The Keystone Species for Healthy Soil

By Woody Woodruff

A keystone species is defined as a species that has a disproportionately large effect on its environment relative to its abundance. These types of species play a critical role in maintaining the structure of an ecological community, which in turn affects many of the other organisms in an ecosystem. The keystone species helps to determine the types, numbers, and needs of various other species in its community.

Dr. Wendy Taheri, Soil Microbiologist with Terra Nimbus LLC recently presented on keystone species at the SARE Soil Health Train the Trainer event. According to Wendy, the keystone species that is now missing from one of the world’s largest ecosystems, our cropland, is Arbuscular Mycorrhiza Fungi, (AMF). In nature, AMF is known as the recycler of nutrients for some 90% of all species of plants. The key role of AMF is to detect stress in its surrounding plant community and works to alleviate that stress through its connection to the plant community’s roots. Wendy listed sixteen reasons why a concerned member of any community you should want AMF in their soil.

  1. AMF increases the soil fertility by making more of it available to plants.
  2. AMF is a key species in its ability to build soil structure and increase water holding capacity, it forms soil aggregates.
  3. AMF produce more nutritious plant products for human and livestock consumption.
  4. AMF has the ability to replace the use of harmful chemicals by doing the work naturally.
  5. AMF eliminates nutrient runoff & leaching by creating glue that holds particles together.
  6. AMF increases a plant’s nutrient use efficiency uptake, especially phosphorus.
  7. AMF increases essential oil production in plants like peppermint.
  8. AMF adds protection from nematodes.
  9. AMF protects plants from fungal and bacterial diseases.
  10. AMF improves drought tolerance.
  11. AMF improves salinity resistance.
  12. AMF promotes earlier flowering.
  13. AMF promotes more flowering and more fruit.
  14. AMF increases more biomass and increased yields.
  15. AMF improves Carbon Sequestration which drives everything in life.
  16. Pollinators can detect chemicals in plants with a connection to AMF and prefer those plants to pollinate.

What do you think happens when that keystone species is missing from the soils ecosystem? We are only just now beginning to understand the consequences. An increase in toxic chemicals and soil disturbances due to industrial farming, coupled with a decrease in plant diversity through mono-cropping has all but eliminated this keystone species from farm soils. We as stewards of the land just didn’t know enough about the effects that our current input driven, heavy impacted farming system was having below the soil’s crust. Dr. Taheri stated it best when she said, “That is what we knew before, now we know more.” And after two days of her explaining the role of the keystone species in our farmland ecosystems and how our choices can have a positive or negative effect on our soil health, I feel that I know more and I am armed to make a positive effect.

IF we wanted agriculture to become a driving force in building healthier soil, growing healthier food, and improving climate extremes, it is clear that this keystone species, Arbuscular Mycorrhiza Fungi has to be permitted and nurtured to colonize our soil and plant communities again. That means that we, as stewards of the land, must look for ways to add diversity, reduce chemical inputs, and end excessive tillage.

Learn more about how soil fungi affect plant life through this cool podcast by radiolab: