Long-termecologicalconsequencesofforestfiresinthecontinuous permafrostzoneofSiberia

• Published in: Environmental Research Letters
• Main Authors: AlexanderVKirdyanov, MatthiasSaurer, RolfSiegwolf, AnastasiaAKnorre, AnatolySProkushkin, OlgaVChurakova(Sidorova), MarinaVFonti, UlfBüntgen
• Other Authors: Институт экологии и географии, Кафедра экологии и природопользования
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2020
• Subjects: activesoillayer; borealforest; permafrost; Siberia; stableisotopes; treerings; wildfire
• Online Access: https://iopscience.iop.org/article/10.1088/1748-9326/ab7469; http://elib.sfu-kras.ru/handle/2311/143116; https://doi.org/10.1088/1748-9326/ab7469

Wildfiresareanimportantfactorincontrollingforestecosystemdynamicsacrossthecircumpolar borealzone.Animprovedunderstandingoftheirdirectandindirect,short-tolong-termimpactson vegetationcoverandpermafrost–vegetationcouplingisparticularlyimportanttopredictchangesin carbon,nutrientandwatercyclesunderprojectedclimatewarming.Here,weapplydendrochronologicaltechniquesonamulti-parameterdatasettoreconstructtheeffectofwildfiresontreegrowth andseasonalpermafrostthawdepthinCentralSiberia.Basedonannually-resolvedandabsolutely datedinformationfrom19Gmelinlarch(Larixgmelinii(Rupr.)Rupr.)treesandactivesoillayer thicknessmeasurements,wefindsubstantialstand-leveldie-off,aswellastheremovalofground vegetationandtheorganiclayerfollowingamajorwildfirein1896.Reducedstemgrowthcoincides withincreasedδ13Cinthecelluloseofthesurvivingtreesduringthefirstdecadeafterthewildfire, whenstomatalconductancewasreduced.Thenextsixtosevendecadesarecharacterizedbyincreased permafrostactivesoillayerthickness.Duringthisperiodofpost-wildfireecosystemrecovery, enhancedtreegrowthtogetherwithpositiveδ13Candnegativeδ18Otrendsareindicativeofhigher ratesofphotosynthesisandimprovedwatersupply.Afterwards,athinneractivesoillayerleadsto reducedgrowthbecausetreephysiologicalprocessesbecomelimitedbysummertemperatureand wateravailability.Revealinglong-termeffectsofforestfiresonactivesoillayerthickness,ground vegetationcompositionandtreegrowth,thisstudydemonstratestheimportanceofcomplex vegetation–permafrostinteractionsthatmodifythetrajectoryofpost-fireforestrecoveryacrossmuch ofthecircumpolarborealzone.Tofurtherquantifytheinfluenceofborealwildfiresonlarge-scale carboncycledynamics,futureworkshouldconsiderawiderangeoftreespeciesfromdifferent habitatsinthehigh-northernlatitudes.