Greenhouse gas emissions resulting from conversion of peat swamp forest to oil palm plantation.

Conversion of tropical peat swamp forest to drainage-based agriculture alters greenhouse gas (GHG) production, but the magnitude of these changes remains highly uncertain. Current emissions factors for oil palm grown on drained peat do not account for temporal variation over the plantation cycle and only consider CO2 emissions. Here, we present direct measurements of GHGs emitted during the conversion from peat swamp forest to oil palm plantation, accounting for CH4 and N2O as well as CO2. Our results demonstrate that emissions factors for converted peat swamp forest is in the range 70-117 t CO2 eq ha-1 yr-1 (95% confidence interval, CI), with CO2 and N2O responsible for ca. 60 and ca. 40% of this value, respectively. These GHG emissions suggest that conversion of Southeast Asian peat swamp forest is contributing between 16.6 and 27.9% (95% CI) of combined total national GHG emissions from Malaysia and Indonesia or 0.44 and 0.74% (95% CI) of annual global emissions

Bodemkenmerken van het afdekkende pakket in relatie tot de kwetsbaarheid van het grondwater in Nederland. De niet met water verzadigde laag

Abstract niet beschikbaarAbstract not availabl

Vulnerability of the groundwater

Om de kwetsbaarheid van het grondwater in Nederland voor verontreiniging te karakteriseren, zijn voor het afdekkende pakket gelegen boven het eerste watervoerend pakket kaarten samengesteld met informatie over enkele bodemkenmerken, die van invloed zijn op de uitspoeling. Hierbij werd onderscheid gemaakt tussen de niet met water verzadigde deklaag en het resterende, waterverzadigde deel van het afdekkend pakket. De grens tussen beide delen van de deklaag werd hierbij gelegd bij de gemiddeld laagste grondwaterstand (GLG). Door deze benaderingswijze is het mogelijk om inzicht te verkrijgen in de kwetsbaarheid van zowel het zeer ondiepe grondwater als van het grondwater in het bovenste watervoerende pakket.DGM/DWB-

Analysis of nickel concentration profiles around the roots of the hyperaccumulator plant Berkheya coddii using MRI and numerical simulations

Abstract Investigations of soil-root interactions are hampered by the difficult experimental accessibility of the rhizosphere. Here we show the potential of Magnetic Resonance Imaging (MRI) as a non-destructive measurement technique in combination with numerical modelling to study the dynamics of the spatial distribution of dissolved nickel (Ni2+) around the roots of the nickel hyperaccumulator plant Berkheya coddii. Special rhizoboxes were used in which a root monolayer had been grown, separated from an adjacent inert glass bead packing by a nylon membrane. After applying a Ni2+ solution of 10 mg l−1, the rhizobox was imaged repeatedly using MRI. The obtained temporal sequence of 2-dimensional Ni2+ maps in the vicinity of the roots showed that Ni2+ concentrations increased towards the root plane, revealing an accumulation pattern. Numerical modelling supported the Ni2+ distributions to result from advective water flow towards the root plane, driven by transpiration, and diffusion of Ni2+ tending to eliminate the concentration gradient. With the model, we could study how the accumulation pattern of Ni2+ in the root zone transforms into a depletion pattern depending on transpiration rate, solute uptake rate, and Ni2+ concentration in solution