Symbiotic relationships are super common in nature – just think of Nemo and the anemone that he made his home. It may seem hard to believe, but plant roots have this same relationship with certain fungi, which are commonly known as mycorrhizae. As I mentioned in an earlier post, myco=fungus and rhizo=roots.

    Fungal Friends

    I won’t go into too much detail here, but let’s just say that this plant root-fungus relationship is a “win-win” for everyone involved. The plant gets nutrients that might otherwise be difficult to obtain because they are far away (the fungi throw out these micro sized tubes to suck nutrients out of the soil and share them with the plant) and the fungi get energy in the form of sugar (made by the plant during photosynthesis).

    Fungal tubes
    Example of the “tubes” a fungus throws out to hunt for nutrients.

    Fungal tips
    Fungal tips on fine roots in tundra soil.

    A recent episode of the podcast Radiolab titled “From Tree to Shining Tree” explored these fungal relationships (amongst other topics) that can connect the root systems of forests. I highly suggest you take a listen here. If you are interested in just the fungal relationships, skip to minute 11:10 or so.

    The Longer the Better

    As covered in previous posts, plants require certain nutrients (namely Nitrogen) to “grow big and strong.” In warmer climates, dead plant material (and animal) is broken down decomposers and detritivores in the soil, making Nitrogen available to plant roots. Since a good chunk of dead material freezes each year before it has time to fully decompose, Nitrogen gets locked down deep into that permafrost layer.

    Soil monolith
    A soil monolith showing the bottom mineral layer, which sits right above the permafrost and below the active layer.

    A plant which forms a symbiotic relationship with root fungi has the potential to extend the length of its roots by several millimeters or even centimeters…possibly long enough to reach down into the depths of that permafrost layer.

    Root extensions
    A graph showing the extended depth of fungal tubes with temperature.

    Which plants are “winning?”

    To determine which roots are accessing the most Nitrogen AND which roots are forming these mycorrhizal relationships AND exactly what fungi are growing on those roots…well, that take further analysis. As mentioned in the last post , all of the root samples were sectioned off into 2 categories…isotope analysis and genetic analysis. The genetic analysis will look at not just what species of plant is throwing down roots in this tundra soil, but what species fungus (or fungi) is throwing down tubes as well. We won’t know these results for quite some time (think months, not weeks), so in the mean time…here are some pictures of roots and their little fungal friends.

    Deep Roots
    Deep roots with mycorrhizae.

    Fine roots
    Another set of fine roots with their mycorrhizae.

    Close up
    Close up of the symbiotic relationship happening deep in tundra soils.

    Stay tuned for the next journal…which will just be a lot of pretty pictures as I say goodbye to the tundra.

    Author
    Date
    Location
    Fairbanks
    Expedition
    Weather Summary
    Clear and sunny
    Temperature
    60

    Comments

    ☼ Grace Nwankwo ☼

    Since the plants use nitrogen to grow, does it take out the nitrogen from the atmosphere and help the Earth or does it NOT help the Earth because once all the nitrogen gas leaves the atmosphere, when some scientists dig up permafrost, and all the nitrogen releases back up into the atmosphere?

    sandeep

    how does plant unlike a fungi decompose. does the plant keep its organic integrity or does it decompose and the nutrients from it go to another plants needs.

    Frank Ochoa

    Hello! ive been reading your journals and they are very interesting! I was curios as to how hard was it to find the plants that you have written about.

    Sandeep Bijoy

    sorry i meant when the plant is decomposing in the permafrost.

    Kevin A.

    How do you determine if in a win win situation example as given that the fungi isn't taking dangerous amounts of nutrients away? And if the plants were moved to a new more tropical area would the relationship still be needed

    Shaniya Dawson

    Is it a bad thing if nitrogen gets locked into the permafrost layer?

    Makiya Cobb

    My questions are, Is fungi important to humans and if so why and What are the nutrients required for fungi to grow larger.

    Ericka Jones

    I know you said that it would take months to find exact results but if you were to make a guess on which plant is winning, do you have any plant in mind?Also, at first, I did find it a bit strange on how root fungi would actually help other roots of plants. If I remember correctly, fungi feeds off of other plants. Only using that little information I had, I assumed plants that grew independently would only be able to grow roots that reached permafrost. I never thought that fungi would be able to help other roots.
    Another question. Is there any conditions the roots or plants need in order to form a root-fungus relationships? If so, what plants are at a disadvantage?

    Hassan Doostdar

    Are there any negative effects associated with too much nitrogen or do the plants just fill up and not absorb the rest? For example would a plant be harmed if you gave it more nitrogen fertilizer than it needed or would it just leave the excess?

    Guest

    Ms. Kemp how long would the roots in the permafrost last?

    Jamal Herard

    that was me

    Lamar King

    Since Plants need nitrogen to get big, is that there is so much of it in the Atmosphere? Since the nitrogen is stored beneath the permafrost is this a good side to climate change since the permafrost is melting?

    Bridget Grason

    Are the soil samples affected by the amounts of fungi and nitrogen affected? What happens if there is more of one or the other, what happens to the soil?

    Nia Howard

    Is it possible for the nitrogen to overpower the soil and prevent it from decomposing?