A general deterioration in physiological condition of several tree species (in addition to oak)

Many of the underlying causes of oak decline such as soil pollution inputs, a compromised tree/soil microbiome, environmental extremes due to climate change and the effects of various sublethal pests and pathogens, also affect most other tree species to varying degrees. Observations suggest there may be a general deterioration in the physiological condition of several other tree species over the last 10-15 years, most likely as a result of these cumulative pressures.

As with oak decline, this is generally most apparent in the southeast and east of the UK, where rainfall levels are much lower, with the southeast being officially classified as ‘semi-arid’. Together with the effects of climate change, this places trees in this region under much greater water stress, with knock on effects upon tree physiological condition. Species that increasingly appear to be affected to some degree include:

• Sweet chestnut (Castanea sativa)
• Yew (Taxus baccata)
• Horse chestnut (Aesculus hippocastanum)
• Sycamore (Acer pseudoplatanus)
• Alder (Alnus glutinosa)
• Birch (Betula pendula and Betula pubescens)