Modelling the effects of temperature and moisture on CO₂ evolution from top- and subsoil using a multi-compartment approach   总被引：3，自引：0，他引：3  

Anja Lomander  Thomas Kätterer  Olof Andrén 《Soil biology & biochemistry》1998,30(14):2023-2030

A novel approach, at least for laboratory conditions, for analysis of the dependence of soil C evolution on temperature is presented. A two-component (labile and refractory organic C) parallel first-order model was fitted to CO₂ evolution rates from top- and subsoil, incubated at different combinations of temperature (constant −4, 0.3, 5, 15, 25, weekly fluctuating between −4 and +5°C) and moisture (17, 26, 36 and 50% H₂O for the topsoil and 16, 23, 31 and 41% for the subsoil) and to the evolution of CO₂ after the addition of roots or stubble of Phalaris arundinacea in the topsoil, measured at 25°C and 36% H₂O (Lomander et al., 1998). The size of the pools and their respective first-order rate constants were optimized simultaneously by a least-squares method. The optimization was carried out separately for top- and subsoil. Quadratic functions were fitted to the temperature and moisture responses. For topsoil samples in which roots or stubble were added, a three-component model (labile, refractory and stubble or roots) was used. The initial partitioning of the soil C, the decomposition rate constants for each partition and the temperature and moisture responses were all assumed to be identical to those of pure topsoil, while the initial pool sizes of added roots and straw were measured. The calculated temperature at which CO₂ evolution ceased (T_min) was −0.83°C, and a recalculation to Q₁₀-values resulted in increasing temperature response with decreasing temperature (Q₁₀=2.2 at 25°C and 12.7 at 0.3°C). Simulated CO₂ evolution rates agreed well with the measurements (R_adj²=0.96 and 0.81) for top- and subsoil, respectively. The multi-compartment approach was superior to the single-compartment approach, which gave R_adj²=0.88 and 0.76 for top- and subsoil, respectively. In general, CO₂ evolution rates obtained from the laboratory experiment were higher than those measured in the field, even after differences in temperature and moisture were taken into account. After 300 d in the laboratory at 25°C and 36% H₂O, 99% and 86% of the added straw and roots, respectively, had disappeared according to the described model. The CO₂-evolution rate per unit of soil carbon was about two times higher for topsoil than for subsoil.  相似文献   

Towards the construction of a resistance risk evaluation scheme     

Ton J. W. Rotteveel  Joost W. F. M. de Goeij  Anja F. van Gemerden 《Pest management science》1997,51(3):407-411

Pesticide resistance management needs an indication of the risk of resistance developing in pests against pesticide applications. This paper describes an evaluation system for the ranking of these risks. The term pests includes all organisms which are causing economic damage in agriculture, including weeds and plant pathogens. The system distinguishes six broad risk categories. It is based on expert judgement of answers to a maximum of ten questions on crop husbandry, pest biology and pest control. The system has been developed for registration purposes in The Netherlands, and is currently being discussed within the European and Mediterranean Plant Protection Organisation (EPPO). ©1997 SCI  相似文献   

Crossreactivity of workshop monoclonal antibodies with canine blood leukocytes     

H. -Joachim Schuberth  H. -Udo Rabe  Anja Beer  Wolfgang Leibold 《Veterinary immunology and immunopathology》1998,60(3-4):419-424

A selection of 164 monoclonal antibodies for determinants on porcine cells were tested on canine leukocytes by flow cytometry. Eighteen mAbs proved to be crossreacting and 16 of these reacted uniformly with cells of three unrelated dogs while two displayed a polymorphic reaction pattern.  相似文献   

Ankyrin repeat proteins comprise a diverse family of bacterial type IV effectors     

Pan X  Lührmann A  Satoh A  Laskowski-Arce MA  Roy CR 《Science (New York, N.Y.)》2008,320(5883):1651-1654

Specialized secretion systems are used by many bacteria to deliver effector proteins into host cells that can either mimic or disrupt the function of eukaryotic factors. We found that the intracellular pathogens Legionella pneumophila and Coxiella burnetii use a type IV secretion system to deliver into eukaryotic cells a large number of different bacterial proteins containing ankyrin repeat homology domains called Anks. The L. pneumophila AnkX protein prevented microtubule-dependent vesicular transport to interfere with fusion of the L. pneumophila-containing vacuole with late endosomes after infection of macrophages, which demonstrates that Ank proteins have effector functions important for bacterial infection of eukaryotic host cells.  相似文献   

Optimizing the size of the area surveyed for monitoring a Eurasian lynx (Lynx lynx) population in the Swiss Alps by means of photographic capture–recapture     

Fridolin ZIMMERMANN  Christine BREITENMOSER‐WÜRSTEN  Anja MOLINARI‐JOBIN  Urs BREITENMOSER 《Integrative zoology》2013,8(3):232-243

We studied the influence of surveyed area size on density estimates by means of camera‐trapping in a low‐density felid population (1–2 individuals/100 km²). We applied non‐spatial capture–recapture (CR) and spatial CR (SCR) models for Eurasian lynx during winter 2005/2006 in the northwestern Swiss Alps by sampling an area divided into 5 nested plots ranging from 65 to 760 km². CR model density estimates (95% CI) for models M₀ and M_h decreased from 2.61 (1.55–3.68) and 3.6 (1.62–5.57) independent lynx/100 km², respectively, in the smallest to 1.20 (1.04–1.35) and 1.26 (0.89–1.63) independent lynx/100 km², respectively, in the largest area surveyed. SCR model density estimates also decreased with increasing sampling area but not significantly. High individual range overlaps in relatively small areas (the edge effect) is the most plausible reason for this positive bias in the CR models. Our results confirm that SCR models are much more robust to changes in trap array size than CR models, thus avoiding overestimation of density in smaller areas. However, when a study is concerned with monitoring population changes, large spatial efforts (area surveyed ≥760 km²) are required to obtain reliable and precise density estimates with these population densities and recapture rates.  相似文献   

Amino acid changes in the spike protein of feline coronavirus correlate with systemic spread of virus from the intestine and not with feline infectious peritonitis     

Emily Porter  Séverine Tasker  Michael J Day  Ross Harley  Anja Kipar  Stuart G Siddell  Christopher R Helps 《Veterinary research》2014,45(1):49

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Effects of rainfall pattern on carbon and nitrogen dynamics in soil amended with biogas slurry and composted cattle manure     

Anja Snger  Daniel Geisseler  Bernard Ludwig 《植物养料与土壤学杂志》2010,173(5):692-698

Soil moisture affects the degradation of organic fertilizers in soils considerably, but less is known about the importance of rainfall pattern on the turnover of C and N. The objective of this study was to determine the effects of different rainfall patterns on C and N dynamics in soil amended with either biogas slurry (BS) or composted cattle manure (CM). Undisturbed soil cores without (control) or with BS or CM, which were incorporated at a rate of 100 kg N ha^–1, were incubated for 140 d at 13.5°C. Irrigation treatments were (1) continuous irrigation (cont_irr; 3 mm d^–1); (2) partial drying and stronger irrigation (part_dry; no irrigation for 3 weeks, 1 week with 13.5 mm d^–1), and (3) periodic heavy rainfall (hvy_rain; 24 mm d^–1 every 3 weeks for 1 d and 2 mm d^–1 for the other days). The average irrigation was 3 mm d^–1 in each treatment. Cumulative emissions of CO₂ and N₂O from soils amended with BS were 92.8 g CO₂‐C m^–2 and 162.4 mg N₂O‐N m^–2, respectively, whereas emissions from soils amended with CM were 87.8 g CO₂‐C m^–2 and only 38.9 mg N₂O‐N m^–2. While both organic fertilizers significantly increased CO₂ production compared to the control, N₂O emissions were only significantly increased in the BS‐amended soil. Under the conditions of the experiment, the rainfall pattern affected the temporal production of CO₂ and N₂O, but not the cumulative emissions. Cumulative NO leaching was highest in the BS‐amended soils (9.2 g NO ‐N m^–2) followed by the CM‐amended soil (6.1 g NO ‐N m^–2) and lowest in the control (4.7 g NO ‐N m^–2). Nitrate leaching was also independent of the rainfall pattern. Our study shows that rainfall pattern may not affect CO₂ and N₂O emissions and NO leaching markedly provided that the soil does not completely dry out.  相似文献   

BiKF AdaMus: a novel research project studying the response and adaptive potential of single species and communities to climate change in combination with other stressors     

Ruth Müller  Cornelia Bandow  Anne Seeland  Dennis Fennel  Anja Coors  Peter K. Ebke  Bernhard Förster  Pedro Martinez-Arbizu  Thomas Moser  Matthias Oetken  Jasmin Renz  Jörg Römbke  Nadine Schulz  Jörg Oehlmann 《Journal of Soils and Sediments》2010,10(4):718-721

Introduction

How will the combination of climate-induced physical/chemical changes and anthropogenic pollution impact key species and biodiversity, and thus the ecosystem functions in future?

Discussion

The project AdaMus within the newly founded Biodiversity and Climate Research Centre BiK^F aims to understand the prospective ecosystem stress responses and adaptive potential of species and communities to multiple stressors to provide reliable predictions of future developments in terrestric, aquatic and marine environments.

Conclusion

Long-term experiments with terrestrial, aquatic and marine species and communities will be conducted under IPCC predicted climate conditions. In terrestric and limnic experiments, additional co-stressors such as pesticides and alien species are introduced to test for interactions. In the case of marine plankton, potential consequences of multiple climate-related changes in the physical environment (temperature, salinity and oxygen) will be analysed.  相似文献   

Incidence and control of the American giant liver fluke, Fascioloides magna, in a population of wild ungulates in the Danubian wetlands east of Vienna     

Ursprung J  Joachim A  Prosl H 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(7-8):316-323

Fascioloides magna,the giant liver fluke, is an introduced parasite imported to Europe with infected game which is endemic in the Austrian wetlands of the Danube from Vienna to the Slovakian border. Due to its pathogenicity (especially in roe deer) and its potential of transmission to domestic ruminants a project on the epidemiology and control of this parasite was carried out between 2000 and 2005. To assess distribution faecal droppings from red deer were collected in an area along the Danube and livers of red and roe deer shot or found dead were examined. Simultaneously, triclabendazole-medicated feed was offered repeatedly in several areas of known fluke presence from 2001. The average prevalence of infection as demonstrated by Fascioloides eggs in droppings (n = 145) was 6.3%, with > 50% in some areas. Infection rates decreased from 11.3% (01/2001) to 1.5% (04/2002) in the whole area. In Fischamend, a highly endemic area, prevalences in monthly samples (n = 25) decreased from 70% (01/2001) to less than 1% (01/2005). Similarly, the number of eggs per gram of faeces was significantly reduced. Of 457 red deer livers 15.8% were positive. In the Fischamend area, a reduction of positive livers was also found (2000:100%; 2005:13%), as well as a reduction of the numbers of flukes/liver. Control of F. magna in the Danubian wetlands by anthelmintic treatment proved to be successful although eradication was not achieved.  相似文献   

Reaction of bovine endothelial cells in vitro to coccidia (Eimeria bovis, Toxoplasma gondii, Neospora caninum) infections as the expression of a non-adaptive immune response     

Taubert A  Hermosilla C  Behrendt J  Zahner H 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(7-8):274-281

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