I would vote for fungi predominantly.

Mr. Andersson,

is it possible to determine by fungi  and how?

A PFLA method (maybe coupled with an extraction method optimized for plant or animal specific fatty acids?) could potentially identify how much of the actual biomass in the humus is of either plant or animal origins, compared to fungal or bacterial origins.  Sounds like an interesting project-- good luck!

Ergosterol can probably be used as a marker for fungi.

Hi Uğur

Bırak bu işleri yaww :))))

A recently published article by Dr.  Lynne Heighton, et al.  (J. Geography and Geology, 6, 214, 2014) addresses this question.  She found if one exhaustively reduces all the sites in humic substances, they are all remarkably alike.  Thus the humic substances differ primarily in the degree and in the sites of oxidation.  She concluded humic substances are all partially reduced cellulosic material.  Fulvic acids exhaustively reduced are also remarkably similar, and structurally discrete from humic substances. Fulvic substances appear to be all partially reduced proteinaceous material.

There are basically two metabolic processes: oxidative and reductive.  Oxidative processes add to the mole fraction of oxygen.  Reductive processes add to the mole fraction of hydrogen.  Reductive processes is the mechanism by which biomolecules are converted to humic substances over the short term.  Coal, natural gas, and oil is the reductive process carried out over eons of time.  If fungi have the necessary enzymes to do the reduction, they could provide the biomechanism by which the reduction takes place.

It is clear, however, that oxidative processes are catabolic, releasing chemical energy, whereas reductive processes are anabolic, storing chemical energy.

The reason coal produces less energy than oil when burned is  because coal has a large number of double bonds.  The loss of a water molecule in a carbohydrate/cellulosic compound produces a double bond without oxidation or reduction.  Forming a triple bond at a double site is oxidation.  Forming a single bond from a double bond adds hydrogen and is a reductive process.

Clearly humic substances are a supply/reservoir of hydrogen energy from which other living things can harvest chemical energy via oxidative processes. .   .

Thank you so much all of you except Karakose:) Its help me a lot such as valuable words but I think I need to more information in both more simple and clear methods. 

My one of the idea that if we know decomposition rate of plant residual by fungi then may we estimate the ratio of humus mass will have came from plants. Or its same for bacteria...OR whats your idea about that?

Complex hydro-carbons are, as discussed above, quite similar after final reactions that result in a stable compound. Hence why coal, humate and fulvate can last for millennia.  The atomic weights are different but the initial sources are unknown. Logic makes one dictate; but logic is not scientific proof.

Early in the process of reduction/oxidation to humate it is possible to differentiate the initial or majority source. However, once the compounds are stabilized humates, complex hydrocarbons, it is not possible.

As Mattias mentioned: there are markers/enzymes/catalysts you can identify early in the process. You then finalize the output of the different input material processes and extrapolate from there.

I do not agree with Lynne Heighton and her data is limited (to put nicely.) There is no such formulation that can show fulvates are from proteins. The contributing factor of producing lighter weighted complex hydrocarbons, and then moving them into different belts/locations/strata in the same soil complex as coal or humate is, in calculation, impossible. Having been to mines where coal, humates and fulvates all are occurring in the same exact spot....and looking at the strata, how would one say : "all the proteins from all the plant, animal, fungi & bacteria over vast million years and more periods of time, moved over here...to this spot...no, over here... this little area over here..over all those years the protein degradation ALL moved here, to this one belt of strata...and then were buried for 100 million years?? Seems silly, no?

That is equal to saying "moving faster than the speed of light is impossible." You can say it, but as you can't prove it...it is just words.

Hi Richard!

Thank you for your nice philosophical&scientifical comments. There is an idiom that "Using a simple tool to solve a complex problem does not result in a simple solution." -- Chairman Larry...

That is a GREAT saying!

If you want an analytical answer separating plant from animal decomposition products, what is required is simply one (or maybe several) marker compounds that are unique to [specific] animals or plants.  Cellulosic material is a structural compound unique to plants.  Collagen and keratin are major structural compounds unique to animals. It could thus be better to examine fulvic substances (soluble in base) as a likely source of markers of animal decomposition because both collagen and keratin are proteins. Acid soluble decomposition products my guess would be primarily of plant material origin.  Analysis of fulvic substances would still be complicated, except the potential exist to detect both [possibly discretely different] proteinaceous compounds of plant and animal origin.

Except stoichiometry.   Dr. Heighton was not about proving anything.  It was just to demonstrate that when decomposition products are fully reduced, they are all [spectroscopically] quite similar.  Nitrogen containing compounds fully reduced can be amines, which are basic.  Compounds made from only carbon and oxygen can rarely if ever be basic. If one partially oxidizes fully reduced compounds, one can get a complex mixture, yes.  Except one cannot escape the nitrogen containing compounds will remain mostly on the base soluble side.  Even if one fully oxidizes nitrogen containing compounds eg. to nitrate, it is STILL not acidic.  Of course some nitrogen compounds will be soluble in acids also, and amino acids that are higher in nitrogen are all soluble in base. 

Given W. Schmidt's response I am now wondering if we are missing a point of distinction.  Looking at the words "soil humus" I suppose you need to examine the phases of organic matter degradation versus laboratory degradation of known compounds. 

In the natural environment, if a tree falls over and is buried under soil, but remains in an aerobic environment, one process of degradation will occur. It will start with, in most cases, fungi and eventually end up with soil cations and base chemistry.

If that same tree falls in a desert, different process....if it falls into soils in a temperate climate, different process than falling in the tropics. If it falls on a savannah, different process, if it falls in a roundup ready GMO field, different process. Each micro and macro zone has soil organisms and soil chemistry that are unique to its "terroir" and hence the process of degradation is different.

If it falls into water, a completely different process, anaerobic, occurs with its own set of organisms and final resultant.

If a cow falls into the soil, any of the above soils, a slightly different process starts, normally with bacteria because a) bacteria are present in large amounts in animals and b) proteins degrade with a different pathway than say lignins/cellulose.

In theory should you put 100 million cows in one spot and not disturb them for 100 million years the resultant degraded stable compound, whether from an anaerobic or aerobic environment, would be different in composition than putting 100 million trees in one spot.

I agree.

However: discussing humus in the soil is an inexact science; organic matter incorporated is normally comprised of both lignins and proteins. In the course of the degradation of both in proximity to each another, intermingled, the small value of weighted input is affected by the larger value of input; if proteins/amino acids are, (lets play) 3% of the total mass then their degradation pathway is completely different than if degraded without 97% cellulose/lignin degradation interaction.

Humates & fulvates are the mined versions of organic compounds, resultant of degradation processes we cannot prove, and are, in theory, from multiple sources of organic matter: animal & vegetable. As with my example above: if you put 100 million dinosaurs in one spot, wait... to have 100 million dinosaurs you needed 100 million dinosaurs worth of food for them to be in that one place and that would normally be plants. Given the meat to eat ratio, you'd need hundreds of millions of vegetation to feed 100 million dinosaurs.

The purpose of this exercise is to say:

soil humus can either be analyzed as a laboratory process extrapolated or the natural process, from 10s if not 100s of thousands of years. In the latter scenario, (a natural degradation process of natural life normally with a ration of more plant to animal tissue), with the above mentioned intermingled compounds of degradation  it is impossible to determine the origin of the input matter.

Don't know if it is impossible, though I concur it can be very difficult. A king dies in England, is buried for 400 years, and DNA evidence is that a queen his lineage had been unfaithful to her husband.   So clearly DNA does remain intact for hundreds of years.  DNA of  a mammoth in  Siberia was isolated after tens of thousands of years.

So there already is clear evidence of chemical/biochemical memory of past chemistry.

The difficulty is in distinguishing between uniqueness and redundancy.  

People have fungal infections.  Don't know much about fungi, except because the starting material is different, the end product of the fungal decomposition will be the same until it is not.   Of course decomposition besides oxidation and reduction can also include de-amination: fungi need N so the biochemistry necessary to obtain  N from food sources will occur, except of course also metabolic pathways will be easier [require less redox energy] then others.   So all markers of chemical decomposition in complex mixture will not be lost at the same rate.   The most chemically intransigent compounds will endure the longest.  So one mechanism to simplify this discussion is to cross of the list of compounds in biodegradation which have a short half-life.  If compounds whose half-life are 10 years, if they are present in soils, either  they are recent additions to the soil, or compounds with much longer half life are also present and also intact.  .    .       .   

Yes, as I said: keeping the proteins separated from the lignins/carbohydrates during decomposition will yield different compounds of degradation. Your example, the king is entombed, therefore the resultant after degradation is confined in one spot and not co-mingled with degradation products of other organic materials, like lignins/cellulose/carbohydrates. .

That was the point of my conclusion above: if you co-mingle animal-origin organic matter with considerably larger amounts of vegetative-origin  materials and decompose them together, it will be impossible to separate the resultants into 2 piles: amino-acid degraded and lignin degraded........ from one sample of humus. And the older the sample the less likely it would ever be sorted out: the balancing of the electrons between the humus as a whole will eventually make all the saturated valence points, hydrocarbons, be similar....like the theory: "all elements/minerals want to be iron."

I concur also.  Interesting that you added minerals and iron to the picture.  My spouse is a horticulturalist who fine tunes micronutrients in soil composition matched to specific plant varieties.  It is clear monocultures of corn or wheat, or herded animals for that  matter, is related to small variations in micronutrient compositions.  Soils that lack iodine result in thyroid problems.  Soil in North Dakota which have trace levels of selenium above a specific level are toxic to cattle.  Micro-environments that are successful and those which are toxic, and even those which are semi-/moderately toxic, each will have a discretely different biomass.  My personal point of view is that specific mineral can have highly specific interactions with very specific animal / plant species proteins, lignins, celluloses, or even other compounds.   Dr. Heighton and I did research on the fate of the simple molecule phytate, which happens to complex strongly with different minerals.  Unambiguously, the complexing with minerals hugely changes its environmental half-life chemically, biochemically, and microbially.  So, in principle [i.e. without as yet any compelling experimental evidence],  choose where to sample to find biomarkers which could be useful in distinguishing animal from plant humic substances still remains possible.

Archeologists do not look for evidence of dinosaur bones randomly. If so, they would hardly ever find them.  No reason to suppose that some places would be more promising to explore for evidence that some chemical markers which distinguish plant from animal degradation could exist.  .      .    Just a place for those interested in the question to explore / to being exploring.    .         .

No harm looking.     .          .

Walter.

Yes. I suggest the use of stable isotopes analysis (13C) combined with MNR 14C. The first indicate the origen of organic matter (C3, C4 or CAM), and by the second you can determine the existence of functional groups that indicate the contribution of roots or senescent leaves materials of present vegetation.

also, by NMR you can determinate animal and plant footprints

The question that arises is the question of time.   Some humic substances are ancient, some are new.   Boggs have humic substances that have no decomposed much more than the human remains found intact in the boggs.  So the question is how does one differentiate old humic substances from newer ones?   Over which range of time does the sensitivity of a method preclude finding an answer because the concentration of the distinguishing compound of interest has biodegraded?  Different microbes could result in different biochemical degradative pathways. So it seems one must integrate a scheme of multiple markers and most usefully confirmatory markers such that multiple methods result in the same answers.   In a puzzle of 10,000 pieces, the same pieces must always fit together in more than one way.  A better example is if someone co-mingled two or more 10,000 piece puzzles together, and asked what can be made out of this?

Maybe nothing, maybe it is too complicated, maybe it is not even worth the effort.  Some problems have exact answers, other not so much. Before DNA evidence, crimes were solved beyond a reasonable doubt.  After DNA evidence, there can still  be reasonable doubt.  In any particular situation, one can discern if one has compelling evidence for a conclusion, though not necessarily if the information will be sufficient to be definitive / unambiguous. .     .

I happen to like the challenge of puzzles, even if I cannot and/or will not solve them and/or solve them correctly. .     .

Excellent response Walter. I read Julio's two additions and thought "That is only possible from newly degraded organic matter." But you said it while I ignored it.

Over the passage of time it becomes less possible to separate animal from plant input materials. Humates and fulvates are impossible to determine and we have been working with them since the early 1990s, as long or longer than any other organization we have found.

Thank you very much each of you for valuable contributions. Really its opened new gates in my mind. I will set up a project related to determining of Humus origin in conifer and broadleaves forests' soils of Turkey as soon as possible. I will inform you about that who knows may be some scientifical cooperation will be needed...

Also I am looking forward to any other additional comments about this question!