Природный потенциал возобновления в пихтовых лесах, поврежденных в ходе инвазии уссурийского полиграфа

Abstract

In the beginning of this century, the cases of invasions of dendrophilous insects becomes more often. The impact of invadors leads to the degradation of forest ecosystems and loss of natural biological diversity. The article discusses the invasion of Polygraphus proximus Blandf. in fir forests of Western Siberia. The aim of the research was to evaluate the potential of natural regeneration of fir forests in Western Siberia, damaged by Polygraphus proximus. Studies are conducted in the southern part of the Tomsk region at 11 test plots. Objects of research were both one breed fir trees, and grass communities of Siberian fir (Abies sibirica Ledeb.) with participation of Siberian pine (Pinus sibirica Du Tour), Siberian spruce (Picea obovata Ledeb.), silver birch (Betula pendula Roth) and aspen (Populus tremula L.). Surveyed plantations belonged to the ripening or ripe age states. The study of natural regeneration was carried out according to standard procedures. Method of transects was used. Measurements were subjected to basic morphological parameters of the undergrowth. The distribution of the natural regeneration area was estimated by calculating the ratio of occurrence and index of scattering. To assess the affinity of the undergrowth, micromosaic structure of the organization of communities was studied. Analysis of the size and morphological structure of natural regeneration have identified the degree of damage of forest stand and condition of the undergrowth. Dynamics of spatial structure is characterized by heterogeneity (index of dispersion exceeds 1). It indicates group location and its variable density. 82 % of teste plots were recorded with mortality of trees in the impact of Polygraphus proximus. In this case the bulk of the deceased undergrowth is from the major category (95 %), and only 5 % is the average undergrowth. The share of deceased major undergrowth was 9.9-50 %. There was a positive relationship between the number of mortality of trees and status category of fir forest. The number of damaged undergrowth in fir forests varies from 1.2 to 29.6 thousand units/ha. Predominant species is fir. Fir forests of Western Siberia, damaged by Polygraphus proximus, have potential of regeneration. Siberian fir will retain edificatoria value.