Genetic research helps forest scientists determine which trees can survive global warming

Research will inform forest planning efforts

Staff Report

FRISCO — Spanish scientists say they can use genetic data to help determine which pine trees are most vulnerable to climate change, and which trees might be able to thrive in a warmer world. Their findings, published inGENETICS, could help forestry managers decide where to focus reforestation efforts and guide the choice of tree stocks.

The study focused on maritime pines, which grows widely in southwestern Europe and parts of northern Africa. But the tree’s important economic value and ecological roles in the region may be at risk as the changing climate threatens the more vulnerable forests and the productivity of commercial plantations.

The modeling approach used by planners doesn’t include two major factors that influence a forest’s fate: genetics and evolution. Genetic differences between tree populations mean that forests vary in how well they cope with warmer, drier conditions.

Ongoing evolution of trees also influences the prevalence of these genetic differences; for example, trees with gene variants allowing them to withstand higher temperatures will become increasingly common as the climate changes.

“These genetic effects are not included in forest range shift models, but we know they can completely change the resulting predictions. Our goal was to identify such effects in a way that can be readily incorporated into the forecasts,” said study leader Santiago González-Martínez, from the Forest Research Centre of Spain’s Institute for Agricultural Research.

After laying out the genetic data, the researchers then looked for evidence that these variants are important for the trees’ fitness by planting seedlings from 19 of the locations together in a dry part of Spain, at the extreme end of the species’ climatic range. This allowed the team to compare how well genetically different trees would survive under similar conditions. After five years, the seedlings carrying gene variants predicted to be beneficial in the local climate indeed tended to have higher survival rates.

These results demonstrate the feasibility of this relatively fast approach of finding and confirming genetic variants associated with climate.

“Now that we have shown that the method works well, we are planning similar experiments on a bigger scale, with more test sites, looking at more genes, and different traits. For example, the single biggest climate change threat to pine forests is the increased frequency of wildfires, so we’re searching for variants that affect fire tolerance,” said González-Martínez.