We use a combination of a model and empirical data to examine the relationship between the scale of the landscape mosaic and individual movement patterns on the measurement of local butter ̄y species diversity. In landscapes where patch sizes are smaller, the type of patch adjacent to the patch surveyed can in ̄uence both local species richness and incidence. In landscapes composed of larger patc...

The accuracy of the habitat simulation method is often questioned due to limited simulated elements and indicator species. This study established an environmental flow assessment by coupling fish with hydrological reference system. obtained through was corrected statistical characteristics natural regime. Huayuankou section in Lower Yellow River assessed. results show that demand 7.9 - 15.4 bil...

ornamental geophytes (ornamental flower bulbs) are international and national heritage considering their contribution to people's life quality around the world. iranian habitats support about 8000 species of flowering plants (belonging to 167 families and 100 genera) of which almost 1700 are endemic. iran is a rich country in terms of distribution of bulbous plants. more than 200 species of bul...

in this study, some habitat characteristics of iranian rose (hulthemia persica) were studied in gonbad watershed in hamedan providence, iran. soil samples were taken by a systematic randomized method at elevation 2000-2400 m above sea level. samples were taken from 0-30 cm depth. in the laboratory, n, p, k% and organic matter (oc%), soil acidity (ph), conductivity (ec) and soil texture were det...

Intraspecific differences in movement behaviour reflect different tactics used by individuals or sexes to favour strategies that maximize fitness. We report movement data collected from n = 23 adult male polar bears with novel ear-attached transmitters in two separate pack ice subpopulations over five breeding seasons. We compared movements with n = 26 concurrently tagged adult females, and ana...

Contamination has a dramatic impact on the health of ecosystem and habitat suitability for the inhabited flora and fauna. The Environmental Protection Agency (EPA) mandates an ecological risk assessment (ERA) that evaluates the potential adverse impact of any anthropogenic activities on the ecosystem (US Environmental Protection Agency, 1997. Ecological Risk Assessment Guidance for Superfund: P...

Many invasive species are too widespread to realistically eradicate. For such species, a viable management strategy is to slow the rate of spread. However, to be effective, this will require detailed spread data and an understanding of the influence of environmental conditions and landscape structure on invasion rates. We used a time series of remotely sensed distribution maps and a spatial sim...

Population Viability Analysis (PVA) is a Monte Carlo simulation method for estimating the probability of extinction of threatened species. There has been a shift in the use of PVA from absolute species risk measurement to relative risk assessment associated with a ranking of management strategies. Furthermore, PVA models have sought to include more spatially explicit information, like habitat s...