Factors influencing bacterial dynamics along a transect from supraglacial runoff to proglacial lakes of a high Arctic glacieri

Abstract

Bacterial production in glacial runoff and aquatic habitats along a c. 500 m transect from the ablation area of a Svalbard glacier (Midre Lovénbreen, 791N, 121E) down to a series of proglacial lakes in its forefield were assessed. In addition, a series of in situ experiments were conducted to test how different nutrient sources (glacial flour and dissolved organic matter derived from goose faeces) and temperature affect bacterial abundance and production in these ecosystems. Bacterial abundance and production increased significantly along this transect and reached a maximum in the proglacial lakes. Bacterial diversity profiles as assessed by denaturing gradient gel electrophoresis indicated that communities in glacial runoff were different from those in proglacial lakes. Heterotrophic bacterial production was mainly controlled by temperature and phosphorus limitation. Addition of both glacial flour and dissolved organic matter derived from goose faeces stimulated bacterial production in those lakes. The results suggest that glacial runoff sustains an active bacterial community which is further stimulated in proglacial lakes by higher temperatures and nutrient inputs from bird faeces. Thus, as in maritime temperate and Antarctic settings, bacterial communities developing in the recently deglaciated terrain of Svalbard receive important inputs of nutrients via faunal transfers from adjacent ecosystems.

Speciation, phase association and potential bioavailability of phosphorus on a Svalbard glacier

“…The concentration of SRP detected in the supraglacial channel water on Werenskioldbreen ranged from \0.5 to 2.9 lg l -1 , and in cryoconite holes from \0.5-2.3 lg l -1 (Table 2). These values are similar to those found in glacial runoff (0.9-1.0 lg l -1 ; Mindl et al 2007) and cryoconite holes (0.9-9.0 lg l -1 ; Säwström et al 2002) on another Svalbard glacier (Midtre Lovénb-reen) or in cryoconites on the White Glacier in the Canadian High Arctic (0.6-13.5 lg l -1 ; Mueller and Pollard 2004). The low concentrations measured during this study were probably caused by several factors.…”

Differences in Bacterial Diversity and Communities Between Glacial Snow and Glacial Soil on the Chongce Ice Cap, West Kunlun Mountains

“…Moreover, most of these studies have been performed in one single habitat. However, a few studies have examined multiple habitats678, including glacial runoff and aquatic habitats. These studies have shown that different habitats harbour different microbial communities and biodiversity, albeit with some common groups, even within the same glacier.…”

Bacterial Community Structures in Freshwater Polar Environments of Svalbard

“…Nutrient fluxes from various sources, i.e. aeolian and guano inputs (60, 61), glacial flour particle release (39), and the transport of entrapped organic and inorganic compounds through cryoconite holes (61), influence in a complex matter biogeochemical cycles as well as the size and structure of microbial communities in the Arctic cryosphere (50). Interactions between ice-covered land and marine ecosystems (25), and freshwater from retreating glaciers (21, 62) also contribute to the Arctic microbial food web.…”

“…The fjords and archipelago of Svalbard have recently attracted attention for assessing the impact of anthropogenic activities and global warming on the microbial ecology of the European part of the Arctic (20, 39, 57, 61). Microbial communities and glacial run-off to ice lakes have been extensively examined; however, information on the structures of microbial communities in the southern part of the Spitsbergen/Svalbard island complex is limited.…”