Nano Interventions: Fungi as Farmers, Plants as Mushroom Hunters- mycorrhizal evolution and its relationship to plants

This is the first part of a multi-part series that will discuss mycorrhizae and their importance to all living beings, specifically for landscape design and ecological restoration applications. This first discussion was written more than 10 years ago by me for an Evolutionary Biology class at Appalachian State University under the mentorship of Dr. Zack Murrell, but nonetheless introduces mycorrhizae as possibly the shepherd of phototrophs to land more than 350-450 million years ago.

Photo courtesy of www.mberg.com.auimagesmycorrhiza.png

A conditional “friendship” between plants and fungi (mycorrhizae) has received a lot of attention recently (note: this was written 10 years ago!) for its application in sustainable agriculture and habitat restoration, along with the fact that this relationship gives us an indirect view into the window of plant’s colonization of land. There is no debate that mycorrhizae benefit plants, however, there is some debate over how mycorrhizae evolved. The debate lies in whether fungal associations with plants evolved and are evolving simply in parallel to plants due to similar adaptive necessities such as similar environmental pressures or if mycorrhizae and plants coevolved with reciprocal gene-for-gene changes (Cairney 2000).


Mycorrhizae literally translates to “fungus-root.” This mutualism between plant and fungus involves a fungus colonizing the cortical tissue of a plant's roots. The fungus benefits the plant host because it helps the plant indirectly absorb nutrients. For example, mycorrhizae can break down molecules into elemental forms that otherwise  are unusable by plants, such as phosphorus. In addition, mycorrhizae can benefit plants by providing protection from pathogens and also offer the plant assistance in retrieving water. In return, the fungus gets carbohydrates, a necessary compound for metabolism, from the plant which is produced through photosynthesis (Cairney 2000).

This mutualism with fungi was essential for phototrophs to come onto land and proliferate (Pirozynski and Malloch 1975). One other example of fungi as "farmers" and plants as "mushroom hunters" aside from mycorrhizae can be demonstrated in lichens (fungi and cyanobacteria or green algae associations), which can withstand harsh environments because of their symbiosis and maintain permanent relations (Hawksworth 1988). Similarly, mycorrhizae helped plants conquer the terrestrial environment and are responsible for not only the diversity of plants today, but also that of fauna, due to their dependence on plants (Simon et al. 1993).

White Pine seedlings grown in sterile conditions (left),
White Pine seedlings grown in forest soil with mychorrhizae.
 Photo courtesy of www.msu.educourseisb202
About 90% of extant land plants form symbioses with fungi (Cairney 2000). In phototrophs that have secondarily reverted back to the aquatic environment, their ability to form relationships with fungi is lost, providing more evidence that phototrophs evolved onto land with the aid of fungal associations (Pirozynski and Malloch 1988). Today, Atlantic white cedar fluctuate their levels of mycorrhizal "infection" during drought and flooding (Cantelmo and Ehrenfeld 1999), which indicate how plants regulate their fungal needs and also may be reminiscent of the first plant’s journey to land. Also, plants that do not form mycorrhizal relations are mostly in highly disturbed habitats or in wet or aquatic habitats where mineral resources are adequate and the diffusion of oxygen prohibits the growth of fungi (Fitter and Peat 1993). Even algae living in tidal zones form mycophycobiosis during low tides to cope with the desiccating stress (Kohlmeyer and Kohlmeyer 1979). Lastly, fossil evidence agrees with molecular data in that arbuscular mycorrhizae form a monopyletic group and arose around 353-462 million years ago, around the same time plants colonized land (Redecker et al 2000).

Arbuscular mycorrhizae.
Photo courtesy of terroirists.nettagmicrobiology

Types of Mycorrhizae

Arbuscular mycorrhizae (AM) are mychorrhizae that actually penetrate the plant's cortical tissue and are the most numerous type of mycorrhizae in present-day plants. However, AM consists of only 130 species (Morton 1990) and shows generality to plant hosts (Perry 1998). AM’s include fungi in the phylum Zygomycota, more specifically the order Glomales, and the plant hosts include most angiosperms, some gymnosperms, Pteridophytes and various lower plants (Smith and Read 1997). These AM associations occur mostly at mid-latitudes where phosphorus for plant consumption is limited (Read 1991). Fossil and molecular evidence significantly indicate that the ancestors of extant plants formed AM relationships (Cairn 2000) and today’s plants who do not have AM have lost their relationship with their ancestral host plant (Barker et al. 1998). Gehrig et al. (1996) have found a fungus endocytobiont, Geosiphon pyriforme, to be related to an ancestral form of Glomales, thus forming a monophyletic group, and is probably most like the Glomus fungi that first aided plants to adapt to land life. In addition, molecular clock analysis suggests that the phylogenetic radiation of ancient Glomales paralleled the colonization of land (Redecker et al 2000).

Photo courtesy of farm3.static.flickr.com

Another type of mychorrhizae, Ectomycorrhizae (ECM), form a sheath around the outside of the root of the plant and are only on woody trees and shrubs (Cairney 2000). ECM fungi permit their host to acquire phosphorus, nitrogen and organic material (Read 1991). ECM have a great importance in shaping the ecosystems of forests and involve fungi that belong to the phylums Basidiomycota, Ascomycota and Zygomycota (Cairney 2000). Interestingly, however, ECM extant plants can also form AM associations, depending on the soil conditions (Smith and Read 1997). In addition, some ECM capable plants only form AM associations at the seedling stage, providing even more evidence that all land plants that exist at the present evolved from an ancestral AM condition (Cairney 2000).

Ericoid mycorrhizae (ERM) occur in extremely nutrient poor soils and at high latitudes and altitudes (Read 1991). The fungi in this association have extensive coils of hyphae that cover the epidermal cells of the plant host and involve specifically Ericad plants (the Heather family) and Ascomycete fungi (Cairney 2000). ERM’s have good saprotrophic abilities permitting them to provide nitrogen and phosphorus and tolerate toxic cations that are in acidic soils (Smith and Read 1997).

Photo courtesy of the botany department at WVU

Coevolution is the reciprocal genetic change among a species or populations (Thompson 1999), while parallel evolution is the result of similar pressures acting on species and results in similar yet independent outcomes. Which evolutionary process acted on plants and fungi in mychorrizal associations? Currently evidence for pure coevolution is lacking (Cairney 2000). However, Juenger and Bergelson (1998) propose that the coevolution is more “diffuse” and at a “guild” level of selection. Cairney (2000) has looked at this very question in his paper, The Evolution of Mycorrhiza Systems. He believes that coevolution did occur, but he sees no evidence that gene-for-gene coevolution is occurring in extant species and that it is simply parallel evolution at the present day.

Despite the lack of direct evidence that coevolution is occurring today in mycorrhizae, I think that coevolution is indeed occurring today. If coevolution were a continuum, then I would suggest the exant fungal and plant species are to a lesser degree coevolving because I believe there is some gene-for-gene reciprocation. Mycorrhizal associations can help a plant survive and reproduce, excluding certain genomes that cannot fully exploit this symbiosis. Generalities occur in fungal associations because of common ancestral lineages and does not infer that parallel evolution is occurring. It is exhibited that in certain environmental conditions certain mycorrhizal associations take place, which could support parallel evolution. Perhaps it is not, since a basis for the two organisms to come together in symbiosis must have been established at some point to permit the relationship. I suggest that mycorrhizal associations are still coevolving, to a degree, in which genetic give and take must take place. It is important when creating fungal phylogenies of those that form mycorrhizae to include plant hosts and vice versa, for mycorrhizae associations were and are the essential associations for plants to survive. 

With the current prevalence and severity of habitat destruction and the overpopulation that permits limited resources, soil structure will never be perfect everywhere on Earth. However, for native plants and ecosystems to become or remain healthy and supporting, mycorrhizae are and will be the mechanism of survival for all life forms. In the future, man will foresee and artificially create these associations for habitat restoration and crop production and this application will be an important factor that will enable humans to feed one another and rebuild plundered ecosystems.

Barker, S.J. Tagu, D. Delp, G. 1998. Regulation of root and fungal morphogenesis in mycorrhizal symbioses. Plant Physiol. 116: 1201-1207

Cairney, J.W.G. 2000. “Evolution of mycorrhiza systems.” Natuwissenschaaften. 87:467-475

Cantelmo, A.J. and Ehrenfeld, J.G. 1999. Effects of microtopography on mycorrhizal infection in Atlantic white cedar pine. Mycorrhiza. 8: 175-180

Fitter, A.H. and Peat, H.J. The distribution of arbuscular mycorrhizas in the British flora. New Phytol. 125, 845-854     

Fitter, A.H. and Moyerson, B. 1996. Evolutionary trends in root-microbe symbioses. Phil Trans R Soc Lond B. 351:1367-1375

Gehrig, H. Schubler, A. Kluge, M. 1996. Geosiphon pyriforme, a fungus forming endocytobiosis with Nostoc, is an ancestral member of Glomales: evidence by SSU rRNA analysis. J Mol Evol. 43: 71-81

Hawksworth, D.I. 1988. Coevolution of fungi with algae and cyanobacteria in lichen symbioses. Coevolution of Fungi with Plants and Animals. Academic Press. 125-148

Heijden, M.G.A. van der. Boller T. Wiemken A. Sanders I.R. 1998. Different arbuscular mycorrhizal fungal species are potential determinants of plant community structure. Ecology. 79: 2082-2091.

Juenger, T. Bergelson, J.1998. Pairwise versus diffuse natural selection and the multiple herbivores of scarlet gilia, Ipomopsis aggregata. Evolution. 52: 1583-1592

Kohlmeyer, E. and Kohlmeyer J. 1979. Marine Mycology: the Higher Fungi, Academic Press

Morton, J.B. Benny, G.L. 1990. Revised classification of arbuscular mycorrhizal fungi. Mycotaxon. 37:471-492

Perry, David. 1998. A movable feast: the evolution of resource sharing in plant-fungus communities.Trends in Ecology and Evolution. Vol.13, issue 11: 432-434

Pirozynski, KA and Malloch, DW. 1975. The origin of land plants: a matter of mycotrophism. BioSystems. 6:153-164

Read, D.J. 1991. Mycorrhizas in ecosystems. Experientia. 47:376-309
Thompson, J.N. 1999 The evolution of species interactions. Science. 284:2116-2118

Redecker, D. Kodner, R. Graham, L.E. 2000. Glomalean fungi from the Ordovician. Science. 289: 1920-1921.

Simon et al. 1993. Origin and diversification of endomycorrhizal fungi and the coincidence with vascular plants. Nature 363: 67-69

Smith M.D. and Read D.J. 1997. Mycorrhizal symbiosis. Academic Press, London

Thompson, J.N. 1999. The evolution of species interactions. Science. 284: 2116-2118.

Extending an Environmental Metaphor with Photoshop

Photo courtesy of NPR and of Robert and Shana ParkeHarrison/Jack Shainman Gallery Guardian

Photo courtesy of NPR and of Robert and Shana ParkeHarrison/Jack Shainman Gallery
Artists, Robert and Shana Parke Harrison, present a metaphor of humankind’s desire to dominate the “Natural” world and simultaneously mend those intrusions.  Presented in a visually compelling dreamscape world, a man, or sometimes groups of men, toil(s) in an effort to remediate a pervasive environmental wasteland.  Often these tasks appear absurd in that they address apparent symptoms by tidying up a world so damaged by a surplus of waste.

The husband and wife team create these surreal images with a combination of digital media, painting, sculpture, and theater.  Their process begins like many others, with a series of sketches and 3 dimensional study models.

Photo courtesy of NPR and of Robert and Shana ParkeHarrison/Jack Shainman Gallery
Through this process they create compelling images that are both tragic and comedic as the men in the images work in vain to address problems with tools ill suited to the pursuit.  They suggest that humankind neither understands the root of the environmental degradation nor do they have to the capacity to deal with the symptomatic results of that degradation. 

Admittedly the duo offers that this work does not present any answers for the ecological squalor much or our planet has descended into  -  “We are not scientists, we’re artists” .  The hope is that these images will help folks “think critically more critically about humans' relationship to technology and nature, and ‘inspire change, one viewer at a time.’"

Oscar Wilde tells us, to paraphrase, that all art is useless.  This work is thought provoking, but ultimately useless.  Recognizing humankind's place in the greater ecosystem is the challenge and these images brilliantly show the futility of acting without thinking and attempting to repair that which we do not understand.  That does not however, preclude the need to seek understanding, set forth thoughtful solutions, and proffer a more symbiotic existence with the planet.


Water Footprint Visualization

In celebration of World Water Day 2011, visualization.org hosted a contest to visualize urban water data, and to assist them draw connections and insights from across the spectrum of health, economic, environmental, and policy perspectives.

The winning entry is from a duo from Harvard: Joseph Bergen and Nickie Huang. Their entry has two basic components. The first screen is an interactive map. Users can scroll over different nations to compare details of water supply and usage around the world. First click on one country and then the hover over another to see how their numbers relate to each other.

When you click on the icon in the center right, a list of consumer products and their related water usage profile are presented.

This graphic and interface could use another level of refinement to improve user interface would be helpful. It's a bit overwhelming in terms of spatial data overload, an injection of simplicity would make the sensory experience more palatable. Play around with it and see what you think.



NextFab: Philadelphia's Nerd Gym

NextFab logo, courtesy of NextFab
From Shopbots to table saws, Philadelphia's latest nerd gym has everything for the aspiring inventor/tinkerer/artist to flex their chops.  NextFab is a membership based fabrication shop. After going through proper safety and operation classes, you can find yourself "printing" a plastic model on their 3d printer or cutting any variety of materials on their laser cutter. You can visit their website for a full list of their machines and classes. In addition, if you don't have the time to fabricate something on your own, you can hire NextFab to make it for you.

Image courtesy of NextFab
Accessibility is a huge component of what NextFab is all about. When NextFab creator Evan Malone was a graduate student at Cornell -New York's only Land Grant University- he found inspiration from the small-scale manufacturing setups, called Fab Labs, developed by MIT professor Neil Gershenfeld. Fab Labs assist underprivileged communities with the development and production of the tools and items they need. National Science Foundation has funded 60 Fab Labs in 18 countries, in mostly rural areas in places like Costa Rica and India. "It's the power of just providing access" to technology, says Malone.

NextFab is nestled into the University City Science Center, on Philadelphia’s Avenue of Technology and they squeeze a lot of heavy and techy based equipment into their 3600 square foot facility. The cozy quarters are a by-product of aspiration for accessibility within an urban condition, and one that is easily worked around.


Stay tuned for breaking news on our friends Kate and Joel from Kaman+Erland who will be using a similar model to create a collaborative that focuses more on hand craftsmanship at their exciting new studio Germantown!


Install Day with Tree-Vitalize

Emily, Liz, and David on Phil Elena St. in Philadlephia. Liz just finished demonstrating her "root massaging" technique on a tree that Charlie Brown would really appreciate.  We want to hire Liz to plant all our trees with love.
Today we helped to plant trees in the Germantown and Mount Airy neighborhoods in Philadelphia with The TreeVitalize Philadelphia Tree Planting Program.  You can check out an older blog of ours that talks about TreeVitalize and its relationship to the Pennsylvania Horticulture Society. It was a cold and drizzly day but our Group, Group G, (the Groups went from A to H) finished in record time and therefore usurped the name Group (a).

David and Liz hard at work at our sidewalk street planting condition. 
We followed the lead of our veteran TreeVitalize planters David and Liz who have a combined 20 years of tree planting experience with the program as well as training from the Philadelphia Horticulture Society (PHS).  We offered our thoughts from time to time but mostly wanted to observe the process and get a feel for how PHS likes to plant trees.  

The trees were bareroot and tiny so we did end up staking them.  Jim urban might not approve, but the idea is that these trees are so thin (1 1/2" caliper max) that the presence of the stakes helps to make them visible.  Our friends at TreeVitalize assure us that they lose more trees to vehicle encounters because often people don't notice until it is too late.  We will be monitoring our trees and maybe even install a Gator bag if we feel like the homeowner needs a little help with the maintenance. 

The Tree Tenders program at PHS seems like it is more than effective with their training and in fact we are planning on attending one of their sessions to get a more in depth exposure to the PHS method.


Micro Interventions: DIY Cartography

Western North Carolina Campus DIY Cartography, Image Courtesy of PLOTS
Maps are exceptionally powerful tools. Aerial photography presents itself as of the most stunning and convincing of those tools.  Traditionally, cartography has been an expensive, time consuming, and highly specialized activity.  To a large degree, it still is.  But what does it mean when you make aerial photography accessible to anyone with $100 worth of supplies and a digital camera?

That is what a group of of "activists, educators, technologists, and community organizers now known as Public Laboratory developed when they came  together with the goal of generating new ways to promote action, intervention, and awareness through a participatory research model."

Photo Courtesy of PLOTS
"The Public Laboratory for Open Technology and Science (PLOTS) collaboratively develops and publicizes accessible technologies for investigating and reporting on local environmental health and justice issues. PLOTS provides an online research space for citizens, linking them to scientists, social scientists, and technologists. PLOTS is an expansion of Grassroots Mapping, where citizens use helium-filled balloons and digital cameras to generate high resolution “satellite” maps."

Their map making goals are simple:
  • low cost
  • data legibility (including a preference for maps and other rich visual means of representation)
  • ease of use/low barrier to entry
  • public participation
  • high quality, environmentally and socially relevant data
  • creative reuse of consumer technology
  • open source and user modifiable design
Image Parts List, Courtesy of PLOTS

Here is a link to a pdf which gives an illustrated process with a parts list:

This pdf has a little more instruction:

Some other great links include:


This is a related organization called Grassroots Mapping that has a ton of great information and a great network of friendly folks:


It's exciting to think about what this can mean as a tool for homegrown community planning to land use and zoning disputes to art and design.  We can 't wait to try this out ourselves at (a)bitotic, in the mean time, Happy Mapping Everyone!


The World Timber Trade

The World Wildlife Federation provides us with a wonderfully composed infographic on the worlds 5 largest timber exporters and who is buying that timber.  Not surprisingly the United States and China are the heavyweight importers.  The European Union is not presented separately but it would seem to dwarf the others with Germany, Italy, and Belgium coming in third to the US and China.

Measure for Measure

A clever "Tree Tape" by designer Nitipak Samsen offers a unique perspective on carbon sequestration for some of our favorite American activities.  It’s a simple measurement tool that you print out and wrap around a tree near you.
For you tree nerds out there, this tool is kind of basic.  The online tool provides a dropdown menu tha lets you choose from only three tree type categories:  rainforest, native hardwood and softwood.  We know from Dendrology class that those monikers are all but useless in truly defining the differences in tree types. But what is truly fun about this tool is the subcategories that let you know such things as, the number of cheeseburgers your local tree helps to offset.

Samsen writes:
Ever wondered how much CO2 absorbed in a tree? And how much is how much?
In the process of developing the BuyProduct project, I designed a tree measuring tape for children.

This tape translates how much CO2 absorbed in the tree into the amount of activities rather than grams of CO2, e.g. 1 hour on a flight or 2 days of breathing.

Since then I received quite a few interests wanted to use it in schools. So I decided to make it available for public to create and try it for themselves.

I’ve made a web app, user selects the tree type and the activity, it will create the PDF which will be printed, cut, glued and ready to try.

Download your own here.

One has to wonder: is the measure of the paper, glue, ink, and electricity required to make the tape is factored into the measure?


Sound Matrix from Sembeo

A very fun (and addictive) music tool.  Their website has two that play at the same time.  Enjoy here or there!



Best iPhone + iPad Apps for Landscape Architects


In celebration of receiving my iPad soon, I put together a list of apps that may be useful for those of us in the landscape architecture field. I am sure this list will become outdated soon enough, but nonetheless, here it is! Please feel free to add to or comment on any of these apps! See part 2 here. 


First at foremost, Dropbox is a must have. You can drag any file from any desktop, iPhone or iPad that has the software and access it from any other machine that also has the software.

Motion X GPS ($.99)
This is the app I use to record tracks and waypoints when I am in the field (mostly doing large scale vegetation analysis). If you want to take pictures with your iphone, this app will geotag them for you if you use the camera interface within the app. You can  email your waypoints, tracks or geotagged photos  to yourself and view them in google maps, google earth or ArcGIS. Doesn't quite replace a GPS unit, but has pretty good accuracy.


So if you studied landscape architecture, I don't need to explain this one. I use Dirr's DVD all the time at work, and now you can have it on your mobile apple device! Not nearly as awesome as Dr. Brahm's labs, but maybe one day there will be a Braham app, with stories and all.

Tree ID ($2.99)
A pretty good app for when you forget how many leaflets a pignut hickory has.

Contribute to invasive species mapping and use to ID invasives in the field. Participatory sensing!

Florafolio ($3.99)
A collection of our native flora.

Botany Buddy ($9.99)
Over 2,000 species. ID or choose plants.

Civil Engineering.

Water and Waste Management Engineer ($4.99)
I have not tried this one yet, but it has pretty much any calculator you need 

Quickly calculate runoff.


AutoCAD WS (free)
View, edit, annotate and share CAD files in the field. The best part is that you can view a google map aerial underneath your CAD linework (well, only if your drawing is georeferenced, which by now all CAD drawings should be, come on people!).


Can't wait to try this app on my iPad. Rates as one of the best apps out there.


GIS and Mapping.

ESRI ArcGIS (free)
View data, collect data with your iPhone or iPad GPS, view attribute info. It's a start in a good direction. Geoprocessing to come.

Soil Web  (free)
Access real-time USDA-NRCS soil data in the field!


Designnear- with a database of over 575 projects, find a cool design project near you!

Any Audubon apps!