Search results for "forestry"
showing 10 items of 1998 documents
Numerical analysis of ionosphere disturbances and Schumann mode splitting in the Earth-ionosphere cavity
2008
[1] The variability of ionosphere properties plays an important role in the Schumann resonances (SR), amplitudes, frequencies, and Q factor. Therefore, as atmosphere ionization is related to solar activity, SR could be devised as a source of indirect parameters that locally from the surface of the Earth could provide space weather information. A proper understanding of this link to SR parameters can be obtained through finite difference time domain (FDTD) simulations, specifically with the numerically obtained modes and frequencies that relate frequency shifts to the day-night asymmetry and polar inhomogeneities. Day-Night asymmetry is observed to have a minor influence in SR; however, larg…
Weed communities of root crops in the Pamir Alai Mts, Tajikistan (Middle Asia)
2013
<p>The paper presents the results of investigations of weed vegetation conducted on root crops in Tajikistan (Middle Asia), one of the world cradles of weed flora. The main research was conducted in the Zeravshanian, southern Tajikistan and Hissar-Darvasian geobotanical regions in 2011. The study was based on 107 phytosociological relevés obtained in various geobotanical regions of the country. The collected material probably presents the majority of variations among the weed communities of root cultivations in the Middle Asia. As a result of numerical analyses, 7 associations were distinguished: <em>Convolvulo arvensis-Cyperetum rotundi</em>, <em>Daturo stramonii-Hi…
Laukkopība
1939
Saturs (nodaļas): Priekšvārdi. Laukkopības būtība un laukkopības zinātnes uzdevumi. I. Augu augšanas faktori un to kārtošana laukā. I I . Augsnas auglība un ražība. III. Nezāles un to apkarošana. IV. Augsnas strādāšana. V. Lauku iedalīšana. VI. Eksperimentālā laukkopība (lauku izmēģinājumi). Literatūra. Lietu saraksts.
Laying date and clutch size of Great Tits(Parus major) in the Mediterranean region: a comparison of four habitat types
1998
Laying data and clutch size of Great Tits were studied in four different habitats in eastern Spain: two holm oak(Quercus ilex) forests, at 500 and 900–950 m a.s.l., a zeen oak(Quercus faginea) forest, at 900–1100 m a.s.l., a pine(Pinus sylvestris) forest, at 1000–1050 m a.s.l., and orange(Citrus aurantium) plantations, at 30 m a.s.l. All sites were placed at about the same latitude (39–41°N), and all were studied during the same years (1992–95). Our results show that (1) laying date did not differ between the natural habitats at the same altitude (range of the means of yearly means 4–8 May); (2) within the same habitat type (holm oak forest) laying date was earlier at low altitude (30 April…
Disentangling the rhizosphere effect on nitrate reducers and denitrifiers: insight into the role of root exudates.
2008
International audience; To determine to which extent root-derived carbon contributes to the effects of plants on nitrate reducers and denitrifiers, four solutions containing different proportions of sugar, organic acids and amino acids mimicking maize root exudates were added daily to soil microcosms at a concentration of 150 μg C g−1 of soil. Water-amended soils were used as controls. After 1 month, the size and structure of the nitrate reducer and denitrifier communities were analysed using the narG and napA, and the nirK, nirS and nosZ genes as molecular markers respectively. Addition of artificial root exudates (ARE) did not strongly affect the structure or the density of nitrate reduce…
Does Physics Need a Second Scientific Revolution? – Christianity Encourages Tackling a Foundational Problem of Physics
2013
V prispevku je avtor opisal asociacijo Carici sempervirentis-Pinetum nigrae, ki uspeva v strmih osojnih legah gorskega sveta nad dolino zgornje Kolpe na Kočevskem (S Slovenija). Njene značilnice in razlikovalnice so Carex sempervirens, Globularia nudicaulis, Aquilegia nigricans, Adenophora liliifolia in Sesleria kalnikensis. Asociacijo ~leni v dve subasociaciji: -salicetosum appendiculatae subass. nova in -gentianetosum symphyandrae subass. nova. Primerjava našega črnega borovja z drugimi črnimi borovji v jugovzhodnoalpskem in dinarskem gorskem svetu z analizo podrobnejše floristične, fitosociološke in geoelementne sestave ter analizo spektra bioloških oblik je pokazala, da se, kljub nekate…
Shifts in size, genetic structure and activity of the soil denitrifier community by nematode grazing
2010
International audience; Bacterial-feeding nematodes represent an important driver of the soil microbial activity and diversity. This study aimed at characterizing the impact of nematode grazing on a model functional bacterial guild involved in N-cycling, the denitrifiers. Bacterial-feeding nematodes (Cephalobus pseudoparvus) were inoculated into soil microcosms whose indigenous nematofauna had previously been removed. The size, genetic structure and activity of the soil denitrifier community were characterized 15 and 45 days after nematodes inoculation using quantitative PCR of the nirK, nirS and nosZ denitrification genes, fingerprinting of the nirK and nirS genes and denitrification enzym…
Proposals for improvement of Annex I of Directive 92/43/ EEC: Central Italy
2021
The main purpose of the 92/43/EEC Habitats Directive is to contribute to the conservation of biodiversity, understood as habitat types and species of the flora and fauna of the European Union. To achieve this goal, natural and semi-natural biodiversity as a whole must be recognized and included in its annexes. As for the conservation of biotopes, named habitat types, Italy is unfortunately lacking as it the Annex I does not include important ecosystems that are typical of its territory, rare for biogeographical reasons or threatened. Therefore, the opportunity to identify a first list of significant habitats for central Italy is discussed here. For each of the new proposed types (new habita…
Optimization of the Mix-Design System for the Sub-ballast Railroad
2017
Bituminous sub-ballast is an alternative solution to the unbound granular sub-ballast used in the railway track due to several benefits that it can provide. Indeed, it contributes to maintain the moisture content in the subgrade unchanged during all year. This decreases the subgrade deterioration process. Moreover, the presence of bituminous sub-ballast can also reduce vertical stiffness variations on the track; it can have a positive effect in the maintenance needs at transition sections (bridge-embankment) and in the attenuation of the vibrations induced by the rail traffic. Despite the importance of the presence of the bituminous sub-ballast to conceive the construction and/or rehabilita…