can we get a CAM in here?

[rgknox]

As a notice to users, currently we only support C3/C4 photosynthetic pathways in FATES.

As a question to the community, is there interest in adding the CAM pathway?

[jkshuman]

I think it is a good idea. There are some interesting dynamics of hydraulic redistribution via the difference between CAM systems and C3/C4, and it is kind of emerging line of research. Though I do not know as much about our ability to capture hydraulic redistribution. For instance this paper: Yu and Foster. 2016. "Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM)" Oecologia. 2016 Apr;180(4):1113-25. doi: 10.1007/s00442-015-3518-9

Abstract: Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

[alistairrogers]

I agree. Lots of epiphytes are CAM. A

From: jkshuman notifications@github.com Sent: Monday, December 17, 2018 5:21 PM To: NGEET/fates fates@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

I think it is a good idea. There are some interesting dynamics of hydraulic redistribution via the difference between CAM systems and C3/C4, and it is kind of emerging line of research. Though I do not know as much about our ability to capture hydraulic redistribution. For instance this paper: "Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM)" Oecologia. 2016 Apr;180(4):1113-25. doi: 10.1007/s00442-015-3518-9

Abstract: Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

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[rosiealice]

But do we have a valid CAM photosynthesis model?

On Mon, Dec 17, 2018, 10:27 PM alistairrogers <notifications@github.com wrote:

I agree. Lots of epiphytes are CAM. A

From: jkshuman notifications@github.com Sent: Monday, December 17, 2018 5:21 PM To: NGEET/fates fates@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

I think it is a good idea. There are some interesting dynamics of hydraulic redistribution via the difference between CAM systems and C3/C4, and it is kind of emerging line of research. Though I do not know as much about our ability to capture hydraulic redistribution. For instance this paper: "Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM)" Oecologia. 2016 Apr;180(4):1113-25. doi: 10.1007/s00442-015-3518-9

Abstract: Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

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[bpbond]

Unasked-for $0.02: I would suggest that it's not enough to say that many plants are CAM, or that there's interesting CAM research that could be done, therefore let's put this in.

IMO the bar for new features should be higher than that because any new code is a nontrivial resource investment: the science approach has to be researched (per @rosiealice 's comment), parameter files changed, code implemented, debugged, and characterized; and then, crucially, it has to be maintained forever.

Anyway, just a thought for the FATES team's consideration. I'm a fan of ruthlessly prioritizing :)

[alistairrogers]

100% agree with you Ben – but it would be cool, when someone has time. A

From: Ben Bond-Lamberty notifications@github.com Reply-To: NGEET/fates reply@reply.github.com Date: Tuesday, December 18, 2018 at 8:12 AM To: NGEET/fates fates@noreply.github.com Cc: Alistair Rogers arogers@bnl.gov, Comment comment@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

Unasked-for $0.02: I would suggest that it's not enough to say that many plants are CAM, or that there's interesting CAM research that could be done, therefore let's put this in.

IMO the bar for new features should be higher than that because any new code is a nontrivial resource investment: the science approach has to be researched (per @rosiealicehttps://github.com/rosiealice 's comment), parameter files changes, code implemented, debugged, and characterized; and then, crucially, it has to be maintained forever.

Anyway, just a thought for the FATES team's consideration. I'm a fan of ruthlessly prioritizing :)

— You are receiving this because you commented. Reply to this email directly, view it on GitHubhttps://github.com/NGEET/fates/issues/449#issuecomment-448216287, or mute the threadhttps://github.com/notifications/unsubscribe-auth/ANTfrcajOVzccSs-GHCJbE5y92gZ7cfIks5u6OnCgaJpZM4ZXOcF.

[macaranga]

From farther afield…. It is probably worth noting that there are almost no CAM trees (a few Clusia are small trees and hemiepiphytes and have been shown to be CAM), so if you don’t have epiphytes in your model, it is unclear why you would want CAM physiology.

Stuart

From: alistairrogers notifications@github.com Reply-To: NGEET/fates reply@reply.github.com Date: Tuesday, December 18, 2018 at 8:55 AM To: NGEET/fates fates@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

100% agree with you Ben – but it would be cool, when someone has time. A

From: Ben Bond-Lamberty notifications@github.com Reply-To: NGEET/fates reply@reply.github.com Date: Tuesday, December 18, 2018 at 8:12 AM To: NGEET/fates fates@noreply.github.com Cc: Alistair Rogers arogers@bnl.gov, Comment comment@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

Unasked-for $0.02: I would suggest that it's not enough to say that many plants are CAM, or that there's interesting CAM research that could be done, therefore let's put this in.

IMO the bar for new features should be higher than that because any new code is a nontrivial resource investment: the science approach has to be researched (per @rosiealicehttps://github.com/rosiealice 's comment), parameter files changes, code implemented, debugged, and characterized; and then, crucially, it has to be maintained forever.

Anyway, just a thought for the FATES team's consideration. I'm a fan of ruthlessly prioritizing :)

— You are receiving this because you commented. Reply to this email directly, view it on GitHubhttps://github.com/NGEET/fates/issues/449#issuecomment-448216287, or mute the threadhttps://github.com/notifications/unsubscribe-auth/ANTfrcajOVzccSs-GHCJbE5y92gZ7cfIks5u6OnCgaJpZM4ZXOcF.

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[dlebauer]

if you don’t have epiphytes in your model, it is unclear why you would want CAM physiology.

Chiming in from Tucson, I'll note that Saguaro 🌵 and almost all cacti, along with agricultural crops agave and pineapple are CAM. Notably, CAM is highly water use efficient because carbon uptake (night) and assimilation (day) are asynchronous - this poses an additional challenge to both measurement and modeling.

[walkeranthonyp]

I'm not familiar with one but there must be something out there?

Not sure this is a high priority though.

On Tue, 18 Dec 2018, 03:06 Rosie Fisher, notifications@github.com wrote:

But do we have a valid CAM photosynthesis model?

On Mon, Dec 17, 2018, 10:27 PM alistairrogers <notifications@github.com wrote:

I agree. Lots of epiphytes are CAM. A

From: jkshuman notifications@github.com Sent: Monday, December 17, 2018 5:21 PM To: NGEET/fates fates@noreply.github.com Cc: Subscribed subscribed@noreply.github.com Subject: Re: [NGEET/fates] can we get a CAM in here? (#449)

I think it is a good idea. There are some interesting dynamics of hydraulic redistribution via the difference between CAM systems and C3/C4, and it is kind of emerging line of research. Though I do not know as much about our ability to capture hydraulic redistribution. For instance this paper: "Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM)" Oecologia. 2016 Apr;180(4):1113-25. doi: 10.1007/s00442-015-3518-9

Abstract: Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub< https://github.com/NGEET/fates/issues/449#issuecomment-448021033>, or mute the thread<

https://github.com/notifications/unsubscribe-auth/ANTfrW9fkSQcmShGl53HO-HtRrkzDaPaks5u6BjJgaJpZM4ZXOcF .

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.

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[walkeranthonyp]

I think Rosie's question is a valid one. Is there a CAM photosynthesis model that is analogous to our C3 and C4 photosynthesis models? I assume there is something out there but that it may not be analogous. The stomatal conductance model would also have to change.

Anyone know of any models we can use? I'd be happy to look at them at least ad see how feasible it might be to bring into FATES.

[dlebauer]

@yuwangcn and @djaiswal have worked on a CAM model.