Table II. Ecophysiological, morphological, and life history traits that vary as a function of climate and/or atmospheric CO₂ concentration, or proxies for climate such as elevation and latitude.

The references listed here are by no means exhaustive.

Trait	Reference
Ecophysiology
Water use efficiency	Ward and Kelly (2004); Ainsworth and Long (2005); Edwards et al. (2012)
Photosynthesis	Ainsworth and Long (2005); Nakamura et al. (2011); Edwards et al. (2012); Leakey and Lau (2012); Ziska et al. (2012)
Chlorophyll fluorescence	Edwards et al. (2012)
Stomatal conductance	Ward and Kelly (2004); Ainsworth and Long (2005); Long et al. (2006)
Carbon-nitrogen ratio	Nakamura et al. (2011); Robinson et al. (2012)
Chlorophyll content of leaves	Nakamura et al. (2011)
Morphology
Leaf thickness, area, length, width	Etterson and Shaw (2001); Etterson (2004); Ainsworth and Long (2005); Byars et al. (2007); Edwards et al. (2012)
Trichome density	Robinson et al. (2012)
Stomatal density	Ward and Kelly (2004)
Root-shoot ratio	Nakamura et al. (2011); Edwards et al. (2012)
Plant biomass	Edwards et al. (2012); Leakey and Lau (2012); Robinson et al. (2012)
Secondary metabolites and chemical defenses against herbivores	Robinson et al. (2012)
Physical defenses against herbivores	Robinson et al. (2012)
Floral traits (e.g., petal and organ size, reflectance)	Edwards et al. (2012); Lacey et al. (2012)
Cold/freezing tolerance	Howe et al. (2003); Savolainen et al. (2007); Zhen and Ungerer (2008)
Phenology
Seed dormancy, germination, and seedling establishment	Donohue et al. (2010)
Bud set phenology	Howe et al. (2003); Savolainen et al. (2007)
Commencement and cessation of growth	Howe et al. (2003); Savolainen et al. (2007)
Reproductive phenology	Franks et al. (2007); Springer and Ward (2007); Inouye (2008); Anderson et al. (2012)