BACKGROUND AND AIMS Leaf longevity is an important plant functional trait that often varies with soil nitrogen supply. Ethylene is a classical plant hormone involved in the control of senescence and abscission, but its role in nitrogen-dependent leaf longevity is largely unknown. METHODS Pot and field experiments were performed to examine the effects of nitrogen addition on leaf longevity and...

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean ...

The genus Nassella, as currently circumscribed, includes 116–117 American species. It is characterized by florets with a strongly convolute lemma, a conspicuous or inconspicuous crown, and a short palea. Using 53 species of Nassella and 22 outgroup species we conducted phylogenetic analyses to test the monophyly of Nassella and relationships among species. Two plastid (trnT-trnL and rpl32-trnL)...

Soil moisture plays a key role in vegetation restoration and ecosystem stability in arid and semiarid regions. The response of soil moisture to rainfall pulses is an important hydrological process, which is strongly influenced by land use during the implementation of vegetation restoration. In this study, vertical soil moisture variations of woodland (Pinus tabulaeformis), native grassland (Sti...

BACKGROUND The Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated. METHODOLOGY/PRINCIPAL FINDINGS In this study, a total of 324 quadrats located on the three main types of...

in order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. physical and chemical properties of soil are effective in distribution of plant species in local area. to determine the effects of some soil properties on species distribution of eurotia ceratoides and stipa barbata in baghedar summer region of bafgh, three ...

Jelen közlemény a Hernád menti kurgánok mohaflorisztikai vizsgálatának eredménye­it ismerteti. Összesen 41 taxon (1 májmoha és 40 lombosmoha) azonosítása történt meg vizsgált kilenc kunhalomról. Előfordulásuk száma alapján Brachythecium rutabulum, Tortulaacaulon var.acaulon Barbula unguiculata bizonyultak leggyakoribb mohafajoknak. További érdekes taxonok sírhalmokról: Acaulon muticum, triquetr...

Five new regional records of the rock lizards in Caucasus are described. The distribution Darevskia alpina (Darevsky, 1967) on northern slope Mount Elbrus has been detailed: species was found Emmanuel glade and gorge Kyzylkol River. easternmost record D. is located upper stream Cherek Bezengi River Kabardino-Balkaria. caucasica vedenica (Darevsky et Roitberg, 1999) first territory Dagestan area...

Abstract The developed system allows to measure the thermal conductivity of solid materials used as insulators in building bioclimatic houses on high Andean zones. A unidirectional heat flow model through a sample dimensions 4.0 cm x 4.2 1.35 has been considered. K-type thermocouples were temperature’s gradient. obtained values were: 0.97 Wm −1 °C for glass, 0.38 ignimbrite, 0.58 roof brick and...