title: Predicting species' tolerance to salinity and alkalinity using distribution data and geochemical modelling: a case study using Australian grasses.
abstract: OBJECTIVE
  Salt tolerance has evolved many times independently in different plant groups. One possible explanation for this pattern is that it builds upon a general suite of stress-tolerance traits. If this is the case, then we might expect a correlation between salt tolerance and other tolerances to different environmental stresses. This association has been hypothesized for salt and alkalinity tolerance. However, a major limitation in investigating large-scale patterns of these tolerances is that lists of known tolerant species are incomplete. This study explores whether species' salt and alkalinity tolerance can be predicted using geochemical modelling for Australian grasses. The correlation between taxa found in conditions of high predicted salinity and alkalinity is then assessed.
  
  
  METHODS
  Extensive occurrence data for Australian grasses is used together with geochemical modelling to predict values of pH and electrical conductivity to which species are exposed in their natural distributions. Using parametric and phylogeny-corrected tests, the geochemical predictions are evaluated using a list of known halophytes as a control, and it is determined whether taxa that occur in conditions of high predicted salinity are also found in conditions of high predicted alkalinity.
  
  
  RESULTS
  It is shown that genera containing known halophytes have higher predicted salinity conditions than those not containing known halophytes. Additionally, taxa occurring in high predicted salinity tend to also occur in high predicted alkalinity.
  
  
  CONCLUSIONS
  Geochemical modelling using species' occurrence data is a potentially useful approach to predict species' relative natural tolerance to challenging environmental conditions. The findings also demonstrate a correlation between salinity tolerance and alkalinity tolerance. Further investigations can consider the phylogenetic distribution of specific traits involved in these ecophysiological strategies, ideally by incorporating more complete, finer-scale geochemical information, as well as laboratory experiments.
authors.affiliation: Centre for Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia and CSIRO Land and Water, GPO Box 1666, Canberra, Australian Capital Territory 2601, Australia C.H.SaslisLagoudakis@gmail.com.
authors.forename: C Haris
authors.initials: CH
authors.lastname: Saslis-Lagoudakis
authors.affiliation: Centre for Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia and CSIRO Land and Water, GPO Box 1666, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Xia
authors.initials: X
authors.lastname: Hua
authors.affiliation: Centre for Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia and CSIRO Land and Water, GPO Box 1666, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bui
authors.affiliation: Centre for Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia and CSIRO Land and Water, GPO Box 1666, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Camile
authors.initials: C
authors.lastname: Moray
authors.affiliation: Centre for Macroevolution and Macroecology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia and CSIRO Land and Water, GPO Box 1666, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Lindell
authors.initials: L
authors.lastname: Bromham
mesh_terms: D001315:Australia; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D063148:Plant Dispersal; D006109:Poaceae / Q000502:physiology*; D054712:Salinity; D055049:Salt Tolerance; D055051:Salt-Tolerant Plants / Q000502:physiology*; D012965:Sodium Chloride / Q000378:metabolism
chemical_list: D012965:Sodium Chloride
keywords: Poaceae; alkalinity tolerance; geochemical modelling; grasses; halophytes; macroevolution; phylogeny; salt tolerance; stress resistance syndrome