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sean

Mycorrhiza

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Sean,

As a forest ecologist and mycologist, I have to comment on this, as I have been and still are an opponent of companies selling these products for many years and wrote two articles (in Dutch) on the subject of artificially introducing mycorrhizae to the roots of trees.

 

In The Netherlands, some fifteen years ago, products developed by Marx, called Tree Saver, Mycor Tree and Root Dip, were introduced on the Dutch "arb-market". At first it was booming bussiness for the exclusive retailer of these "preparations" until a collegue and I wrote an article ending with the following conclusions :

 

- After evaluating (the summaries of) the by then 200.000 articles written on the subject, we concluded, that one third of the short term (2-5 years) studies showed a benificial effect on the condition of the trees after the preparation had been applied to the roots, one third showed no, i.e. a neutral effect and one third even showed a short term detrimental effect.

At that time, no case studies evaluating the effects after 10 to 15 years were performed. Follow ups on some of the case studies however showed, that the short term benificial effects after 5 to 10 years were followed by detrimental effects, which can be explained by the trees initially showing better growth being "too speedy runners", where slow growth in accordance with the succession within the tree species specific life cycle should have taken place and because of that finally ended up dead long before passing the finish line of the life time marathon.

Conclusion : the trees only grew faster because of the appliance of a water buffering gel with minerals and nutrients and not because of the spores of mycorrhizal fungi (see the next paragraph).

 

- Apart from the fast uptake minerals and/or blood and bone powder and a water buffering jelly, the preparations contain spores of one to three ectomycorrhizal macrofungi, such as Pisolithus arhizus, Laccaria spp. and Thelephora terrestris, and of endomycorrhizal microfungi, such as Glomus, Endogone and Gigaspora species.

P. arhizus is an indiginous species, associating with very young birch, willow and pine growing on mounds of extreme acidious waist of cole mines, which mycelium needs a Ph 1-2 to develop. Both Laccaria and Thelephora terrestris are pioneers, of which the by wind dispersed spores are always and everywhere present, which means they don't need to be introduced at all. And if a tree would benefit from (unnecessary) artificial introduction of spores, only tree species associated with ectomycorrhizal macrofungi could.

Because spores of Glomus, Endogone and Gigaspora are from 0,1 to 0,6 millimetres in size, they need dispersion in the soil through worm canals and by ants, which "plant" them on the roots of trees of whose mycorrhizal structures they in return "harvest" secreted sugar from. So artificially introducing these spores in the soil implicates, that they become locked in, because the ants (and the worms) are not introduced as well. Besides, only trees which are associated with AM-fungi can benefit from their introduction, provided the spores ever reach the tree roots.

So introducing these products into the soil food web is like firing a shower of shot hoping one of the balls hits target and could unintendedly be a stimulant for extra and better growth of grasses and other plants, which also depend on endomycorrhizal microfungi for deliverance of the nutrients from the soil.

And finally there is the aspect of ecosystem falsification by introducing a modified species of Pisolithus, which already is indigenous.

 

- And then there is the effect of competition between different species already present or introduced in the soil food web. In an experiment in a Dutch city, Platanus was planted alongside a street. Only half of the trees were given a root dip before being planted. For the first three years, the trees, which had not been "treated", grew better and showed more and better foliage then the "treated" trees did. After three years, the last ones started to recover and it took them more then five years to be just as vital as the non-treated trees meanwhile were.

The explanation lies below surface. The trees were coming from a very old nursery, were they already had been living in symbiosis with one or more species of endomycorrhizal microfungi, which were then transported on/with the roots to the new location. Immediately after replant, a territorial war started between the already present mycorrhizae and the introduced spores trying to get a foothold on the roots. And where did they get their money (energy) for warfare from : from the roots of their "sugar daddy", which under the circumstances, could not afford itself to share so much energy, which it needed itself for recovering from the shock of being uprooted and replanted.

 

- The following examples demonstrate the innecessity of introduction of spores. Beech has a special relationship with Laccaria amethystina, of which the mycelium is colonizing the finer and secondary tree roots of seedlings and old beeches coming to the end of their life cycle. Because of this it has been very beneficial for replanted beech hedges to introduce some spores and hyphae rich "litter" from the soil of a beech forest in the plant holes.

A friend once brought a young birch from the forest to her backyard and planted it in a wooden barrel. After two years, the surface of the soil was completely covered with Telephora terrestris.

At a tree nursery, around very young Tilia's planted in degradeble containers, a Hebeloma spp. spontaneously fruited. After moving the Tilia's outside, they were replanted three times before twelve of them reached their final destination. Three years after the definitive replant the Hebeloma reappeared with lots of fruitbodies, showing the trees had meanwhile become so vital, that they could afford sharing their energy supply with the mushroom.

A tree company asked me to deliver a lecture at a conference. Outside some new techniques were demonstrated. The paving stones around a very well foliaged Acer were removed and a hole was dug to show the effects of the previous introduction of oxygen and nutrients at one metre depth into the soil. The roots from that depth did not show any signs of being covered with endomycorrhizae. After me lifting another paving stone, a colony of "sugar" ants was disturbed, living from the secretion of the endomycorrhizae on the roots, which had grown upwards to collect oxygen and moisture from condensation in the cavity underneath the stone.

 

Final conclusion. Selling these products is very beneficial and profitable to the retailers and - on the long run - detrimental to the condition of the tree.

Even though recently some "new" products were developed by a Dutch company, which still are in its experimental testing phase, I refuse taking on assignments of clients still applying these preparations. As I sometimes say to tree managers asking my opnion : its best for your budget and less detrimental to the tree to hold your purse with copper coins up side down above the plant hole of the tree, then to empty your wallet for these expensive products.

Edited by Fungus

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So where do you really stand then Gerrit ????

 

 

:lol:

 

 

 

 

Thanks for your well informed opinion, helps me support & back up this debate when I talk to other managers & suppliers. :thumbup1:

 

 

.

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Seem to know your subject Gerrit whats your view on Biochar providing 'accomodation' for micorrizals (see Johannes Lehman Proff of Biogiochemistry at Cornell, lecture on You tube )

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Sean,

As a forest ecologist and mycologist, I have to comment on this, as I have been and still are an opponent of companies selling these products for many years and wrote two articles (in Dutch) on the subject of artificially introducing mycorrhizae to the roots of trees.

: its best for your budget and less detrimental to the tree to hold your purse with copper coins up side down above the plant hole of the tree, then to empty your wallet for these expensive products.

 

I was never a fan of these products, preferring to transplant trees that already had their associated fungi.

 

and it upsets me when I see people selling the products and specifying them or contracting with them when they do not understand these things even nearly enough to make an informed use of them.

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whats your view on Biochar providing 'accomodation' for mycorrizals

 

Of Terra Preta or Biochar, no effects on the development of endo- and/or ectomycorrhizae as elements of (already present) natural soil food webs and habitats have been researched and reported, other then that natural soils require active carbon to maintain micro and macro populations in the soil, of which the mycelia of micro- and macrofungi are an essential, if not the most important interlinking constituents, and are not "accomodated" by the inactive carbon of Biochar.

As Biochar is mainly used for reforestation and agriculture in the tropics, i.e. for soil fertility management of overexploited and exhausted soils, I don't think there are much benificial effects to be expected of these products for European natural forests and woodlands, or even detrimental effects for tree species specific ecosystems of indigenous tree species must be feared, because of the possible changes in the (biochemistry of) tree species specific soil food webs triggered by inactive carbon changing the composition and variation of the micro- and macro-organisms living in and of the soil food webs on which indigenous trees largely depend.

So in my opinion, we would be wise to stay away from these products primarely developed for food production purposes and for production forests of tropical hardwood.

Edited by Fungus

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I hear what you say but there is plenty of poor hill ground in the UK that may benefit I have been running a trial with biochar on nursery grown Chestnut and oak started last autumn as yet no difference to the control but have noticed a difference in grass growth on peaty soils this could be down to the high ph of biochar reducing the acidity ,will let you know how it goes

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I hear what you say but there is plenty of poor hill ground in the UK that may benefit I have been running a trial with biochar on nursery grown Chestnut and oak started last autumn as yet no difference to the control but have noticed a difference in grass growth on peaty soils this could be down to the high ph of biochar reducing the acidity ,will let you know how it goes

 

how it will go is eventualy the surrounding geology/ecology will restore.

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I hear what you say but there is plenty of poor hill ground in the UK that may benefit I have been running a trial with biochar on nursery grown Chestnut and oak started last autumn as yet no difference to the control but have noticed a difference in grass growth on peaty soils this could be down to the high ph of biochar reducing the acidity

 

That's exactly what I meant to say with my statement on the mycorrhizae products : the results of in vivo experiments can never be attributed to either or both of the natural or artificially introduced elements, and if they could, one at least needs up to fifteen years of monitoring and field research to be able to evaluate the either beneficial or detrimental effects.

Besides, poor hill ground is one of the best soils for the spontaneous and natural development of forests of indigenous tree species with the highest biodiversity at its optimum, which only is attained after hundreds of years of undisturbed development and natural selection and succession.

And the extremely rich in biodiversity and highly specialized species specific ecosystems of oaks are ectomycorrhizal by nature, opposed to the very poorly developed non-species specific endomycorrhizal root systems of Aesculus, which the tree, on top of this, must also share with partially the same endomycorrhizal symbionts of the grasses, which seem to profit more then the Chestnut does.

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Gerrit, would it be possible to have the reference for the articles which contained the conclusions you and your colleague drew on 'off the shelf mycorrhizal inocculants'.

 

Also as a slightly related follow up presumably you would not percieve similar reservations about the in vitro multiplication of specific native locally occuring (to the trees being treated)mycorrhizae to be reintroduced to the soil profile? (I am specifically thinking about the published work done by Francesco Ferrini et al.)

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