Beneath high-country pastures live fungal communities that feed plants by gathering nutrients and water in the soil, yet little is known about how they function on New Zealand's high-country stations. Lincoln University master's student Nicole Parnell is trying to find out, Farmers Weekly reports.

Parnell is studying how three grazing regimes affect the fungi at Mount Grand Station in Central Otago: one area run with sheep and beef, one with sheep only, and one once grazed by sheep but now retired. Her results could help high-country farmers use the natural fertility of their soils to farm more resiliently.

The fungi in question are arbuscular mycorrhizal fungi, or AMF, which associate symbiotically with plants around the world. They support native grasslands, help plants cope with nutrient and drought stress, and resist erosion by stabilising soil structure, but how exotic pasture plants affect AMF communities is unknown.

"Animals shape the plant communities we see above ground. Plants shape the fungal communities we see below ground and therefore grazing has an indirect effect on the below-ground communities," Parnell said. Sheep and beef cattle graze very differently, she noted, and areas historically grazed by sheep are dominated by tussock communities that exotic grasses are now invading. Understanding how that invasion changes the fungal relationships is a step towards conserving what native systems remain while keeping productive ones going.

Parnell, who is studying for a master's in Natural Resources Management and Ecological Engineering and spent a semester in Vienna, presented the work in Lincoln University's Three Minute Thesis competition, where she won the prize for best master's student. "If we can understand what's going on underground, we can all make sustainable management decisions," she said.

Source: Farmers Weekly NZ