Andosols

[StephanMantelISRIC]

This discussion is to document the RSG Andosols and document examples from sites and soils of Andosols with identified diagnostics and qualifiers

[StephanMantelISRIC]

Submitted by Olafur Arnalds, Iceland:

My name is Olafur (Oli) Arnalds, a professor emeritus and a soil scientist in Iceland. I have been involved with Andosols most of my professional carrier ([www.moldin.net] - google scholar at the bottom). I am the author of “The Soils of Iceland” in the World Soil Series published by Springer. Also led the writing of WRB lecture notes on Andosols last year. I am officially retired, yet I remain semi-active like many.

I had the honor to lead a WRB excursion around Iceland during an exceptionally cold spring that ended in COVID for me and some others. Quite memorable, I must say, but overall, an interesting trip.

I led a classification of Icelandic soils, completed around 2004. During that time I was the steering committee of the COST 622 action on volcanic soils in Europe, together with Francois Bartoli, Peter Buurman, Otto Spaargaren, Georges Stoops, Fabio Terribile and others. I conferred with Alan Hewitt of New Zealand, Larry Wilding (Texas – I was a PhD student of his long ago), John Kimble (USA) and others when working on the classification.

During this time, I had many fruitful discussions with Otto Spaargaren (which is sorely missed), and we made several Monoliths together involving Icelandic soils. My main concern at the time was Gleysols keying out before Andosols, and how vitric soils are treated. We have a special class for Vitrisols in Iceland, which is needed (40% of the soils and very different from other Iceland’s Andosols/Andisols). Otto and several others encouraged me to write up a proposal for Vitrisols, but I never found time for it. So, finally now I am working on explaining the rationale for Vitrisols in Iceland.

Around 2000 Otto and I discussed the Gleysol/Andosol dilemma from an Icelandic point of view, which has a much broader context. Japan and New Zealand key out Andosols separately as we do. AND, now, as I am working on the Vitrisol rationale paper I came across the correspondence with Otto that both of you were a part of (yes, I know, 25 years is a long time - :), a blast from the past). The letter from Otto Spaargaren (April 5th, 2001) reads as follows; (my question that he refers to is below, a concern about keying out Andosols before Gleysols):

“Your second question has already been taken care off after our discussion in Wageningen. I had an e-mail exchange about this with Freddy Nachtergaele (FAO) and Seppe Deckers (Catholic University Leuven, Belgium), and we all agreed that in wet soils the andic characteristics are more important than the gley characteristics. Moreover, it is unlikely that the gley characteristics (i.e. grey, blue colours for example) will show in volcanic soils, which makes it even more difficult to differentiate between Gleysols and Andosols. Therefore, in the revised edition of WRB the occurrence of andic or vitric horizons in Gleysols will be excluded.”

On the basis of this, we reported the Gleyic Andosols and Histic Andosols (Icelandic system) to ISPRA as Andosols for the European soil map. They are Andisols according to the US system, of course. And I would like to stress the point Otto made, determining gleying in Iceland becomes extremely difficult and will not even show up in wet soils (and the vitric materials are black basalts). Will be kind of arbitrary.

Now, I am not contesting the WRB classification per se. WRB is an enormous accomplishment as it is – yet ever evolving. Just a bit surprised that the conclusion stated by Otto in his letter did not materialize (and I did not realize that until much later). I know that Peter Chad and Cezary Kabala are not keen on the idea of excluding Andosols from Gleysols as is done by the Icelandic system, Japan and New Zealand (and Soil Taxonomy does not have Gleysols) – and I think is quite necessary. We did discuss this a bit during the field trip and there was an e-mail exchange with Cezary.

However, I think this needed to come forward (to bad I did not have the letter at hand during the WRB Iceland fieldtrip), to prove that this actually occurred, and in part to explain our grouping of soils (Vitrisols, Brown Andosols (dryland), Gleyic Andosols, Histic Andosols and Histosols, and few more). Which we will continue to use or will be subjected to whatever changes future generations will decide on up here in the cold land.

[StephanMantelISRIC]

Dear Peter (and Cezary),

Thanks a lot for your prompt reply and the clarification given. Indeed, bringing the Andosols forward as you proposed in 2013 was a more elegant solution than the one given in WRB2006. I also agree that RSG-Champions (from Blume’s Stagnosols to Brinkman’s Planosols) can unduly influence decisions. This seem to have happened here when a un-named Gleysol champion overruled your support to place Andosols before Gleysols.
As your examples show, in all major Andosol countries and (not to forget) in Soil Taxonomy andic properties have precedence over gleyic ones. This indicates that the way decisions are made in the WRB working group sometimes depend on the whim or loudness of voice of a single member. Other examples that were hardly scientifically justified include the downgrading of Fluvisols (boosting Gleysols) and Retisols (boosting Stagnosols and Planosols). Perhaps not surprisingly, all soils that may be affected by wetness. In all these cases, national soil correlators have seen their carefully constructed national soil maps upset by a fundamental name change in WRB.
It would help if in the future:
• There would be minutes of meetings (why do we have a WRB Secretary?) distributed to the WRB mailing list members.

• When fundamental changes at RSG level are proposed, the WRB chair would contact the national chairs of soil science societies and ask for their opinion/endorsement.
• A systematic documentation of WRB is to be provided at all levels (as you are aware a start was made of this - now at the KU Leuven soil monolith website soon to be moved to the IUSS one)

Freddy Nachtergaele

[StephanMantelISRIC]

Dear Freddy,

I support your comment on the need for documentation of WRB WG meetings and decisions made based on them so that all can be traced and reasoned back in time for diagnostics and the key. Your work on that for the documentation centre and making that available soon on the WG website is very valuable.
A good example is the documentation of the development of the Digital Soil and Terrain Databases methodology that have reports for all the expert meetings and workshops that focused on the work towards an agreed methodology.

I think it also counts for the field excursions. It would be very valuable to have someone in the group write a report about the field excursion. After all these excursions are correlation studies of the local conditions and the working of the WRB key and comparison with other classifications. E.g. we have impressions but not a generally available documentation about what we learn from the Iceland and Japan (or the other excursions for that matter).

Greetings, Stephan

[StephanMantelISRIC]

Dear Freddy,

I don't remember how broad was the consensus for giving Gleysols priority over Andosols in 2013. But I do remember about the two other decisions, which you brought up: The consensus was very broad!

Kind regards
Peter

[StephanMantelISRIC]

Dear colleagues,
thank you for your remarks and proposals. I like the suggestions to include more people into the discussion and to document the discussion and opinions.
But, of course, we cannot document and spread each email or personal communication. As you may know, we plan to initiate the discussion on possible changes in the next WRB edition after the congress in Nanjing. We will ask some fundamental questions and then follow the prevailing opinions. All formal steps, and the opinions and decisions emerging during the formal steps will be documented. It is possible, we will use the technical opportunities described by Stephan in his email.
Of course, we would like to include as many people as possible to our discussions, including national representatives (if they are not active members of the IUSS Working Group). However, we should remember about the function of the WRb Working Group. I cannot accept an argument that Andosols should preceed Gleysols just because andic is prioritized higher than gleyic in Soil Taxonomy, if there are no separate Gleysols in ST, and everything, even Entisols are before any "Aqu-". And the same refers to all opinions possibly provided by national representatives, based on the specific solutions and models accepted locally. If we decided in WRB than the long-term soil saturation with water, as the phenomenon, has larger importance for land use and soil ecological functions, and soil productivity in agriculture and forestry, than specific parent material or various soil processes, we should provide respective arguments documenting that this prioritization was wrong, if we want to change the order of RSGs. This is why, before we change the positioning of Andosols, which is not excluded, I will ask national representatives and other experts to provide examples of wet (waterlogged) Andosols from various climate zones to analyse (and judge) whether soil moisture or soil material is more important for soil functioning in the ecosystems on a global scale.

All the best,
Cezary

[StephanMantelISRIC]

Dear Cezary,

I am grateful that you accept suggestions for a better documentation and for consulting a larger user international community when making fundamental changes at RSG level.

I admit I am a bit surprised when you state: "If we decided in WRB than the long-term soil saturation with water, as the phenomenon, has larger importance for land use and soil ecological functions, and soil productivity in agriculture and forestry, than specific parent material or various soil processes, we should provide respective arguments documenting that this prioritization was wrong, if we want to change the order of RSGs" !!! Do you mean that we should take into account ecological/productivity considerations in soil classification???

We should not confuse land (soil) evaluation with soil classification
Many soil parameters (and obviously water saturation) will have to be considered in evaluating soil suitability for agriculture, forestry and ecological functions. However, this is not the prime objective of soil classification that has to reflect in the first place pedogenetic processes driven by environmental factors and characterized by precise classes of stable soil properties. From that point of view, andic properties have, I believe, a more direct link with pedogenetic factors than most aspects of gleyic properties.

The point made of volcanic soils as classified in Iceland, Japan, partly in New Zealand and in Soil Taxonomy (used in many countries with volcanic soils in (Latin) America and Asia) is simply that these cover the major countries/areas where volcanic soils occur and where andic properties are given precedence over gleyic ones. WRB has a major role to play as a reference system, serving as a correlating system for different national systems. It is therefore not wise to take an opposite independent view, making correlations more difficult for everyone.

Best regards
Freddy