Quantitative wood anatomy and stable carbon isotopes indicate pronounced drought exposure of Scots pine when growing at the forest edge

Frontiers in Forests and Global Change

Forests and Global Change

Jelena Lange¹  Annette Menzel²  Kerstin Treydte³  Patrick Fonti³  Marina Fonti³  Andreas Rigling⁴  Arthur Gessler⁵  Georg von Arx⁶  Romy Rehschuh⁷  Allan Buras⁸ 

[1] Department of Physical Geography and Geoecology, Charles University, Prague, Czechia;Ecoclimatology, TU Munich, Munich, Germany;Institute for Advanced Study, Technical University of Munich, Garching, Germany;Forest Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland;Forest Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland;Forest Ecology, Institute of Terrestrial Ecosystems, ETH Zurich, Zürich, Switzerland;Forest Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland;Institute of Terrestrial Ecosystems, ETH Zurich, Zürich, Switzerland;Forest Dynamics, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland;Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland;Institute of General Ecology and Environmental Protection, Chair of Biodiversity and Nature Conservation, TU Dresden, Dresden, Germany;Land Surface-Atmosphere Interactions, TU Munich, Munich, Germany;Ecoclimatology, TU Munich, Munich, Germany;

关键词: tree rings;    hotter drought;    forest microclimate;    tree physiology;    dieback;    Pinus sylvestris;   

DOI  :  10.3389/ffgc.2023.1233052

 received in 2023-06-02, accepted in 2023-09-28,  发布年份 2023

来源: Frontiers

【 摘 要 】

Climate change poses a major threat to global forest ecosystems. In particular, rising temperatures and prolonged drought spells have led to increased rates of forest decline and dieback in recent decades. Under this framework, forest edges are particularly prone to drought-induced decline since they are characterized by warmer and drier micro-climatic conditions amplifying impacts of drought on tree growth and survival. Previous research indicated that forest-edge Scots pine trees have a higher growth sensitivity to water availability compared to the forest interior with consequent reduction of canopy greenness (remotely sensed NDVI) and higher mortality rates. Yet, the underlying physiological mechanisms remain largely unknown. Here, we address this knowledge gap by comparing stable carbon isotope signatures and wood anatomical traits in annual rings of trees growing at the forest edge vs. the forest interior and between trees that either survived or died during the extreme drought of 2015. Our analyses suggest that the exposure to drought of forest-edge Scots pine likely results in a reduction of stomatal conductance, as reflected by a higher δ13C of stem wood, thinner cell walls, and lower mean ring density. Moreover, we found dead trees to feature larger mean hydraulic lumen diameters and a lower cell-wall reinforcement, indicating a higher risk to suffer from cavitation. In conclusion, the typically drier micro-climatic conditions at the forest edge seem to have triggered a larger reduction of stomatal conductance of Scots pine trees, resulting in a lower carbon availability and significantly altered wood anatomical properties under an increasingly drier climate.

【 授权许可】

Unknown   
Copyright © 2023 Buras, Rehschuh, Fonti, Lange, Fonti, Menzel, Gessler, Rigling, Treydte and von Arx.