Algal Community Change in Mountain Lakes of the Alps Reveals Effects of Climate Warming and Shifting Treelines¹

Abstract

The biological communities of mountain lakes are suspected to be highly sensitive to global warming and associated catchment changes. To identify the parameters determining algal community responses, subfossil pigments from 21 different mountain lakes in the Bavarian‐Tyrolean Limestone Alps were investigated. Sediment cores were radio‐isotopically dated, and their pigment preservation evaluated. General additive models (GAM) of pigment compositions were calculated with temperature as the explanatory variable and generalized linear models with several lake parameters explaining log‐transformed GAM P‐values. Lake depth and trophic state were identified as major control variables of the algal community and productivity changes. Shifts in a deep oligotrophic alpine lake (lg(P) = −1.04) were half as strong as in a shallow mesotrophic alpine lake (lg(P) = −1.86) with faster warming and higher productivity forcing the development of biomass. Phytoplankton and macrophyte pigments increased clearly with warming, at lower altitudes, and decreased at the treeline, so that periphytic pigments dominated alpine sediments. This pattern is probably the result of interactions of UV radiation and allochthonous inputs of DOM. Our findings suggest that (sub)alpine shallow lakes with higher nutrient levels are most vulnerable to climate change‐driven changes whereas deep, nutrient‐poor lakes appear more resilient.

Limnochemistry and Plankton Diversity in Some High Altitude Lakes of Kashmir Himalaya

“…These lake ecosystems are characterized by small growing seasons, lower temperatures, longer ice periods, extended snow cover, higher elevations, and strong ultra-violet radiations. Small variations in these characteristics results in strong reactions of biodiversity, community structure, and productivity of alpine lake phototrophs, therefore forming planktonic biota sensitive senitals of minute environmental variations (Moser et al, 2019;Kuefner et al, 2021). Some studies on diversity and assemblage pattern of phytoplankton in HALs of Kashmir had been carried out by (Hutchinson, 1937); (Loffler, 1969); (Zutshi et al, 1972).…”

“…Ever since the resurgence in phytoplankton research might be elucidated by development in the theoretical and methodological characteristics. Lakes at high altitudes are unique ecosystems that are often described by lower temperatures, oligotrophy, low productivity, simple food web structure, and strong ultra-violet radiation in surface waters (Xing et al, 2009;Kuefner et al, 2021). Biological assemblages at higher elevations are modified to severe environmental conditions of unfavorable boreo-alpine environment (Kuefner et al, 2021).…”

“…Lakes at high altitudes are unique ecosystems that are often described by lower temperatures, oligotrophy, low productivity, simple food web structure, and strong ultra-violet radiation in surface waters (Xing et al, 2009;Kuefner et al, 2021). Biological assemblages at higher elevations are modified to severe environmental conditions of unfavorable boreo-alpine environment (Kuefner et al, 2021). Plankton display a significant role in the productivity and transmission of nutrients in the aquatic ecosystems and therefore acts as a vital bioindicator for monitoring and evaluating the degree of contamination in the aquatic systems (Gao et al, 2018).…”

Phytoplankton assemblage shifts with dissolved organic matter properties: A functional perspective for sentinel lakes

“…In mountain lakes, phenological variations regulate phytoplankton communities, making them useful indicators mirroring environmental conditions (Kuefner et al, 2021;Oleksy et al, 2020).…”

“…In mountain lakes, phenological variations regulate phytoplankton communities, making them useful indicators mirroring environmental conditions (Kuefner et al, 2021; Oleksy et al, 2020). High‐altitude phytoplankton communities have been widely described during the ice‐free season.…”