Gavrilova O., Gryazkin A., Paramonov S. Influence of growing conditions on the biometric characteristics of the pine undergrowth // Resources and Technology. 2026. №1, Vol. 23. P. 103‒116.

Influence of growing conditions on the biometric characteristics of the pine undergrowth

Gavrilova
Olga Ivanovna

PetrGU, ogavril@mail.ru

Gryazkin
Anatoly

St. Petrerburg Forestry Engineering University named after S.M. Kirov, lesovod@bk.ru

Paramonov
Sergey

St. Petersburg Chemical and Pharmaceutical University of the Ministry of Health of the Russian Federation, sergei.paramonov@pharminnotech.com

Key words:
vaccinium type of pine; pine undergrowth; length and weight of needles

Summary: The purpose of this study was to determine the main biometric characteristics of pine seedlings growing under different light conditions. Original comparative data on the biometric characteristics of pine undergrowth growing under the canopy of the mother stands and in the open area are presented. The object of the study was an undergrowth of pine 0.5—2.5 m high, growing in different light conditions: under the canopy of cowberry pine and in a clearing in the wood. The research region was the Leningrad Region. The undergrowth was recorded on circular accounting platforms of 10 m2 each, in accordance with RF Patent no. 2084129. For each model specimen of pine undergrowth, the height, age and growth over the years, as well as the age of the needles on the lateral and central shoots, were determined. For a detailed study, 3 model specimens of pine undergrowth were selected from each height group. The total number of model copies was 30. The length and weight of the needles were measured in laboratory conditions, the density of the shoots was determined, and the average total increase was determined. It is shown that the basic biometric characteristics of under-growth growing in an open area were always higher than those of undergrowth growing under the canopy of stands. Depending on the growing conditions, the length of the needles varied to a lesser extent than the weight of the needles. The length of needles in height groups varied from 3.43 to 5.22 cm for undergrowth growing in an open area, and from 2.42 to 3.29 cm for undergrowth growing under the canopy of stands. The range of needle weight variation ranged from 1.71 to 3.41 g for undergrowth growing in an open area, and from 0.71 to 1.43 g for undergrowth under the canopy of the parent stand. The illumination under the canopy of the cowberry pine was on average 18.7 thousand lux and accounted for 27 % of the illumination in the open. The functioning of the assimilation apparatus ultimately determines the intensity of accumulation of wood, the main product of forestry production. In conditions of heat deficiency, illumination is the main factor determining the intensity of production processes in the taiga zone. The results obtained can be used for comparison with data obtained in other conditions and other geographical areas.

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Resources and Technology

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Influence of growing conditions on the biometric characteristics of the pine undergrowth