Carbon Budgets for Catchments Across a Managed Landscape Mosaic in Southeast Sweden: Contributing to the Safety Assessment of a Nuclear Waste Repository

Abstract

Ecosystem budgets of matter contribute to the assessment of transport and accumulation of bioavailable contaminants in a landscape, since flows of matter and energy ultimately determine the rates at which contaminants will be partitioned in the environment. This study compares ecosystem properties, such as net primary production (NPP), sequestration of matter and fluxes to food sources for humans, which are of potential interest to describe fluxes and accumulation of bioavailable radionuclides in 14 catchments within a larger catchment area in southeast Sweden. The carbon budgets, used as a proxy for organic matter, are mainly based on local estimates of pools and fluxes, which have been distributed across a landscape mosaic of different vegetation types and management regimes using a geographical information system (GIS). NPP varied by a factor close to two (432 - 709 g x Cx m(-2)x y(-1)), while net ecosystem production ranged between -124 and 159 gx C x m(-2) x y (-1) for the different catchments. Carbon sequestration mainly occurred in the vegetation while the soil organic carbon pool was mainly a source of carbon. Large herbivores consumed on average 4.5 % of the above-ground green tissue production. When arable land was present in the catchment, the flux of carbon to humans was highest from crops and, in decreasing order, milk and beef, followed by the flux from hunting and berry/fungus picking. The results can be used to estimate the potential assimilation of radionuclides in vegetation and the potential exposure to humans of bioavailable radionuclides.

Spatial distribution of fine-roots in boreal forests in eastern Sweden

“…The soil pH (H 2 O) was about 6.7 for the humus layer (0-30 cm) at (Lundin et al 2004) and (Lundin et al 2005) 2 (Hägglund 1973) 3 (Löfgren 2005) 4 (Nord. Ministerråd.…”

“…The tree density (number of trees ha −1 ) was 1340, 780 and 3340 at the Forsmark and 200, 400 and 1600 at the Laxemar sites respectively. The field-layer vegetation was extensively developed at sites with a more sparsely developed tree layers (Löfgren 2005).…”

“…The investigated areas were chosen at a distance of about 10 km from the two nuclear power plants. Basic data sets and a more comprehensive description on those forest sites are to be found in Stadenberg (2007, 2008), Löfgren (2005) and in Löfgren et al (2006).…”

Spatial distribution of unmonitored inland water discharges to the sea

“…The Swedish Nuclear Fuel and Waste Management Co (SKB) currently investigates a siting in Forsmark or Simpevarp of a deep repository for the storage of high-level radioactive nuclear waste. As a consequence, detailed hydrogeochemical and ecological studies have been carried out in the areas Löfgren et al, 2006;Karlberg et al, 2006;Avila et al, 2006), as well as airborne surface geophysical and elevation investigations, mapping of quaternary deposits, soils, water courses, catchment boundaries and morphometry of lakes, lithological mapping of rock surfaces, surface water and groundwater sampling and vegetation analyses of land, lakes and sea (for further details, see summary of Lindborg, 2005a,b; available electronically at website www.skb.se). Below, we briefly summarise the main hydrogeological and surface hydrological characteristics and main similarities/differences between the sites.…”

Humans and Ecosystems Over the Coming Millennia: Overview of a Biosphere Assessment of Radioactive Waste Disposal in Sweden

“…An ecosystem approach has been used to understand the major fluxes and pools of water and organic matter in the landscape and estimate the constraints on the systems (e.g., water resources, available area, primary production, and import/export; Andersson and Sobek 2006; Jansson et al 2006; Kumblad et al 2006; Löfgren et al 2006; Sobek et al 2006; Wijnbladh et al 2006; Saetre et al 2013). …”