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Title: Global scale environmental control of plant photosynthetic capacity

Photosynthetic capacity, determined by light harvesting and carboxylation reactions, is a key plant trait that determines the rate of photosynthesis; however, in Earth System Models (ESMs) at a reference temperature, it is either a fixed value for a given plant functional type or derived from a linear function of leaf nitrogen content. In this study, we conducted a comprehensive analysis that considered correlations of environmental factors with photosynthetic capacity as determined by maximum carboxylation (Vc,m) rate scaled to 25°C (i.e., Vc,25; μmol CO2·m–2·s–1) and maximum electron transport rate (Jmax) scaled to 25°C (i.e., J25; μmol electron·m–2·s–1) at the global scale. Our results showed that the percentage of variation in observed Vc,25 and J25 explained jointly by the environmental factors (i.e., day length, radiation, temperature, and humidity) were 2–2.5 times and 6–9 times of that explained by area-based leaf nitrogen content, respectively. Environmental factors influenced photosynthetic capacity mainly through photosynthetic nitrogen use efficiency, rather than through leaf nitrogen content. The combination of leaf nitrogen content and environmental factors was able to explain ~56% and ~66% of the variation in Vc,25 and J25 at the global scale, respectively. As a result, our analyses suggest that model projections of plant photosynthetic capacity andmore » hence land–atmosphere exchange under changing climatic conditions could be substantially improved if environmental factors are incorporated into algorithms used to parameterize photosynthetic capacity in ESMs.« less
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [2] ;  [9] ;  [9]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of California, Irvine, CA (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Univ. of Western Sydney, NSW (Australia)
  5. National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  7. Univ. of Minnesota, St. Paul, MN (United States); Univ. of Western Sydney, NSW (Australia)
  8. Colorado State Univ., Fort Collins, CO (United States)
  9. Univ. of California, Irvine, CA (United States)
Publication Date:
OSTI Identifier:
1238734
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Ecological Applications
Additional Journal Information:
Journal Volume: 25; Journal Issue: 8; Journal ID: ISSN 1051-0761
Publisher:
Ecological Society of America
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES