Editorial: trees, climate and the rest

Abstract

As I write this editorial, with COP26 in Glasgow and a recent bold statement of how UK government policy is embracing trees, there is perhaps some glimmer of a hope of optimism. However, as it was once said, “Fine words butter no parsnips”; or in other words, “actions speak louder than words”. So we will see what comes of some of the fine words which we sincerely hope will prove to be more than hot air. With promises of mass tree-planting across Britain however, there must come some serious health warnings. The first of these is that container-grown saplings should not be in peat-based compost (whether of UK origin or from overseas). If they are peat-grown, then there is zero carbon benefit and maybe worse – because their cultivation has destroyed a peat bog and the peat is being oxidised into carbon dioxide. The Forestry Commission has already admitted to this environmental folly and I suspect some conservation organisations may need to look closer to home too. On the subject of planting trees, then this can bring enormous benefits if we have the “right tree, right place” mantra. However, there are other ways to grow yourself a forest or a wood, and my favoured approach is natural regeneration, and with a helping hand from our populations of jays. This bird is nature’s forester and will take acorns and plant them totally free of charge and in a far more natural way than people can. My good friend Ted Green is absolutely spot-on in this observation of how our native oakwoods originally spread. Old-fashioned foresters understood this and would put out bird-tables laden with acorns to be scavenged and planted. The final point is that you should never plant trees on existing areas of good wildlife habitat or on important archaeological sites. I have heard of both happening quite recently. Additionally, in assessing sites for new trees and for carbon capture, then we should consider less fashionable outcomes such as wood-pasture, i.e. open lands with trees spaced out, or even planting (or letting trees outgrow) in established hedgerows. There is also important research emerging to show how unimproved grasslands and heaths for example can hold huge amounts of carbon and compare well against plantations; and so such areas need protection not planting. This last issue of the journal for 2021 brings us three major contributions. Colin Price (2021) carries on his detailed analysis of CAVAT methodologies and approaches. This is part of an on-going discussion and debate centred on amenity tree valuation methods, and has great relevance to the calculation of compensation values for trees perhaps lost in developments, etc. Of course, with all such models, what you put in at the outset may be significantly subjective and that ultimately influences or even determines what comes out at the end. In the case of some amenity tree valuations, this may significantly and substantially under-value highly biodiverse 40-year-old spontaneous woodland in comparison to planted, maiden, amenity trees of inherently lower ecological interest. We have recently experienced the impacts of this in Sheffield (UK) where such an evaluation was part of the developer’s justification for removal. The models are, after all, merely Arboricultural Journal 2021, VOL. 43, NO. 4, 197–198 https://doi.org/10.1080/03071375.2021.2008710