تأثیر برخی عوامل توپوگرافی روی پراکنش نمدار(Tilia Platyphyllos Scop.)در جنگل واز مازندران

The present research was conducted to find the influence of some topographic factors on distribution of large-leaved lime (Tilia platyphyllos Scop.) and its natural regeneration characteristics in "Vaz" forest (northern Iran). After identification of site and preparation of topography map, selective sampling method was carried out for tree inventory in plots. The sample plots were circular in 1000-m2 areas with at least 2-3 dominant lime trees in each. In the plots, altitude, slope gradient, direction, forest storey, tree type and natural regeneration were investigated. Results indicate that in this habitat the average diameter at breast height and height of Tilia platyphyllos is 36.9 cm and 23 m, respectively. Tilia platyphyllos prefers 1200-1400 m altitude, 75-100% slope gradient and northeastern to eastern directions and benefits from denser trees in these environments. It consists of some tree types together with Fagus orientalis, Carpinus betulus and Parrotia persica, whereas the dominant type is Tilia platyphyllos-Fagus orientalis. In most of tree types, lime occurs in the upperstorey. Natural regeneration of lime is often observed as sprout (coppice shoot).