Wild Andean camelids promote rapid ecosystem development after glacier retreat

Knowing mechanisms that facilitate the emergence of post-glacial ecosystems is urgently required given rapid recent glacial retreat in high latitude and high elevation regions. We examined the effect of nutrient hotspots created via communal dung deposition by wild, native Andean camelids on soil abiotic and biotic properties and plant cover in the rapidly deglaciating Cordillera Vilcanota, southeastern Peru. Animal-modified proglacial soils were significantly enriched in all measured edaphic properties compared to reference glacial-till soils of the same age adjacent to animal-modified soil patches. Organic matter composition, soil moisture, available inorganic nitrogen, and plant cover were nearly zero in glacial-moraine reference soils, but were at least one order of magnitude greater in animal-modified soils. Likewise, DNA concentrations were almost two orders of magnitude higher in modified soils (23 ± 9 µg DNA g soil^-1) compared to reference soils (0.6 ± 0.3 µg DNA g soil^-1). Animal-modified soil microbial community composition differed significantly from reference soils for both prokaryotes and eukaryotes, and eukaryote ASV richness was significantly higher in camelid latrines than in controls. Nutrient transfer into glacier forefields by native camelids shortcuts a 100+ year lag between glacier retreat and primary succession. Our results suggest that nutrient transfer into glacier forefields by wild, native animals may be an important, natural mechanism by which tropical Andean species can expand upslope at a pace relevant to climate change.