Variability of the quality and quantity of organic matter in soil affected by multiple wildfires

Purpose

Fire in mountainous areas can lead to increased variability of their soil organic matter (SOM) due to spatial inhomogeneity and pre-fire fuel distribution. Here, we elucidated if this was the case in our study area and how this affected the reliability of solid-state ¹³C NMR spectroscopy applied for the study of the medium-term impact of fire on SOM

Materials and methods

The study occurred in the Sierra de Aznalcóllar, Southern Spain, which experienced their last intense fire 7 years before sampling. In a first approach (method 1), the corners and the center of a randomly chosen square with a side length of 15 m were sampled and analyzed separately. For comparison, composite samples (method 2) were obtained from three soils. We characterized material from unburnt, burnt, and double burnt regions. Data describing the physical and chemical properties of the soils together with the NMR spectroscopic characterization were analyzed using ANOVA.

Results and discussion

Both sampling methods yielded comparable results with comparable standard errors. No major differences between the fire-affected and unburnt soils were observed with respect to physical and chemical properties and C and N contents, but solid-state ¹³C NMR spectroscopy indicated a small but significant elevation of aromaticity in the soils with fire history.

Conclusions

The analysis showed that sampling with reduced replicates (method 1) can still lead to representative NMR data. The more complex sampling of comparing three composite samples (method 2) did not decrease the standard error. Our results also indicate that in the study area typical properties of the soil and its SOM induced by former burnings will not persist beyond a few decades.

     

The "Friedrich-Loeffler-Institut": past, present and future of research in infectious diseases of animals

The Friedrich-Loeffler-Institut, founded in 1910 by Friedrich Loeffler, the discoverer of the first animal virus, foot-and-mouth disease virus, is the oldest virological research facility in the world. Beyond viruses, its area of competence has significantly expanded since its foundation and now also covers bacterial, parasitic and prion diseases of livestock, poultry and aquatic animals. Presently located at four sites within Germany (Insel Riems, Jena,Tübingen,Wusterhausen) the tasks of the institute as delineated in the Animal Disease Act encompass research on infectious animal diseases including zoonoses, import/export examinations, epidemiological studies in case of outbreaks of notifiable animal diseases, acting as reference laboratory for notifiable animal diseases and nationwide quality management of diagnosis of notifiable animal diseases. It is obliged to publish and maintain up-to-date diagnostic regimes for notifiable animal diseases, and it publishes a yearly report on animal health in Germany. With the increasing importance of infectious diseases of animals, in particular those potentially harmful to man (zoonoses), the Friedrich-Loeffler-Institut will be moving into new facilities including laboratories and animal facilities up to the highest biosafety level at its main site Insel Riems on the occasion of its 100th anniversary.     

Der Einfluß geometrischer Faktoren auf die H2O-Abgabe aus künstlichen Aggregaten und das Wachstum von Roggenkeimlingen

The influence of geometric factors on the water release from artificial aggregates and growth of rye-seedlings Rye-sprouts were cultivated in pots on artificial aggregates of different sizes, but with altogether equal water contents in all variants, at high and low relative humidity. In the course of the experiment, growth of plants and delivery of water were measured. At the end of the experiment, dry- and fresh-matter of roots and sprouts as well as distribution of water within the aggregates were determined. With decreasing aggregate size growth and beginning of fading were accelerated. At low relative humidity the production of dry-matter was higher in case of smaller aggregates compared to larger ones. Delivery of water increased with decreasing aggregate size. The change in water content from the border of the aggregate towards the centre can be expressed as a straight line. The slope of the line increases with decreasing aggregate size. The slopes are modified by the influence of plants and climatic conditions. The water is extracted to a content lower than the permanent wilting point. This is more pronounced with small aggregates and a high evaporative demand.     

Effects of antibiotics on soil microorganisms: time and nutrients influence pollution-induced community tolerance

A method for the detection of the effects of antibiotics on soil microbial communities was optimised in the present study. We investigated the influence of measurement time and nutrient status on the pollution-induced community tolerance (PICT), using the sulfonamide sulfachloropyridazine (SCP) as model compound. The tolerance development in soil microcosms that were exposed to SCP under different conditions was compared with the background tolerance in SCP-unexposed microcosms. The tolerance of bacterial extracts from the soil microcosms was determined in Biolog^® multiwell plates as the SCP sensitivity of a range of physiological processes. The background tolerance was not affected by soil nutrient amendments, but an influence of the inoculum density in the microtiter plates was observed. Still, the variance of the background tolerance was low, which is in favour of the usage of community tolerance measurements for a selective detection of a toxicant impact. In line with the assumptions of the PICT concept, soil amendment with SCP led to an increase in community tolerance. This tolerance development was enhanced upon additional soil amendment with fresh pig slurry, and less by alfalfa meal addition. Tolerance increases were observed after a soil exposure to SCP of only 7 days, possibly because nutrient input facilitates the fast adaptation of the soil microbial community. However, a further increase in exposure time led to variable changes in the observed tolerance. Prolonged tolerance detection in the microtiter plates (11 days) enabled a clearer differentiation between different soil treatments, as it better resolved the EC₅₀ values of processes with a high tolerance to bacteriostatic antimicrobial compounds. For the detection of antibiotic effects on soil microbial communities, it is therefore recommended to use nutrient amendments (possibly fresh pig slurry), to standardize the soil exposure time, and to extend the period of Biolog plate measurement beyond 7 days.     

Der Einfluß künstlicher vertikaler Grobporen in einer verdichteten Bodenmatrix auf das Wachstum von Winterweizen II. Wachstum von Winterweizen auf einem primären Pseudogley

The influence of artificial vertical macropores in a compacted soil on the growth of winterwheat. II. Growth of winterwheat on a pseudogley In a pseudogley the effect of artificial vertical macropores in a compacted structure was compared to a compacted structure without artificial vertical macropores and to a loosened structure. Only in a very wet year (830 mm precipitation), water extraction and yield were positively influenced by the artificial vertical macropores in the compacted structure. Compared to the compacted structure without artificial macropores, where most of the water was extracted from the upper 25 cm of the soil, with vertical macropores most water was extracted from the depth 25–50 cm. In a dry year (700 mm precipitation), the difference in water extraction between the compacted structures with and without vertical macropores was only small. Most water was extracted from the loosened structure, but yield was reduced compared to both compacted structures. However, in the dry year, water extraction from the compacted structure without artificial macropores was uniform for the depth 0–50 cm, whereas for the structure with artificial macropores and for the loosened structure most water was extracted from the depth 0-25 cm. Neither in the wet nor in the dry year, vertical root extension was increased by the vertical macropores, but in the wet year root mass was positively influenced by the vertical macropores.     

Genetic diversity of seeds from four German Douglas fir (Pseudotsuga menziesii) seed orchards

European Journal of Forest Research - In Germany, Douglas fir (Pseudotsuga menziesii Franco) is seen as a valuable species for future cultivation in times of climate change. Local seed production...     

Virus infections of the European Eel in North Rhine Westphalian rivers

Viral infections have been suggested to play a role in the decline of the panmictic population of the European eel (Anguilla anguilla). However, despite the importance of knowledge about pathogenic eel viruses, little is known about their spread in the wild European eel population and only a few eel pathogenic viruses have been described so far. In this study, we aimed to investigate the health status of the A. anguilla stock in North Rhine Westphalia (NRW) State of Germany. For this purpose, we examined tissue samples of 16 elvers, 100 yellow eels and 6 silver eels, sampled from the rivers Rhine, Lippe and Ems. Virus detection was performed via a combination of cell culture and PCR. Next to the detection of frequently encountered pathogenic eel viruses (anguillid herpesvirus 1 and eel virus European X (EVEX)), we isolated the eel picornavirus 1 (EPV-1) from tissue of yellow eels and elvers and demonstrate the distribution of EPV-1 in wild eel population in NRW.     

Effects of tension of the girth strap on respiratory system mechanics in horses at rest and during hyperpnea induced by administration of lobeline hydrochloride

OBJECTIVE: To determine whether tension of the girth strap of a saddle would sufficiently affect rib motion and reduce lung volume to alter pulmonary resistance in horses. ANIMALS: 10 healthy adult horses. PROCEDURE: We used classical techniques to measure the effects of tightening a girth strap (15 kg of tension) on pulmonary dynamics during eupnea and hyperpnea in horses. Respiratory impedance was evaluated by use of oscillometry, and resistance and reactance data were partitioned into lung and chest wall components. Rib cage and abdominal contributions to tidal volume and minute ventilation were measured by use of respiratory inductance plethysmography. Effects of strap tension on functional residual capacity (FRC) were measured during eupnea by use of a helium-dilution technique. In a subgroup of 6 horses, we also measured transdiaphragmatic pressures during eupnea and hyperpnea induced by administration of lobeline hydrochloride (0.2 mg/kg, i.v.). RESULTS: Pulmonary resistance measured by use of oscillometry but not by use of classical methods was significantly increased by the tension of the girth strap. However, the increase in pulmonary resistance could not be explained by a decrease in FRC. Motion of the rib cage was significantly reduced during eupnea and hyperpnea. However, ventilatory variables (tidal volume, minute ventilation, and peak flows), FRC, and transdiaphragmatic pressures were unaltered by strap tension. CONCLUSIONS AND CLINICAL RELEVANCE: Although tension of the girth strap caused measurable changes in respiratory mechanics (loss of rib motion and increased pulmonary resistance), there was no evidence that ventilation was limited.     

Thoracic high-resolution computed tomography in the diagnosis of metastatic carcinoma

Three dogs were presented for investigation of recurrent pyrexia of unknown origin, chronic vomiting and respiratory distress, respectively. One dog was markedly underweight and the other two were cachexic. Physical examination and initial diagnostic tests failed to establish the underlying cause of the presenting signs. Thoracic radiographs were within normal limits for the age of the dog. In each case there was a high index of suspicion for an occult neoplastic process in view of the profound unexplained weight loss present. High-resolution computed tomography (HRCT) of the thorax was performed. The lung fields were divided into three zones for analysis and a novel classification scheme was used to describe the HRCT findings in each zone. Postmortem examination and histopathology confirmed the presence of an infiltrating metastatic carcinoma in all three cases. The HRCT changes correlated closely with the pathological findings. The authors conclude that HRCT of the lung should be considered for pulmonary metastatic screening in the dog and introduce a classification system for HRCT findings, based on terminology used in human medicine.