ВСТРЕЧАЕМОСТЬ ДРЕВЕСНЫХ ПОРОД В ЛЕСНЫХ ФИТОЦЕНОЗАХ ЗАПАДНОЙ СИБИРИ ПО ШИРОТНОМУ ГРАДИЕНТУ

• Main Author: ВЕТЛУЖСКИХ НАТАЛЬЯ ВЛАДИМИРОВНА
• Format: Text
• Language: unknown
• Published: Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования «Национальный исследовательский Томский государственный университет» 2016
• Subjects: ВСТРЕЧАЕМОСТЬ ДРЕВЕСНЫХ ВИДОВ,ЛЕСНАЯ РАСТИТЕЛЬНОСТЬ,ШИРОТНЫЕ ГРАНИЦЫ,ЗОНАЛЬНЫЕ СООБЩЕСТВА,OCCURRENCE OF TREE SPECIES,FOREST VEGETATION,LATITUDINAL LIMITS,ZONAL COMMUNITY; taiga; Siberia
• Online Access: http://cyberleninka.ru/article/n/vstrechaemost-drevesnyh-porod-v-lesnyh-fitotsenozah-zapadnoy-sibiri-po-shirotnomu-gradientu; http://cyberleninka.ru/article_covers/16508187.png

Исследовались географические закономерности изменения флористического состава лесных фитоценозов Западно-Сибирской равнины по широтному градиенту от 55 до 68° с.ш. Проанализирован видовой состав лесных сообществ 13 широтных отрезков. Выявлен процент встречаемости по описаниям девяти древесных видов растений. Впервые дана характеристика зональных лесных сообществ конкретных широтных отрезков Западно-Сибирской равнины и определено, насколько относительная встречаемость лесообразующих древесных видов отображает описанные границы зон и подзон. The aim of this work was to describe zonal forest communities of concrete latitudinal segments of the West-Siberian plain and define how the relative occurrence of forest-forming tree species corresponds to the described boundaries of zones and subzones. We studied geographical pattern changes of floristic composition of forest communities over the West-Siberian plain (from 55 to 68° n.l.). Our research was conducted in the central part of West Siberia on the territories of Novosibirsk, Omsk, Tomsk and Tyumen oblasts. To collect field material, we selected forest phytocenoses of drained habitats without obvious signs of anthropogenic loading on loamy substrates, where sample plots were laid (10 x 10 = 100 sq. m), on which we fixed the total vegetation projective cover, specified the height and the density of the tree layer and determined the species composition of the community and the projective cover of each species in percentage terms. We analyzed 13 latitudinal sections of forest-forming trees and described the main characteristics of forest communities. Basing on descriptions of nine woody species we defined the percentage of occurrence. It was for the first time that the relative occurrence of forest-forming tree species and characteristics of forest communities were shown for particular latitudinal sections. It allowed us to define the limits of forest-steppe and forest zones of the West Siberian plain. It turned out that Betula pubescens has the widest section range of occurrence. Significantly reducing the occurrence north of 58° n.l, Betula pendula marks the boundary between the southern and middle taiga forests. The northern boundary of the middle taiga forest communities occurrence shows a decline in the percentage of Populus tremula occurrence after 61° n.l. North of 56° n.l. there are coniferous trees, which prove the beginning of subtaiga distribution, and the increase in the percentage of their occurrence to the north of 58 parallel shows the boundary between the southern and middle taiga forests. Picea obovata is situated farthest to the north, and after the 65°, as well as the birch, is admixture in disturbed larch forests. Abies sibirica, demonstrating a high percentage of occurrence in the first layer from 58 to 61° n.l. may be a marker of forest communities of the middle taiga. Pinus sibirica, rarely occurring after the 65th parallel, marks the boundary between the north-taiga forests and woodland subzones. Pinus sylvestris increases the percentage of occurrence in zonal north-taiga forests. At 61° n.l. is the boundary between forests of the northern and the middle taiga, which is well marked by Larix sibirica occurrence, and the fact that it replaces coniferous species to the north of 65° n.l. of the parallel, shows the boundary between the northern taiga and woodland subzones. The article contains 1 Figure, 1 Table, 29 References.