Real‐time warming of Alpine streams: (re)defining invertebrates' temperature preferences

Abstract

The accelerating climate crisis intensifies environmental changes in high‐altitude ecosystems worldwide, with rising air temperature among the main stressors. While past research in alpine streams has primarily focused on how retreating glaciers might affect the ecology of glacier‐fed streams on the long run, observations of real‐time alterations of water temperature in such pristine environments are rare. Using long‐term measurements of water temperature (2010–2017) together with datasets on benthic invertebrate communities from 18 glacial and nonglacial alpine and subalpine streams in the European Alps, we illustrate significant ecological relationships of water temperature regimes and the identity of benthic communities and forecast changes thereof due to considerable warming of stream water. Besides reporting multiannual warming of all observed streams during summer with a mean rate of 2.5(±0.6)°C decade−1, this work redefines temperature optima and ranges using robust regression modelling and thereby identifies potential winners and losers among the invertebrate species. We conclude that the various invertebrate taxa in alpine stream networks will respond differently to thermal alterations and that the herein modelled temperature ranges of invertebrates is an essential step towards the understanding of future shifts in species distributions and success.

Glacial Stream Ecology: Structural and Functional Assets

“…To assess the potential influence of degree glacier cover in the catchment on the egg development of alpine stream invertebrate species, we used experimental data from Schütz and Füreder [19] and compared the identified day-degree demands at distinct breeding temperatures between typical glacial specialists (Diamesinae) and other chironomid species. We then used this published data set (day-degree demand per breeding temperature level, Schütz and Füreder [15]) and combined it with the environmental characters (water temperature and catchment glacier cover) and invertebrate communities of sampled glacial and non-glacial streams in the Hohe Tauern national park. This allowed us to (a) verify the validity of the experimental breeding experiments for alpine streams, and (b) to transfer experimental relationships between water temperature and breeding success to the temperature conditions in the here sampled streams.…”

“…Differing habitat conditions between streams, and also changing conditions within same waters, produce a mosaic of distinct habitat templates in alpine streams and consequently shape benthic invertebrate communities. In theory, individual traits and the phenotypic plasticity of distinct species limit their range of suitable habitat conditions for their occurrence [13][14][15], which in summary mediate the composition of occurring invertebrate communities.…”

Rock glaciers and paraglacial features influence stream invertebrates in a deglaciating Alpine area

“…latitarsis) , but also for other species that are considered as losers based on their sensitivity to climate change and warming temperatures (e.g. Besacier Monbertrand et al., 2019; Niedrist & Füreder, 2020), and that include rare, threatened and/or endemic taxa (e.g. Drusus adustus , endemic of the Eastern Alps, according to Waringer & Graf, 2011).…”

Riverine landscapes: Challenges and future trends in research and management

“…Rising water temperatures due to global climate change can affect stream communities significantly, especially in high‐altitude ecosystems. Revisions of temperature optima are needed to model future shifts in species distributions induced by global warming, as was undertaken for benthic invertebrates in alpine regions (Niedrist & Füreder, 2021). The study by Reitsema et al (2021) highlights the importance of macrophytes in riverine metabolism, hydromorphology, and nutrient dynamics.…”