Variability of Needle Density of Dwarf Mountain Pine (“Pinus mugo”) in the Eastern Carpathians

Abstract

The variability of needle density of dwarf mountain pine (Pinus mugo Turra) in relation to shooting type and twig age was analyzed using three populations growing on different substrata (volcanic, limestone, and crystalline schists, respectively) in the Eastern Carpathians (Romania). The needle density was evaluated using the total number of needles and the dry mass relative to shoot length and surface area. The number of needles per shoot length unit was significantly lower on volcanic bedrock compared with limestone and crystalline schists, respectively. The mass of needles per shoot length was not significantly influenced by the type of substratum. The dry mass of needles relative to the shoot surface area varied significantly between substrata. The pine population on limestone bedrock showed significant differences in needle density between the main and secondary shoots. The needle density relative to shoot surface area decreased significantly with shoot age. The needle mass relative to shoot length did not vary significantly with shoot age.