Wood anatomy of ivy-hosting black alder (Alnus glutinosa Gaertn.)

The study aims at investigating the impact of ivy (Hedera helix L.) on the growth and on some wood anatomical characteristics of black alder trees. Ivy-hosting and non-hosting black alder have a similar wood anatomy in terms of qualitative properties. However, in ivy-hosting trees tangential and radial diameter of vessels are narrower (p <0.001), and inter-vessel pits are smaller (p <0.01), whereas vessel frequency is higher (p<0.05) than those of non-hosting ones. The average maximum ray height is greater (p<0.05), and ray number mm-1 is lower (p < 0.001) than those of non-hosting individuals. In addition, the last ten years’ average radial growth has decreased 39.5% compared to that of non-hosting black alder.