Aug 29, 2017

Leap‐frog in slow‐motion: divergent responses of tree species and life stages to climatic warming in Great Basin sub‐alpine forests

by
Smithers, Brian V., North, Malcolm P., Millar, Constance I., Latimer, Andrew M.
,
Global Change Biology
  • States that in response to climate warming, subalpine treelines are expected to move up in elevation since treelines are generally controlled by growing season temperature
  • States that where treeline is advancing, dispersal differences and early life stage environmental tolerances are likely to affect how species expand their ranges; species with an establishment advantage will colonize newly available habitat first, potentially excluding species that have slower establishment rates
  • Uses a network of plots across five mountain ranges to describe patterns of upslope elevational range shift for the two dominant Great Basin sub-alpine species, limber pine and Great Basin bristlecone pine
  • Finds that the Great Basin treeline for these species is expanding upslope with a mean vertical elevation shift of 19.1 m since 1950, which is lower than what we might expect based on temperature increases alone
  • Finds that limber pine is successfully “leap-frogging” over bristlecone pine
  • Results indicate the potential for the species composition of treeline to change in response to climate change
  • More broadly, it shows how species differences in dispersal and establishment may result in future communities with very different specific composition