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Semi-natural dry grasslands host some of the most valuable habitats in Europe, due to their biodiversity heritage. Nevertheless, a strong decline in their extension, due to the cessation of traditional management, has been observed in the last decades. The aim of the study was to assess plant community changes due to abandonment and the effect of spring grazing in sub-Mediterranean dry grasslands, focusing on the plant functional traits involved in this turnover. The study area is located in the central Apennines (Italy), where grasslands were grazed by sheep in late winter and spring until 1980 and are nowadays abandoned. Relevés sampled (using the Braun-Blanquet method) in different years, namely in 1976–1980 (grazed pasture) and again in 2010 (abandoned pasture) were compared. Results indicated that abandonment leads to the increase of species richness. Traits and strategies indicator sets were: therophyte for the grazed pasture; geophytes, flower palatability, early flowering strategy, clonal ability and presence of storage organs for the abandoned ones. Traits related to low levels of stress (tolerance strategies) are heavily reduced in grazed systems, and thus the functional composition of plant community is mostly characterised by traits promoting avoidance strategies. In abandoned conditions a higher number of species can co-exist thanks to the micro-scale variation of soil features and niche diversification. The research findings also revealed grazing timing as a key factor for understanding changes of plant functional trait patterns and spring grazing as a threat for orchid species.
Tiller demography of a perennial caespitose grass Festuca pallens Host was studied on permanent plots in two types of dry grasslands. The field work was done in the Považský Inovec Mts. (Western Carpathians) during 1993–1995. The permanent plot in the Poo badensis-Festucetum pallentis was located on a steep, strongly eroded S-facing slope covered with dolomit outcrops, scree and sparse vegetation (20%) dominated by Festuca pallens. The permanent plot in the Festuco pallentis-Caricetum humilis was located on the even ridge plateau with shallow stony soil and vegetation covering about 70% dominated by Carex humilis and Festuca pallens. The aim was to estimate the basic characteristics of tiller life cycle in Festuca pallens: tillering, flowering, mortality and life span. Tillers of Festuca pallens are exclusively intravaginal with a leaf rosette and polycyclic (can live for more than three years). A proximate maximum life span of orthotropic tiller parts was five or six years. The proportion of flowering tillers in the studied populations varied between the years from 3% to 10%. The mortality of tillers due to flowering represented about 50% of the overall tiller mortality. Flowering was mostly accompanied by an intensive pregenerative tillering. Tillering culminated twice a year – in spring and in autumn. About a quarter of the axillary buds developed into daughter tillers immediately after their formation. The fate of tillers in terms of survival, flowering and daughter tiller production can be predicted by their size. Both components of tiller size – leaf number and leaf length – influenced the fate of tillers although the predictive ability was stronger for leaf number. The two studied populations differed significantly in leaf number, leaf length and the height of inflorescences. These characteristics are supposed to be determined by external habitat conditions. The individual tiller life cycle (survival, life span, daughter tiller production) did not differ between the populations, thus the factors by which it is determined seem to be identical. These results support the idea that the basic processes and structures of tiller ontogeny are internally fixed for each species while external environmental conditions can only induce variability in absolute size.
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