A method (Barometric Process Separation, BaPS) was developed for the quantification of gross nitrification rates and denitrification rates in oxic soil using intact soil cores incubated in an isothermal gas tight system. Gross nitrification rates and denitrification rates are derived from measurements of changes (i) in air pressure within the closed system, which are primarily the result of the activities of nitrification (pressure decrease), denitrification (pressure increase), and respiration (pressure neutral), and (ii) of O2 and CO2 concentrations in the system. Besides these biological processes, the contribution of physicochemical dissolution of produced CO2 in soil water to the pressure changes observed is to be considered. The method allows collection of additional information about the contribution of nitrification and denitrification to N2O emission from soil, provided simultaneous measurements of N2O emission are performed. Furthermore, BaPS can be used to quantify the percentage of N2O lost from nitrification. The advantage of BaPS is that disturbance of the soil system is minimized compared with other methods such as the use of gaseous inhibitors (e.g., acetylene) or application of 15N compounds to the soil. We present the theoretical considerations of BaPS, results for nitrification rates, denitrification rates, and identification of soil N2O sources in a well‐aerated coniferous forest soil using BaPS. The suitability of BaPS as a method for determination of gross nitrification is demonstrated by validation experiments using the 15N‐pool dilution technique.

Potential effects of future warming should be reflected in life history patterns of aquatic organisms observed in warmer climates or in habitats that are different in ambient temperature. In the special case of the dragonfly Gomphus vulgatissimus (L.) (Odonata: Gomphidae) previous research suggests that voltinism decreases from south to north. We analysed data on voltinism from 11 sample sites along a latitudinal gradient from about 441N to 531N, comprising small streams to medium-sized rivers. Furthermore, to simulate different conditions and to allow projections for future climate change scenarios, we developed a population dynamic model based on a projection matrix approach. The parameters of the model are dependent on temperature and day length. Our field results indicate a decrease in voltinism along the latitudinal gradient from southern to northern Europe and a corresponding increase of voltinism with higher temperatures. An increase in voltinism with width of the running water implies an effect of varying habitat temperature. Under the impact of global warming, our model predicts an increased development speed, particularly in the northern part of the latitudinal gradient, an extension of the northern range limit and changes in phenology of G. vulgatissimus, leading to an extension of the flight season in certain regions along the gradient.

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Abstract:An analysis of scaling eects is performed to evaluate whether data aggregation is a useful regionalization tool or whether it leads to an unacceptable loss of information. One issue concerns the appropriate resolution of digital elevation models (DEMs) used to derive geomorphological input parameters for hydrological models. In particular, the scale problem of watershed division by a channel network and smaller sub-basins is addressed. The investigation involved commercially available data sets with dierent horizontal and vertical resolutions and systematically aggregated DEMs. A stream network and the contributing subareas were derived from a DEM with a distinct critical support area. By varying this threshold area various watershed con®gura-tions were obtained. The sensitivity of surface runo simulations to all watershed con®gurations was studied with synthetic storms and by means of an in®ltration excess runo model.The study revealed that elevation data with dierent resolutions diverge enormously in landscape representation and in the derived parameters such as slopes,¯ow directions and channel networks. Coarse DEMs show a smoother terrain and shorter¯ow paths than highly resolved data. The contributing threshold area controls the extent of the watershed con®guration and therefore determines the drainage density. These topographic and geomorphological features were used to explain dierences in the runo simulation results. When watershed con®gurations with a varying extent of the channel network were derived from a distinct DEM and then used to simulate surface runo, the drainage densities of the con®gurations correlated with the simulated runo volume. A distinct drainage density, however, did not necessarily lead to similar simulation results when dierent DEMs were used. Since the hydrological model permits rein®ltration, the runo volume depends directly on the lengths of the overland¯ow. Therefore, the mean length of the overland¯ow paths might to a certain degree be considered as a scaling factor.

In conclusion, we were able to show that the TNF-alpha secretion of PM was significantly higher in patients with proven endometriosis compared to the control group. These results were found to be statistically significant and were in accordance with the histological findings. Thus, due to its immunomodulating potential, TNF-alpha may be a marker of both activity and stage of endometriosis.