DOI: 10.1111/gcb.14805
论文题名: Surprising lack of sensitivity of biochemical limitation of photosynthesis of nine tree species to open-air experimental warming and reduced rainfall in a southern boreal forest
作者: Stefanski A. ; Bermudez R. ; Sendall K.M. ; Montgomery R.A. ; Reich P.B.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2020
卷: 26, 期: 2 语种: 英语
英文关键词: B4WarmED
; biochemical limitation
; boreal forest
; experimental warming
; J max
; rainfall reduction
; V cmax
Scopus关键词: ambient air
; boreal forest
; numerical model
; photosynthesis
; rainfall
; sensitivity analysis
; soil moisture
; temperature effect
; Minnesota
; United States
英文摘要: Photosynthetic biochemical limitation parameters (i.e., Vcmax, Jmax and Jmax:Vcmax ratio) are sensitive to temperature and water availability, but whether these parameters in cold climate species at biome ecotones are positively or negatively influenced by projected changes in global temperature and water availability remains uncertain. Prior exploration of this question has largely involved greenhouse based short-term manipulative studies with mixed results in terms of direction and magnitude of responses. To address this question in a more realistic context, we examined the effects of increased temperature and rainfall reduction on the biochemical limitations of photosynthesis using a long-term chamber-less manipulative experiment located in northern Minnesota, USA. Nine tree species from the boreal-temperate ecotone were grown in natural neighborhoods under ambient and elevated (+3.4°C) growing season temperatures and ambient or reduced (≈40% of rainfall removed) summer rainfall. Apparent rubisco carboxylation and RuBP regeneration standardized to 25°C (Vcmax25°C and Jmax25°C, respectively) were estimated based on ACi curves measured in situ over three growing seasons. Our primary objective was to test whether species would downregulate Vcmax25°C and Jmax25°C in response to warming and reduced rainfall, with such responses expected to be greatest in species with the coldest and most humid native ranges, respectively. These hypotheses were not supported, as there were no overall main treatment effects on Vcmax25°C or Jmax25°C (p >.14). However, Jmax:Vcmax ratio decreased significantly with warming (p =.0178), whereas interactions between warming and rainfall reduction on the Jmax25°C to Vcmax25°C ratio were not significant. The insensitivity of photosynthetic parameters to warming contrasts with many prior studies done under larger temperature differentials and often fixed daytime temperatures. In sum, plants growing in relatively realistic conditions under naturally varying temperatures and soil moisture levels were remarkably insensitive in terms of their Jmax25°C and Vcmax25°C when grown at elevated temperatures, reduced rainfall, or both combined. © 2019 John Wiley & Sons Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159936
Appears in Collections: 气候变化与战略
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作者单位: Department of Forest Resources, University of Minnesota, St. Paul, MN, United States; Department of Biology, Behavioral Neuroscience, and Health Sciences, Rider University, Lawrenceville, NJ, United States; Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
Recommended Citation:
Stefanski A.,Bermudez R.,Sendall K.M.,et al. Surprising lack of sensitivity of biochemical limitation of photosynthesis of nine tree species to open-air experimental warming and reduced rainfall in a southern boreal forest[J]. Global Change Biology,2020-01-01,26(2)