Pedodiversity and ornithogenesis of a tiny Antarctic Island (Half Moon): landform-geology-vegetation interrelationships.

Abstract

The harsh Antarctic climate limits soil formation and the development of terrestrial ecosystems, with most biological activity concentrated in the short summer season in ice-free areas. There, penguins play a crucial role in nutrient transport from marine to terrestrial environments, significantly impacting soil properties through guano deposition. This study focuses on characterizing the ornithogenic soils of Half Moon Island in Maritime Antarctica, examining how lithology, vegetation, and geomorphology influence their formation and distribution. Fieldwork conducted during the 2014/2015 austral summer included excavating and sampling 21 soil profiles. Soils were analyzed for physical and chemical properties and classified. Half Moon Island's soils are predominantly Cryosols and Leptosols, characterized by little development, high gravel content (skeletic), and significant cryoturbation. High variability in soil chemical properties was observed, with principal component analysis highlighting distinct clusters based on landscape position, geology, vegetation and ornithogenic influence. The findings underscore the diverse pedoenvironments of Half Moon Island, shaped by past and present ornithogenic activity and post-glacial geomorphological processes. This research highlights the soil variability in Antarctic environments and the significant ecological importance of seabird colonies on small, isolated islands.