64 research outputs found
High-power ytterbium-doped fiber laser delivering few-cycle, carrier-envelope phase-stable 100 µJ pulses at 100 kHz
Invasion impact is conditioned by initial vegetation states
Abstract
Biological invasion is a crucial problem in the world because of its negative consequences for protected areas. The degradation stage of vegetation might affect the success of invasion. One of the most abundant and threatening invasive species is the common milkweed (Asclepias syriaca L.) which has invaded already 23 countries of Europe and in several habitat types its further spreading is promoted by climate change. Pannonian sand grassland is one of the most threatened habitat by common milkweed invasion. Therefore, invasion in sand grassland vegetation is an important issue. However, the effects of the invasive plant in the open sand grassland are rather controversial. In order to clarify the existing contradictory results, the study was carried out in a strictly protected area, near Fülöpháza (Hungary) in a reserve core area in a UNESCO biosphere reserve. Microcoenological study was applied to determinate the fine-scale community characteristics of non-invaded and invaded stands in natural and seminatural vegetation and data were processed by Juhász-Nagy's information theory models. Shannon diversity of species combinations (compositional diversity) which describes the ways of the coexistence of species, and the number of realized species combinations were used for measuring beta diversity. Differences between stands were analyzed by two-way ANOVA. The maximum compositional diversity of species and main life-forms (annuals, perennials and cryptogams) did not differ significantly between the non-invaded and invaded stands. In contrast, significantly larger characteristic areas of compositional diversity were detected in the invaded stands. Based on these results, it could be concluded that diversity of species combinations did not change but those values have shifted to coarser scales in case of invaded stands. The direction of this change suggests a kind of impoverishment in the presence of Asclepias. Thus, it is worth mentioning from the invasion management point of view that protection of the habitats against disturbance is a more cost-effective and successful way than protection against the establishment or extirpation of invasive species, since disturbance facilitates the invasions throughout the impoverishment of the community
The mineralogical composition of calcium and calcium-magnesium carbonate pedofeatures of calcareous soils in the European prairie ecodivision in Hungary
Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L.) Karst
The Norway spruce (Picea abies), the most important tree species in European forests, is
relatively sensitive to salt and does not grow in natural saline environments. Yet many trees
are actually exposed to salt stress due to the common practice of de-icing of mountain
roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate
use of reproductive seed material on reforestation sites, ensuring better chances of seedling
survival in salt-affected areas, we have studied the responses of young spruce seedlings to
salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers
in Picea abies, using as experimental material seedlings obtained by germination of
seeds with origin in seven populations from the Romanian Carpathian Mountains. These
responses included general, conserved reactions such as the accumulation of ions and different
osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or
activation of antioxidant systems. Although changes in the contents of different compounds
involved in these reactions can be associated to the degree of stress affecting the plants,
we propose that the (decreasing) levels of total phenolics or total carotenoids and the
(increasing) levels of Na+ or K+ ions in Picea abies needles, should be considered as the
most reliable and useful biomarkers for salt stress in this species. They all show very high
correlation with the intensity of salt stress, independently of the genetic background of the
seeds parental population, and relatively easy, quantitative assays are available to determine
their concentrations, requiring simple equipment and little amount of plant material.Funding: Sorin Schiop is a PhD student at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. This paper was published under the frame of European Social Found, Human Resources Development Operational Programme 2007-2013, project no. POSDRU/159/1.5/S/132765. Mohamad Al Hassan is a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium).Schiop, ST.; Al Hassan, M.; Sestras, AF.; Boscaiu Neagu, MT.; Sestras, RE.; Vicente Meana, Ă“. (2015). Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L.) Karst. PLoS ONE. 10(8). doi:10.1371/journal.pone.0135419Se013541910
Ubiquitous miR159 repression of MYB33/65 in Arabidopsis rosettes is robust and is not perturbed by a wide range of stresses
Consequences of climate change for the soil climate in Central Europe and the central plains of the United States
An integrative approach to identify hexaploid wheat miRNAome associated with development and tolerance to abiotic stress
The dissolved organic matter as a potential soil quality indicator in arable soils of Hungary
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