The present survey was carried out in Oak (Quercus brantii Lindl.) woodlands of Arghvan valley protected area, in Ilam province, western Iran. The main aim of this study was to survey the understory vegetation of oak in different classes of altitude (1400-1600, 1600-1800 and >1800 m) in the southern aspects, and their relationship with physical and chemical properties of soil. Four transects, w...

Nitrogen dioxide (NO2) vertical tropospheric column densities (VTCs) retrieved from the Global Ozone Monitoring Experiment (GOME) are compared to coincident ground-based tropospheric NO2 columns. The ground-based columns are deduced from in situ measurements at different altitudes in the Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME NO2 VTC data retrieved by a colla...

The extent of hybridisation and gene flow between the three M onocalyptus species, Eucalyptus pulchella, E coccifera (series Piperitae) and E delegatensis (series Oh/iquae) at Snug Plains (600 m) in southeastern Tasmania was examined. The flowering time of E pulchella was two months later than usual for this normally low-altitude species. It consequently overlapped the flowering period of both ...

Newcomers acclimatizing to high altitude and adult male Tibetan high altitude natives have increased ventilation relative to sea level natives at sea level. However, Andean and Rocky Mountain high altitude natives have an intermediate level of ventilation lower than that of newcomers and Tibetan high altitude natives although generally higher than that of sea level natives at sea level. Because...

In high altitude plants, flowering quickly ensures reproductive success within a short snow-free period, but limits maturation time and fecundity. Natural selection on prefloration intervals may therefore vary in contrasting snowmelt environments and could influence the outcome of phenological responses to climatic change. This study investigated adaptive differentiation and plasticity of prefl...

Relatively little is known about how the life histories of perennial forb species, and especially their lifetime patterns of growth, vary across environmental gradients. We used a post hoc approach (herb-chronology) to determine plant age and previous growth (width of successive annual rings in roots) in three species of perennial forb (two long-lived species [Penstemon venustus, Lupinus laxifl...

Introduction. Broadband LMDS (Local Multi-Point Distribution Systems) is a wireless point-to-multipoint communication system operating above 20GHz (usually around 26− 31GHz) that can be used to provide digital voice, data, Internet, and video services. One possible solution for LMDS is to use High-Altitude Aeronautical Platforms (HAAPs), which are situated in the stratosphere, 20− 22km above th...

To investigate the influence of hypoxia during the early stage of incubation on embryonic developmentand hatching events, and consequently on incidence of ascites in broiler chickens, one thousand fertile eggswere incubated in two commercial incubators. Half the eggs were incubated in a low altitude incubator untilhatched. The second half were incubated in a high altitude incubator until day 10...