Sökning: "boreal lakes"

Visar resultat 1 - 5 av 64 avhandlingar innehållade orden boreal lakes.

1. 1. Regulation of carbon dioxide emission from Swedish boreal lakes and the Gulf of Bothnia

   Författare :Grete Algesten; Mats Jansson; Pirkko Kortelainen; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; lakes; boreal; Gulf of bothnia; CO2; NEE; DOC; mineralization; sediment; catchment; net heterotrophy; Naturgeografi och sedimentologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

   Sammanfattning : The global carbon cycle is subject to intense research, where sources and sinks for greenhouse gases, carbon dioxide in particular, are estimated for various systems and biomes. Lakes have previously been neglected in carbon balance estimations, but have recently been recognized to be significant net sources of CO2. LÄS MER

3. 2. Bacterial use of allochthonous organic carbon for respiration and growth in boreal freshwater systems

   Författare :Martin Berggren; Mats Jansson; Michael L. Pace; Umeå universitet; []
   Nyckelord :lakes; streams; boreal; bacterial respiration; bacterial production; bacterial growth efficiency; allochthonous organic carbon; low molecular weight compounds; naturgeografi; Physical Geography;

   Sammanfattning : Aquatic systems worldwide receive large amounts of organic carbon from terrestrial sources. This ‘allochthonous’ organic carbon (AlloOC) affects critical physical and chemical properties of freshwater ecosystems, with consequences for food web structures and exchange of greenhouse gases with the atmosphere. LÄS MER

4. 3. Molecular analysis of lake-sediment organic matter : long-term dynamics and environmental implications in boreal lakes

   Författare :Sofia Ninnes; Richard Bindler; Xiao-Ru Wang; Christian Bigler; Hendrik Vogel; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake sediment; Holocene; organic matter; Pyrolysis-GC MS; mid-infrared spectroscopy; boreal;

   Sammanfattning : Lake sediment organic matter is material composed of residues from plants, algae, animals, fungi and bacteria. Its molecular composition is dependent on the sources as well as secondary biotic and abiotic transformations, which combined generates a highly complex matrix. LÄS MER

5. 4. Methane dynamics in northern lakes : Insights from multi-scale observations

   Författare :Jonathan Schenk; David Bastviken; Magnus Gålfalk; Damien Maher; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Methane; Lakes; Variability; Sampling design; Models;

   Sammanfattning : Methane (CH4) is a potent greenhouse gas which is emitted to the atmosphere from both natural and anthropogenic sources. Current evidence indicates that lakes account for a large part of the global emissions of CH4, but their contribution is difficult to quantify because of large temporal and spatial variability in processes leading to CH4 fluxes from lakes to the atmosphere. LÄS MER

7. 5. The role of inland waters in the carbon cycle at high latitudes

   Författare :Erik Lundin; Jan Karlsson; Reiner Giesler; Robert Striegl; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lakes; streams; carbon C ; carbon dioxide CO2 ; methane CH4 ; dissolved inorganic carbon DIC ; boreal; sub-arctic; arctic; emission; sediments; burial; budget; limnologi; Limnology; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys; naturgeografi; Physical Geography;

   Sammanfattning : Understanding the drivers of climate change requires knowledge about the global carbon (C) cycle. Although inland waters play an important role in the C cycle by emitting and burying C, streams and lakes are in general overlooked in bottom-up approached C budgets. LÄS MER