Question: Does the relative importance of stochastic and deterministic factors change during primary succession? Location: Small depressions (potholes) located onMount St. Helens, Washington (4611305100N, 12210901000W, 1290m). Methods: Pothole vegetation was described in 1993, 1997 and from 2001 to 2008. Explanatory variables included location and elevation (spatial factors), soil factors and L...

RESUME In this paper, two different methods for fractional vegetation cover (FVC) retrieval from CHRIS (Compact High Resolution Imaging Spectrometer) data based on vegetation indices have been analyzed. The first method uses NDVI (Normalized Difference Vegetation Index) values, as suggested, among others, by Carlson and Ripley (1997) and Gutman and Ignatov (1998), and the second method uses VAR...

abstract gully erosion is a kind of water erosion that has high priority in fars province due to sediment production and enormous damages to land, roads and infrastructures. in this study, 15 gullies were selected and their morphometric characteristics, such as catchment area, soil, cover vegetation and climate were measured. in order to determine influential factors on the sediment production ...

Urban greenness is increasingly recognized as an essential constituent of the urban environment and can provide a range of services and enhance residents' quality of life. Understanding the pattern of urban greenness and exploring its spatiotemporal dynamics would contribute valuable information for urban planning. In this paper, we investigated the pattern of urban greenness in Hangzhou, China...

in this study, the environmental effects of land use changes on vegetation cover and emitted land surface temperature in two urban and non-urban areas of ardakan in yazd province, iran, were studied and compared temporally, using remote sensing technique. for this purpose, contemporary land sat satellite images in 1990 and 2002 were acquired and used. then vegetation cover maps were generated u...

Predation by nonnative fishes has reduced abundance and increased extinction risk for amphibian populations worldwide. Although rare, fish and palatable amphibians have been observed to coexist where aquatic vegetation and structural complexity provide suitable refugia. We examined whether larval Long-toed Salamanders (Ambystoma macrodactylum Baird, 1850) increased use of vegetation cover in la...

Arctic ecosystems have been afflicted by vast changes in recent decades. Changes in temperature, as well as precipitation, are having an impact on snow cover, vegetation productivity and coverage, vegetation seasonality, surface albedo, and permafrost dynamics. The coupled climate-vegetation change in the arctic is thought to be a positive feedback in the Earth system, which can potentially fur...

[1] While it is generally believed that the magnitude and composition of vegetation cover influence land-atmosphere water and carbon fluxes, observations indicate that in some cases, fluxes are insensitive to land cover contrasts. This seeming inconsistency may be resolved by contrasting fluxes over short and long timescales. To explore this potential contrast, we developed and tested a model d...

Mountainous regions are especially vulnerable to climate and land use change. For a monitoring of subtle changes detailed and continuous land cover information is necessary. Therefore vegetation cover fractions are derived for the Naryn river catchment in Kyrgyzstan using a remote sensing multi-scale approach. First a very high resolution QuickBird image is classified into discrete classes usin...

Cover estimates by eye is a prevailing method to assess abundance. We examined cover estimates with regard to bias and random variation. Ten observers working with a national forest vegetation survey estimated sixteen 100 m 2 -plots, placed in two different vegetation types. These had similar species composition but were clearly distinguishable in the field. In specieswise analyses, observer bi...