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21.
Comparison of ecological condition and conservation status of English yew population in two Austrian gene conservation forests 总被引:1,自引:0,他引:1
DHAR Amalesh RUPRECHT Herwig KLUMPP Raphael VACIK Harald 《林业研究》2007,18(3):181-186
English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha (DBH ≥5 cm), average DBH and average height were 492 n.hm^-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n.hm^-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals.hm^-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species. 相似文献
22.
Mria Oszvald Sndor Tmskzi Oscar Larroque Eszter Keresztnyi Lszl Tams Ferenc Bks 《Journal of Cereal Science》2008,48(1):68-76
While the effect of protein content and composition on the functional properties of wheat flour is well studied, our knowledge on the same properties of rice flour is limited. This work was conducted to study the relationship between the dough mixing properties of flour from different rice cultivars and protein content and composition. An efficient sonication-based two-step extraction procedure was applied to isolate rice flour proteins. The size-exclusion HPLC (SE-HPLC) method, originally developed for separating wheat proteins, was applied with some minor modifications in order to study the size distribution of rice flour proteins. Four fractions were distinguished on the SE-HPLC profile and were further characterized by SDS-PAGE. Fractions I–III consisted of glutelins, while fraction IV contained albumin, globulin and prolamin proteins. When rice dough was characterized on the basis of mixing parameters in a micro z-arm mixer, significant differences were observed depending on the protein composition of the flour. Statistical analysis results indicated that the functional properties of the flour from different rice cultivars were associated with the amount of polymeric proteins and their size distribution. 相似文献
23.
Herwig Ruprecht Amalesh Dhar Bernhard Aigner Gerald Oitzinger Raphael Klumpp Harald Vacik 《European Journal of Forest Research》2010,129(2):189-198
In Europe, the English yew species (Taxus baccata L.) is endangered. Intensive human land-use, including forest management, has caused a decrease of the yew populations all
over Europe. In Austria, gene conservation forests are used for the in situ conservation of populations of this rare tree
species by silvicultural treatments. In order to improve the conservation management in these gene conservation forests, this
study addresses the relation between competition and viability of yew populations through the use of structural diversity
indices. The structural indices, which include mingling, tree–tree distance, diameter, and tree height differentiation, were
determined for a structural group of four trees as well as the neighbouring trees of the male and female yews at the monitoring
plots on a regular grid in three gene conservation forests. Although the three study sites provided quite different environmental
conditions for English yew, the vitality of each individual yew was influenced by the inter-specific competition of the neighbouring
tree species at all sites. Low vitality was associated with a small mean distance to neighbours and large tree height differentiation.
In conclusion, we suggest that a combination of different structural indicators is needed for an integrative assessment of
conservation status in the gene conservation forests. This would help improve the evaluation of the impact management has
on yew population viability. 相似文献
24.
Jaenicke R 《Science (New York, N.Y.)》2005,308(5718):73
Suspended atmospheric particles play a crucial role in any global climate scenario: They can both enforce and suppress radiative forcing. In developing climate modeling further, a deeper understanding of atmospheric aerosol is needed. Because of extreme local and temporal variations, proper incorporation of aerosols into models requires modeling of the aerosol itself. It turns out that cellular material and proteins compose up to 25% of the atmospheric aerosol. Consequently, the source strength of the biogenic aerosol in general must be corrected and should be estimated on the order of other major aerosol sources. 相似文献
25.
In recent years the freshwater fish market has required more processed goods, as young consumers purchase ready-to-cook food
products. In Middle European aquaculture systems carp are the main species. The appearance of new species (African catfish,
trout, salmon), as well as the improved import possibilities of value-added fish products have introduced new challenges for
fish farmers. In order to maintain the share of carps in fish sales, it is indispensable to develop up-to-date products that
meet the needs of present generations. It is necessary to find processing methods that remove the fish bone and the off flavours
occurring in Cyprinids. Smoking of carp has a strong tradition in the region, thus there are advantages to the development
of smoked carp products, mainly in the form of boned fillets. The present study investigates two smoking methods aimed at
ensuring basic information for product innovation. Analyses of the variation of weight, dry matter and lipid content during
hot and cold smoking are presented for the case of three species: the common, silver, and grass carp. To determine the most
acceptable products, the paper details the results of organoleptic tests, in which five characteristics (appearance, consistence,
flavour, smell, and succulence) were investigated. Evaluation results indicate that the hot-smoked carp products are more
acceptable, therefore it is hoped that these products, packed in a modified atmosphere, will achieve a strong market share
in the near future. 相似文献
26.
Eszter Kása Jelena Lujić Zoran Marinović Tímea Kollár Gergely Bernáth Zoltán Bokor Béla Urbányi Kinga Katalin Lefler Dušan Jesenšek Ákos Horváth 《Fish physiology and biochemistry》2018,44(6):1499-1507
Vitrification was applied to the sperm of two endangered fish species of So?a River basin in Slovenia, the Adriatic grayling (Thymallus thymallus) and marble trout (Salmo marmoratus) following testing different cooling devices and vitrifying media. Sperm was collected, diluted in species-specific non-activating media containing cryoprotectants, and vitrified by plunging directly into liquid nitrogen without pre-cooling. Progressive motility, curvilinear velocity, and straightness of fresh and vitrified-warmed sperm were evaluated with computer-assisted sperm analysis (CASA). Fertilization trials were carried out to test the effectiveness of vitrification in the case of grayling. A protocol utilizing a glucose-based extender, 30% cryoprotectants (15% methanol + 15% propylene glycol), 1:1 dilution ratio, and droplets of 2 μl on a Cryotop as cooling device yielded the highest post-thaw motility values for both Adriatic grayling (7.5?±?6.5%) and marble trout (26.6?±?15.8%). Viable embryos were produced by fertilizing eggs with vitrified grayling sperm (hatching 13.1?±?11.7%, control hatching 73.9?±?10.4%). The vitrification protocol developed in this study can be utilized in the conservation efforts for the two species as an alternative to slow-rate freezing when working in field conditions or when specific equipment necessary for slow-rate freezing is not available. 相似文献