Sir, – (as sent to the Scottish Government):

Dear ScotGov,

Having been intrigued by recent hyperbole that only trees save the environment, and that farming is a big problem and, disturbingly, that consequent ScotGov policy is being built atop such rhetoric, I thought to look at some actual science.

This peer-reviewed data originates from scientific experiments in temperate climates, where farming and forestry techniques are comparable with Scotland, or are indeed in Scotland.

Vesterdal et al (2002), established that converting arable land to forestry resulted in a net soil carbon loss of 11.8 mg/ha over a 30-year period – approximately the time taken to grow a commercial tree on good land. If this timber is not burned, it may be considered carbon neutral – carbon removed from soil being redistributed to the biomass of a tree.

But why take formerly stable, locked away carbon from deeper soil levels and redistribute some of it into wood and allow the remainder to respirate into the atmosphere, carbon that would otherwise have remained locked up in the first place, beyond any effect agriculture has on just the very top layer of soil?

The same study concluded that it is only beyond 30 years of establishment that soil carbon returns to former levels, once a forest floor and corresponding bio-activity is established. But, of course, then it is harvested and the process restarts, invalidating any environmental gain.

The former study looked at conversion of arable land to forestry. Recognising that most of your afforestation policy is taking place on LFA permanent pasture and hill and that our responsible, expert arable farmers rightfully wouldn't consider ruining their family lands by extinguishing future food resilience, Corre et al (1999) confirmed there was no difference in soil carbon between permanent pasture and mature woodland on an identical land type, that being a mineral soil.

Granted, this is older science. Ironically, though, we might reasonably expect such information having been available for so long that policy ought to be better informed. More recently, Carlo et al (2019) discovered a more worrying state of affairs. On land with 30-year-old trees on former farmland 'soil CO2 emissions were significantly greater than in undisturbed natural riparian forest.'

Thus, the only way planting new woods can be better than agriculture in terms of soil carbon, is if all new plantings are undertaken on already carbon depleted soils, not on permanent pasture on the LFA, which is safely stacked full of the stuff and perennially continues to sequester, in the absence of any direct state incentive or reward.

New woodland would need to be left alone to grow into mature, unharvested, naturally regenerating forests, if climate change mitigation is the true goal?

This notwithstanding the ecological, biodiversity, hydrological deserts that establish under a new darkness of blanket non native species, which makes up the majority of current anti competitive, state incentivised planting – the commercial (sole) goal of the planters would not, therefore, exist.

I wonder what the speculative, absentee, tax advantaged planters who seemingly have so many of your ears and who cynically laud themselves as planet saviours, especially when it comes to carving funding pots originally established to protect family farming and the associated folks who actually live and work in a place, would say about that? Their agents ought to have an idea, because much of the data I refer to was taken from the Journal of Forest Ecology and Management.

Perhaps they could wheel out an alternative scientific viewpoint, in which case we would arrive at an unfortunately sad conclusion that blinkered, confused policy making of trees trees trees over and above traditional family farming, can only be one of politics, with no basis in either the moral or scientific truth of ecologically sound land management.

Work supported by Defra and the Woodland Trust, by Cannell, in 1998 – 'Growing trees to sequester carbon' – also looked at this question, again some time ago. Amongst the findings, it stated: "A forest covering twice the area of the UK would be needed to absorb all UK emissions..." and "these are sombre realities for anyone imagining that forestry can solve the greenhouse gas problem."

Don't get me wrong, I like trees. A right tree in the right place, is entirely correct. I actively manage my own mature woodlands, but you don't pay BPS for that, whereas you do for damaging new plantings and you changed your laws recently so that now I need your 'permission' to go near my own trees.

McNally et al (2017) stated in the Global Change Biology Journal that permanent pasture, depending on soil type and management, can sequester anywhere between 10 and 42 tonnes of carbon per ha, per year. Friggins et al (2020) proved in the paper 'Tree planting in organic soils does not result in net carbon sequestration on decadal timescales', well, they prove exactly what the title says.

This experimental work is ongoing in Scotland and demonstrates that when LFA land is afforested, the net effect is increased overall carbon emissions.

How odd that the state now sponsors increased CO2 emissions at the expense of soil carbon protective LFA agriculture and that your contracted agri advisors'. Carbon calculators do not respect or measure any soil sequestration or storage whatsoever and only count one side of a tree's carbon flux, whilst ignoring the other.

But forget the farming, forget the ecology, forget the hydrology, forget the biodiversity crisis, forget actual scientific proof, and forget your social responsibility to the fabric of economically fragile rural communities, because according to somebody's carbon calculator, you would plant this land instead?

William McLaren Moses (BSc (Hons))

Wigtownshire NFUS LFA monitor.