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Biotic resistance in freshwater fish communities: species richness, saturation or species identity?

Journal Articles & Books
Diciembre, 2015

Some communities are susceptible to invasions and some are not. Why? Elton suggested in 1958 that the ability of the community to withstand invading species – its biotic resistance – depends on the number of resident species. Later contributors have emphasized the habitat's ability to support species, as well as the contribution of individual species to the resistance. In this study we use information from 184 introductions of Arctic char into Swedish lakes to study both abiotic and biotic aspects of the resident community's ability to resist introductions.

Modelling the effect of habitat fragmentation on climate‐driven migration of European forest understorey plants

Journal Articles & Books
Diciembre, 2015
Suiza
Noruega
Europa

AIM: The rate of climate change might exceed the migration capacity of plants, particularly where habitats became fragmented by human land use. Except for some tree species, the extent to which habitat fragmentation decreases migration rates has nevertheless been little evaluated. Here, we compare simulated migration rates of understorey herbs, which comprise the big part of temperate forest plant diversity, under varying levels of fragmentation at a continental scale. LOCATION: Europe.

Trend analysis of medium- and coarse-resolution time series image data for burned area mapping in a Mediterranean ecosystem

Journal Articles & Books
Diciembre, 2014

In this study, the Breaks for Additive Seasonal and Trend (BFAST), a recently introduced trend analysis technique, was employed for the detection of fire-induced changes in a Mediterranean ecosystem. BFAST enables the decomposition of time series into trend, seasonal and noise components, resulting in the detection of gradual and rapid land cover changes. Normalised Difference Vegetation Index (NDVI) time series derived from the MODIS and VEGETATION (VGT) standard products were analysed.

Kernel-based extreme learning machine for remote-sensing image classification

Journal Articles & Books
Diciembre, 2013

This letter evaluates the effectiveness of a new kernel-based extreme learning machine (ELM) algorithm for a land cover classification using both multi- and hyperspectral remote-sensing data. The results are compared with the most widely used algorithms – support vector machines (SVMs). The results are compared in terms of the ease of use (in terms of the number of user-defined parameters), classification accuracy and computation cost.

Monitoring post-fire vegetation recovery in the Mediterranean using SPOT and ERS imagery

Journal Articles & Books
Diciembre, 2014

This study examined the effect of two different forest fires 19 and 23 years ago on the Mediterranean island of Thasos. An object-based classification scheme was developed to map the major land-cover types using multi-temporal Système Pour l’Observation de la Terre (SPOT) and European Remote-Sensing (ERS) (C-band VV) images covering the time period from 1993 to 2007. The developed scheme mapped the post-fire land-cover types accurately: 0.84 Kappa coefficient and 90.5% overall accuracy.

comparison of support vector machines and manual change detection for land-cover map updating in Massachusetts, USA

Journal Articles & Books
Diciembre, 2013
Estados Unidos de América

The remote sensing community has recently adopted land-cover map updating methodologies using spectral image differencing, change masking and concatenation procedures to monitor land change accurately and consistently. Unfortunately, map updating requires costly, time-consuming manual image interpretation to achieve accurate spectral threshold placement for land-change masking. The purpose of this study is to minimize time and costs associated with manual image interpretation of change thresholds by developing a new, semi-automated method using support vector machines (SVM).

On the novel use of model-based decomposition in SAR polarimetry for target detection on the sea

Journal Articles & Books
Diciembre, 2013

In this study, we show the novel applications of model-based scattering power decomposition analyses in synthetic aperture radar (SAR) polarimetry for man-made target detection on the sea surface. Model-based decomposition technique is primarily used for land-cover classification mainly because microwave scattering from land is composed of various scattering mechanisms.

Assessment of fire selectivity in relation to land cover and topography: a comparison between Southern European countries

Journal Articles & Books
Diciembre, 2014
Turquía
Chipre

Land cover distribution is one of the factors that influence fire behaviour and its consequences in the landscape. The relation between land cover type and fire was investigated at a broad scale, in order to analyse land cover differences in fire proneness. The selection ratio for nine different land cover categories was calculated for the fire perimeters mapped in Southern Europe between 2000 and 2008. The results obtained were then compared per country and region. The fire proneness of topographic classes and its potential association with land cover types were also assessed.

Definition of British Water Beetle Species Pools (Coleoptera) and their Relationship to Altitude, Temperature, Precipitation and Land Cover Variables

Journal Articles & Books
Diciembre, 2006

Pooled water beetle species lists from 1826 British national grid 10-km squares were analysed using multivariate ordination and classification methods. The relationships of pool groups to the climate, altitude and land cover variables were assessed using constrained and partial ordinations. Ordination of the species pool data indicated a major trend between squares in the north-west of Scotland and those in southern England, illustrating differences in acid and basic water standing water. Secondary variation was from acid standing water to fast-flowing streams and rivers.

Centrarchid Assemblages in Floodplain Lakes of the Mississippi Alluvial Valley

Journal Articles & Books
Diciembre, 2013
América Septentrional

The family Centrarchidae is a principal and visible component of the ichthyofauna in most warmwater ecosystems in North America, and many of its species provide key recreational fisheries. We examined the significance of various local environmental factors to 13 centrarchid species in 53 floodplain lakes (remnant channels) of the Mississippi alluvial valley to identify major environmental gradients influential in structuring centrarchid assemblages.

Macrophytes in shallow lakes: Relationships with water, sediment and watershed characteristics

Journal Articles & Books
Diciembre, 2013

We examined macrophyte–environment relationships in shallow lakes located within the Prairie Parkland and Laurentian Mixed Forest provinces of Minnesota. Environmental variables included land cover within lake watersheds, and within-lake, water and sediment characteristics. CCA indicated that sediment fraction smaller than 63μm (f