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Báo cáo lâm nghiệp: "ce nucleation and frost resistance of Pinus canariensis seedlings bearing needles in three different developmental states"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Ice nucleation and frost resistance of Pinus canariensis seedlings bearing needles in three different developmental states. | Ann. For. Sci. 64 2007 177-182 INRA EDP Sciences 2007 DOI 10.1051 forest 2006102 177 Original article Ice nucleation and frost resistance of Pinus canariensis seedlings bearing needles in three different developmental states Vanessa C. Luisa Dunja TASCHLERb Juerguen HACKERb María Soledad JlMENEZa Gerhard WlESERc Gilbert NEUNERb a Department of Plant Biology Plant Physiology University of La Laguna Avda. Astrofisico Francisco Sanchez s n.38207 La Laguna Tenerife Canary Islands Spain b Institute of Botany University of Innsbruck Sternwartestrasse 15 6020 Innsbruck Austria c Federal Research and Training Centre for Forests Natural Hazards and Landscape Alpine Timberline Ecophysiology Rennweg 1 6020 Innsbruck Austria Received 21 February 2006 accepted 20 July 2006 Abstract - Frost resistance and ice formation in different developmental states of needles of P. canariensis seedlings were assessed. Regrowth after frost damage was used to determine the overall frost survival capacity. Two distinct freezing exotherms E1 E2 were registered. E1 was between -1.7 and -2.0 C. Initial frost damage LT10 was 1.5-2.7 C below E1. E2 was between -5.6 and -6.0 C and either corresponded with LT50 or occurred in between LT10 and LT50. Current year needles were less frost resistant than 1-year-old needles. The overall recuperation capacity of seedlings revealed that frost survival may be underestimated when only needle damage is assessed. Freezing of seedlings with or without roots had no effect on the frost resistance of needles but recuperation capacity was significantly affected. Seedlings survived -10 C during summer indicating that they withstand the lowest naturally occurring frosts in Tenerife. extracellular ice formation freezing exotherm Pinus canariensis regrowth subzero temperatures Résumé - Nucleation de glace et resistance au froid de semis de Pinus canariensis portant des aiguilles à trois differents stades de dévelop-pement. La resistance au froid et la formation de glace .