Search for projects with tag "nitrogen"
We aim to evaluate the non-symbiotic N2 fixation in forest soils. We are planning to collect soil samples from approx. 15 sites of the thinning-fertilization long-term experiment to measure the non-symbiotic N2 fixation in soils. We expect to collect samples along a latitudinal gradient in order to evaluate the effect of temperature on non-symbiotic N2 fixation.
[ID: 192] The carbon, nitrogen, and phosphorus budget of the Åheden long-term nitrogen deposition experiment
This project made a comprehensive inventory of element stocks of carbon, nitrogen, and phosphorus in the organic layer, 0-10 and 10-20 cm into the mineral soil in 2017, after 13 years of annual N addition rates at 3, 6, 12, and 50 kg N ha-1 yr-1 (n=&). 10 cores were collected in each plot and subsamples analysed by IRMS and spectrophotometry.
[ID: 191] Saprotrophic and mycorrhizal effects on decomposition at different rates of nitrogen deposition
This project utilised the Åheden long-term nitrogen addition experiment with five nitrogen addition rates and a trenching/tree root isolation treatment in a split plot design. We measured decomposition in needles and humus incubated in the soil and profiled the microbial communities using a combination of PLFA and fungal DNA sequencing.
[ID: 189] Nitrogen deposition and soil respiration
Nitrogen deposition can enhance the boreal forest carbon sink but the amount of carbon stored in the soil per unit of nitrogen deposition is likely to depend on competition for nitrogen between different sinks in the soil. In this project we use the Åheden long-term nitrogen addition experiment and a root trenching treatment to study the impact of a gradient of simulated nitrogen deposition rates on the emissions of carbon from respiration in the tree root zone, as well as from free living heterotrophic organisms.
[ID: 151] The impacts of long-term, high intensity N addition on soil organic matter accumulation in a boreal forest
PI: Shun Hasegawa
N addition is reported to influence decomposition of soil organic matters and potentially enhance carbon accumulation in boreal or temperate forests. Here, we investigate the effect of chronic N addition on boreal forests situated in norther Sweden with an aim of discerning the mechanisms altering the balance of accumulation and decomposition of soil organic matters. We will collect soil samples from the organic layer at Svartberget, Åheden, Rosinedal, Flakaliden and analyze molecular composition of soil organic matters as well as enzymatic activities responsible for C decomposition.
[ID: 114] Spatial pilot
PI: Sandra Jämtgård
We want to investigate if there is a difference in the small scale spatial variation in nitrogen availability between soils of different forest production rates.
[ID: 107] Comparison of ecosystem C and N stocks in Norway spruce vs. Scots pine stands throughout Sweden
PI: Robert Blasko
We are evaluating the performance of Norway spruce vs. Scots pine stands at the sites equally suitable for both species in the experiments at Kulbäcksliden 1028-1029, Flakaträsk 2458, Övra 1061, and Björkheden 1062. The aim is to evaluate how the different species productivity affects C and N stocks of he ecosystem and some of the important C fluxes; soil CO2 efflux and litterfall.
PI: Robert Blasko
The original aim of this experiment was to compare the growth of Scots pine vs. Norway spruce, and their mixture at a medium fertility site near Främlingshem suitable for the growth of both species. Our aim was to evaluate the effects of tree species and their mixing on ecosystem C and N stocks, as well as on some of the important C fluxes.
[ID: 105] Effects of intensive N fertilization on ecosystem C and N stocks, soil CO2 efflux, and litterfall
PI: Robert Blasko
We use intensive nutrient enrichment experiments 1523-1527 along a latitudinal gradient in Sweden to evaluate the effects of intensive nutrient (NPK) fertilization (100 kg N ha-1 year-1) on the ecosystem C and N stocks, soil CO2 efflux, and litterfall C inputs.
PI: Hyungwoo Lim
We determine carbon accumulation in response to 35-years tree nutrition optimization. Tree nutrition has been administrated based on annual foliar nutrient detection and corresponding fertilization treatment. Aboveground carbon accumulation is determined by standing biomass and belowground carbon accumulation is determined by both soil carbon stock and root biomass. Based on litterfall production and consecutive measurements on tree dimensions, annual net primary production is estimated.