Jaroměřská Tereza Novotná, Ambrosini Roberto, Richter Dorota, Pietryka Miroslawa, Niedzielski Przemyslaw, Souza-Kasprzyk Juliana, Klimaszyk Piotr, Franzetti Andrea, Pittino Francesca, Vondrovicová Lenka, Senese Antonella, Zawierucha Krzysztof
Department of Ecology, Faculty of Science Charles University Prague Czech Republic.
Department of Environmental Science and Policy University of Milan Milan Italy.
Ecol Evol. 2025 Mar 24;15(3):e71064. doi: 10.1002/ece3.71064. eCollection 2025 Mar.
Cryoconite holes (water reservoirs) significantly contribute to biodiversity and biogeochemical processes on glacier surfaces. However, the lack of seasonal observations of cryoconite biota limits our knowledge of glacial ecosystem functioning. We studied photoautotrophs, consumers and sediment characteristics (community structure, biomass, elemental composition, organic matter content, δC, δN) from cryoconite holes in the upper and lower parts of the Forni Glacier ablation zone (Italy) throughout the ablation season. Dominant cyanobacteria were Oscillatoriaceae and Leptolyngbyaceae, while dominant green algae were Zygnemataceae and Chlorellaceae. Tardigrades () were the dominant consumers. The biomass of consumers negatively correlated with the biomass of green algae, indicating that grazing likely controls algal communities in the upper part. Green algae dominated the upper part, while a shift from green algae- to cyanobacteria-dominated communities was observed in the lower part during the season. The increase in δC of cryoconite organic matter (OM) in the lower part followed the trend of the community shift of photoautotrophs potentially affected by precipitation. Also, δC of tardigrades positively correlated with δC of cryoconite OM in the upper part, indicating some cryoconite OM as their food. Some photoautotrophic taxa appeared only on specific dates, and no spatio-temporal changes in the cryoconite general elemental composition were found. Our data indicate that changes in the community structure and biomass of cryoconite biota on the Forni Glacier likely depend on the interplay between phenology, stochastic events (e.g., rainfall) and top-down or bottom-up controls. We demonstrate that multiple observations are essential for understanding the ecology of biota inhabiting cryoconite holes throughout the ablation season.
冰尘穴（蓄水池）对冰川表面的生物多样性和生物地球化学过程有显著贡献。然而，缺乏对冰尘生物群的季节性观测限制了我们对冰川生态系统功能的了解。我们在整个消融季节研究了意大利福尔尼冰川消融区上部和下部冰尘穴中的光合自养生物、消费者以及沉积物特征（群落结构、生物量、元素组成、有机质含量、δC、δN）。优势蓝细菌为颤藻科和细鞘丝藻科，而优势绿藻为双星藻科和小球藻科。缓步动物是优势消费者。消费者的生物量与绿藻的生物量呈负相关，表明放牧可能控制着上部的藻类群落。绿藻在上部占主导地位，而在该季节下部观察到从绿藻主导群落向蓝细菌主导群落的转变。下部冰尘有机质（OM）的δC增加遵循了可能受降水影响的光合自养生物群落转变趋势。此外，上部缓步动物的δC与冰尘OM的δC呈正相关，表明一些冰尘OM是它们的食物。一些光合自养类群仅在特定日期出现，并且未发现冰尘总体元素组成的时空变化。我们的数据表明，福尔尼冰川冰尘生物群的群落结构和生物量变化可能取决于物候、随机事件（如降雨）以及自上而下或自下而上控制之间的相互作用。我们证明，多次观测对于理解整个消融季节栖息在冰尘穴中的生物群生态至关重要。
