Understanding Roots

I think I read someplace that plants not only feed microbes, but exchange substances between themselves. Have you ever heard of that? I live in Fairbanks, Alaska, and the soils are very cold just a short way down. I think the deepest roots I've ever seen growing here were willow, and probably less than two feet under. Do you have any information regarding how roots function in this environment? Raised beds are pretty popular for gardening here, and I'm considering planting some trees on mounds to see if that has a salutary effect. I'm thinking it may warm up quicker in spring and stimulate early growth.

Heyyyy, Victor. Swede Johansen, eh? Well, don't worry, I won't hold it against ye. Roots of plants do indeed produce in-soil specific compounds called root exudates. These compounds are unique to each plant, and act as chemical signals to microbes, fungi, and other plants (legumes and their nodule-bacillus are the first example that springs to mind.) Some root exudates repel or attract certain insect larvae, bacteria, nematodes, competing plants, etc., but more interestingly, root exudates may hold part of the secret to inter-plant communication- any plant that has been attacked by a predator or illness releases "stress hormones" into the soil, and the plants in the surrounding area begin produce defensive compounds or chemical repellents in response, before they have even come onto contact with the offending party. In this way, the one plant acts as a sort of martyr, letting her cohabitants benefit from her loss. Plants can also exchange complex nutrients through roots, like the carrot-tomato or anise hyssop-grape interactions, in which the fruit of one plant actually absorbs qualities of her neighbor. Exudates and the extent to which they play a role in the soil food web is documented, and observable, but the significance if such miracles continues to be hotly debated among gardeners and academics. If you're going for trees, Oak is good for anywhere near a compost pile, and locust and alder will help produce lots of nitrogen, but siberian pea shrub might be your best ticket up thar in the arctic. And Hey! Don't forget to remember your tap-rooted herbs- mullein, dock, dandelion, comfrey- having them around pays off in spades.
Personally, I like to think that all the plants sing to each other, and some of them prefer to sing their parts together, kind of like a botanical gospel choir...
Recommended reading: Louise Riotte, Peter Tompkins/ Christopher Bird, or Researchy-type stuff for the sceptics

hau Ben and Victor, indeed all plants produce exudates through the roots, they form part of the network of nature. There are repellent ones, attractant ones and many communication ones. Just like was alluded to in the movie "Avatar" all plants are part of this network, there is still plenty of research to be done but what we know already is that 1)plants can and do talk to each other, these can take the form of warnings, good news and bad news. There are chemical interactions between fungi and roots which are symbiotic and many plants envelop their "ground" with aelopathic compounds to prevent competition. Ben gives a good set of explanations of several of the wonders of the networking plants do.

Ben Johansen wrote:Heyyyy, Victor. Swede Johansen, eh? Well, don't worry, I won't hold it against ye. Roots of plants do indeed produce in-soil specific compounds called root exudates. These compounds are unique to each plant, and act as chemical signals to microbes, fungi, and other plants (legumes and their nodule-bacillus are the first example that springs to mind.) Some root exudates repel or attract certain insect larvae, bacteria, nematodes, competing plants, etc., but more interestingly, root exudates may hold part of the secret to inter-plant communication- any plant that has been attacked by a predator or illness releases "stress hormones" into the soil, and the plants in the surrounding area begin produce defensive compounds or chemical repellents in response, before they have even come onto contact with the offending party. In this way, the one plant acts as a sort of martyr, letting her cohabitants benefit from her loss. Plants can also exchange complex nutrients through roots, like the carrot-tomato or anise hyssop-grape interactions, in which the fruit of one plant actually absorbs qualities of her neighbor. Exudates and the extent to which they play a role in the soil food web is documented, and observable, but the significance if such miracles continues to be hotly debated among gardeners and academics. If you're going for trees, Oak is good for anywhere near a compost pile, and locust and alder will help produce lots of nitrogen, but siberian pea shrub might be your best ticket up thar in the arctic. And Hey! Don't forget to remember your tap-rooted herbs- mullein, dock, dandelion, comfrey- having them around pays off in spades.
Personally, I like to think that all the plants sing to each other, and some of them prefer to sing their parts together, kind of like a botanical gospel choir...
Recommended reading: Louise Riotte, Peter Tompkins/ Christopher Bird, or Researchy-type stuff for the sceptics

Well I'm frequently called upon to correct that Norwegianized misspelling of my name, since there's a JohanSEN expressway around here. Ja, half Swedish, anyway, and I've got the name to prove it. Siberian pea and alder are quite useful here and widely used. I'm familiar with the concept that the soil web isn't only food, but also information, and I've read Thompkins/Bird. I was wondering if Robert had come across any new research on it. I thought I had come across some factoid that plants directly exchange nutrients and even moisture between themselves, in addition to exuding various microbial foodstuffs. I suppose only a fraction has thus been revealed about how these kinds of functions operate. It's fascinating.

Victor, Plant Physiology. org Each year there are at least 3 papers published on the interactions of plants with each other and with micro organisms, the functions of these interactions.
This site has all the research they have published available by year. You can even download the papers in PDF format for later reference.

Bryant RedHawk wrote:Victor, Plant Physiology. org Each year there are at least 3 papers published on the interactions of plants with each other and with micro organisms, the functions of these interactions.
This site has all the research they have published available by year. You can even download the papers in PDF format for later reference.

Nice...thanks!