Premium
Photosynthetic pathway and ecological adaptation explain stomatal trait diversity amongst grasses
Author(s) -
Taylor S. H.,
Franks P. J.,
Hulme S. P.,
Spriggs E.,
Christin P. A.,
Edwards E. J.,
Woodward F. I.,
Osborne C. P.
Publication year - 2012
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2011.03935.x
Subject(s) - stomatal conductance , photosynthesis , biology , stomatal density , ecophysiology , interspecific competition , ecology , transpiration , habitat , botany , adaptation (eye) , neuroscience
Summary• The evolution of C 4 photosynthesis in plants has allowed the maintenance of high CO 2 assimilation rates despite lower stomatal conductances. This underpins the greater water‐use efficiency in C 4 species and their tendency to occupy drier, more seasonal environments than their C 3 relatives. • The basis of interspecific variation in maximum stomatal conductance to water ( g max ), as defined by stomatal density and size, was investigated in a common‐environment screening experiment. Stomatal traits were measured in 28 species from seven grass lineages, and comparative methods were used to test for predicted effects of C 3 and C 4 photosynthesis, annual precipitation and habitat wetness on g max . • Novel results were as follows: significant phylogenetic patterns exist in g max and its determinants, stomatal size and stomatal density; C 4 species consistently have lower g max than their C 3 relatives, associated with a shift towards smaller stomata at a given density. A direct relationship between g max and precipitation was not supported. However, we confirmed associations between C 4 photosynthesis and lower precipitation, and showed steeper stomatal size–density relationships and higher g max in wetter habitats. • The observed relationships between stomatal patterning, photosynthetic pathway and habitat provide a clear example of the interplay between anatomical traits, physiological innovation and ecological adaptation in plants.