PMC

(A) Relative abundance of predicted functional genes in five alpine lakes and (B) relative abundance of metabolism related genes as a function of WAS in Kelvin (1/(KT_(WAS))) during early growing season and (C) later growing season.

Relationships between taxonomic richness of microbiota in five alpine lakes and average water temperature after circulation in spring (WAS) in Kelvin (1/(KT_(WAS))). (A) Relationship between Chao1 and 1/(KT_(WAS)) in the early growing season. (B) Relationship between S_obs and 1/(KT_(WAS)) in the early growing season. (C) Relationship between Chao1 and 1/(KT_(WAS)) in the late growing season. (D) Relationship between S_obs and 1/(KT_(WAS)) in the late growing season.

Indices of richness (a,c,e,g Chao1, b,d,f,h, S_obs) recorded from planktonic microbiota for five alpine lakes (A–D) during the entire study period, (E,F) during early growing season, (G,H) during late growing season. Lowercase letters and ^∗ indicate that subgroups differ (p < 0.05), while uppercase letters and ^∗∗ indicate that subgroups differ at (p < 0.01).

(A) Map of study area and the five alpine lakes in the “Niedere Tauern” region of the Austrian Alps. (B) Depth-integrated sampling of water column. The subsamples were taken at every 1 m (MOA, OLA, and WIR), every 2 m (GIG), or every 3 m (TWA) from surface. The maps were generated with “ggmap” in R, a package based on Google Maps.

Redundancy analysis (RDA) of planktonic microbiota composition in five alpine lakes during the early growing season (A) and the late growing season (B). The first characters indicates the lake name (G: GIG, M: MOA, O: OLA; T: TWA; W: WIR), and the second character indicates the sampling period (J: July, early stage of growing season, A: August, later stage of growing season).

Non-metric multidimensional scaling (NMDS) plots of beta-diversity recorded from five alpine lakes using the Bray-Curtis matrix. (A) NMDS plots for individual lakes. (B) NMDS plots for samples from early and late growing season. (C) NMDS plots for individual lakes in the early growing season. (D) NMDS plots for individual lakes in the late growing season. Ellipses represent 95% confidence intervals (p < 0.05). ANOSIM (indicated by R and p values) revealed a significant dissimilarity between groups of individual lakes or growing seasons (p < 0.05).