Gårdsjön Status Report for 1991-1992: The first Year of Treatment

Nitrogen addition weekly to catchment G2 at Gårdsjön began April 1991. During the first year of treatment a total of 230 meq/m²yr NH4No3 was added in 33 mm of water plus 90 meq/m²/yr deposited in 631 mm throughfall. Runoff contained significantly higher concentrations of No3 (but not NH4) beginning in November 1991. No respons was seen during the growing season. None of the other components and processes (soil solution, mineralization, fine-roots, mycorrhiza and vegetation) studied as part of NITREX showed significant response during the first year of treatment

Flexibility and diversity in subsistence during the late Mesolithic: faunal evidence from Asnæs Havnemark

In 2007, excavations at the late Mesolithic (Ertebølle) coastal site of Asnæs Havnemark recovered a wealth of flint, bone, and ceramic artefacts. A comprehensive analysis of the faunal remains resulted in over 50,000 identified specimens. Roe deer and gadids predominate, but there are a wide variety of other species represented. Stable isotope analyses of dog bones point to the importance of marine resources. Oxygen isotope analyses of otoliths indicate that fishing was conducted in multiple seasons of the year. Comparison with other late Mesolithic sites demonstrates that while generally the same species of animals were exploited everywhere, there are major differences in the relative abundances of species. The broad subsistence base available and flexibility in how it was exploited weaken arguments for a subsistence crisis brought on by environmental stresses as the causal mechanism for the adoption of domesticated plants and animals at the onset of theNeolithic

Nitrex project - Gårdsjöen, Status report for 1990-91

At the NITREX site at Gårdsjön, Sweden, ambient nitrogen deposition of 90 meg m² yr 1 will be experimentally increased by 286 meg m² yr 1 to an entire forested catchment G2 to study the potential for nitrogen saturation. Investigations include mearsurements of catchment inputs and outputs, as well as studies of vegetation, soil, mycorrhiza, fine roots and fish response. Results from the pre-treatment period 1990-91 show acidic runoff and soil solution with high concentrations of inorganic aluminium. Concentrations of nitrate and ammonium are very low, indicating no nitrogen satuation. The trees are slightly-to-moderately defoliated, and the needles are discolored. The nutrient contents of needles indicate that no elements are in the deficiency or the toxin range. The mycorrhiza of the root mat at the forest floor are generally 100 % alive and healthy. At catchment G2 nitrogen addition began April 1991.NMF/NAVF, SN

Abundant non-native tree species in Europe: traits and effects on ecosystems

Vytauto Didžiojo universitetasŽemės ūkio akademij