title: Substantial variation in leaf senescence times among 1360 temperate woody plant species: implications for phenology and ecosystem processes.
abstract: OBJECTIVE
  Autumn leaf senescence marks the end of the growing season in temperate ecosystems. Its timing influences a number of ecosystem processes, including carbon, water and nutrient cycling. Climate change is altering leaf senescence phenology and, as those changes continue, it will affect individual woody plants, species and ecosystems. In contrast to spring leaf out times, however, leaf senescence times remain relatively understudied. Variation in the phenology of leaf senescence among species and locations is still poorly understood.
  
  
  METHODS
  Leaf senescence phenology of 1360 deciduous plant species at six temperate botanical gardens in Asia, North America and Europe was recorded in 2012 and 2013. This large data set was used to explore ecological and phylogenetic factors associated with variation in leaf senescence.
  
  
  RESULTS
  Leaf senescence dates among species varied by 3 months on average across the six locations. Plant species tended to undergo leaf senescence in the same order in the autumns of both years at each location, but the order of senescence was only weakly correlated across sites. Leaf senescence times were not related to spring leaf out times, were not evolutionarily conserved and were only minimally influenced by growth habit, wood anatomy and percentage colour change or leaf drop. These weak patterns of leaf senescence timing contrast with much stronger leaf out patterns from a previous study.
  
  
  CONCLUSIONS
  The results suggest that, in contrast to the broader temperature effects that determine leaf out times, leaf senescence times are probably determined by a larger or different suite of local environmental effects, including temperature, soil moisture, frost and wind. Determining the importance of these factors for a wide range of species represents the next challenge for understanding how climate change is affecting the end of the growing season and associated ecosystem processes.
authors: Department of Biology, Carleton University, Ottawa, ON, Canada.
authors: Zoe A
authors: ZA
authors: Panchen
authors: Biology Department, Boston University, Boston, MA 02215, USA, primack@bu.edu.
authors: Richard B
authors: RB
authors: Primack
authors: Biology Department, Boston University, Boston, MA 02215, USA.
authors: Amanda S
authors: AS
authors: Gallinat
authors: Botanic Garden and Botanical Museum Berlin-Dahlem, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.
authors: Birgit
authors: B
authors: Nordt
authors: Botanic Garden and Botanical Museum Berlin-Dahlem, Dahlem Centre of Plant Sciences, Freie Universität Berlin, Berlin, Germany.
authors: Albert-Dieter
authors: AD
authors: Stevens
authors: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing, China and.
authors: Yanjun
authors: Y
authors: Du
authors: Morton Arboretum, Lisle, IL 60532, USA.
authors: Robert
authors: R
authors: Fahey
mesh_terms: D001208:Asia; D002244:Carbon / Q000378:metabolism; D016922:Cellular Senescence; D057231:Climate Change; D017753:Ecosystem; D005060:Europe; D009656:North America; D010641:Phenotype; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology*; D012621:Seasons; D013045:Species Specificity; D013696:Temperature; D013997:Time Factors; D014197:Trees / Q000235:genetics / Q000502:physiology*
chemical_list: D002244:Carbon
keywords: Leaf senescence; botanical gardens; climate change; deciduous woody plants; growing season; phenology; phylogeny; shrubs; trees; vines