Drivers of Epilithic Biofilms in Greenland Streams: The Role of Nutrients, Temperature and Catchment Slope Across a Climate Gradient.

The Arctic is warming faster than the global average, making it critical to understand how this affects ecological structure and function in streams, which are key Arctic ecosystems. Microbial biofilms are crucial for primary production and decomposition in Arctic streams and support higher trophic levels. However, comprehensive studies across Arctic regions, and in particular within Greenland, are scarce.

Methane and carbon dioxide fluxes at high spatiotemporal resolution from a small temperate lake.

Lakes are hotspots for CH and CO effluxes, but their magnitude and underlying drivers are still uncertain due to high spatiotemporal variation within and between lakes. We measured CH and CO fluxes at high temporal (hourly) and spatial resolution (approx. 13 m) using 24 automatic floating chambers equipped with continuously recording sensors that enabled the determination of diffusive and ebullitive gas fluxes.

Predicting water quality from geospatial lake, catchment, and buffer zone characteristics in temperate lowland lakes.

Lakes provide essential ecosystem services and strongly influence landscape nutrient and carbon cycling. Therefore, monitoring water quality is essential for the management of element transport, biodiversity, and public goods in lakes. We investigated the ability of machine learning models to predict eight important water quality variables (alkalinity, pH, total phosphorus, total nitrogen, chlorophyll a, Secchi depth, color, and pCO) using monitoring data from 924 to 1054 lakes.

Wind drives fast changes of light climate in a large, shallow re-established lake.

With ever greater frequency, wetlands and shallow lakes that had been diverted for agriculture are being re-established to reduce nutrient loss and greenhouse gas emission, as well as to increase biodiversity. Here, we investigate drivers of water column light attenuation (K) at multiple time scales and locations in Lake Fil, Denmark, during the first five years after its re-establishment in 2012. We found that K was generally high (overall mean: 3.

Large pools and fluxes of carbon, calcium and phosphorus in dense charophyte stands in ponds.

Bicarbonate and calcium set bounds on photosynthesis and degradation processes in calcareous freshwaters. Charophytic algae use bicarbonate in photosynthesis, and direct variable proportions to assimilate organic carbon and to precipitate calcium carbonate on their surfaces. To evaluate pools of organic carbon (C), carbonate carbon (C), and phosphorus (P) in dense charophyte vegetation, we studied apical and basal tissue and carbonate surface precipitates, as well as underlying sediments in ten calcareous ponds.

From drought to flood: Sudden carbon inflow causes whole-lake anoxia and massive fish kill in a large shallow lake.

Fish kills are a recurring phenomenon in hypereutrophic lakes. The effects of a sudden injection of anoxic bottom water into surface waters are well known, as well as the degradation of phytoplankton blooms and the release of phytoplankton toxins. However, in this study we report on a new, climate-related cause of fish kills in a shallow lake.

Shallow plant-dominated lakes - extreme environmental variability, carbon cycling and ecological species challenges.

Background: Submerged plants composed of charophytes (green algae) and angiosperms develop dense vegetation in small, shallow lakes and in littoral zones of large lakes. Many small, oligotrophic plant species have declined due to drainage and fertilization of lakes, while some tall, eutrophic species have increased. Although plant distribution has been thoroughly studied, the physiochemical dynamics and biological challenges in plant-dominated lakes have been grossly understudied, even though they may offer the key to species persistence.