Radial growth in Pinus contorta relative to changing climate patterns in British Columbia: Genetic response to annual climate variations, 1973-2005 Sierra Curtis-McLane1, Sally Aitken1 1. Department of Forest Sciences, University of British Columbia,

1
Radial growth in Pinus contorta relative to
changing climate patterns in British Columbia
Genetic response to annual climate variations,
1973-2005Sierra Curtis-McLane1, Sally
Aitken11. Department of Forest Sciences,
University of British Columbia, Vancouver, BC
V6T1Z1 sierracm_at_interchange.ubc.ca
Introduction
Methods
Expected results
The unprecedented rate of climate change that
occurred during the twentieth century is
projected to continue throughout and beyond the
fossil fuel era, provoking concerns regarding how
plant species are and will continue to respond to
new climatic conditions1. Studies regarding how
trees have responded to historic changes in
temperature and precipitation are particularly
critical for predicting how species may migrate
and adapt under future climate change scenarios.
This study will evaluate ring width indices for
Pinus contorta spp. latifolia (lodgepole pine)
throughout its range in British Columbia in order
to examine correlations between growth and
climate trends over the last three decades.
Sampling will take place in 35 year-old
provenance trials, allowing for genetic
comparisons of growth responses for six
populations planted across an environmental
gradient over time2.

• Field sites
• Lodgepole pine common gardens across the species
  range in BC and the southern Yukon

• Climate variable radial growth correlations
• Positive correlation with precipitation of the
  current and previous year
• Positive correlation with spring and summer
  temperature except when threshold temperatures
  exceeded
• Negative correlation with summer heatmoisture
  index when threshold index exceeded.
• Climate-genotype growth interactions
• Greater absolute radial growth in warmer climates
  than colder climates for all populations at all
  sites
• Annual radial growth increasing temporally for
  all populations at all sites
• Population with climate index most similar to
  trial site will have greatest percent increase in
  radial growth over time
• Greater variation in annual radial growth
  increment in populations from species range
  margins, regardless of where planted.

• Objectives
• Assess genotype-environment interactions in
  lodgepole pine populations planted across an
  environmental gradient by examining correlations
  between radial growth and climate variables over
  the last 30 years
• Assess the potential for expansion/contraction
  of the lodgepole pine species range based on
  observed deviations of growth from normalized
  radial increments.

Potential field sites Selected to cover as wide
a climatic and latitudinal range as possible.
Mapped by mean annual temperature (-18 to 12 C).

• Sampling methodology
• take radius cores at breast height
• - 12 trees per provenance
• - 7 provenances per trial site (5
• standard, 1 standard B, 1 local)
• - 15 trial sites
• TOTAL 1,260 tree cores
• Analyses
• mount, sand and crossdate cores3
• perform analyses comparing
• annual growth to climate variables
• within and between-population growth variation
  relative to climate and location
• growth rates at and in populations from the
  species range margins.

8
6
Mean stem area increment (cm2)
4
2
4
5
1
2
3
Site
Genetic growth correlations Hypothetical results
for five fictitious populations (A - E)
reciprocally planted in five fictitious sites (1
5) across a north-south climatic gradient (see
inset map). Arrows represent expected growth
trends over recent decades pink indicates
populations expected to have the greatest percent
increase in radial growth green indicates
populations expected to have the most variation
in growth.
Albreda 52 N
Takhini 60 N
Manning 49 N
Champion 49N
Lodgepole pine in a common garden population
growth differences
References
Acknowledgments

1. Davis, M.B. and Shaw, R.G. (2001) Science 292
   673-679
2. Rehfeldt, G.E. et al. (1999) Ecol. Monogr. 69
   375-407
3. Stokes, M.A. and Smiley, T.L. (1968) U. Chicago
   Press

This project was funded by the BC Forestry
Investment Account through the Forest Genetics
Council of BC.