Siberian Silk Moth Outbreak Dynamics in Dark-Coniferous Forests of the Altai
V. I. KHARUK1,2, M. L. DVINSKAYA1, D. A. DEMIDKO1, E. V. FEDOTOVA1,2, U. A. BUDNIK2
1V. N. Sukachev Institute of Forest, SB RAS, 660036, Krasnoyarsk, Akademgorodok, 50/28
2Siberian Federal University, 660041, Krasnoyarsk, Svobodny ave., 79
Keywords: сибирский шелкопряд, вспышки размножения насекомых, ксилофаги, мониторинг лесов, изменения климата, темнохвойная тайга, усыхание хвойных, Siberian silkmoth, insect outbreaks, xylophagous insects, pest monitoring, climate change, dark-conifer taiga, conifer mortality
Abstract
Spatial and temporal dynamics of fir-dominant stand mortality in the Altai Mountains was studied based on remote sensing and GIS methods. Mortality was primarily caused by Siberian silkmoth ( Dendrolimus sibiricus Tschetv.). Spatial distribution of stands mortality was dissimilar with respect to relief features. Initially pest outbreak occurred on the south-west slopes (about 10 steepness) and elevation about 400 a.s.l. Then mortality spread uphill and downhill and to the steeper slopes and those of the eastern exposure. About 45 % of total (6 thousand ha) mortality was due to secondary pest (bark beetles) attacks. Based on remote sensing technique an initial phase of pest outbreak was determined with one-decade precision. Siberian silkmoth outbreak happened at increase in air temperature and decrease in precipitation and late frosts. Weakened by Siberian silkmoth and water stress trees became sensitive to secondary pest’s attacks. Observed and predicted warming and aridity increase will facilitate Siberian silkmoth outbreaks both within its range and northward of its current border.
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