Mass, fractional and chemical composition of litter from birch STANDS on unused agricultural lands in Vologda OBLAST
D. V. Gichan, D. N. Teben’kova, V. N. Ivanova, S. A. Argetkina, A. A. Kolycheva
A. S. Isaev Center for Forest Ecology and Productivity, Russian Academy of Sciences, Moscow, Russian Federation
Keywords: birch stands, litter, phytomass, fractional composition, carbon, nitrogen, unused agricultural lands
Abstract
This paper presents comparative estimates of the input volumes and fractional composition of plant litter in a 15-year-old cereal birch forest and a 25-year-old tallgrass alder-willow birch forest, representing the initial stage of tree and shrub vegetation overgrowth on an abandoned arable land in the Cherepovets district of Vologda Oblast. The total litter input averages 1942 kg ha/year and does not differ between the biogeocenoses. 85.2 % of the litter is classified as the active fraction. The predominant fractions for the biogeocenoses are birch ( Betula L.) leaves and twigs, as well as alder ( Alnus Mill.) and willow ( Salix L.) leaves. The cereal birch forest, in contrast to the tallgrass alder-willow birch forest, is characterized by higher inputs of aspen ( Populus tremula L.) seeds and leaves and lower inputs of willow fractions (branches and leaves). Maximum litter fall input occurs in August-September (27-35 % of the annual input). The peak in the cereal birch forest occurs at the end of August, and in September in the alder-willow tall-herb birch forest. The minimum litter fall input for both types of biogeocenoses occurs during the dormant period (November-March) - 15 % of the annual input per month. The average input of carbon with litter fall is 861.5 kg C/ha/year, and nitrogen - 22.8 kg N ha/year.
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