Modeling the impact of global change on regional agricultural land use through an activity-based non-linear programming approach

Assessing the impact of climate change on agriculture is a new challenge for quantitative model-based policy analysis. The impact of climate change will vary strongly across regions depending on pre-existing climatic, agronomic, and political conditions. Most of the present modeling approaches, which aim to analyze the impact of global change on agriculture, deliver aggregated results both with regard to content and spatial resolution. To deliver results with a higher spatial resolution and to produce a more detailed picture of agricultural production, the county-based agro-economic model known as ACRE-Danube was developed. The German and Austrian part of the Upper Danube basin, a study area with great diversity in agricultural landscapes and climatic conditions, was chosen for study. For the analysis, two scenarios of climatic and socio-economic change were derived. The first and more economically and globally oriented scenario, termed “Full Liberalization,” included significant temperature increases. The second and more environmentally and regionally oriented “Full Protection” scenario included a moderate temperature increase. Both scenarios produce different results regarding agricultural income and land use. While the developments in the Full Protection scenario are small, the Full Liberalization scenario yields extreme regional changes in agricultural income, an increase in cereal production and extensive grassland farming.     

Formation of 5-methyl-4-hydroxy-3[2H]-furanone in cytosolic extracts obtained from Zygosaccharomyces rouxii

Formation of the flavor compound and precursor 4-hydroxy-5-methyl-3[2H]-furanone (HMF, norfuraneol) was demonstrated in cytosolic protein extracts obtained from Zygosaccharomyces rouxii after incubation with a number of carbohydrate phosphates. 4-Hydroxy-5-methyl-3[2H]-furanone was produced from d-fructose-1,6-diphosphate, d-fructose-6-phosphate, d-glucose-6-phosphate, 6-phosphogluconate, d-ribose-5-phosphate, and d-ribulose-1,5-diphosphate. Enzyme assays revealed d-fructose-1,6-diphosphatase, phosphohexose isomerase, d-glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase activity in the cytosolic extracts. Model studies showed the spontaneous formation of HMF from d-ribulose-5-phosphate. It is assumed that d-ribulose-5-phosphate is generated in cytosolic extracts by the action of the investigated enzymes from the carbohydrate phosphates and is then chemically transformed to HMF. The hypothesis was proven by the production of HMF in solutions containing commercially available enzymes and [6-(13)C]-d-glucose-6-phosphate.     

Soil education: A public need Developments in Germany since the mid 1990s

Soil is a public good that has important public functions. However, public knowledge about soils was rather scanty in Germany up until the mid 1990s. This article summarizes and comments on the developments that have taken place in Germany since then with regard to the four major dimensions of soil education—time, target groups, actors, and media. In summary, a wealth of initiatives was started (and has since vanished), leaving behind a number of remarkable results like internet and e‐learning sites, exhibitions, and science trails. Meanwhile, intellectual results have also become visible, with most citizens now being able to respond to questions on what soil and its functions are and how they are endangered. Progress is still lacking, however, in education—a minimum of soil science knowledge is still not sufficiently anchored in official school curricula, and institutions for this task are not in place. Finally, it is strongly urged to use the opportunity that soil protection has recently been on the agenda of the European Union in order to develop international perspectives for soil education, especially in the field of e‐learning.     

Mineral dust around the Sahara—from source to sink. A review with emphasis on contributions of the German soil science community in the last twenty years

Natural mineral dust has manifold environmental effects reaching from fertilizing aquatic and terrestrial ecosystems to affecting the earth's radiation balance and thus impacting on climate. The Sahara is considered the largest source of natural mineral dust on the globe, so much research attention has been paid to source identification, dust mobilization, transport, and effects in the sink areas. This paper gives a review of the research results concerning these topics emphasizing soil‐science‐related aspects of the last 20 y and the identification of knowledge gaps.     

Untersuchungen zur Charakterisierung des pflanzenverfügbaren Phosphats in Thüringer Carbonatböden

Investigations on the characterization of plant available phosphate in Thuringian calcareous soils Phosphate availability in Thuringian calcareous soils and its characterization by CAL‒, NaHCO₃-, H₂O- and CaCl₂-soil tests was investigated in laboratory and pot experiments. Soil CaCO₃ contents > 10% increase the pH value of CAL solution and thus decrease phosphate extractability. The increase of pH also causes an inadequate assessment of plant available phosphate by H₂O- and CaCl₂-soil tests. The CAL soluble P content of the soil corrected by the pH value of the extraction solution was most suitable for the forecast of P uptake of corn in a pot trial. From both parameters P availability indices for calcareous soils can be calculated which are comparable with those in soils containing < 5% CaCO₃. The equation, which still has to be verified in field experiments, reads as CAL-P_corrected = CAL-P_measured · (1 + 0.83·〈pH-value_{CAL solution} — 4.1〉).     

Comparison of morphological traits and molecular markers to analyse diversity and structure of alfalfa (<Emphasis Type="Italic">Medicago sativa</Emphasis> L.) cultivars

Diversity and structure of populations may differ substantially between morphological traits and molecular markers. Explanations of such discrepancies are crucial for further progress in breeding as well as for the maintenance of genetic resources. Our objective was to compare indices of among-cultivars differentiation for morphological traits (Q_ST) and molecular markers (F_ST) in alfalfa (Medicago sativa), a legume forage species. Ten cultivars representing the Northern and Southern types commonly grown in Europe were investigated. For each cultivar, 40 genotypes were analysed with 16 SSR markers and four morphological traits measured in two locations and several cuts. Q_ST values were in general high (0.02–0.39) compared to the differentiation observed with molecular markers (F_ST = 0.01), especially for growth habit, indicating that morphological traits were more efficient to structure the diversity than molecular markers. For morphological traits, a clear separation of Northern and Southern cultivars was observed, whereas for molecular markers, no clear structure was detected. Nevertheless, the grazing type cultivar Luzelle was separated from the rest of the cultivars for both morphological traits and molecular markers. Although pairwise differences between cultivars were significant for both morphological traits and molecular markers, the main part of the variation was found within cultivars. This large within-cultivar variation may be explained, besides the outcrossing reproductive mode and autotetraploid genetics, by the recent history of M. sativa domestication in Europe and the frequent seed exchanges. Selection for morphological traits (Q_ST > F_ST) was achieved without modification of within-cultivar neutral diversity.     

Using summed individual species models and state-of-the-art modelling techniques to identify threatened plant species hotspots

Reliable identification of hotspot areas with high numbers of threatened plant species has a central role in conservation planning. We investigated the potentiality of identifying the distribution, richness and hotspots of threatened plant species at a 25 ha resolution using eight state-of-the-art modelling techniques (GLM, GAM, MARS, ANN, CTA, GBM, MDA and RF) in a taiga landscape in north-eastern Finland. First, the individual species models developed based on occurrence records of 28 species in the 1677 grid squares and derived from different statistical techniques were extrapolated to the whole study area of 41 750 km². Second, the projected presence/absence maps were then combined to create species richness maps, and the top 5% of grid cells ranked by species richness were classified as hotspots. Finally, we created an overall summary map by combining the individual hotspot maps from all eight modelling techniques and identified areas where the individual hotspots maps overlapped most. There were distinguishing differences in projections of the geographic patterns of species richness and hotspots between the modelling techniques. Most of the modelling techniques predicted several hotspot locations sporadically around the study area. However, the overall summary map showed the highest predictive performance based on Kappa statistics, indicating that the locations where the hotspot maps from the eight models coincided most harboured highest observed species richness. Moreover, the summary map filtered out the patchy structures of individual hotspot maps. The results show that the choice of modelling technique may affect the accuracy and prediction of hotspot patterns. Such differences may hamper the development of useful biodiversity model applications for conservation planning, and thus it is beneficial if the conservation decision-making can be based on sets of alternative maps and overlaying of predictions from multiple models.     

The effect of surface variability factors on wind‐erosion susceptibility: A field study in SW Niger

The effects of several surface treatments and factors that influence wind‐erosion susceptibility were measured with the means of a mobile wind tunnel. The test surfaces are situated in the SW part of the Republic of Niger in W Africa. The measurement program included the determination of total and dust‐mass fluxes and surface‐specific wind‐erosion parameters like aerodynamic roughness and friction velocities. Different treatments and variations were investigated on one typical and common sand surface type: different densities of stone cover, different kinds of millet‐residue alignments, and different topsoil humidities as well as the effect of different densities of fallow vegetation. The on‐site experiments in a controlled wind‐tunnel environment allowed the observation of effects that were only scarcely described in wind‐erosion literature. Increased stone cover resulted in increased emission due to increased turbulence and channelling effect, in spite of increased surface roughness. Millet‐residue alignment in transversal orientation to the wind direction resulted in far higher emission reduction as documented in the literature. Topsoil humidity, though far above the known threshold for erosion, could not completely inhibit particle entrainment because of the quick development of a thin superficial layer of dry particles.