Browning affects pelagic productivity in northern lakes by surface water warming and carbon fertilization.

Global change impacts important environmental drivers for pelagic gross primary production (GPP) in northern lakes, such as temperature, light, nutrient, and inorganic carbon availability. Separate and/or synergistic impacts of these environmental drivers on pelagic GPP remain largely unresolved. Here, we assess key drivers of pelagic GPP by combining detailed depth profiles of summer pelagic GPP with environmental and climatic data across 45 small and shallow lakes across northern Sweden (20 boreal, 6 subarctic, and 19 arctic lakes).

Landscape determinants of pelagic and benthic primary production in northern lakes.

Global change affects gross primary production (GPP) in benthic and pelagic habitats of northern lakes by influencing catchment characteristics and lake water biogeochemistry. However, how changes in key environmental drivers manifest and impact total (i.e.

Author Correction: Carbon dioxide stimulates lake primary production.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Carbon dioxide stimulates lake primary production.

Gross primary production (GPP) is a fundamental ecosystem process that sequesters carbon dioxide (CO) and forms the resource base for higher trophic levels. Still, the relative contribution of different controls on GPP at the whole-ecosystem scale is far from resolved. Here we show, by manipulating CO concentrations in large-scale experimental pond ecosystems, that CO availability is a key driver of whole-ecosystem GPP.

Global change-driven effects on dissolved organic matter composition: Implications for food webs of northern lakes.

Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes.

Importance of coastal primary production in the northern Baltic Sea.

In this study, we measured depth-dependent benthic microalgal primary production in a Bothnian Bay estuary to estimate the benthic contribution to total primary production. In addition, we compiled data on benthic microalgal primary production in the entire Baltic Sea. In the estuary, the benthic habitat contributed 17 % to the total annual primary production, and when upscaling our data to the entire Bothnian Bay, the corresponding value was 31 %.

Viruses in subarctic lakes and their impact on benthic and pelagic bacteria.

Virus-bacterium interactions were investigated in the pelagic and benthic habitats in a set of lakes along an altitudinal gradient in the subarctic northern Sweden. Viral and bacterial abundances showed a significant variation between the lakes, with the highest benthic microbial abundances recorded in a high-altitude lake [993 m above sea level (a.s.

Whole-lake estimates of carbon flux through algae and bacteria in benthic and pelagic habitats of clear-water lakes.

This study quantified new biomass production of algae and bacteria in both benthic and pelagic habitats of clear-water lakes to contrast how carbon from the atmosphere and terrestrial sources regulates whole-lake metabolism. We studied four small unproductive lakes in subarctic northern Sweden during one summer season. The production of new biomass in both benthic and pelagic habitats was calculated as the sum of autotrophic production by algae and heterotrophic production by bacteria using allochthonous organic carbon (OC).

Light limitation of nutrient-poor lake ecosystems.

Productivity denotes the rate of biomass synthesis in ecosystems and is a fundamental characteristic that frames ecosystem function and management. Limitation of productivity by nutrient availability is an established paradigm for lake ecosystems. Here, we assess the relevance of this paradigm for a majority of the world's small, nutrient-poor lakes, with different concentrations of coloured organic matter.