Changes in the Composition of the Needles of Pinus austriaca Link during the Ageing-process

In spring the young needles of coniferous trees begin to develop. They grow during summer and finish their growth in autumn. In one year they are practically full-grown, but remain at the tree during some years before they drop. The growing zone is localized in the basal part of the needle. This zone is very small; already at a distance of about i cm from the base no growth occurs. Above this zone the needle is full-grown. This fact can be demonstrated from both the anatomical and chemical properties of the needle. Unfortunately it is not possible to measure the division of growth in the basal part because this part is wholly included by membranous scales. After removal of the scales it desiccates very soon. Neither it is possible to cover the base again with the scales after every measurement as desiccation and injury have seriously affected it.