mechanisms of vegetation-ring formation in water-limited systems.a common patch form in dryland landscapes is the vegetation ring. vegetation patch formation has recently been attributed to self-organization processes that act to increase the availability of water to vegetation patches under conditions of water scarcity. the view of ring formation as a water-limited process, however, has remained largely unexplored. using laboratory experiments and model studies we identify two distinct mechanisms of ring formation. the first mechanism pertains to conditions ...201021187102
ecotypic variation of summer dormancy relaxation associated with rainfall gradient in the geophytic grass poa bulbosa.summer dormancy is an adaptive trait in geophytes inhabiting regions with a mediterranean climate, allowing their survival through the hot and dry summers. summer dormancy in poa bulbosa is induced by increasing day-length and temperature and decreasing water availability during spring. populations from arid habitats became dormant earlier than those from mesic habitats. relaxation of dormancy was promoted by the hot, dry summer conditions. here we test the hypothesis that dormancy relaxation is ...201020156924
water deficit and induction of summer dormancy in perennial mediterranean grasses.summer dormancy is a trait conferring superior drought survival in mediterranean perennial grasses. as the respective roles of environmental factors and water deficit on induction of summer dormancy are unclear, the effect of intense drought were tested under contrasting day lengths in a range of forage and native grasses.200919369219
winter photosynthetic activity of twenty temperate semi-desert sand grassland species.the winter photosynthetic activity (quantified by net co(2) assimilation rates and chlorophyll (chl) a fluorescence parameters) of 20 plant species (including two lichens and two mosses) of a hungarian temperate semi-desert sand grassland was determined on one occasion per year in 1984, 1989 and 1994. throughout winter, the overwintering green shoots, leaves or thalli were regularly exposed to below zero temperatures at night and daytime temperatures of 0-5 degrees c. in situ tissue temperature ...200818346813
the effects of long-term grazing exclosures on range plants in the central anatolian region of turkey.over the last fifty years, almost half of the steppe rangeland in the central anatolian region of turkey (car) has been converted to cropland without an equivalent reduction in grazing animals. this shift has led to heavy grazing pressure on rangeland vegetation. a study was initiated in june 2003 using 6 multiscale modified-whittaker plots to determine differences in plant composition between areas that have not been grazed in 27 years with neighboring grazed plant communities. a total of 113 p ...200717203339
regulation of summer dormancy by water deficit and aba in poa bulbosa ecotypes.survival of many herbaceous species in mediterranean habitats during the dry, hot summer depends on the induction of summer dormancy by changes in environmental conditions during the transition between the winter (growth) season to the summer (resting) season, i.e. longer days, increasing temperature and drought. in poa bulbosa, a perennial geophytic grass, summer dormancy is induced by long days, and the induction is enhanced by high temperature. here the induction of summer dormancy in a medit ...200717202183
variation in onset of summer dormancy and flowering capacity along an aridity gradient in poa bulbosa l., a geophytic perennial grass.variation in the onset of summer dormancy and flowering capacity of 16 populations of poa bulbosa, collected along a steep north-south aridity gradient in israel (810-110 mm rain year(-1)), was studied under controlled conditions in a phytotron (16 h daylength, 22/16 degrees c day/night) and under natural conditions in a garden experiment in a net-house. plant age at the onset of dormancy varied markedly amongst populations (7-16 weeks under controlled conditions) and was positively correlated w ...200312547692
[spreading of fungi of fusarium lk : fr. genus in the soil of mountain-forest reservation of chatkala].the species composition of fusarium genus is more rich and diverse in agrophytocenoses than in natural soils of vertical zones of the chatkala mountain systems. soils at the height of 600-700 m were the poorest in the number of fusarium genus fungi while agrophytocenoses were the richest in the fungi. certain differences in the species diversity and the number of fusarium genus were found in the soil of the root zone of plants poa bulbosa, juniperus sarevschanica and festuca valesiaca. the maxim ...200212190036
opposite effects of daylength and temperature on flowering and summer dormancy of poa bulbosa.the timing of flowering and summer dormancy induction plays a central role in the adaptation of mediterranean geophytes to changes in the length of the growth season along rainfall gradients. our aim was to analyse the role of the variation in the responses of flowering and summer dormancy to vernalization, daylength and growth temperature for the adaptation of poa bulbosa, a perennial geophytic grass, to increasing aridity.200616467351
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