title: Frost Induces Respiration and Accelerates Carbon Depletion in Trees.
abstract: Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm(-3) yr(-1) on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.
authors.affiliation: Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America.
authors.forename: Or
authors.initials: O
authors.lastname: Sperling
authors.affiliation: Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America.|Ecology Graduate Group, University of California Davis, Davis, CA 95616, United States of America.
authors.forename: J Mason
authors.initials: JM
authors.lastname: Earles
authors.affiliation: Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, Via 15 Leonardo da Vinci 44, 10095 Grugliasco, TO, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Secchi
authors.affiliation: Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America.
authors.forename: Jessie
authors.initials: J
authors.lastname: Godfrey
authors.affiliation: Department of Plant Sciences, PES #2316, One Shields Avenue, University of California Davis, Davis, CA 95616, United States of America.
authors.forename: Maciej A
authors.initials: MA
authors.lastname: Zwieniecki
mesh_terms: D002244:Carbon / Q000378:metabolism*; D019069:Cell Respiration / Q000502:physiology*; D003080:Cold Temperature; D010788:Photosynthesis / Q000502:physiology; D018547:Plant Stems / Q000378:metabolism / Q000502:physiology; D014197:Trees / Q000378:metabolism* / Q000502:physiology*; D014934:Wood / Q000378:metabolism / Q000502:physiology
chemical_list: D002244:Carbon