Soil pockets phosphatization and chemical weathering of sites affected by flying birds of Maritime Antarctica

Abstract

The majority of ornithogenic soils studied in Antarctica focus on the infl uence of penguins, wherever little reports evaluated the infl uence of fl ying birds on soil genesis. This study aimed to characterize the morphologic, chemic, physic, mineralogic, and micromorphologic ornithogenic soil pockets infl uenced by fl ying birds in Snow Island, Maritime Antarctica. Fifteen soil pockets were selected, described, sampled and analyzed, these sites constitute the main areas with intense long-term terrestrial biological activity in Snow Island. In order to investigate the impact of phosphatization, we compared the soil pockets with the surrounding soils and soils affected by penguins.Zone of phosphatization have a high concentration of P, K, and Ca. The XRD patterns for the clay fraction of ornithogenic soils show that phosphate minerals are the main crystalline phases (leucophosphite, minyulite, fl uorapatite, and apatite). We show that even under typical periglacial conditions, sites infl uenced by fl ying birds present active chemical weathering processes. The phosphatization release exchangeable bases and accelerate mineralogical and micromorphological transformations in soils. Under the current global warming trend and expected sea-level rise, the ornithogenic environments are susceptible to accelerated erosion rates and a great part of these hotspots may be lost for the open sea.

Lithological controls on soil properties, Snow Island, Maritime Antarctica

“…enhancing vegetation growth. 11,33,45,47 Our data (Table 2) agree with Cannone et al, 2 who proposed that in Antarctica, avian influences are more important than all other factors in affecting the soil properties.…”

“…44 These results are similar to others reported from elsewhere in Maritime Antarctica. 17,19,33,[45][46][47] Previous studies on Snow Island show that soils on marine terraces have low clay content (<12%); high sand proportions, dominated by coarse sand (>79%); and high coarse (>40%), comprised mainly of rounded pebbles. 5 Campbell and Claridge 1 reported that soils from beach deposits in Antarctica are frequently weakly developed with a predominance of pebbles in the coarse fractions, with the surfaces of boulders and pebbles generally fresh, unweathered, and without the brownish stains usually attributed to release of iron.…”

“…Commonly, pedoenvironments affected by avian phosphatization have a high concentration of P, K, and Ca. 33 Antarctic biota promotes significant ecosystem changes, resulting in unique soils by sea-land transfers of nutrients. 5,33,45,47 Only one soil (P-15) had an organic horizon at the surface, with high OC (Table 2).…”

“…48 High levels of Na + in this soil group are attributed to salt sprays brought by winds, as reported by previous works in Maritime Antarctica. 33,45 On the President Head Peninsula, soils derived from andesite had to andesite-derived soils on the Byers Peninsula (mean: 0.19 kg kg À1 ). 49 Soils formed from basalt or basalt-andesite mixtures are typically dark colored and coarse textured with low proportions of fines.…”

“…33 Antarctic biota promotes significant ecosystem changes, resulting in unique soils by sea-land transfers of nutrients. 5,33,45,47 Only one soil (P-15) had an organic horizon at the surface, with high OC (Table 2). According to Campbell and Claridge, 1 these soils are frequently concentrated in highly localized areas, often with a local patchy and discontinuous distribution.…”