Pirkko Kortelainen

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Because freshwater covers such a small fraction of the Earth’s surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking published estimates of gas exchange, sediment accumulation, and(More)
Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report(More)
One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies.(More)
[1] We estimated organic carbon (OC) burial over the past century in 40 impoundments in one of the most intensively agricultural regions of the world. The volume of sediment deposited per unit time varied as a function of lake and watershed size, but smaller impoundments had greater deposition and accumulation rates per unit area. Annual water storage(More)
Associations between catchment characteristics (altitude, slope, proportion of peatland, site fertility, total stem volume, and its distribution among the main tree species), climatic drivers (temperature sum, latitude, precipitation and runoff) and atmospheric deposition and concentrations and export of C, N, P and Fe in 21 unmanaged boreal catchments(More)
Thirty-three patients had an arthrodesis of the knee by means of an intramedullary nail introduced through the greater trochanter. Fifteen of the procedures were done for a failed knee arthroplasty; eight had failed because of infection and seven, because of aseptic loosening. Twenty-nine of the thirty-three knees united three to four months after the first(More)
Seasonal and between stream variation (catchment dependent variation) in losses of organic and inorganic carbon via downstream transport and outgassing of CO(2) into the atmosphere were studied in 11 small boreal catchments situated in close proximity to each other. Of these catchments four were undrained peatland rich catchments, four drained peatland rich(More)
The quantity of carbon dioxide (CO2) emissions from inland waters into the atmosphere varies, depending on spatial and temporal variations in the partial pressure of CO2 (pCO2) in waters. Using 22,664 water samples from 851 boreal lakes and 64 boreal streams, taken from different water depths and during different months we found large spatial and temporal(More)
Nitrogen export from diffuse and point sources and its retention in the major river basins of Finland is quantified and discussed. The estimated total export from river-basins in Finland was 119,000 tonnes N a(-1) for the period 1993 to 1998 based on N export from different land use types defined in a GIS-based assessment model, incorporated with estimates(More)
The terrestrial export of dissolved organic matter (DOM) is associated with climate, vegetation and land use, and thus is under the influence of climatic variability and human interference with terrestrial ecosystems, their soils and hydrological cycles. We present a data-set including catchments from four areas covering the major climate and land use(More)