the trees? Where are they planted? Are those trees good for the rest of nature?

Take a look around Wales and what you will see is lots of non-native conifers. In fact, over a third (close to half by some estimates) of all woodland in Wales is exactly this (source: Woodlands for Wales ( and INCC Natur Cymbru Summer 2022). Typically, these are in mono-culture plantations and a quick walk around shows a problem. Very little else lives within them. In the most common native broadleaves (Oak, Willow and Birch) you will find well over 200 insect species, whereas the number is under 40 in a Spruce and half that again in Larch and Fir (source: INCC ). You’ll see the same story comparing plant life on the ground within woodlands … conifer woods are dark and bare, the falling needles having a long-term impact on the soil though acidification.

Why so many conifers? They grow quick and straight and present a better financial return than alternatives. In terms of carbon capture, it is complicated. Young trees capture less, fast growing bigger trees capture more and then older trees capture less again. Conifers cover the first two stages, but never get old as they will be harvested. Hardwoods capture more per kilogram of growth but grow more slowly. A long-established broadleaf woodland will cover all three stages. But then it also depends on how the wood that is simply harvested is used. Furniture or burning for biofuel clearly have different implications. Wales has some seemingly perverse biofuel projects encouraged by subsidy (again, another story).

Where you plant also makes a big difference. We have historically all too frequently planted on boggy peat ground as it is poor for farming and so available. But this is already an amazing carbon capturing environment and has (because it has not been intensively farmed) decent biodiversity. So put conifers on that land and we actually release carbon captured in the peat we destroy and reduce biodiversity. A lose, lose outcome.

Furthermore, plant in the wrong environment and the success rate of those trees is much diminished. Overall, a well-intentioned dash for growing tree cover could have some perverse consequences for both carbon capture and biodiversity.

Images above (L to R) show the naturally seeded Oak, sucker Blackthorn with Oak, and Alder, which are coming up all over Cefn Garthernor

But back to my self-seeding and sucker native trees. They only grow because the conditions are right, there is no cash cost and in the complex habitat being created at Cefn Garthenor they will not only capture carbon but add to biodiversity. But there is no government encouragement to allow this to happen. In fact, as it stands if I increase the wooded portion of land the still important farm basic payment scheme (a subsidy most farmers rely on) will reduce its payment to me. I’m lucky that my project does not need to follow the money, but most land does.

Images above (L to R) show the Aspen coming up at end of April, in leaf at end of May and well over 2m high by start of October 2022

This whole area is more complicated than at first it may appear. But it would help if subsidies required a greater proportion of indigenous broadleaf tree planting and if biodiversity was also properly considered as part of site selection. And if farmers did not get punished for allowing natural tree growth.

This blog post is hardly in depth, but hopefully gives a feel for some of the issues involved. Natur Cymru (the magazine of the Initiative for Nature Conservation Cymru) has a great article in the Summer 2022 edition. The INCC gets (by choice) no government funding, so seems more capable of getting to the heart of things when compared with many other studies. For INCC see Initiative for Nature Conservation Cymru – Speaking out for Nature


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