UNDERSTORY VEGETATION COVER COMPONENTS ASSESSMENT IN ANTHROPOGENICALLY DISTURBED BIRCH STANDS OF KRASNOYARSK FOREST-STEPPE

Abstract

The vegetation cover characteristics of anthropogenically disturbed birch stands of Krasnoyarsk forest-steppe are studied. The research purpose is to study the current state of under
story vegetation cover of the birch stands, which have been exposed to recreational and anthropogenic impacts for a long time, as well as to assess the degree and nature of its change
over the 12-year period since the last research. The studies were carried out on the sample plots laid out in mixed herbs birch stands. Cenosises are characterized by V–VI age classes,
II–IV quality classes, and 0.6–0.9 density of stocking. The birch stands are located in the main transfer of Krasnoyarsk industrial emissions. Phytocenoses were under significant anthropogenic and recreational impact for a long time. At each facility, 30 sites (1 m² each) were laid, where species composition, horizontal and vertical structure, projective cover and occurrence of undergrowth and forest live cover species were assessed. The comparative analysis of floristic lists was performed using the Sørensen-Czekanowski coefficient (Ksc). The degree of species diversity was estimated by using the Shannon index; the degree of recreational transformation – synanthropization index. Cuttings were taken from 10 sites (20 × 25 cm each) for recording the phytomass stock of forest live cover on each sample area. Plants were cut off at the litter level, sorted by species, dried and weighed. Rating scales of digression were used to study the recreation influence. The degree of anthropogenic impact was determined by the content of toxic ingredients in plants of living ground cover. It is found that the toxic elements concentration in plants does not reach excessive values at which homeostasis disturbance happens. It was concluded that the changes in vegetation cover observed in 2017 in relation to the state of 2005 are more due to recreational than anthropogenic impact; which changed due to the introduction of a new technology at the JSC “RUSAL Krasnoyarsk Aluminum Plant”, which made it possible to reduce toxic industrial
emissions. According to the study results, the species composition of the undergrowth and forest live cover was determined, the features of its change over a 12-year period were revealed. It is noted that species diversity has decreased and the proportion of synanthropic species has increased across all plots. Total forest live cover phytomass and individual species phytomass are determined at each plot. The regularities of change in different species contribution to the total stock of phytomass, depending on recreational impact changes, were identified. The ground cover recreational digression stages are determined by analyzing the changes in species diversity, the quantitative ratio of ecological-cenotic groups, the structure and the absolute value of phytomass.

For citation: Goncharova I.A., Skripal’shchikova L.N., Barchenkov A.P., Shushpanov A.S. Understory Vegetation Cover Components Assessment in Anthropogenically Disturbed
Birch Stands of Krasnoyarsk Forest-Steppe. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 1, pp. 75–87. DOI: 10.37482/0536-1036-2020-1-75-87

Funding: The study was carried out within the framework of the basic research projects of the Sukachev Institute of Forest SB RAS “Biodiversity of Indigenous Coniferous and Derivative Forest Ecosystems” (No. 0356-2016-0301) and “Dynamics of Siberian Forests in a Changing Climate. Monitoring of the Living State, Productivity and Ranges of the Main
Forest-Forming Species of Woody Plants” (No. 0356-2018-0739).