Elise Gallois , Logan Berner, Kristine Bakke Westergaard, Jesamine Bartlett

Dog sledding in High Arctic Svalbard is a key tourist attraction, and the keeping of animals and livestock has historically been in practice in the settlements of the archipelago. The resulting waste disposal practices - particularly those involving the disposal of animal faeces and fodder - hugely enrich soils with excess nutrients. Here, we explore how animal husbandry affected changes in tundra vegetation greenness from 1985 to 2021 using Landsat satellite observations from 31 sites in Svalbard. In particular, we assessed changes in annual maximum vegetation greenness at contemporary and historical animal husbandry sites using the Normalized Difference Vegetation Index (NDVI) to extract dates of peak-season greenness, green-up, and plant senescence. We found that while peak-season greenness increased across all of our study sites, the greening signal was enhanced at active dog-yards and historic animal husbandry sites. In addition, the greening signal was stronger at all animal husbandry sites compared to reference ‘non-disturbed’ tundra sites. Across sites, the date of tundra vegetation greening shifted up to 0.81 days earlier, and the date of plant senescence shifted slightly later from 1985 to 2021. Our analysis shows nutrient enrichment from animal husbandry can stimulate long-term increases in tundra vegetation productivity, with a lasting impact of nutrient enrichment at abandoned animal husbandry sites.