scholarly journals Carbon Fixation Trends in Eleven of the World’s Largest Lakes: 2003–2018

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3500
Author(s):  
Michael Sayers ◽  
Karl Bosse ◽  
Gary Fahnenstiel ◽  
Robert Shuchman
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Great Lakes ◽  
Satellite Remote Sensing ◽  
Carbon Fixation ◽  
African Great Lakes ◽  
Wind Speeds ◽  
Bear Lake ◽  
Great Slave Lake ◽  
Significant Production

Large freshwater lakes provide immense value to the surrounding populations, yet there is limited understanding of how these lakes will respond to climate change and other factors. This study uses satellite remote sensing to estimate annual, lake-wide primary production in 11 of the world’s largest lakes from 2003–2018. These lakes include the five Laurentian Great Lakes, the three African Great Lakes, Lake Baikal, and Great Bear and Great Slave Lakes. Mean annual production in these lakes ranged from under 200 mgC/m2/day to over 1100 mgC/m2/day, and the lakes were placed into one of three distinct groups (oligotrophic, mesotrophic, or eutrophic) based on their level of production. The analysis revealed only three lakes with significant production trends over the study period, with increases in Great Bear Lake (24% increase over the study period) and Great Slave Lake (27%) and a decline in Lake Tanganyika (−16%). These changes appear to be related to climate change, including increasing temperatures and solar radiation and decreasing wind speeds. This study is the first to use consistent methodology to study primary production in the world’s largest lakes, allowing for these novel between-lake comparisons and assessment of inter-annual trends.

Antarctic marine primary production, biogeochemical carbon cycles and climatic change

1992 ◽  
Vol 338 (1285) ◽  
pp. 289-297 ◽  
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Primary Production ◽  
Climatic Change ◽  
Carbon Fixation ◽  
Algal Growth ◽  
Ice Cover ◽  
Phytoplankton Production ◽  
Numerical Predictions ◽  
Model Predictions

In the Southern Ocean, inorganic macronutrients are very rarely depleted by phytoplankton growth. This has led to speculation on possible additional CO 2 drawdown in this region. However, the effects of climate change can only be predicted once the role of environmental and biotic factors limiting phytoplankton carbon fixation are understood. It is clear that the Southern Ocean is heterogeneous, and no single factor controls prim ary production overall. Ice cover and vertical mixing influence algal growth rates by m odulating radiance flux. Micronutrients, especially iron, may limit growth in some areas. Primary production is also suppressed by high removal rates of algal biomass. Grazing by zooplankton is the major factor determining magnitude and quality of vertical particle flux. Several of the physical controls on phytoplankton production are sensitive to climate change. Although it is impossible to make numerical predictions of future change on the basis of our present knowledge, qualitative assessments can be put forward on the basis of model predictions of climate change and known factors controlling prim ary production. Changes in water temperature and in windinduced mixing are likely to be slight and have little effect. Model predictions of changes in sea-ice cover vary widely, making prediction of biogeochemical effects impossible. Even if climatic change induces increased nutrient uptake, there are several reasons to suspect that carbon sequestration will be ineffective in comparison with continuing anthropogenic CO 2 emission.

scholarly journals Impact of annual and seasonal precipitation and air temperature on gross primary production in Mediterranean ecosystems in Europe

2016 ◽  
Author(s):  
Svenja Bartsch ◽  
Bertrand Guenet ◽  
Christophe Boissard ◽  
Juliette Lathière ◽  
Jean-Yves Peterschmitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Air Temperature ◽  
Seasonal Variations ◽  
Carbon Fixation ◽  
Gross Primary Production ◽  
Mediterranean Ecosystems ◽  
Early Spring ◽  
Annual Variations ◽  
Temperature And Precipitation

Abstract. Mediterranean ecosystems are significant carbon sinks but are also particularly sensitive to climate change but the carbon dynamic in such ecosystem is still not fully understood. An improved understanding of the drivers of the carbon fixation by plants is needed to better predict how such ecosystems will respond to climate change. Here, for the first time, a large dataset collected through the FLUXNET network is used to estimate how the gross primary production (GPP) of different Mediterranean ecosystems was affected by air temperature and precipitation between the years 1996 and 2013. We showed that annual precipitation was not a significant driver of annual GPP. Our results also indicated that seasonal variations of air temperature significantly affected seasonal variations of GPP but without major impact on inter annual variations. Inter-annual variations of GPP seemed largely controlled by the precipitation during early spring (March–April), making this period crucial for the future of Mediterranean ecosystems. Finally, we also observed that the sensitivity of GPP in Mediterranean ecosystems to climate drivers is not ecosystem type dependent.

Long-term primary production trends in the Laurentian Great Lakes: a comparison of geochemical methods

2021 ◽  
Author(s):  
Euan D. Reavie ◽  
Meijun Cai ◽  
Carsten Meyer-Jacob ◽  
John P. Smol ◽  
Josef P. Werne
Keyword(s):  
Primary Production ◽  
Great Lakes ◽  
Laurentian Great Lakes

A Small Member State and European Foreign Policy: Shaping or Taking? The Case of Belgium and the African Great Lakes

2008 ◽  
Vol 3 (3) ◽  
pp. 233-252 ◽  
Author(s):  
Skander Nasra
Keyword(s):  
Foreign Policy ◽  
Member State ◽  
Great Lakes ◽  
European Integration ◽  
Integration Process ◽  
Policy System ◽  
African Great Lakes ◽  
Foreign Policies ◽  
Small Member

AbstractThe European integration process has altered the conditions under which national foreign policies in Europe are made. Departing from this assumption, this article explores whether and under what conditions a small EU member state can influence European foreign policy. To this end, the role that Belgium has played in the construction of European foreign policy towards the African Great Lakes is examined. This article argues that a small EU member state can significantly influence European foreign policy, resulting in reinforcement of its national foreign policy. Yet this influence is conditioned by two intertwined factors: the nature of EU involvement; and the characteristics of the Union's foreign policy system. Depending on these elements, a small member state can supersede the quantifiable notion of 'smallness' and actively shape the construction of European foreign policy.

scholarly journals Regional variability of acidification in the Arctic: a sea of contrasts

2014 ◽  
Vol 11 (2) ◽  
pp. 293-308 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
Y. Aksenov ◽  
A. C. Coward ◽  
T. R. Anderson
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Arctic Ocean ◽  
Canadian Arctic ◽  
Atmospheric Co2 ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Regional Variability ◽  
The Arctic Ocean ◽  
The Impact

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, with potentially negative consequences for calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2 and changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic, and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP8.5 (an Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) scenario with the highest concentrations of atmospheric CO2). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via impact of climate change (changing temperature, stratification, primary production and freshwater fluxes) were examined by undertaking two simulations, one with the full system and the other in which atmospheric CO2 was prevented from increasing beyond its preindustrial level (year 1860). Results indicate that the impact of climate change, and spatial heterogeneity thereof, plays a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because diminishing ice cover led to greater vertical mixing and primary production. As a consequence, the projected onset of undersaturation in respect to aragonite is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian seas. We conclude that, for future projections of acidification and carbonate saturation state in the Arctic, regional variability is significant and needs to be adequately resolved, with particular emphasis on reliable projections of the rates of retreat of the sea ice, which are a major source of uncertainty.

Variability in ice phenology on Great Bear Lake and Great Slave Lake, Northwest Territories, Canada, from SeaWinds/QuikSCAT: 2000–2006

2009 ◽  
Vol 113 (4) ◽  
pp. 816-834 ◽  
Author(s):  
Stephen E.L. Howell ◽  
Laura C. Brown ◽  
Kyung-Kuk Kang ◽  
Claude R. Duguay
Keyword(s):  
Northwest Territories ◽  
Bear Lake ◽  
Great Slave Lake ◽  
Ice Phenology

scholarly journals Desertification in Forest, Range and Desert Landuses of Tehran Province, Under the Impact of Climate Change

2016 ◽  
Author(s):  
Hadi Eskandari Dameneh ◽  
Moslem Borji ◽  
Hassan Khosravi ◽  
Ali Salajeghe
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Net Primary Production ◽  
Degradation Process ◽  
Early Warning Systems ◽  
Land Uses ◽  
Emission Scenarios ◽  
Desert Ecosystems ◽  
Tehran Province ◽  
The Impact

Abstract. Persistence of widespread degradation in arid and semi-arid region of Iran necessitates using of monitoring and evaluation systems with appropriate accuracy to determine the degradation process and adoption of early warning systems; because after transition from some thresholds, effective reversible function of ecosystems will not be very easy. This paper tries to monitor the degradation and desertification trends in three land uses including range, forest and desert lands affected by climate change in Tehran province for 2000s and 2030s. For assessing climate changes of Mehrabad synoptic stations the data of two emission scenarios including A2 and B2 were used using statistical downscaling techniques and data generated by SDSM model. The index of net primary production resulting from MODIS satellite images was employed as an indicator of destruction from 2001 to 2010. The results showed that temperature is the most effective driver force which alters the net primary production in rangeland, forest and desert ecosystems of Tehran province. On the basis of monitoring findings under real conditions, in the 2000s, over 60 % of rangelands and 80 % of the forests have been below the average production in the province. On the other hand, the long-term average changes of NPP in rangeland and forests indicated the presence of relatively large areas of these land uses with production rate lower than the desert. The results also showed that, assuming the existence of circumstances of each emission scenarios, the desertification status will not improve significantly in the rangelands and forests of Tehran province.

Sign in / Sign up

Export Citation Format

Share Document