Tree physiological monitoring of the 2018 larch budmoth outbreak: preference for leaf recovery and carbon storage over stem wood formation in Larix decidua

Описание

Тип публикации: статья из журнала

Год издания: 2020

Идентификатор DOI: 10.1093/treephys/tpaa087

Ключевые слова: zeiraphera griseana, cell wall thickness, european alps, insect outbreak, non-structural carbohydrates (nsc), stable isotopes, tree rings, wood formation

Аннотация: Insect defoliation impacts forest productivity worldwide, highlighting the relevance of plant-insect interactions. The larch budmoth (Zeiraphera griseana Hübner) is one of the most extensively studied defoliators, where numerous tree ring-based analyses on its host (Larix decidua Mill.) have aided in identifying outbreak dynamics oПоказать полностьюver the past millennia. Yet, outbreaks have been widely absent after the early 1980s, and little is known about the in situ tree physiological responses and the allocation of carbon resources during and after defoliation. In summer 2018, we tracked an ongoing larch budmoth outbreak in a well-studied larch forest in the Swiss Alps. We performed biweekly monitoring on an affected and unaffected site using a unique combination of xylogenesis observations, measurements of non-structural carbohydrates, isotopic analysis of needle assimilates and ground-based and remote-sensed leaf trait observations. The budmoth induced a defoliation that lasted 40 days and could be detected by satellite observations. Soluble sugars significantly decreased in needles and stem phloem of the defoliated trees, while starch levels remained stable in the stem and root xylem compared to the control. Carbon and oxygen isotope ratios in needle assimilates indicated that neither photosynthetic assimilation rates nor stomatal conductance was different between sites before, during and after the outbreak. Defoliated trees ceased cell wall thickening 17 days earlier than unaffected trees, showing the earliest halt of ring formation recorded from 2007 untill 2013 and causing significant thinner cell walls, particularly in the latewood. No significant differences were found for cell enlargement rates and ring width. Our study revealed that an outbreak causes a downregulation of cell wall thickening first, while no starch is mobilized or leaf physiology is adjusted to compensate for the reduced carbon source due to defoliation. Our observations suggest that affected larch trees prioritize leaf recovery and carbon storage over wood biomass development. © The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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Издание

Журнал: Tree physiology

Выпуск журнала: Vol. 40, Is. 12

Номера страниц: 1697-1711

ISSN журнала: 17584469

Издатель: NLM (Medline)

Персоны

  • Peters Richard L. (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland; Univ Ghent, Fac Biosci Engn, Dept Plants & Crops, Lab Plant Ecol, Coupure Links 653, B-9000 Ghent, Belgium)
  • Miranda Jose Carlos (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland; Univ Politecn Madrid, Sch Forestry Engn, Forest Genet & Ecophysiol Res Grp, Ciudad Univ S-N, Madrid 28040, Spain)
  • Schoenbeck Leonie (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • Nievergelt Daniel (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • Fonti Marina (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland; Siberian Fed Univ, Inst Ecol & Geog, 79 Svobodny Pr, Krasnoyarsk 660041, Russia)
  • Saurer Matthias (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • Stritih Ana (Swiss Fed Inst Technol, Inst Landscape & Spatial Dev, Planning Landscape & Urban Syst PLUS, Stefano Franscini Pl 5, CH-8093 Zurich, Switzerland; WSL Inst Snow & Avalanche Res SLF, Fluelastr 11, CH-7260 Davos, Switzerland)
  • Fonti Patrick (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • Wermelinger Beat (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Hlth & Biot Interact, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • von Arx Georg (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)
  • Lehmann Marco M. (Swiss Fed Res Inst Forest Snow & Landscape Res WS, Forest Dynam, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland)