“Complexity is a matter of how the observer specifies the system either explicitly or implicitly in the way questions are cast. What makes ecology complex is the challenge of the questions we dare to ask of nature…” T.F.H. Allen and David W. Roberts
This wonderful post reminds me of the above quote from the forward on Robert Rosens book “Life Itself”. Excited to see how these questions unfold
Whow! Very nice article. I never came across these 23 questions!
Reading your article begs the question: How does Regenerative Agriculture, and Landscape regeneration, fit into this picture? What are the key critical hydrological elements that would help us understand our work better?
For example,
- How can we easily model the impact of biology on soil's hydrological characteristics ("soil health")? There most be some Kolmogorov-like scaling law that, on one end, starts with dead soil (properties defined by physics) and ends with a fully living soil (properties defined by biology). There will also be a "brittleness" parameter somewhere, as some landscapes create capping, others not.
- Or, how do we define and measure "landscape vibrancy" - like soil health at a landscape scale? Again, this will depend on some "brittleness" - grasslands are healthy in a different way than temperate forests.
- How can we measure "landscape resilience" quantitatively, and can we derive a "landscape-resilience indicator" that helps in management decisions (or at least in assessment)?
- And what do cows and ruminant herds have do to with all of that?!?
(Landscape is here a similar term for "critical zone", I guess)
This warrants a broader discussion, though ... sounds like a project :-)
Yeah i wonder if there is an equation that relates how much biology in the soil there is, to how absorbent it is. I know there is an equation for the makeup of the soil particle size, that relates it to permeability to water flow.. And then can we model how regenerative ag builds up the soil absorbency in the hydrological models........ Do you come from a hydrology background Thorsten? The 23 questions I think didnt get as famous as they might have.....
My background is kind of funny - Earth System Science Masters (where I met Lynn Margulis and Schellnhuber), then Agricultural economics - Hydrology integrated modelling. So the typical academic "jack of all trades, master of none". Since then, I am freelancing in Regenerative Food Systems at large, and I am the jack-of-all trades on our regenerative farm.
I co-authored a paper that may be relevant here: "Fu B, Horsburgh JS, Jakeman AJ, Gualtieri C, Arnold T, Marshall L, Green TR, Quinn NW, Volk M, Hunt RJ, Vezzaro L. Modeling water quality in watersheds: From here to the next generation. Water Resources Research. 2020 Nov;56(11):e2020WR027721. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020WR027721 The paper has 64 citations now and has good traction.
I gave this paper its first structure, and drafted the part on Soil Health & land management - basically, identifying it as an open question. I also drafted the part on knowledge management for modeling ("4.3 Cultivating and Applying Procedural Knowledge for Modeling Processes"). I had reviewed soil water response modelling in a number of runoff models, they all assume dead soil and then use phyiscal formulas for sand/silt/clay.
To your question: I don't know of any model that uses such a scaling law to describe biology. I have not followed this since we wrote that paper.
Our writing pre-dated the "23 questions" publication - a parallel development, I believe. I also don't recognize many "interdisiplinary' hydrologists on the 23-question paper - that are people who are not from within any of the hydrological sub disciplines (geo-hydrology, interception zone hydrology, etc) like myself. I do recognize some of the names though, some are authors of the most important hydrological papers.
Thats a good paper of yours that overviews a lot of stuff.... Heres my hypothesis regarding soil. Floods obey a power scaling law. In different watersheds the scaling exponent can be different. My guess is that as the soil carbon increases (which means the soil absorbency increases), the scaling exponent will change. I have some more details I am working on that explains why this will happen. I am looking for people to collaborate on this idea for a paper....
Happy to help. I very much enjoy publishing academically - tickles my Asperger happiness nerves, I guess :-)
Content-wise, one of the big issues is soil capping and macropore infiltration - the way how the surface boundary splits up water flow into runoff or infiltration. Capping happens biologically AND/OR chemically, and depends on the ecoregion's "brittleness" - to use yet another undefined term introduced by Allan Savory. We'd need to pay attention how to deal with that - it greatly impacts flooding regardless of soil health underneath the cap. For hydrologists, this remains a mystery - mainly because they don't even consider the living aspect of soil.
I can also reach out to some of the hydrologists from this paper. Fu and especially Jakeman are BIG names in the field and it is useful to partner with big names as co-authors for a high impact factor (as I probably don't have to tell you ;-).
I think charges matter a lot, since clay soil won't let a drop sink into the soil in a flood event. Clay is negatively charged and the interaction with gypsum, which makes the whole mess water permeable, is an important interaction.
This charge also effects how deep tree roots can punch (the root tips are negatively charged), I read mushroom tendrils are positively changed with some even being piezoelectric materials, sand flip flops on charge based on how big or small it is, etc. All the above change how much water the ground holds dramatically.
Thank you for this review. I’m just beginning to learn about water from an applied perspective (looking forward to starting Zach Weiss’s class the end of this month). I am looking forward to more of your podcasts. A couple of months ago I went to a cool lecture by Dr. Magali Nehemy who might be an interesting guest. See lecture abstract below:
Abstract: Forests cover about 30% of the world’s land surface and provide drinking water for billions of people. Despite their significance, forest ecosystems face rapid climate change and anthropogenic disturbances while we have little understanding of those impacts of long-term water availability and forest water use. Forest water use has been investigated through paired watershed studies. While providing insights at a watershed scale, paired watershed studies are a ‘black box approach’, offering limited understanding of the underlying mechanisms driving forest water use, transpiration sources, and their effects on streamflow. Natural tracers of water (stable isotopes of hydrogen and oxygen) provide unique opportunities to investigate forest water use mechanistically, providing understanding of transpiration source water and the age of transpiration. In this talk, I will provide new insights gained using stable isotopes regarding the hydrological coupling and decoupling between transpiration source water and streamflow. Through a synthesis of controlled experiments and field investigations across diverse biomes, I will emphasize the significance of incorporating tree hydraulic traits, storage dynamics, and topography in the exploration of forest water use. This holistic approach promises to enhance our comprehension of the intricate relationships governing water dynamics within forest ecosystems.
Bio: Magali Nehemy is an assistant professor in the School of the Environment at Trent University.
Yes and this research threatens a belief amongst some forestry/farmer folks that “trees steal the water from downstream needs”. It also may have some implications for our knowledge of how the all water cycle works.
Very thorough and excellent summary of the 23 questions, of which only a handful I was aware and of those only a few I have more than a novice understanding. My background is civil engineering and although not specifically hydrology and catchment and containment structures and systems, I do have a healthy respect for water, both from the perspective of physics and ecology.
I believe Questions 7 and 8 regarding the critical zone are closely linked with Question 10 land use change impact.
“What controls the spatial pattern of the critical zone across different landscapes? Does the vegetation know what kind of bedrock lies beneath the root zone, and does the bedrock know what is growing on top of it?”
I believe further biological and soil science research will show vegetation does know.
“How will a climatically changed atmosphere and a land surface modified by human activities affect the deeper critical zone and vice versa? ….. Can landscape degradation be reversed?”
My suspicion is that landscape and soil degradation at current scale and pace is occurring much faster than the speed of current mitigation efforts and technological know how.
Thanks glad you liked the summary......... When I first read the question "Does the vegetation know what kind of bedrock lies beneath the root zone"? I thought thats a curious question. Maybe the vegetation can be affected by what happens below through the connection of mycelia that reach down to the bedrock........ And yeah the connections in the critical zone impact the rate of change in the landscape and soil degradation....
I have no training in this field, but if the answers to some of these questions function like some of the answers to Hilbert's ten, there will be unexpected connections discovered between the 23. Restacking.
“Complexity is a matter of how the observer specifies the system either explicitly or implicitly in the way questions are cast. What makes ecology complex is the challenge of the questions we dare to ask of nature…” T.F.H. Allen and David W. Roberts
This wonderful post reminds me of the above quote from the forward on Robert Rosens book “Life Itself”. Excited to see how these questions unfold
The more I look, the more complex ecology seems to be :)
Whow! Very nice article. I never came across these 23 questions!
Reading your article begs the question: How does Regenerative Agriculture, and Landscape regeneration, fit into this picture? What are the key critical hydrological elements that would help us understand our work better?
For example,
- How can we easily model the impact of biology on soil's hydrological characteristics ("soil health")? There most be some Kolmogorov-like scaling law that, on one end, starts with dead soil (properties defined by physics) and ends with a fully living soil (properties defined by biology). There will also be a "brittleness" parameter somewhere, as some landscapes create capping, others not.
- Or, how do we define and measure "landscape vibrancy" - like soil health at a landscape scale? Again, this will depend on some "brittleness" - grasslands are healthy in a different way than temperate forests.
- How can we measure "landscape resilience" quantitatively, and can we derive a "landscape-resilience indicator" that helps in management decisions (or at least in assessment)?
- And what do cows and ruminant herds have do to with all of that?!?
(Landscape is here a similar term for "critical zone", I guess)
This warrants a broader discussion, though ... sounds like a project :-)
Yeah i wonder if there is an equation that relates how much biology in the soil there is, to how absorbent it is. I know there is an equation for the makeup of the soil particle size, that relates it to permeability to water flow.. And then can we model how regenerative ag builds up the soil absorbency in the hydrological models........ Do you come from a hydrology background Thorsten? The 23 questions I think didnt get as famous as they might have.....
My background is kind of funny - Earth System Science Masters (where I met Lynn Margulis and Schellnhuber), then Agricultural economics - Hydrology integrated modelling. So the typical academic "jack of all trades, master of none". Since then, I am freelancing in Regenerative Food Systems at large, and I am the jack-of-all trades on our regenerative farm.
I co-authored a paper that may be relevant here: "Fu B, Horsburgh JS, Jakeman AJ, Gualtieri C, Arnold T, Marshall L, Green TR, Quinn NW, Volk M, Hunt RJ, Vezzaro L. Modeling water quality in watersheds: From here to the next generation. Water Resources Research. 2020 Nov;56(11):e2020WR027721. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020WR027721 The paper has 64 citations now and has good traction.
I gave this paper its first structure, and drafted the part on Soil Health & land management - basically, identifying it as an open question. I also drafted the part on knowledge management for modeling ("4.3 Cultivating and Applying Procedural Knowledge for Modeling Processes"). I had reviewed soil water response modelling in a number of runoff models, they all assume dead soil and then use phyiscal formulas for sand/silt/clay.
To your question: I don't know of any model that uses such a scaling law to describe biology. I have not followed this since we wrote that paper.
Our writing pre-dated the "23 questions" publication - a parallel development, I believe. I also don't recognize many "interdisiplinary' hydrologists on the 23-question paper - that are people who are not from within any of the hydrological sub disciplines (geo-hydrology, interception zone hydrology, etc) like myself. I do recognize some of the names though, some are authors of the most important hydrological papers.
Thats a good paper of yours that overviews a lot of stuff.... Heres my hypothesis regarding soil. Floods obey a power scaling law. In different watersheds the scaling exponent can be different. My guess is that as the soil carbon increases (which means the soil absorbency increases), the scaling exponent will change. I have some more details I am working on that explains why this will happen. I am looking for people to collaborate on this idea for a paper....
Happy to help. I very much enjoy publishing academically - tickles my Asperger happiness nerves, I guess :-)
Content-wise, one of the big issues is soil capping and macropore infiltration - the way how the surface boundary splits up water flow into runoff or infiltration. Capping happens biologically AND/OR chemically, and depends on the ecoregion's "brittleness" - to use yet another undefined term introduced by Allan Savory. We'd need to pay attention how to deal with that - it greatly impacts flooding regardless of soil health underneath the cap. For hydrologists, this remains a mystery - mainly because they don't even consider the living aspect of soil.
I can also reach out to some of the hydrologists from this paper. Fu and especially Jakeman are BIG names in the field and it is useful to partner with big names as co-authors for a high impact factor (as I probably don't have to tell you ;-).
Ok cool. Lets connect
I think charges matter a lot, since clay soil won't let a drop sink into the soil in a flood event. Clay is negatively charged and the interaction with gypsum, which makes the whole mess water permeable, is an important interaction.
This charge also effects how deep tree roots can punch (the root tips are negatively charged), I read mushroom tendrils are positively changed with some even being piezoelectric materials, sand flip flops on charge based on how big or small it is, etc. All the above change how much water the ground holds dramatically.
Idea for paper title "The hydrology of Land Regeneration" ... love it.
Thank you for this review. I’m just beginning to learn about water from an applied perspective (looking forward to starting Zach Weiss’s class the end of this month). I am looking forward to more of your podcasts. A couple of months ago I went to a cool lecture by Dr. Magali Nehemy who might be an interesting guest. See lecture abstract below:
Abstract: Forests cover about 30% of the world’s land surface and provide drinking water for billions of people. Despite their significance, forest ecosystems face rapid climate change and anthropogenic disturbances while we have little understanding of those impacts of long-term water availability and forest water use. Forest water use has been investigated through paired watershed studies. While providing insights at a watershed scale, paired watershed studies are a ‘black box approach’, offering limited understanding of the underlying mechanisms driving forest water use, transpiration sources, and their effects on streamflow. Natural tracers of water (stable isotopes of hydrogen and oxygen) provide unique opportunities to investigate forest water use mechanistically, providing understanding of transpiration source water and the age of transpiration. In this talk, I will provide new insights gained using stable isotopes regarding the hydrological coupling and decoupling between transpiration source water and streamflow. Through a synthesis of controlled experiments and field investigations across diverse biomes, I will emphasize the significance of incorporating tree hydraulic traits, storage dynamics, and topography in the exploration of forest water use. This holistic approach promises to enhance our comprehension of the intricate relationships governing water dynamics within forest ecosystems.
Bio: Magali Nehemy is an assistant professor in the School of the Environment at Trent University.
Cool you are taking Zach Weiss's class. For those of you interested in his work, see this previous post and interview with him https://climatewaterproject.substack.com/p/halting-our-drought-fire-flood-path ... I took a look at Magali Nehemy work. Looks interesting. Her research group is tracking the water to see if transpiration comes from streamflow, or the bedrock... https://www.magalinehemy.com/researchprojects
Yup and spoiler alert, the vast amount of the water is coming from groundwater and not the streams/rivers contrary to common assumptions.
Ok thats pretty interesting... So its older water that gets transpired.
Yes and this research threatens a belief amongst some forestry/farmer folks that “trees steal the water from downstream needs”. It also may have some implications for our knowledge of how the all water cycle works.
Mycelium and transfer of nutrients was my thinking when I read that. Microbes busy at work.
Very thorough and excellent summary of the 23 questions, of which only a handful I was aware and of those only a few I have more than a novice understanding. My background is civil engineering and although not specifically hydrology and catchment and containment structures and systems, I do have a healthy respect for water, both from the perspective of physics and ecology.
I believe Questions 7 and 8 regarding the critical zone are closely linked with Question 10 land use change impact.
“What controls the spatial pattern of the critical zone across different landscapes? Does the vegetation know what kind of bedrock lies beneath the root zone, and does the bedrock know what is growing on top of it?”
I believe further biological and soil science research will show vegetation does know.
“How will a climatically changed atmosphere and a land surface modified by human activities affect the deeper critical zone and vice versa? ….. Can landscape degradation be reversed?”
My suspicion is that landscape and soil degradation at current scale and pace is occurring much faster than the speed of current mitigation efforts and technological know how.
Thanks glad you liked the summary......... When I first read the question "Does the vegetation know what kind of bedrock lies beneath the root zone"? I thought thats a curious question. Maybe the vegetation can be affected by what happens below through the connection of mycelia that reach down to the bedrock........ And yeah the connections in the critical zone impact the rate of change in the landscape and soil degradation....
Oops! The reply to you ended up as a comment.
I have no training in this field, but if the answers to some of these questions function like some of the answers to Hilbert's ten, there will be unexpected connections discovered between the 23. Restacking.