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
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.