Taxation characteristics and life state of Quercus robur l. in various forest conditions in the Tunnel beam (Dnipro city)

Abstract

Influence of  forest conditions on the taxation characteristics and the vital state of Quercus robur L. was analyzed. The plants were planted on artificial plantations laid in a tunnel beam in the city of Dnipro in 1961. The experimental plots was located in thalweg (mesohygrophilic conditions – L3) and on the slope of the northern exposure (mesoxerophilic conditions – L1). The 301 specimen of Q. robur L. trees grow on the slope (SG1), and 357 specimen in the thalweg beam was found. The oak trees of three morphological races were planted in tunnel beam: Q. r. pectinata Schneid, Q. r. longiloba Lash, Q. r. Laciniata Schneid. The Q. r. pectinata Schneid are dominate: in the thalweg – 82.70 % (SG3), on the slope (SG1) – 78.60 %. It was found, that in talweg the plants have a larger average height and average trunk diameter. In mesohygrophilic conditions more plants are assigned to the last two classes of height (16.1–18.0 and 18.1–20.0 m), than in mesoxerophilic. The tallest trees grows in thalweg. There are 22 m heigh, and on the slope – 19.5 m. In accordance with calculations, the average height of trees in thalweg is 16 m; on the slope it is 14 m, diameter 42 cm and 32 cm, respectively. Most of the trees in the the experimental plots are in the category of vitality state: healthy tree. There are more such trees in mesohygrophilic conditions than in mesoxerophilic ones (76.40 and 63.90 %, respectively). Weakened trees on the slope of the beam are 32.70 on the slope of the beam, and in the thalweg 17.40 %. The vital status index of oak plantations on the slope is 88.0 %, and in the talwez – 91.0 %. There is no fresh dead wood and dead wood of previous years on the experimental plots. The indeх of the vitality state of the planting in mesohygrophilic conditions is higher, than in mesoxerophilic conditions. Favorable conditions of water supply conduced to the better growth of branches shoots and leaves on them. Tree pathologies are more common on the slope of the beam in mesoxerophilic growth conditions.  The analysis of oak trees damage shown, that the largest part falls on the dry top of slope. There are no fungus cup and  tumors on the trunks, only one tree with excrescence was found. Such trunk pathologies as inclination, curvature, multi-stemmeds and dryness of thick skeletal branches was revealed. There were much less of trunk pathologies in mesoxerophilic conditions.