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EcoClimLab / growth_phenology

Cameron Dow's growth phenology project
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try tree-ring analysis over more months #57

Closed teixeirak closed 3 years ago

teixeirak commented 3 years ago

@camerondow35 , it would be valuable and informative to check whether we see any additional signals of interest in the tree-ring analysis if we extend the time period back to previous spring (at least April, better Jan) and out to Oct (while we're at it; #43 ).

The motivation is in the following draft paragraph of discussion: "Our finding that interannual variation in woody growth is more strongly linked to conditions during the peak growing season than to growing season length aligns with parallel findings for NEE.9,10 However, there is also a disconnect between the woody growth responses to spring temperatures observed here and parallel studies on NEE implying that annual C sequestration increases – at least modestly – with spring temperatures2 or with the length of the carbon uptake period9,10. We show that the extra C does not go into woody growth, raising the question of where this C goes. There are two main possibilities, which hold contrasting implications for the response of forest C balance to rising spring temperatures. First, C that is fixed in late summer or fall may be used for woody growth that is not apparent from diameter measurements in the current year: either used for thickening of cell walls, a process that lags behind stem expansion29, or saved within trees as non-structural carbohydrates and used towards growth the following year30,31. Tree-ring evidence from SCBI suggests that both processes may influence the climate sensitivity of annual woody growth, but that this dynamic is complex and unlikely to result in substantial additional growth in the following year.24 "

By running the proposed analysis, we can test whether previous spring temperatures have any effect. From Ryan's paper, I don't think they will. Ruling that out would reduce the remaining uncertainty.

teixeirak commented 3 years ago

Note: I'd be surprised if we end up wanting to show this figure in the main article, although we may consider it for the extended data.

camerondow35 commented 3 years ago

image

Interesting. While it's not as pronounced as the summer effect, i'd say there is definitely a positive effect of previous May tmax for ring porous species. Also that positive correlation with current year october is still interesting. Lots to think about here!

camerondow35 commented 3 years ago

The differences between wood type are also cool...

ValentineHerr commented 3 years ago

Popping here to suggest something that will give you more work (so feel free to ignore): the left panel is harder to read because there is a lot more rows. I wonder if it would be worth: a) splitting it in half and have 3 panels... or b) making it twice a long...

If you opt for that option b), you could use the white space under the second panel for the legend (which would then need to be the same for both panels - not currently the case).

Let me know if you decide to do something and need help.

teixeirak commented 3 years ago

Wow, @camerondow35 , that's interesting!

The previous summer responses are similar to what we showed in Helcoski et al, but of course for many more sites.

The previous spring effect in the ring-porous species does look quite consistent.... and that October effect is way too consistent to be some strange artifact. I want to run these past some of our coauthors again.

teixeirak commented 3 years ago

@ValentineHerr , I like two panels because they're split into ring and diffuse porous species. I know the squished boxes on the ring-porous species are not ideal (but they'll probably just be vertically squished.... don't think we'll show all months in the main paper).

We definitely need to standardize the colorbars though. I'll leave it up to @camerondow35 to let you know if he needs help on that.

The plan is also to fix it up (currently doing manually in ppt) to create the fig in the paper. Of course, with your coding skills you could automate all that, but doing it manually works.

teixeirak commented 3 years ago

Based on email conversation with Neil, Grant, and Justin, the strong consensus is to leave October out of this paper. The previous year also is not very relevant.

Please keep a copy of this figure, though. I do want to include a statement about lack of significant influence of previous spring temperatures.

teixeirak commented 3 years ago

@camerondow35 , a reminder to please re-make these figures.