Prediction of plant species occurrence as affected by nitrogen deposition and climate change on a European scale.

Plant species occurrence in Europe is affected by changes in nitrogen deposition and climate. Insight into potential future effects of those changes can be derived by a model approach based on field-based empirical evidence on a continental scale. In this paper, we present a newly developed empirical model PROPS, predicting the occurrence probabilities of plant species in response to a combination of climatic factors, nitrogen deposition and soil properties.

Feasibility of coupled empirical and dynamic modeling to assess climate change and air pollution impacts on temperate forest vegetation of the eastern United States.

Changes in climate and atmospheric nitrogen (N) deposition caused pronounced changes in soil conditions and habitat suitability for many plant species over the latter half of the previous century. Such changes are expected to continue in the future with anticipated further changing air temperature and precipitation that will likely influence the effects of N deposition. To investigate the potential long-term impacts of atmospheric N deposition on hardwood forest ecosystems in the eastern United States in the context of climate change, application of the coupled biogeochemical and vegetation community model VSD+PROPS was explored at three sites in New Hampshire, Virginia, and Tennessee.

Model-Based Analysis of the Long-Term Effects of Fertilization Management on Cropland Soil Acidification.

Agricultural soil acidification in China is known to be caused by the over-application of nitrogen (N) fertilizers, but the long-term impacts of different fertilization practices on intensive cropland soil acidification are largely unknown. Here, we further developed the soil acidification model VSD+ for intensive agricultural systems and validated it against observed data from three long-term fertilization experiments in China. The model simulated well the changes in soil pH and base saturation over the last 20 years.

Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.).

Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still limited. Here, a field-contaminated paddy soil was subjected to two flooding and drainage cycles in a pot experiment with two rice plant cultivars, exhibiting either high or low Cd accumulation characteristics.

Modeling diffusive Cd and Zn contaminant emissions from soils to surface waters.

Modeling contaminant transport of diffusive contaminants is generally difficult, as most contaminants are located in the top soil where soil properties will vary strongly with depth and often a strong gradient in contaminant concentrations exists. When groundwater periodically penetrates the contaminated layers, stationary models (like most 3D models) cannot adequately describe contaminant transport. Therefore we have combined a hydrological instationary model using a 1D distributed column approach with a simple geochemical model to describe contaminant transport in the soil.

Evaluation of the performance and limitations of empirical partition-relations and process based multisurface models to predict trace element solubility in soils.

Here we evaluate the performance and limitations of two frequently used model-types to predict trace element solubility in soils: regression based "partition-relations" and thermodynamically based "multisurface models", for a large set of elements. For this purpose partition-relations were derived for As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, Se, V, Zn. The multi-surface model included aqueous speciation, mineral equilibria, sorption to organic matter, Fe/Al-(hydr)oxides and clay.

Using advanced surface complexation models for modelling soil chemistry under forests: Solling forest, Germany.

Various dynamic soil chemistry models have been developed to gain insight into impacts of atmospheric deposition of sulphur, nitrogen and other elements on soil and soil solution chemistry. Sorption parameters for anions and cations are generally calibrated for each site, which hampers extrapolation in space and time. On the other hand, recently developed surface complexation models (SCMs) have been successful in predicting ion sorption for static systems using generic parameter sets.

Bioavailability pathways underlying zinc-induced avoidance behavior and reproduction toxicity in Lumbricus rubellus earthworms.

We investigated possible bioavailability pathways underlying zinc-induced avoidance behavior and sublethal reproduction impairment in Lumbricus rubellus. Clay-loam (pH 7.3) and sandy soil (three pH values of 4.

Enhancement of PAH biodegradation in soil by physicochemical pretreatment.

The effects were studied of short-term heating of contaminated soil and its soaking in an organic solvent on the subsequent biodegradation of PAHs. In a clayey dredged sludge with a high organic-matter content (12%), heating at 120 degrees C for one hour increased the degree of degradation after 21 days of an aged PAH contamination from 9.5 +/- 0.