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1.
Rural depopulation and recent landscape changes in a Mediterranean region: Consequences to the breeding avifauna 总被引:8,自引:0,他引:8
We studied the vegetational and avifaunistic changes following rural depopulation in an area covering 2,600 ha north of Montpellier
(Southern France). The study area is covered by a mosaic of Mediterranean habitats that includes cultivation, grasslands,
shrublands, and woodlands and is representative of the natural features present and of the human usage practiced so far in
this part of the Mediterranean.
We sampled the vegetation and the bird fauna in the same 193 census plots in 1978 and in 1992. At both the habitat and landscape
scales the cover of woody plants increased significantly. Open habitats tend to disappear. As a consequence the abundance
of open-habitat bird species decreased significantly whereas the abundance of forest birds increased significantly. These
changes favor a pool of forest species widespread in western Europe and reduce habitat availability for open habitat and shrubland
species. Many of the latter are Mediterranean species whose distribution in Western Europe could become reduced under current
landscape dynamics. Our observation of more woodlands and their typical birds and of less open habitats and their associated
avifauna is not consistent with the traditional worry shown by the public and the managers about the regression of forests
and woodlands in the Northern Mediterranean as a consequence of fire. 相似文献
2.
Baranov AS Graml R Pirchner F Schmid DO 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1993,110(1-6):385-392
SUMMARY: Muzzle dermatoglyphics - n. ridges, granula and vibrissae - were analysed in various breeds. Differences among these in most traits were significant. Herd effects accounted for about 1/10 of the variance and heritability, estimated by combining sib, halfsib and dam-daughter correlations corrected for herd differences was above 50% for ridges and vibrissae and about 30% for granula. Genetic correlations between ridge counts and n. vibrissae in different nose fields, respectively, were high as they were between the former and n. granula but they were negative or very low between vibrissae and the other two traits. Asymmetry among the counts in the two muzzle sides was significant for nearly all traits, Heritabilities were low, around 10 to 20%, and the crossbreds had less asymmetry than their parental breeds. The correlations among asymmetry measures were low. ZUSAMMENFASSUNG: Rassenunterschiede und genetische Variabilit?t von Flotzmaulmustern Flotzmaulmerkmale - Zahl von Leisten, Warzen und Haaren - wurden in verschiedenen Rassen untersucht. Unterschiede zwischen diesen waren für alle Merkmale signifikant. Herdeneinflüsse verursachten etwa 1/10 der Varianz und Heritabilit?tswerte, gesch?tzt aus Korrelationen zwischen Zwillingen, Halbgeschwistern und T?chter-Müttern, korrigien für Herdeneinflüsse, variierten zwischen 36 und mehr als 50%. Genetische Korrelationen zwischen Leistenzahl und Zahl von Haaren in verschiedenen Flotzmaulfeldern waren hoch, ebenso wie die zwischen ersteren und Zahl von Warzen, aber sie waren negativ oder sehr gering zwischen Haaren und den andern beiden Merkmalen. Asymmetrie zwischen Zahlen in beiden Flotzmaulh?lften war signifikant für fast alle Merkmale. Heritabilit?tswerte waren niedrig, etwa 10-20% und Kreuzungstiere zeigten weniger Asymmetrie als ihre Herkunftsrassen. Die Korrelationen zwischen Asymmetriema?en waren niedrig. 相似文献
3.
The utility, vehicle required, the time needed for assembly and relocation and the costs associated with six different rainfall simulators were studied. The results can be summarized as follows:
- 1 The simulator designed by Kainz & Eicher (1990) is the least expensive to operate. This simulator also has excellent experimental versatility. Its only restriction is a short slope length.
- 2 The rainfall simulator of Karl & Toldrian (1973) is also inexpensive to operate, but because of disadvantages such as low falling height, wind susceptibility, and the need for more workers than other simulators, it should be used mainly where other simulators are not practical (forests, steep slopes, or long slopes).
- 3 The rainfall simulator of Richter et al. (1988) has limited mobility in the field and is highly susceptible to wind drift. Moreover, its narrow plots do not cover a representative unit of a cultivated field.
- 4 The modified Swanson-type simulator (Auerswald, (1986) is suitable for large plots if a sufficient water supply is available.
- 5 The simulator of Kromer & Vöhringer (1988) has the highest fixed costs, but labour is used efficiently.
- 6 The simulator of Schmidt (1983) can only be considered for stationary use because of its long assembly time. Other disadvantages are narrow plot size and high wind susceptibility.
4.
5.
Effects of CO2 Enrichment and Drought on Photosynthesis,Growth and Yield of an Old and a Modern Barley Cultivar 下载免费PDF全文
I. Schmid J. Franzaring M. Müller N. Brohon O. C. Calvo P. Högy A. Fangmeier 《Journal of Agronomy and Crop Science》2016,202(2):81-95
Susceptibility of crops to drought may change under atmospheric CO2 enrichment. We tested the effects of CO2 enrichment and drought on the older malting barley cultivar Golden Promise (GP) and the recent variety Bambina (BA). Hypothesizing that CO2 enrichment mitigates the adverse effects of drought and that GP shows a stronger response to CO2 enrichment than BA, plants of both cultivars were grown in climate chambers. Optimal and reduced watering levels and two CO2 concentrations (380 and 550 ppm) were used to investigate photosynthetic parameters, growth and yield. In contrast to expectations, CO2 increased total plant biomass by 34 % in the modern cultivar while the growth stimulation was not significant in GP. As a reaction to drought, BA showed reduced biomass under elevated CO2, which was not seen in GP. Grain yield and harvest index (HI) were negatively influenced by drought and increased by CO2 enrichment. BA formed higher grain yield and had higher water‐use efficiency of grain yield and HI compared to GP. CO2 fertilization compensated for the negative effect of drought on grain yield and HI, especially in GP. Stomatal conductance proved to be the gas exchange parameter most sensitive to drought. Photosynthetic rate of BA showed more pronounced reaction to drought compared to GP. Overall, BA turned out to respond more intense to changes in water supply and CO2 enrichment than the older GP. 相似文献
6.
7.
Nottingham RM Hosking BC Schmid HR Strehlau G Junquera P 《Australian veterinary journal》2001,79(1):51-57
OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on coarse and fine woolled sheep under New Zealand conditions. DESIGN: Randomized clinical field trials. PROCEDURE: In a first field trial, coarse wooled sheep treated with a ready-to-use, 5% dicyclanil formulation were compared with untreated control sheep for up to 21 weeks. In a second field trial, fine woolled sheep, treated with the same dicyclanil formulation, were compared with untreated sheep for up to 19 weeks. Efficacy was assessed by calculating the aggregated cumulative strike rate. RESULTS: For trial 1 (coarse woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 21 after treatment reached 3.9% and 19.1% for treated and untreated sheep, respectively. For the treated animals the aggregated cumulative strike rate reached the 1% and 2% benchmarks between weeks 11 and 12. For trial 2 (fine woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 19 reached 0.6% and 7.5% for treated and untreated sheep, respectively. Wool length at the time of application did not substantially influence the efficacy of dicyclanil. CONCLUSION: Under New Zealand field conditions, a ready-to-use 5% spray-on formulation of dicyclanil protected coarse woolled sheep for at least 12 weeks and fine woolled sheep for at least 19 weeks. 相似文献
8.
W Erhardt C Ring H Kraft A Schmid H M Weinmann R Ebert B Schl?ger M Schindele R Heinze N Lomholt 《DTW. Deutsche tier?rztliche Wochenschrift》1989,96(3):92-99
For investigations of CO2-stunning of feeder- and slaughter-pigs parameters of behaviour, blood-gas-analyses and electroencephalograms were chosen. The following results were obtained: 1. Blood-gas-analyses proved that the CO2-stunning does not produce unconsciousness due to a lack of oxygen. 2. The criterias of general anaesthesia: unconsciousness, muscle-relaxation and analgesia with total reversibility could be confirmed. 3. The violent convulsive symptoms were evaluated as reactions identical with the stage II of GUEDEL's scheme of anaesthesia. 4. Muscular agitation, which sometimes appeared a few seconds before the stage of excitation, was judged to belong either to the start of the excitation phase or to the end of Guedel's stage of analgesia, during which the sensitivity is decreased. Neither study of behavior nor objective measurements showed, during the first 10 to 20 seconds of exposure to the CO2, any sign of pain or suffering related to the Act for Prevention of Cruelty to Animals, and accordingly such suffering should not be ascribed to the CO2 stunning method. 相似文献
9.
10.
Max Becker 《Plant foods for human nutrition (Dordrecht, Netherlands)》1968,15(1):48-64
Summary A review is given about publications of the last 30 years, concerning problems of high nitrate content of feeds. Nearly 10 areas of scientific work can be discerned. The most important of them have to do with: Analysis of nitrate and nitrite; danger of poisoning by feeds and water rich in nitrate; physiological and pathological consequences of high doses of nitrate or nitrite; reduction of nitrate (in the rumen and in the fermentation of plants) to nitrite, hydroxylamine and ammonia; behaviour of nitrate in the process of silage making; adverse effects upon the functions of the thyroid gland by nitrite and the disturbances of the availability of vitamin A and vitamin E by nitrate-nitrite.
Résumé On a donné un rapport sur les travaux scientifiques publiés dans les dernières trente années, concernant les problèmes d'une teneur haute en nitrate dans les fourrages. On peut discerner à peu près dix régions de travail scientifique. Les plus importantes sont: analyses du nitrate et du nitrite; le danger des intoxications par les fourrages et par l'eau, qui sont riches de nitrate; les conséquences physiologiques et pathologiques des doses hautes du nitrate ou du nitrite; la réduction du nitrate (dans le panse des ruminants et dans les fourrages en fermentation) au nitrite, au hydroxylamine et à l'ammonique; les réactions du nitrate pendant la préparation des silages; les influences défavorables aux fonctions de la glande thyroide par le nitrite; et les actions de déranger l'utilisation de la vitamine A et de la vitamine E par nitrate-nitrite.相似文献