Tree Health in England

Earl of Caithness Excerpts

Thursday 9th June 2022 Grand Committee

[The Earl of Caithness (Con)]

My Lords, I think we are all extremely grateful to the noble and right reverend Lord for introducing this important debate. It is not just the loss of diseased trees that we need to consider but all the consequences. Ash holds a special place in the ecosystem of woodlands. Because of its characteristics, it is a good tree for reducing atmospheric CO₂, while 1,058 species from birds to lichens are associated with ash. As with elm trees, the large-scale loss of ash is having a significant impact on a range of species and habitats, as well as the economics of broad-leaved woodlands.

Much is known about the phenology of autumnal leaf fall, gene tolerance and microbial symbionts associated with resistance of ash, but progress on that alone will not solve the problem. Far too many in the forestry establishment still think that disease is an act of God and wilfully do not look at the influence of us humans and the effect we have on this situation. That influence is called management; more accurately, I call it bad management. We know that most of our woodlands in this country are in bad condition—what an indictment.

Planting blocks of the same species with a view to clear-felling is a recipe for increasing disease and pest problems and is unnatural. For over 50 years I have banged the drum for working with nature and for mixed, uneven-age forestry. Dense woods put the trees under pressure and ash, like oak, is very intolerant of lateral competition. Stressed trees are more susceptible to disease. Dense stands lead to quiet, humid conditions, which increase spore production and retention within the stand.

Some enlightened companies, such as SelectFor Ltd, have been pursuing irregular silviculture and continuous cover for many years. It has backed its belief with scientific research, using the universities of Salford and York. Initial results indicate that even with genetically tested trees other factors, such as environment and management, are involved in the trees’ ability to survive infection. The University of Birmingham’s work supports this: initial results show that ash survive better if planted alongside cherry but worse if planted alongside lime.

These bits of work demonstrate the importance of management and Defra should help to fund them. Management should feature strongly in the forthcoming government paper. On funding, how much is Defra spending on trees and disease research in the current year? What is the budget for the next two years? Why are some NGOs receiving 100% grant support when taxpayers’ money is better utilised to leverage private sector finance?

I also ask my noble friend to stop everybody using the facetious slogan “right tree in right place”. I remind him: right tree—lodgepole pine; right place—Flow Country in Caithness; result—disaster.