In Europe an abundance of humus taxonomies exists starting with early approaches in the late 19th century. Frequently used in an international context, they do not cover all site conditions in the ...European area. Although having basic concepts and general lines, the European (and North American, Canadian) classification systems differ in important parameters used for the description and classification of humus forms. These discrepancies result in incongruities, so they require adjustments when exchanging partially compatible soil data, even between nearby countries. In 2003, 26 European specialists in humus forms met in Trento (Italy) and decided to formulate rules of classification based on morphogenetic descriptions and diagnostic horizons, adapted to European ecological conditions. Taking into account old and new European and North American systems of humus forms classification, six main references (Anmoor, Mull, Moder, Mor, Amphi and Tangel) were defined, each of them further divided into more detailed categories. This inventory assigned a strong discriminatory power to the action of soil animals. Both semiterrestrial (anoxic) and terrestrial (aerated) topsoils were classified. Descriptors of diagnostic horizons were conceived in accordance with recent international soil classifications. Assigning an ‘ecological value’ to each main humus form along a gradient from biologically active forms, degrading and incorporating all organic remains, to those characterized by the accumulation of poorly transformed organic matter, this European system of classification avoids a strong hierarchical structure and allows a flexible approach open to additional ecological contributions and renditions.
► European specialists conceive principles of a new classification of humus forms. ► Only morphological characters with evident functional effects were considered. ► Ten basic humus forms were circumscribed, available in a wide array of ecosystems. ► Environmental factors determine the structure of the classification tree.
In this study the hydrological regime of Norway spruce (Picea abies) and birch (Betula pendula) growing on heavy soils in the south east of Austria was analysed. Results from the year 2003 ...characterised by an extremely hot and dry summer are presented in this paper. Due to the extreme weather conditions the soil water content in August 2003 was very low (0.10–0.25m3m−3) in the topsoil (0–50cm) with no explicit difference between both tree species.
Sap flow was measured in 11 trees of each of both tree species using the heat field deformation (HFD) method. Only the qualitative variability of sap flow was analysed so that data of sap flow per section (SFS) were used. The SFS of the birch trees was about three times higher than that of the spruce trees. In June 2003 the daily SFS of the birch trees averaged 0.87kgcm−1 and of the spruce trees 0.23kgcm−1. Due to the proceeding drought in August 2003 these values were reduced to 0.39kgcm−1 and 0.11kgcm−1, respectively. A comparison of daily potential evapotranspiration (PET) with daily SFS values showed that the transpiration of the trees followed the atmospheric demand in June and in the second half of July. In August 2003 the SFS depended solely on the soil water content. Birch trees began to transpire earlier in the morning and could keep their maximum SFS longer during the midday hours than the spruce trees, when sufficient soil water was available. As the drought stress proceeded, significant differences in the diurnal variations of SFS were detected for both tree species. Most of the investigated birch trees could maintain their common daily SFS dynamic whereas spruce trees showed a different pattern. One part of the spruce trees showed a midday depression of SFS, whereas the others closed their stomata during the whole day.
Summary
Background
Equine incisors are often reduced in height during corrective dental procedures. Increased knowledge of subocclusal dentine thickness and pulp morphology may help prevent ...iatrogenic pulpar exposure. Although such data exist for equine cheek teeth, there are currently no reliable data for incisors.
Objectives
To measure the distances between pulp cavities and the occlusal as well as the labial surfaces of equine incisors and to test if these distances change with age. Furthermore, pulp morphology with regard to number and orientation of pulp horns was investigated.
Study design
Observational study using cadaver material and high‐resolution computed tomography.
Methods
Upper and lower incisor arcades were removed from heads of 13 horses and scanned with high‐resolution computed tomography. 3D Models were reconstructed and configuration as well as number of the pulp horns was evaluated. Anatomical marker points were set to measure distances between the pulp horn tips and the labial and occlusal surfaces.
Results
Subocclusal dentine thickness ranged between 1.5 and 11.7 mm in upper and 0.7 and 6.7 mm in lower incisors. It decreased with tooth age. Distance to labial aspect ranged between 3.5 and 9.0 mm in upper and 3.8 and 8.1 mm in lower incisors and increased with tooth age.
Main limitations
Details of horse management, feeding and previous dental care were not available. Therefore, it remains unknown how these factors influenced the results.
Conclusions
Although mean subocclusal dentine thickness of greater than 4.1 mm was found, equine incisors occasionally have less than 1 mm of thickness with potential for iatrogenic pulpar exposure during incisor reduction. Therefore, great care should be exercised by any practitioner during incisor reduction.
In a spatially explicit climate change impact assessment the modified patch model PICUS v1.2 was applied to simulate the transient response of current forests in Austria under three climate change ...scenarios which were based on regionalized GCM-scenario data. The forest model was initialized with ground-true stand and soil data from more than 2800 sample plots of the Austrian Forest Inventory (AFI). A comparison of simulated equilibrium species composition under current climate and expert reconstructions of PNV at the sample plots of AFI showed that the model responded realistically to the spatial variability of soil and climate characteristics. In deriving potential climate change impacts the simulation under current climate was used as a reference. Impact criteria representing the period 2000–2050 and long-term criteria derived from simulated site-specific potential natural vegetation (PNV) were used in a multiple-criteria approach to calculate short-/mid-term as well as long-term climate change impact indices. The study showed that neither transient short-/mid-term nor long-term PNV-based indices alone are sufficient to indicate the possible consequences of climate change on existing forests. Based on the results of the study the combined use of such climate change impact indices is recommended. A major finding was that beyond a temperature increase of approximately +1
°C (no changes in precipitation) the proportion of inventory plots showing severe climate change impacts increased markedly. While at higher elevations under warmer climates the set of suitable tree species increased due to increased competitivity of broadleaved species, the study suggests that under the set of analysed climate change scenarios at low-elevation sites
Picea abies would become unsuitable as a crop species. Limitations of the presented approach are discussed and conclusions regarding possible consequences for forest management are drawn.
The dominant nitrogen (N) fluxes were simulated in a mountain forest ecosystem on dolomitic bedrock in the Austrian Alps. Based on an existing small-scale climate model the simulation encompassed the ...present situation and a 50-yr projection. The investigated scenarios were current climate, current N deposition (SC1) and future climate (+2.5
°C and +10% annual precipitation) with three levels of N deposition (SC2, 3, 4). The microbially mediated N transformation, including the emission of nitrogen oxides, was calculated with PnET-N-DNDC. Soil hydrology was calculated with HYDRUS and was used to estimate the leaching of nitrate. The expected change of the forest ecosystem due to changes of the climate and the N availability was simulated with PICUS. The incentive for the project was the fact that forests on dolomitic limestone stock on shallow Rendzic Leptosols that are rich in soil organic matter are considered highly sensitive to the expected environmental changes. The simulation results showed a strong effect due to increased temperatures and to elevated levels of N deposition. The outflux of N, both as nitrate (6–25
kg N
ha
−1
yr
−1) and nitrogen oxides (1–2
kg N
ha
−1
yr
−1), from the forest ecosystem are expected to increase. Temperature exerts a stronger effect on the N
2O emission than the increased rate of N deposition. The main part of the N emission will occur as N
2 (15
kg N
ha
−1
yr
−1). The total N loss is partially offset by increased rates of N uptake in the biomass due to an increase in forest productivity.
A combination of the risk factors “elevated temperature and nitrogen inputs” will increase the rate of nitrate leaching and the emission of nitrogen oxides from a forest ecosystem in the Austrian limestone Alps.
We assessed the impact of prophylaxis with the oral itraconazole solution and amphotericin B solution on fungal colonization and infection in a randomized study among patients with hematological ...malignancies and neutropenia. Infecting and colonizing Candida strains of patients suffering from candidiasis were genotyped by random amplification of polymorphic DNA (RAPD) analysis. A total of 106 patients were evaluated in this study: 52 patients in the itraconazole and 54 in the amphotericin B arm. During neutropenia fungal colonization in the oropharynx occurred in 11 (19.6%) and 24 (40.6%) and in the rectum in 11 (19.6%) and 23 (38.9%) courses in the itraconazole and amphotericin B groups ( P<0.05), respectively. Candida albicans was the most prevalent species in both study groups. Mixed fungal colonization with Candida krusei and Candida glabrata was increased in the amphotericin B group, yet without clinical importance since infections were due to C. albicans. The occurrence of invasive candidiasis was significantly increased in multicolonized compared to monocolonized patients. In the amphotericin B group 20 and in the itraconazole group 2 neutropenic patients showed multicolonization with Candida spp. ( P<0.05). Overall fungal infections were 3.8% in the itraconazole and 14.8% in the amphotericin B group ( P<0.05). RAPD typing showed oropharynx strains involved in superficial infections in four of five patients. In all four patients with deep fungal infections, it appears that the colonizing rectum strains were identical to infecting strains of Candida spp. Itraconazole solution significantly reduced Candida colonization and infection compared to amphotericin B solution. Most patients remained infected with the colonized strains for the entire study period, irrespective of antifungal prophylaxis.
The morpho-functional classification of humus forms proposed in a previous issue by Zanella and collaborators for Europe has been extended and modified, without any change in diagnostic horizons, in ...order to embrace a wide array of humus forms at worldwide level and to complete and make more effective the World Reference Base for Soil Resources. For that purpose 31 Humus Form Reference Groups (HFRGs) and a set of prefix and suffix qualifiers are proposed, following the rules erected for the WRB. An exhaustive classification key, respecting the principles of WRB, is suggested and examples of classification are given for some already well known humus forms.
► A World Reference Base for Humus Forms is now available following the rules erected for the WRB. ► A wide array of terrestrial and semi-terrestrial humus forms at worldwide level are considered. ► 31 Humus Form Reference Groups and a set of prefix and suffix qualifiers are proposed. ► An exhaustive classification key is suggested. ► Examples of classification are given for well-known humus forms.
Core Ideas
A common humus classification system improves communication among soil scientists.
A cellular phone application can be used for global soil mapping and monitoring purposes.
The humus ...classification can be combined with different soil classification systems.
The name TerrHum is an abbreviation of the words “Terrestrial” (not hydromorphic, not submerged) and “Humipedon” (organic and organic‐mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published as a Special Issue entitled “Humusica 1– Terrestrial Natural Humipedons” in the journal Applied Soil Ecology. The iOS application TerrHum allows the storage of the main content of Humusica 1 on a cellular phone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a virtual cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The application is in continuous evolution.
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