Plant symbiotic relationships

In recent years I’ve observed complex symbiotic relationships among birds and my pear trees, insects and my pear trees, blackberries and my pear trees. One such relationship I find interesting and confusing is the symbiotic relationship between the aggressive growing heirloom blackberry and how fast nearby trees begin to grow and fruit when it is present. Why is that? I’ve observed the behavior 10 or more times. Is it the threat? The fact that the blackberry kills grass and changes the soil? What are your thoughts? Ants and soil fungi and bacteria to earthworms are all connected closely to our trees. Dead trees seem to be an important part of nature’s balance. Should we be hauling old apple and pear wood out of our orchard because I started leaving mine there? I noticed certain relationships can only exist with some things in nature if things are undisturbed.


I have made the same observations from childhood. I destroy trees I find harmful and add trees I find beneficial. I try to never plant the same species next to each other unless I have to. For myself creating a food forest means also using native trees and plants in the mix for the benefits they bring. My main fertilizer is leaves, logs, and biochar to create a naturalistic forest floor. I also raise 20 species of isopods in containers to add to the forest habitat as I create it.


I believe part of what you are observing is the fungal neural network. Mycorrhiza (from Greek μυκός mykós, “fungus”, and ῥίζα rhiza, “root”;
Mycorrhizal connections between the tree and blackberry can alert the tree of possible pathogenic dangers, also the fungi will transfer food between them depending on the wants and the needs. Some of these networks are square miles wide. These fungi also help boost the immune systems of bees by offering a nectar to them that has been studied and proven to increase the immune system of honeybees. Some believe the loss of these networks is part of the reason for colony collapse disorder. More studies are going on right now where they are giving the bees the nectar and seeing if they have less incidence of Colony collapse disorder. It is a formal University study with controls and in multiple locations throughout the USA.
It’s the blackberries too! And not just the wild ones, I have observed for only 2 years, but it was amazing, my tomato plants planted among the blackberry canes seem resistant to the multitude of leaf diseases they get. They now for two years have fared way better than my in ground or potted tomatoes.


As long as the blackberries are competing with the grass you can’t know if it’s the blackberries or lack of grass. Blackberries are part of tree ecosystems and probably don’t exude the toxic chemicals grasses are known to in their competition with trees. A problem with blackberries is that bugs love them and won’t likely stay put.

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This is a very profound , and complex topic.
I believe sod is mostly only people friendly,
It may be what got us out “out of the trees” into a savanna in the first place.
There is something comforting about sod from a human perspective .but not nessicarily from a trees perspective
In natural succession ,trees hardly ever grow out of sod,usually there is a transition to tall perennials ( blackberry goldenrod etc.) then the tree seedlings take hold. Sod is extremely competitive to a tree.
This cycle is what the permaculture movement is after.
The challenge is to get the right plants in there,that mimic a natural succession,and is people friendly .
Sod is easy year to manage ,from a comercial perspective ,more pleasing to the eye of most people.not nessisarly the best from a trees perspective .

I believe a large part of the decline of our polinators is do in large part to the over use of herbicides and weed eaters ,eliminating the wild plants that they rely on. Think of 30 years ago , how many wild plant their were around houses and farms , that “was” the habitat those pollinators relied on , now it is mostly gone. The mowed lawn , with round up borders , and not a “bug” in site has become the socially acceptable norm. This is NOT the right thing to do.

I do have sod, but have been mowing less, letting the wild flowers bloom in areas, not mowing every thing at once, but leaving areas un mowed, plants I used to see as weeds now I see as beneficial ,.

It’s easer to not " weedeat "and often better.

I recommend to get a beverage , and sit on the line between a mowed area and and unmowed one and pay attention . It is amazing ,the amount of life in the unmowed area. And it’s mostly all good.
So why do we mow so much ?

Because it is socially acceptable
It looks good
Makes managing easyer
We don’t have temperate zone permaculture plants that fit.?
So we don’t get snake bit ( important here ! )
Not necessarily for the benifit of the plant we are trying to grow

Complex and profound . Indeed .!

Sorry if I wondered off topic, "it’s all the same topic " isn’t it !

I have found that blackberrys make really good companions to young fruit trees. Production is good on blackberrys in the early years.
And the trees seem to like their friends
As the trees mature ,production of blackberrys has declined here.
Just as in nature .


I’ve witnessed several types of bees feeding on the mycelia of my wine caps that i dug up in the garden. the smell of it draws them in and once 1 finds it , many more come. its amazing! i totally agree with you! the more fungi you have on your property the better. read Dr Paul Staments Mycelium Running. a great read!


The savanna certainly was a great area for early humans- as long as there were a few low branched trees for them to escape from predators. I agree that may be part of the instinctive appeal of sod, but it was also an essential means of protecting feudal estates by allowing a clear view of invading warriors and time to prepare to battle or flee. Once the look of expansive, well grazed sod became a normal feature on estates it was probably passed on long after the establishment of a more secure form of civilization, with the less wealthy imitating it as best they could on smaller properties.

Now native mini-prairies are a bit of a rage, although few around here manage to establish them successfully, getting ripped off by fake experts. On Bob’s thread about visiting Alan’s orchard he has pictures of an orchard I manage that has a successful version of one on 3 or 4 acres of the property. There are also very frequently mowed soccer fields and some other somewhat less mowed lawn there. I wish the manager would mow under the fruit trees more in spring because tall grass seems to encourage scab here by causing the dew to sit longer on the leaves.

The meadow is certainly an Eden for pollinators of every sort and provides special food for a wide range of birds as well. It is also very beautiful to those who appreciate wild landscapes. The landowner is exceptionally proud of it.


Interesting observation Clark. Could be (and likely is with complex systems) due to several effects/factors.

It may be the BB’s eliminating the grass as you observed, but what/how do they do that? By changing the microbe balance of the soil? By using up spare nitrates? Something else? Or most likely a combo of these sorts of things.

Hard to say, and we humans are not likely to ever know all the inter-relationships in the soil that goes on between the plants, microbes a soil critters. But while interesting to investigate, it may be enough to notice these effects at a macro level, and use them in our orchards/gardens.


my favorite symbiosis is the carnivorous plants Nepenthes rajah.
because it is a toilet for rodents. the rodents eat the sweet part of the plant and then eventually shit in the plant. and the shit is then used as a source of nutrients

Some plants also produce nectar when the attacked/eaten. the nectar then attracts ants which attack the plant eater, e.g. aphids

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The three-way symbiotic relationships between specific microscopic mites, fungi, and crop plant species are some I’d be be happier without.