Small Mammals, Mycorrhizal Fungi, and Forest Regeneration

Small mammals and mycorrhizal fungi are integral component to forests, yet much remains unknown about how their interactions contribute to the health and resiliency of forests. At the Second College Grant ASCC installation in northern New Hampshire, University of New Hampshire researchers are studying the role of small mammals (mice, voles, chipmunks) in dispersing mycorrhizal fungi and subsequent effects on forest regeneration. 

Mycorrhizal fungi are important symbionts that colonize roots and assist trees with nutrient and water uptake. Timber harvests can significantly reduce mycorrhizal fungal diversity. However, small mammals that consume fungal fruiting bodies, like mushrooms and truffles, may be important for dispersing fungal spores in their scat, thereby repopulating regenerating forests with local fungi.

Southern Red-backed Vole
Southern red-backed voles (Myodes gapperi) are among the most common small mammal species at Second College Grant and disperse a diverse array of spores from mushrooms and truffles. Photo Credit: Ryan Stephens, University of New Hampshire
Truffle Spores
Microscopic spores from the truffle genus Octaviania found in the scat from a southern red-backed vole (Myodes gapperi). Photo Credit: Ryan Stephens, University of New Hampshire

 

 

 

 

 

 

 

 

 

 

 

To assess linkages among small mammals, mycorrhizal fungi, and trees, postdoctoral fellow, Ryan Stephens, and advisors Dr. Rebecca Rowe and Dr. Serita Frey are conducting field surveys of small mammals in one-acre gap cuts at the Second College Grant ASCC site. They are using these surveys along with microscopy and genetic analysis of small mammal scat to determine the type, distance, and abundance of mycorrhizal spores that small mammals are dispersing into cleared forest gaps. The research team also has initiated a greenhouse experiment to determine the role of small mammal-dispersed spores on mycorrhizal colonization and growth of tree seedlings. They have also established fenced exclosures in the field, which prevent access by small mammals, to assess their influence on plant regeneration and soil fungal communities over time. Results of this research will shed light on how animals contribute to the response of forests to disturbance, including regeneration following timber harvest. 

Author: Ryan Stephens, Postdoctoral Fellow, University of New Hampshire 

Small fenced enclosure
Fenced small mammal exclosures in one-acre gap cuts will help determine the influence of small mammals on plant regeneration and soil fungal communities following timber harvest. Photo Credit: Ryan Stephens, University of New Hampshire
Red spruce seedlings in a greenhouse
Seedlings of red spruce (Picea rubens) grown in the greenhouse with various treatments of small mammal scat and field collected soils. Photo Credit: Ryan Stephens, University of New Hampshire