An introduction to the AdapTree project for the general public

Motivation

    • Forests provide thousands of jobs and billions of dollars worth of employment income, tax revenue, and economic activity to Canadians. In addition, they provide a broad range of ecosystem services including water, recreation, biodiversity, and carbon sequestration.
    • All of these benefits depend on healthy forests. Climate change is threatening forest health.Tree populations, adapted to specific climatic areas, are becoming mismatched  as climate changes.
    • The change is happening too fast for tree populations to adjust through selection of the fittest and migration as they have done over the past millennia.
    • In BC and Alberta, about 150 million spruce and lodgepole pine trees are planted annually by forest companies and provincial agencies. Typically, foresters collect and use seed locally for this planting. In the past, the resulting seedlings were well-adapted to the locations in which they were planted.  However, a rapidly changing climate threatens forest health and productivity, and is predicted to result in widespread maladaptation of trees.

SOME OF THE RECENT AFFECTS OF CLIMATE CHANGE ON OUR FORESTS

Dothistroma, a pine needle blight, is causing defoliation, mortality and plantation failures in parts of the province were it was previously rare. Spruce and aspen dieback, occuring in our interior forests, is partly attributed to the presence of drier conditions resulting from the combination of decreased precipitation and increased temperatures. The Mountain Pine Beetle epidemic has been exasperated by the occurrence of several consecutive winters with warmer temperatures.

SUMMARY

  • This project is a large-scale effort to apply state-of-the art genomics and climate-mapping technologies to this problem of mismatch.
  • The target species are the commercially important interior spruce and lodgepole pine.
  • We will match existing and naturally occurring genetic populations of these two species with the appropriate climate areas under climate change.
  • Information generated will help the provincial forestry agencies in BC and Alberta structure their policy for tree planting.
  • With such knowledge-based policy, foresters working to replant harvested areas will be able to make informed decisions regarding seed source.
  • This will improve the long-term health of public forests and have an economic impact on the benefits that flow from these forests (hundreds of millions of dollars annually).

Graph based on: Wang, T., Hamann, A., Yanchuk, A., O’Neill, G. A. and Aitken, S. N., 2006. Use of response functions in selecting lodgepole pine populations for future climate. Global Change Biology. (12: 2404–2416).

RESEARCH GOALS

  • Identify lodgepole pine and spruce genes that are key to health and productivity under different temperature and moisture regimes
  • Evaluate the diversity of BC and Alberta’s natural lodgepole pine and spruce populations and reforestation seedlots in relation to future climates
  • Develop policy recommendations to re-allocate seed used for reforestation so it will better match future climates
  • Evaluate ecological, economic, social, and policy implications of these results for forest-dependent communities and ecosystems

FINDING GENES THAT MATTER: THE STEPS INVOLVED

Step 1

  • Plants were subjected to various treatments (heat, cold, drought, long and short days).
  • Their RNA was isolated from tissue samples. RNA is the transcribed DNA or ‘transcriptome’. This reflects the genes being actively expressed in these stressful environments.
  • This results in some 10,000 candidate genes, or genes which are likely candidates to be involved in adaptation
  • These genes are sequenced, that is, their genetic code is determined in detail (e.g., AAATCGCAC…)
  • re-sequence these candidate genes for a large set of plants (>250 seed sources of pine and >250 of spruce)
  • The exact sequence of these genes will show some variation among seed sources. Variation for a single nucleotide (code letter) is called SNP (single nucleotide polymorphism).
  • After taking a small amount of tissue for genotyping, continue to grow, observe and measure these plants (or phenotypes)
  • find candidate adaptive SNPs by comparing phenotypes and genotypes. This is done by bio-informaticians using powerful computers

 

  • match the variation in candidate SNPs with adaptive variation
  • grow all seed sources in controlled environments, representing climates with mean annual temperatures of 1, 6 and 11 °C
  • analyse the genotype (analyzed DNA) and phenotype (observed adaptive traits) of the same individual
  • find which part of the genetic variation is meaningful for adaptation to climate
Phenotyping: Large numbers of plants are being phenotyped in six environments including a greenhouse, out door nursery beds, and 4 controlled environment growth chambers. Observed adaptive traits are: growth, bud break, bud set, cold hardiness, drought hardiness, carbon isotope composition.

WIDER CONTEXT: Socio-economic research

This research raises a number of community-level economic, social and value-based questions.

  1. Are rural community residents aware of the local risks of global climate change?
  2. Are certain forest adaptation strategies more acceptable than others?
  3. What are the contextual factors and attributes of an adaptation strategy that makes it acceptable or unacceptable?

We will conduct a multiple case study to address the research questions in four communities (two in BC and two in Alberta). Each of the communities will be located in interior spruce or lodgepole pine dominated forest ecosystems. In addition to community-specific contextual research and economic impact modeling, we will conduct focus groups with participants representing the forest industry, government, economic, education, health, social services, First Nations and others. This investigation will be supplemented by a survey of forest-dependent community leaders (Mayors and members of Council) in BC and Alberta.

WIDER CONTEXT: Policy research

  • An in-depth policy analysis will clarify existing policy and possible obstacles to change.
  • A better understanding can provide policy makers and the public with the tools to actively participate in decision making.
  • We develop realistic and cost-effective strategies for assisted migration of forest trees. Carefully considering uncertainty in climate change projections, and understanding how species populations are genetically adapted to climatic environments are key ingredients.
  • The ultimate outcome of this project is policy changes in seed source selection to help mitigate the effects of climate change on our forests.

SOME MEMBERS OF OUR RESEARCH TEAM

December 2011

Group Photo, December 2011