Defense Response Characteristics of Suburban Pine Stands of Krasnoyarsk City at Early Stage of Anthropogenous Damage
G. G. Polyakova1, V. A. Senashova1, M. V. Polyakov2, N. V. Pashenova1
1V. N. Sukachev Institute of Forest, Russian Academy of Sciences, Siberian Branch, Akademgorodok, 50/28, Krasnoyarsk, 660036 Russian Federation
2Academician M. F. Reshetnev Siberian State Aerospace University, Prospekt Krasnoyarski Rabochi, 31, Krasnoyarsk, 660014 Russian Federation
Keywords: Ceratocystis laricicola, fungal extractives, stem phloem, defense response, suburban pine stands, permanent sample plots, anthropogenous damage, Krasnoyarsk city
Abstract
In 2002–2013, on permanent sample plots (PPs), the condition of suburban middle-aged pine stands of Krasnoyarsk was investigated. Annual assessments of parameters of defense response of stem phloem of the sample trees on the action of extractives from mycelium Ceratocystis laricicola (Redfern & Minter) were carried out. The size of a phloem necrosis and its shift along a stem relative to inoculation hole were measured. The pine stands (polluted and conditionally background) are convenient for determining condition changes at early stages of damage. These stands are affected by different anthropogenic factors, but don't differ in vigor state as visually estimated on a 6-point scale of Forest Regulation of Russian Federation. PPs have similar forest inventory characteristics, except for PPs on an edge of polluted pine forest where the site class is reduced. Significant shift of necrosis in phloem up on a stem within two years following a year when there was a spring creeping fire is registered. It proves the reversal of normal basipetal transport of assimilates toward crown and feasibility of using necrosis asymmetry for assessment of fire influence on physiological condition of pine stands. The increase of necroses size (decrease of resistance) after a fire was noted during later period in comparison with reversal of transport of assimilates in the stem. Influence of a chemical burn of needles on acropetal shift of necrosis was expressed to a lesser extent in comparison with a fire.
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