Questions we're addressing - vvandermeersch/climategrowthshifts GitHub Wiki

Overarching question

  • How does climate affect tree growth (and maybe: has this changed in recent years) across western North America (minus Canada mostly) and beyond maybe?

Related questions

  • From May 2026: Do trees that have shocks grow less in non-shock years than non-shocky-trees?
  • Effect of longer GSL vs warmer? (Or is this better to focus this on east coast trees where seasons are longer but not so much drier?)
  • How do VPD and soil moisture interact to affect tree growth?
  • Look for shift over time (after 2010)? Probably subset down to the few species where you have a lot of later data and/or focus on MORA.
  • Look at species variation in climate responses (and short and long-term responses?) and what predicts it? For example, range distribution (climate etc.), phylogeny, some simple traits (wood stuff, roots, height, generation time). Does length scale for long-term contribution make sense for the traits?
  • What explains more variation? Species attributes in the model or climate responses (by species)? As in: do species responses climate to tell most of the story? (It would be interesting also to see if traits correlate more with species response to climate or GPs of species, if we could get species GPs.)
  • Maybe build a growth climate niche from the model -- what are optimal conditions? Could put hypervolumes on phylogeny ... Possibly use for forecasting to see which will move well outside optimum.
  • Forecast from the model (e.g., 10% drier, 10% warmer), what will change?
  • Maybe also try to forecast the C implications from the model? For example, we could imagine scenarios where we look at how much C is gained if the world just warms versus how much is gained versus warmth, drought and more VPD ... we could also maybe pinpoint which tree could lead to the most C loss if it went extinct or such. (We'd need to leverage FIA data or such though to guess at density so this would be harder.)

Des etapes...

Also known as separate papers

  1. How do tree rings respond to climate? How does this vary across species ($\rho, \kappa$ and climate responses)? Forecast from this basic shifts in climate (+1 C and -10 % soil moisture etc.) and see which species is affected the most ... and try to extrapolate this to carbon, sort of (attention!).
  2. Build a growth climate niche from the model and add traits to predict
  3. Changes over time (2010 etc.) ... solve divergence problem while we're at
  4. Legacies!

2-4 are see how it goes based on etape 1! Lizzie is excited by legacies sooner.

Maybe we also address

  • How does effects of climate compare to neighborhood effects (for MORA probably)?
  • Is there evidence for differing climate sensitivity across species ranges?

Someday ideas

  • Merge FIA pest data with FIA stand data and tree cores from FIA to test how competition versus pests (and climate) affect growth (Jonathan's requested idea)

MORA-specific

  • How does climate affect tree growth across MORA? (Victor suggests! Compare pre-1980 and post-1980.)