Search results for "grasslands"
showing 10 items of 39 documents
Phytosociological and distributional researches on the grasslands of the class Lygeo-Stipetea in western Sicily.
2009
The thermo and meso-xerophilous pseudo-steppic vegetation is widespread in the driest areas of the Mediterranean Region and is primarily referred at the class Lygeo-Stipetea. This sintaxon includes communities dominated by several hemicryptophytes, which are also associated to some geophytes and therophytes. In Sicily this vegetation is distributed from sea level to 1300-1400 m, on different substrates (limestone, gypsum, schists, calcarenites, conglomerates, etc.), within the thermo and mesomediterranean belt dry to subhumid. Principally, are secondary grasslands used for grazing, localized on previously deforested areas, where the periodic burnings play a fundamental role in maintaining t…
On the origin and evolution of the Mediterranean dry grasslands.
2006
A synthesis on the functional types of Mediterranean dry grasslands is outlined. Three different types are outlined: wintergreen perennial dry grasslands, wintergreen ephemeral dry grasslands, summergreen perennial dry grasslands. The first type is the most primitive, including several relict species, often characterized by very disjoint, sometimes anfi-saharian distribution ranges. The second type is resulting from an evolutionary trend towards short-lived life strategy, triggered by climatic and topographic perturbations that affected the Mediterranean region in the Plio- and Pleistocene. The third type, only marginally occurring in the Mediterranean region, is deriving from Holarctic and…
An “Uncertainty Principle” for the Mediterranean annual dry grasslands
2009
Preliminary results of diachronic researches on the spatial arrangement and species richness in Mediterranean annual dry grasslands (Tuberarietea guttatae) demonstrated that the patchiness resulted minimized and the temporal stability maximized at elevations offering the best compromise between the summer drought stress and the winter cold stress. Moreover, the temporal stability of the Mediterranean annul dry grasslands could not necessarily be related with their demographic inertia, meaning that the turnover and rearrangement of species within the community do not necessarily implicate significant changes in the average species composition over time. On the other hand, the survival chance…
Impressions from the 4th EDGG Research Expedition to Sicily: community composition and diversity of Mediterranean grasslands.
2012
Effects of temperatures on the spatial arrangement in Mediterranean annual dry grasslands
2009
Some preliminary results of diachronic researches on the spatial arrangement and species richness in Mediterranean annual dry grasslands belonging to the class Tuberarietea guttatae are presented. Our results are based on 12 permanent plots, set in three places at different heights in Southern and Central Sardinia. Sites were chosen to have annual species richness and plant density not significantly different. The relationship between patchiness and temporal stability was investigated at the scale of the square plots. We used the mean abundance divided by the SD in abundance (S = xm/r), as the measure of temporal stability of populations (Tilman 1999) and the Shannon-Wiener index to evaluat…
The Lygeo-Stipetea class in Sicily
2010
Basing on literature data and unpublished relevés from Sicily, a survey of the syntaxa belonging to the class Lygeo-Stipetea Rivas-Martínez 1978 is presented. This perennial vegetation is characterized by the dominance of big caespitose hemicryptophytes, and it is widely distributed in Sicily from the sea level up to 1500 m a.s.l. The class is represented in Sicily by two orders, floristically and ecologically well differentiated: Lygeo-Stipetalia, including the sole alliance Moricandio-Lygeion exclusively of clayey substrates, and Hyparrhenietalia hirtae, including five alliances (Hyparrhenion hirtae, Avenulo cincinnatae-Ampelodesmion mauritanici, Thero-Brachypodion ramosi, B…
Élaboration du plan de gestion de l’espace naturel sensible des versants de Vuillafans et Châteauvieux-les-Fossés
2014
The value of the “Espace Naturel Sensible des versants de Châteauvieux et Vuillafans” is based on a natural habitats mosaic that support an originality and a diversity of flora and entomological that we want to preserve. However, in dry grasslands which are habitats of the European community, we can see gradually the emergence of shrub and reforestation due to the difficult to mechanize hills and very fragmented private lands that favored the abandonment of agricultural practices on the slopes. To efficiently program the management of this area, a management plan, which is now a recognize tools for managers of natural areas, was written. To achieve the management plan objectives, the privat…
Dabiskie zālāji Vidzemes augstienes agroainavā: biodaudzveidība un tās saglabāšanas sociālekonomiskie aspekti
2015
Bakalaura darba „Dabiskie zālāji Vidzemes agroainavā: biodaudzveidība un tās saglabāšanas sociālekonomiskie aspekti” mērķis ir noskaidrot dabisko zālāju daudzveidību Vidzemes augstienē un tās saglabāšanas sociālekonomiskos faktorus. Visā Latvijas teritorijā dabisko zālāju platības samazinās, tomēr to saglabāšanai ir liela nozīme, jo dabiskajos zālājos ir ļoti augsta gan dzīvnieku, gan augu sugu daudzveidība. Dabiskie zālāji nespēj pastāvēt bez cilvēka klātbūtnes, tieši tāpēc ir svarīgi zināt iemeslus, kāpēc dabiskie zālāji tiek pamesti vai apsaimniekoti nepareizi. Dabisko zālāju biodaudzveidība Vidzemes augstienē samazinās, zemes īpašnieki novērtē dabas vērtību, bet, ņemot vērā šī brīža aps…
Functional ecology for evaluating and predicting the aptitude of permanent grassland to provide services
2013
National audience; Applying the principles of functional ecology helps better predict the services which can be provided by permanent grassland. Farming practices and environmental characteristics influence the functional composition of grassland. Functional plant types have a generic effect on forage services which can be assessed. 13 types of grassland composed of distinct functional types were defined based on 1,283 sample grassland fields located on 8 sites. This approach was validated by checking 8 Ellenberg indicator values (used to evaluate environmental characteristics and farming practices) against climatic data and descriptive data for farming practices. The interest of a function…
Agroecological potential and prospects of alternative use of natural feed resources for bioenergetics
2018
Produkcja biomasy dla biogazu, paliw stałych i ciekłych jest ważna w szerokim zakresie zastosowań niekonwencjonalnych źródeł energii. Jednakże produkcja i wykorzystanie biomasy do celów energetycznych również wymaga kosztów finansowych i prowadzi do zmian w strukturze obszarów upraw w produkcji rolnej. Czynniki te powodują wzrost cen produktów rolnych. Zmiana klimatu i wysokie koszty zasobów mineralnych przyczyniają się do poszukiwania i rozwoju nowych sposobów pozyskiwania zasobów energetycznych. Badania nad produkcją biomasy z użytków zielonych w celach energetycznych są w Europie istotne i priorytetowe, a ich wyniki mają ogromną wartość praktyczną. Dlatego konieczne jest rozwiązanie prob…