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471.
Jochen?MayerEmail author Franz?Buegger Erik?Steen?Jensen Michael?Schloter Jürgen?He? 《Biology and Fertility of Soils》2004,39(3):153-164
The turnover of N derived from rhizodeposition of faba bean (Vicia faba L.), pea (Pisum sativum L.) and white lupin (Lupinus albus L.) and the effects of the rhizodeposition on the subsequent C and N turnover of its crop residues were investigated in an incubation experiment (168 days, 15 °C). A sandy loam soil for the experiment was either stored at 6 °C or planted with the respective grain legume in pots. Legumes were in situ 15N stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition. In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller amount of 15–17% was present as microbial biomass and between 30 and 55% of mineralised rhizodeposition N was present as microbial residue pool, which consists of microbial exoenzymes, mucous substances and dead microbial biomass. The effect of rhizodeposition on the C and N turnover of crop residues was inconsistent. Rhizodeposition increased the crop residue C mineralisation only in the lupin treatment; a similar pattern was found for microbial C, whereas the microbial N was increased by rhizodeposition in all treatments. The recovery of residual 15N in the microbial and mineral N pool was similar between the treatments containing only labelled crop residues and labelled crop residues + labelled rhizodeposits. This indicates a similar decomposability of both rhizodeposition N and crop residue N and may be attributable to an immobilisation of both N sources (rhizodeposits and crop residues) as microbial residues and a subsequent remineralisation mainly from this pool.Abbreviations C or Ndec
C or N decomposed from residues
- C or Nmic
microbial C or N
- C or Nmicres
microbial residue C or N
- C or Nmin
mineralised C or N
- C or Ninput
added C or N as crop residues and/or rhizodeposits
- dfr
derived from residues
- dfR
derived from rhizodeposition
- Ndfr
N derived from residues
- NdfR
N derived from rhizodeposition
- Nloss
losses of N derived from residues
- SOM
soil organic matter
- WHC
water holding capacity 相似文献
472.
Franz Ludwig Graf Stauffenberg 《European Journal of Forest Research》1989,108(1):327-333
Ohne Zusammenfassung 相似文献
473.
Muller CB Ride SM Fouke J Whitney T Denton DD Cantor N Nelson DJ Plummer J Busch-Vishniac I Meyers C Rosser SV Schiebinger L Roberts E Burgess D Beeson C Metz SS Sanders L Watford BA Ivey ES Frank Fox M Wettack S Klawe M Wulf WA Girgus J Leboy PS Babco EL Shanahan B Didion C Chubin DE Frize M Ganter SL Nalley EA Franz J Abruña HD Strober MH Zimmer Daniels J Carter EA Rhodes JH Schrijver I Zakian VA Simons B Martin U Boaler J Jolluck KR Mankekar P Gray RM Conkey MW Stansky P Xie A Martin P 《Science (New York, N.Y.)》2005,307(5712):1043
474.
475.
Ternes M Lutz CP Hirjibehedin CF Giessibl FJ Heinrich AJ 《Science (New York, N.Y.)》2008,319(5866):1066-1069
Manipulation of individual atoms and molecules by scanning probe microscopy offers the ability of controlled assembly at the single-atom scale. However, the driving forces behind atomic manipulation have not yet been measured. We used an atomic force microscope to measure the vertical and lateral forces exerted on individual adsorbed atoms or molecules by the probe tip. We found that the force that it takes to move an atom depends strongly on the adsorbate and the surface. Our results indicate that for moving metal atoms on metal surfaces, the lateral force component plays the dominant role. Furthermore, measuring spatial maps of the forces during manipulation yielded the full potential energy landscape of the tip-sample interaction. 相似文献
476.
Halberg F Cornélissen G Katinas G Schwartzkopff O Johnson D 《Journal of circadian rhythms》2005,3(1):2
We honor Theo Hellbrugge's acclaimed endeavors in the rehabilitation, or rather the prehabilitation of handicapped children. So far, he has focused on obvious handicaps, and we trust that he will include concern for everybody's silent handicaps in the future by screening for abnormal variability inside the physiological range. Therein, we introduce cis- and trans-years, components of transdisciplinary spectra that are novel for biology and also in part for physics. These components have periods, respectively, shorter and longer than the calendar year, with a counterpart in magnetoperiodism. Transyears characterize indices of geomagnetic activity and the solar wind's speed and proton density. They are detected, alone or together with circannuals, in physiology as well as in pathology, as illustrated for sudden cardiac death and myocardial infarction, a finding calling for similar studies in sudden infant death syndrome (SIDS). As transyears can beat with circannuals, and depend on local factors, their systematic mapping in space and time by transdisciplinary chronomics may serve a better understanding of their putative influence upon the circadian system. Longitudinal monitoring of blood pressure and heart rate detects chronome alterations underlying cardiovascular disease risk, such as that of myocardial infarction and sudden cardiac death. The challenge is to intervene in a timely fashion, preferably at birth, an opportunity for pediatricians in Theo Hellbrugge's footsteps. 相似文献
477.
Theresa Bonatotzky Franz Ottner Egill Erlendsson Guðrún Gísladóttir 《European Journal of Soil Science》2022,73(2):e13224
Icelandic soils develop in a dynamic environment affected by both natural processes and anthropogenic impacts. We present an extensive investigation of soil mineralogy and pedogenesis in a disturbed (i.e., by solifluction) pedon under such conditions. The study focuses on two distinct tephra layers, a rhyolitic tephra from the Öræfajökull eruption in 1362 CE (Ö1362) and a basaltic Veiðivötn tephra from 1477 CE (V1477). Both tephra layers form an important parent material in the study area south of Vatnajökull, Iceland. The Andosol developed from tephra and aeolian material, rich in volcanic glass. The pH (H2O) values were between 5.5 and 6.6 and clay mineralogy displayed a predominance of allophanic material in both soil and tephra. The pedon can be seen in its early stage of chemical weathering and soil development. Despite the overall predominance of non- and poorly-crystalline short-range order secondary materials and Fe (hydr)oxides in the clay-size fraction, we found indication of smectite. High exchangeable Ca2+ and Mg2+ concentrations reflect enhanced aeolian input of volcanic material, while elevated exchangeable-Na+ concentrations are most likely caused by the oceanic composition of precipitation. The impact of erosion and aeolian processes on pedogenesis seemed to be higher between the deposition of Ö1362 and V1477, than in the soils above. Both, soil and tephra layers appeared disturbed by erosion–deposition processes over time. Characterised by a significantly coarser particle size composition, low soil organic carbon (SOC) content, and a more diverse mineralogy, a distinct fluvial sediment layer at 10–30 cm depth appeared sharply contrasting to the other soil layers in the profile. This possibly reflects the diverse composition of glaciofluvial material from a landslide originating from a Kvíárjökull moraine in the north. Changed weathering patterns and properties in the soils above the Ö1362 tephra indicated soil degradation following the deposition of the rhyolitic tephra. 相似文献
478.
Variability of certain chemotypes in three accessions of German chamomile (Matricaria chamomilla L.)
Bettina Faehnrich Pietro Nemaz Chlodwig Franz 《Genetic Resources and Crop Evolution》2014,61(7):1237-1244
In 203 analyzed chamomile plants, several compounds appreciated for their medicinal value, were evaluated qualitatively and quantitatively. α-Bisabolol and its oxides A and B were measured by gas chromatography; matricine as a precursor of chamazulene, was assessed semi-quantitatively by matching visually thin layer chromatography bands with a concentration range of the pure substance and the flavonoids apigenin and apigenin-7-glycoside were quantified by high performance liquid chromatography. Mean values of all compounds were compared in the three chamomile accessions ‘Manzana’, ‘Lutea’ and ‘Hungarian 2’. Correlations between different substances over all data were calculated. Moreover, certain groups combining particular properties according to their desired purpose or specificity, were formed. Their incidence in the particular chamomile varieties was determined. ‘Manzana’, a tetraploid cultivar, exhibited the highest share of the valuable bisabolol–matricine-type and the lowest ratio of bisabolol-oxides to bisabolol. To develop ‘high-quality-populations’, defined individuals of this cultivar shall be selected for further breeding. 相似文献
479.
Franz Conen Kristiina Karhu Jens Leifeld Barbara Seth Pekka Vanhala Jari Liski Christine Alewell 《Soil biology & biochemistry》2008,40(10):2703-2705
Predictions of future climate change critically depend on the temperature sensitivity of soil organic carbon decomposition. One question of debate is whether temperature sensitivity differs between young or labile and old or more stable carbon pools. We re-analysed soil that has previously led to the conclusion that old soil carbon is more temperature sensitive. The re-analysis gave different results compared to the earlier study, most likely due to small differences in an otherwise very similar experimental approach. This study illustrates how conclusions may depend upon details of the experimental setting. 相似文献
480.
Martinek B Bago Z Flöck M Hochsteiner W Schilcher F Kofler J 《Veterinary journal (London, England : 1997)》2006,172(1):181-184
Clinical, ultrasonographic, radiographic and pathological findings of a chondrosarcoma diagnosed in an 8-year-old Simmental cow are reported. The primary site was located in the cartilage of the right scapula at the angulus cranialis. The tumour had already spread to the lungs at the time of diagnosis. This is the first report of a bovine scapula chondrosarcoma. 相似文献