title: Evolutionary history underlies plant physiological responses to global change since the last glacial maximum.
abstract: Assessing family- and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Here, we used stable carbon isotopes, leaf nitrogen content and stomatal measurements to assess changes in leaf-level physiology in a mixed conifer community that underwent significant changes in composition since the last glacial maximum (LGM) (21 kyr BP). Our results indicate that most plant taxa decreased stomatal conductance and/or maximum photosynthetic capacity in response to changing conditions since the LGM. However, plant families and species differed in the timing and magnitude of these physiological responses, and responses were more similar within families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA.
authors.forename: Katie M
authors.initials: KM
authors.lastname: Becklin
authors.forename: Juliana S
authors.initials: JS
authors.lastname: Medeiros
authors.forename: Kayla R
authors.initials: KR
authors.lastname: Sale
authors.forename: Joy K
authors.initials: JK
authors.lastname: Ward
mesh_terms: D000222:Adaptation, Physiological; D005075:Biological Evolution; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism; D057231:Climate Change; D009584:Nitrogen / Q000378:metabolism; D018515:Plant Leaves / Q000033:anatomy & histology / Q000502:physiology; D018521:Plant Physiological Phenomena; D054046:Plant Stomata / Q000033:anatomy & histology; D064028:Tracheophyta
chemical_list: D002247:Carbon Isotopes; D009584:Nitrogen
keywords: Atmospheric [CO2]; climate change; last glacial maximum; leaf nitrogen content; maximum photosynthetic capacity; packrat middens; stomatal conductance; stomatal index