Vegetal Studies

Just a note to say that this semester's "Spinoza and Ecology" reading group went well, and that we'll be continuing in January with Gregory Bateson, Félix Guattari and a few other authors who have taken Spinoza with an ecological bent. If it interests anyone, I'd recommend Dianne Chisholm's new publication on ecology, systems theory and indigenous storytelling entitled “To Think with a Haida Ecology of Mind: Robert Bringhurst's Ecological Imperative for an. Endangered World". She tells me it will be fresh off the press in early 2011.

I've gotten more than a few inquiries about the Spinoza reading group from people who couldn't make it to the meetings. If any of these people are still interested in getting cozy with Baruch, I would gladly facilitate a repeat "Ethics" series. Or perhaps we could change it up with the Theological-Political Treatise.

In addition, an update on the plants:

They are still alive! We've received our seed order from High Mowing Organic Seeds, and I will be starting the germination process as soon as I return from Alberta in January. There should be edible vegetables by February/March.

The watering system is finally taking shape. Morgan has constructed an impressive 10ft stand for the water tank, and we've got a basic pipe network temporarily strung up. After our finals are over, we'll start doing 'wet' runs of the completed system. Hopefully, the plants will stay hydrated over the semester break, in the absence of us pesky humans.

Looking forward!

(Your plant group will find this interesting, methinks. Track down the references too, some interesting stuff.- David Morris)

Copyright © 2010 Elsevier Ltd. All rights reserved.
Trends in Ecology & Evolution, 18 October 2010

doi:10.1016/j.tree.2010.09.003

Swarm intelligence in plant roots

František Baluška^1,  

, Simcha Lev-Yadun^2,  

 and Stefano Mancuso^3,  

¹ IZMB, University of Bonn, Kirschellee 1, 53115 Bonn, Germany
² Department of Science Education - Biology, Faculty of Natural Sciences, University of Haifa - Oranim, Tivon 36006, Israel
³ LINV, Plant, Soil & Environmental Science, University of Firenze, Viale delle idee 30, 50019 Sesto Fiorentino (FI), Italy

Swarm intelligence in animals and humans has recently been reviewed [1]. These authors posited that swarm intelligence occurs when two or more individuals independently, or at least partly independently, acquire information that is processed through social interactions and is used to solve a cognitive problem in a way that would be impossible for isolated individuals. We propose at least one example of swarm intelligence in plants: coordination of individual roots in complex root systems.

Plants develop extremely complex root systems, which colonize large soil areas. For example, calculations for one winter rye plant revealed 13 815 672 roots with a surface area of about 130 times that calculated for shoots [2]. Growing root apices show complex behaviour based on ‘intelligent’ decisions about their growth directions [3,4]. Moreover, growing roots show coordinated group behaviour that allows them to exploit the soil resources optimally. There are three possible communication channels for context-dependent information transfer among the numerous root apices of the same plant. Firstly, neuronal-like networks within plant tissues that support rapid electrical and slower hydraulic and chemical information transfer between the root apices [5,6]. Secondly, secreted chemicals and released volatiles allow rapid communication between individual roots. Thirdly, there is a possibility that the electric fields generated by each growing root [7] might allow electrical communication among roots. These electric activities and electric fields show maximal values [7,8] at the transition zone of growing root apices [3] which behaves as a ‘brain-like’ command centre [6,9]. Roots may use swarm intelligence for their navigation, coordination, cooperation, as well as for their ‘war-like’ aggressions [10]. It is important that every root has its own identity provided by its unique sensory history accumulated via its own command centre. Each root apex acts both as a sensory organ and as a ‘brain-like’ command centre to generate each unique plant/root-specific cognition and behaviour [3,6,9].

Recent advances in the emerging field of sensory plant ecology suggest that the sensory information collected by one plant is shared with neighbouring plants [11,12]. In the case of root apices, sensory information appears to be processed collectively in the root system to optimize root-mediated territorial activities [13,14,15,16]. These root apices solve cognitive problems such as where to grow and whether to grow at all, to fight or retreat in a face of competitive roots and root systems [10] and to enter symbiotic relationships with mycorrhiza fungi (and 

Rhizobium bacteria in the case of some species) [3,4,5,6,13,14,15]. So roots enjoy a rich ‘social’ life at the individual plant level and they continuously solve problems that could be called cognitive [4,13].

Swarm intelligence is essential for the evolutionary success of roots and, consequently, the whole plant. The accumulating data on the complicated and sophisticated integration of the root community at the individual plant level described above composes the basic level on top of which similar integrated actions occur at the group level. The fact that certain plant species are able to distinguish between self and non-self roots [13,14,15,16] helps plants to integrate the mutual self- and non-self signals for decisions at the community level to invest more or less in root growth towards resources, in communication, or in chemical defences according to neighbour relatedness. Thus, plants acquire information through and within their root system, which is processed through social interactions and which provides solutions to cognitive problems that are not available to isolated individuals, allowing them to better exploit and survive in the three-dimensional, competitive and hazardous dark underground world.

It emerges that the swarm intelligence does not have to be restricted to animals. Plants can learn and remember through epigenetic modifications and biochemical processes [13,17]. Moreover, the concepts of plant intelligence, memory, behaviour and cognition are elaborated and prove to be relevant for higher plants [5,13,18,19]. In conclusion, the swarm intelligence concept should be considered as a working hypothesis for plants until enough theoretical analyses and experimental data accumulate to dismiss or accept it concerning adaptive plant behaviour.

Winter is nearly upon us, and what could be a better time to begin a vegetable garden?!