The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Teucrium chamaedrys is a typical plant of dry grassland communities at xeric sites on calcareous soils in Franconia (Southern Germany). The morphological–anatomical appearance of limestone plants in the form of nanism or dwarfing has been interpreted by Gregor Kraus approximately 100 years ago as a consequence of the dry and hot environmental conditions. In the present study the mechanisms of adaptation...
The assessment of trace-gas uptake by plants is of basic interest in plant ecophysiology and atmospheric chemistry. For tall vegetation and extensive canopies micrometeorological methods and modelling of deposition or combinations of both are usually the methods of choice. However, distinguishing between the aerodynamically driven components of deposition and stomatal uptake is difficult and estimates...
Nitric acid (HNO 3 ) and ozone (O 3 ), secondary products of photochemical reactions of nitrogen oxides (NO x ) and volatile organic compounds, are important pollutants in arid regions with large outputs from petrol combustion. In the Los Angeles (LA) air basin, nitrogen dry deposition rates in forests downwind of the urban areas can reach 35–40kgha −1 year −1 ...
In some Bothriochloa species, the foveola or pit – a depression located in the lower glume of the sessile spikelet – has been interpreted as being an extrafloral nectary, although neither the structure has been studied nor the secretion was chemically characterized. On this basis, we analyzed the characteristics and structure of the foveola and the chemical composition of the secretion in Bothriochloa...
Growth pattern and photosynthetic activity of different bamboo species (Phyllostachys viridi-glaucescens Rivière et C. Rivière, Phyllostachys pubescens Mazel ex Lehaie, Phyllostachys bambusoides Siebold et Zucc., and Bambusa ventricosa McClure) growing at the Botanical Garden of Rome were studied. Among the considered species, P. pubescens had the highest mean culm height (14.3±0.6m) and diameter...
We describe the spectrum of visitors of seven Mediterranean legumes and identify the potential pollinators by observing insects’ behavior on flowers. The diversity of each population's insect assemblage (flower visitors and potential pollinators) is calculated in order to estimate to which degree pollination systems are specialized. The importance value (PI) for main taxa of potential pollinators...
Infrageneric classification of Paspalum is mainly based on characters of the inflorescence and spikelets. Some of the inflorescence characters usually used are the width and external morphology of the rachises of the racemes. Nevertheless, morphological terminology used in the literature is frequently imprecise. We examine the internal structure of the rachises of the racemes in Paspalum to: (a) compare...
Secretory cavities, unicellular papillae and hair trichomes of the flower of Myrtus communis have been investigated morphologically, anatomically and histochemically. Secretory cavities located adjacent to the epidermis of sepals, petals, receptacle, stamens, ovary and style show both a schizolysigenous, a combination of schizogenous and lysigenous development. At maturity, the glands are made up...
CO 2 exchange and water relations of selected lichen species were investigated in the field and also in the laboratory, at a height of 3106m above sea level in the Austrian Alps, during the short snowless summer period from middle of July to the end of August. In the course of the field investigations, clear summer days were quite rare. Altogether 14 diurnal courses of CO 2 exchange...
The target of this paper is the correlation of disturbance characteristics of a traditionally used extensive summer pasture in the Alpine foothills (Southern-Bavaria, Germany) and corresponding seasonal population dynamics of the clonal plant Apium repens (FFH Annex II species). The basic hypothesis is that an extensive cattle grazing of its habitats (flood meadows) provides an optimum disturbance...
Although water-limited environments are detrimental to cotton growth and productivity worldwide, identification of cotton (Gossypium hirsutum L.) genotypes that are less sensitive to drought may improve productivity in drought prone areas. The objective of the study was to assess genotypic variation for drought tolerance in cotton varieties using physiological attributes as selection criteria, and...
Norway spruce (Picea abies [L.] Karst.) has a pronounced ability to create different crown types embracing strongly hypotonic, epi-hypotonic, strongly amphitonic types as well as respective intermediate ones. Data of Holzer and Schultze (1987) were reanalyzed in order to identify major environmental components that may shape ecotypes and contribute to Gruber's (1989) hypothesis that phenotypic plasticity...
Leiothrix curvifolia var. lanuginosa and Leiothrix crassifolia are endemic and sympatric species in the Brazilian rupestrian grasslands, a habitat that has a predominance of sandy and shallow soils with low water retention. Based on the premise that soil moisture is one of the abiotic factors that affects most reproduction in plants, we hypothesized that the flowering phenology events and establishment...
Salsola affinis is a dominant annual inhabiting saline deserts of Xinjiang, China. Experiments were conducted to determine the effects of temperature, winged perianths and NaCl on seed germination and on germination recovery from the effects of saline conditions after transfer to distilled water. Freshly harvested seeds could germinate equally well in light and darkness at 5–30°C. Attached winged...
The objectives of the study, conducted during the 2003/2004 growing season in the National Park of Bou Hedma (South Tunisia), were to quantify the effects of the single-woody species Acacia tortilis subsp. raddiana on grass species composition, on total plant cover, on density of perennial species, on dry matter (DM) yield and on soil nutrients at lightly and heavily grazed sites. In each study site,...
A first study of the pollination biology of a Mediterranean Aristolochia species in its natural habitat is presented. In all, 183 flowers of Aristolochia pallida Willd. were investigated, which in total contained 73 arthropods, dominated by two groups of Diptera, black fungus gnats (Sciaridae representing 37%) and scuttle flies (Phoridae representing 19%), respectively. However, only Phoridae are...
Two 1ha plots of a Southern Brazilian subtropical riverine forest, subject to different frequency and duration of floods, were compared to detect the differences in physiognomic structure, tree community composition, richness and diversity. Each plot was made up of 100 contiguous 10×10m subplots, where 3451 trees with pbh ⩾15cm were measured and identified. The survey observed 30 tree species, in...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.