Sökning: "anthropogenic nitrogen enrichment"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden anthropogenic nitrogen enrichment.

  1. 1. Importance of tannins for responses of aspen to anthropogenic nitrogen enrichment

    Författare :Franziska Bandau; Benedicte Albrectsen; Michael Gundale; Lisbeth Josson; Umeå universitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; aspen; foliar condensed tannins; genetic variability; anthropogenic nitrogen enrichment; plant growth; plant defense; litter decomposition; Populus tremula; asp; kondenserade tanniner; genetisk variabilitet; antropogent kväve; tillväxt; växtförsvar; förna nedbrytning; Populus tremula; Environmental Science; miljövetenskap; ekologisk botanik; Ecological Botany; Entomology; entomologi; Physiological Botany; fysiologisk botanik; Population Biology; populationsbiologi;

    Sammanfattning : Boreal forests are often strongly nitrogen (N) limited. However, human activities are leading to increased N inputs into these ecosystems, through atmospheric N deposition and forest fertilization. LÄS MER

  2. 2. Land use effects on greenhouse gas emissions from boreal inland waters

    Författare :Marcus Klaus; Jan Karlsson; Peter Staehr; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; greenhouse gas; boreal forest; carbon cycling; whole-ecosystem experiment; limnology; metabolism; forest clearcutting; nitrogen enrichment;

    Sammanfattning : Anthropogenic activities perturb the global carbon and nitrogen cycle with large implications for the earth’s climate. Land use activities deliver excess carbon and nitrogen to aquatic ecosystems. In the boreal biome, this is mainly due to forestry and atmospheric deposition. LÄS MER

  3. 3. Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes

    Författare :Anne Deininger; Ann-Kristin Bergström; Jan Karlsson; Antonia Liess; Carolyn L. Faithfull; John A. Downing; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; autochthony; basal production; boreal; global change; dissolved organic carbon; food web efficiency; N deposition; phytoplankton; seston stoichiometry; whole lake enrichment; zooplankton; limnologi; Limnology;

    Sammanfattning : Anthropogenic activities are increasing inorganic nitrogen (N) loadings to lakes in the northern hemisphere. In many boreal lakes phytoplankton are N limited, wherefore enhanced N input may affect the productivity of pelagic food webs. LÄS MER

  4. 4. The effect of simulated anthropogenic nitrogen deposition on the net carbon balance of boreal soils

    Författare :Nadia Maaroufi; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Anthropogenic activities have globally increased nitrogen (N) deposition and carbon dioxide (CO₂) gas emissions. It is proposed that anthropogenic N deposition may increase the size of boreal forest CO₂ sink, because boreal ecosystems are N limited. LÄS MER

  5. 5. Nitrate stable isotopes and major ions in snow and ice from Svalbard

    Författare :Carmen Paulina Vega Riquelme; V. A. Pohjola; R. Pettersson; E. Isaksson; C. E. Bøggild; Kumiko Goto-Azuma; Uppsala universitet; []
    Nyckelord :nitrate stable isotopes; nitrate; NOx proxies; ice cores; percolation; ion relocation; Svalbard; stabila isotoper av nitrat; nitrat; indikator för kväveoxider; iskärnor; perkolation; joniska omlokalisering; Svalbard; Earth Science with specialization in Physical Geography; Geovetenskap med inriktning mot naturgeografi;

    Sammanfattning : Increasing atmospheric reactive nitrogen (Nr), as consequence of human activities, has generated accumulation of nitrate (NO3-) in Arctic regions. The Arctic has fragile nitrogen limited ecosystems that can be altered by increases of dry or wet deposition of Nr. LÄS MER