ecosystem importance: if barren, add llamas (Introduction)

by David Turell , Friday, October 27, 2023, 22:03 (391 days ago) @ David Turell

Tried and worked in Peru:

https://www.sciencenews.org/article/melting-glacier-peru-llamas-climate

"When glaciers melt, they leave behind barren landscapes that can take decades to support plants and animals. But a new study found that within just three years, such exposed land was revitalized by llamas, whose activity nourished the soil and fostered plant growth.

"By the foot of Peru’s shrinking Uruashraju glacier, researchers partnered with local farmers to capture and herd llamas on four designated plots. For three days a month from 2019 to 2022, the llamas (Llama glama) grazed the plots, fertilizing them with dung and dispersing viable seeds from droppings and fur.

"By the end of that time, the otherwise arid and easily eroded soil stabilized, grew richer in nutrients and supported 57 percent more plant cover than before, geographer Anaїs Zimmer and colleagues report September 24 in Scientific Reports.

"Such a revival of the ancestral Andean practice of camelid herding could potentially cushion the crops, animals and livelihoods of local communities from the impacts of climate change, says Zimmer, of the University of Texas at Austin.

"As is the case worldwide, glaciers are disappearing in Peru’s Cordillera Blanca mountains at an unprecedented rate. And as the ice shrinks, nearby ecosystems wither: They lose access to summertime supplies of freshwater and sometimes encounter harmful acidic minerals in rocks once covered by the glaciers.

" Llamas may help counter some of these effects. Their transformation of the land, as seen in the new study, could reduce rock weathering and help the soil hold onto more moisture, thus limiting the acidic runoff that can poison farmers’ crops. Such contamination is one reason local farmers partnered with the researchers. The animals’ behavior could one day even generate new pasturelands as soil quality improves.

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"...the size and speed of the changes the llamas helped bring about surprised the researchers. From 2021 to 2022, the average amount of plant cover in the llama plots grew from about 9 percent to nearly 14 percent — faster than it did in four control plots. Four new types of plant species also moved into the experimental plots over the course of the study.

"The research underscores the valuable roles animals play in shaping landscapes, says ecologist Kelsey Reider of James Madison University in Harrisonburg, Va., who was not involved with the new research. Sprinkling nutrients such as phosphorus over the soil can produce similar effects on plant growth, she says, but “the animals themselves are doing a lot.”

"For one, animal poo is special: It holds onto both moisture and microbes. For another, in grazing and trampling on plants, the llamas weed out dominant plants, making space for new species."

Comment: it is not always a top predator that is needed. This shows the effect any living organisms have on transforming the Earth.