Anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.) growing in a habitat with varying environmental characteristics

We investigated the influence of a habitat with varying environmental characteristics on the anatomical structure and localisation of lignin in needles and shoots of Scots pine (Pinus sylvestris L.). A dune in South-West Estonia was chosen as the study area because it has extreme environmental characteristics: primitive sandy soil, deficiency of water, heavy winds and high light exposure. Analysis showed that the needles of all age and the current-year shoots of pines growing on the foot of the dune had the largest average cross section, mesophyll and parenchyma areas. The degree of the lignification of needles at the foot, on the slope and on the top of the dune differed distinctly. Intensive lignification of the cellular walls of the xylem was observed in needles and shoots of the pines, growing at the foot, but not in the trees growing on the top of the dune. Analysis showed that the anatomical structure and localisation of lignin, both in needles and in shoots, depend on their age, the trees location (foot, slope or top of the dune) and soil mineral composition.