Kaarina Lukkari

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Metal tolerance of a range of birch clones (Betula pendula and Betula pubescens) originating from metal-contaminated sites in England, Wales, Belgium and Finland were tested in soils supplemented with several concentrations of copper (Cu) or zinc (Zn) (500, 2000, 5000 mg kg-1 dry wt. soil of CuSO(4).5H2O or ZnSO(4).7H2O) for 4 months and with sub-toxic(More)
Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances(More)
In the sedimental organic matter of eutrophic continental seas, such as the largest dead zone in the world, the Baltic Sea, bacteria may directly participate in nutrient release by mineralizing organic matter or indirectly by altering the sediment's ability to retain nutrients. Here, we present a case study of a hypoxic sea, which receives riverine nutrient(More)
BACKGROUND External nutrient discharges have caused eutrophication in many estuaries and coastal seas such as the Baltic Sea. The sedimented nutrients can affect bacterial communities which, in turn, are widely believed to contribute to release of nutrients such as phosphorus from the sediment. METHODS We investigated relationships between bacterial(More)
Disturbance-mediated species loss has prompted research considering how ecosystem functions are changed when biota is impaired. However, there is still limited empirical evidence from natural environments evaluating the direct and indirect (i.e. via biota) effects of disturbance on ecosystem functioning. Oxygen deficiency is a widespread threat to coastal(More)
<lb>The SEGUE-project assembled and analysed new information about the eutrophying effects of nutrient loading<lb>and the biogeochemical processes which affect nutrient cycling in the Gulf of Finland and the Archipelago Sea.<lb>The project also studied how political decisions and policies concerning water protection affect the state of the<lb>Gulf. In(More)
We studied the distribution of biogenic silica (BSi) and other potentially bio-available Si pools (NaCl-, NaBDand NaOH-extractable Si) in short (0–25 cm) sediment cores from estuarine, coastal and open-sea areas in the Gulf of Finland (northeastern Baltic Sea). The BSi pool (150–1200 μmol g–1 DM, dry matter) was the largest potentially bio-available Si(More)
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