Understanding how post-glacial ecosystems emerge is crucial due to the rapid retreat of glaciers in high-latitude and high-altitude regions.
In the Andes, native camelids like alpacas, llamas, vicuñas, and guanacos impact the landscape with their social behaviors. They live in family groups and create communal dung piles, which change soil properties and plant communities. This suggests they play a key role in developing new high-Andean ecosystems after glacier loss.
A CU Boulder study examined how communal dung from wild Andean camelids affects soil properties and plant growth in the Cordillera Vilcanota, Peru. The study found that these dung piles create nutrient hotspots, significantly enriching the soil and promoting plant cover in areas where glaciers are retreating.
Vicuñas is one of two wild South American camelids that live in the high Andes. They use communal dung piles, called latrines, much like humans use bathrooms. These latrines impact soil and plant life.
For the past two decades, Steven Schmidt, an ecology professor, has studied how microbial life and plants respond to retreating glaciers in the Peruvian Andes.
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Deglaciated soils in the Andes are nutrient-poor and can stay plant-free for over a century. However, Steven Schmidt and his team noticed patches of plants growing from vicuña dung piles over the last ten years.
Working with animal ecologist Kelsey Reider, they trekked to the Peruvian Andes and sampled soils up to 18,000 feet above sea level. They found that soils with vicuña dung had significantly more moisture and key nutrients than nearby barren soils.
For example, latrine soil had 62% organic matter, while deglaciated soil exposed for 85 years without latrines had only 1.5% organic matter. High elevations have fluctuating temperatures, but the organic matter in latrines stabilized temperature and moisture, creating a different microclimate.
The team found high DNA concentrations and diverse microorganisms in vicuña latrine soil, indicating these dung piles support thriving microbes and plants. Vicuña dung helps plants colonize barren areas faster by providing nutrients and seeds from lower elevations, attracting various organisms.
Camera footage showed plant patches attracting rare species and large carnivores like pumas. Vicuñas also eat the vegetation in their latrines. It could take hundreds of years for deglaciated areas to become grasslands, which might help species affected by shrinking cold habitats.
However, species colonization is slower than glacier retreat. Glaciers have been melting rapidly, losing about 267 billion tons of ice yearly between 2000 and 2019. Continued warming could result in the loss of 68% of glaciers, impacting the water supply for nearly a quarter of the world’s population.
Bueno de Mesquita said, “The vicuñas help some alpine organisms, but we can’t assume they’ll all be okay because climate change is happening faster than ever.”
Journal Reference:
- Reider, K.E., Bueno de Mesquita, C.P., Anderson, K. et al. Wild Andean camelids promote rapid ecosystem development after glacier retreat. Sci Rep 14, 31913 (2024). DOI: 10.1038/s41598-024-83457-6
Source: Tech Explorist
