Essays about: "biogenic silica"

Showing result 1 - 5 of 11 essays containing the words biogenic silica.

  1. 1. Mercury accumulation in lake sediments on different time scales – the influence of algal primary production

    University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Author : Anne Rebotzke; [2023]
    Keywords : mercury; lake sediment; primary productivity; algal scavenging; biogenic silica; diatom proxy; chlorophyll-a; organic matter;

    Abstract : The aim of this work is to test the proposed approach of algal scavenging as a driver of sediment mercury (Hg) on different time scales and to gain a better understanding of the mechanisms of Hg accumulation in lake sediments. A 3000-year sediment record from Nylandssjön in northern Sweden was analysed for this purpose, as well as a 20-year sediment record from the seasonal sediment traps of this lake. READ MORE

  3. 2. A study of carbon, nitrogen, and biogenic silica concentrations in Cyperus papyrus, the sedge dominating the permanent swamp of the Okavango Delta, Botswana, Africa

    University essay from Lunds universitet/Geologiska institutionen

    Author : Giulia Lodi; [2022]
    Keywords : Okavango Delta; papyrus; total nitrogen; total organic carbon; biogenic silica; Earth and Environmental Sciences;

    Abstract : Okawangodeltat är södra Afrikas största våtmark och en av världens minst påverkade våtmarker. Kunskapen om hur våtmarkssystemet fungerar är begränsad, särskilt vad gäller halter av näringsämnen och omsättning av näringsämnen i de dominerande våtmarksväxterna. READ MORE

  4. 3. Odensjön - A new varved lake sediment record from southern Sweden

    University essay from Lunds universitet/Geologiska institutionen

    Author : Hanna Hertzman; [2021]
    Keywords : Varved lake sediment; late Holocene; organic sediments; diatoms; land-use history; southern Sweden; palaeolimnology; Earth and Environmental Sciences;

    Abstract : Annually laminated (varved) sediments provide opportunities to reconstruct climate change and human impact on the environment with high temporal resolution. Depending on the character of the varves, such sediments can provide insight into the delivery of both autochthonous and allochthonous material from the lake and its catch- ment and answer questions regarding both regional and local responses to climate- and land-use changes. READ MORE

  5. 4. Environmental change during the Holocene : A comparative multi-proxy study of landscape disturbances in Northern Sweden

    University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

    Author : Mégane Capel; [2019]
    Keywords : Holocene; Lake-Water TOC; climate; lake sediment; vegetation;

    Abstract : Varved lake sediments were used to provide information on how a landscape is affected by disturbances of different scales, from global (i.e. climatic) to local (i.e. READ MORE

  6. 5. Records of environmental change and sedimentation processes over the last century in a Baltic coastal inlet

    University essay from Lunds universitet/Geologiska institutionen

    Author : Hanna Nilsson; [2019]
    Keywords : Baltic Sea; eutrophication; coastal areas; archipelago; laminated sediments; nutrient inputs; carbon and nitrogen content; biogenic silica; sedimentation; environmental impact; marine geology; Earth and Environmental Sciences;

    Abstract : The marine ecosystem in the Baltic Sea is affected by multiple stress factors, e.g. eutrophication and deoxygenation, overfishing and anthropogenic pollution. Here we evaluate the short-term trends of dissolved oxygen in bottom waters and changes in the primary productivity within a coastal inlet in the Baltic Sea. READ MORE