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Issuesland coverLandLibrary Resource
There are 2, 240 content items of different types and languages related to land cover on the Land Portal.
Displaying 1225 - 1236 of 2218

Tree density and biomass assessment in agricultural systems around Lake Victoria, Uganda

Journal Articles & Books
December, 2008
Uganda

Soil erosion caused by low vegetation cover associated with agricultural land use in the catchment is blamed for the eutrophication of Lake Victoria. Above-ground biomass as an indicator of vegetation cover and biodiversity was assessed using the Normalized Difference Vegetation Index, estimation of tree density and biomass with the aim of assessing the extent to which vegetation covers the soil surface. Tree density is significantly different between agricultural and semi-natural systems with an average of 96 and 90 trees ha⁻¹ observed in Rakai and Mayuge respectively.

Are Swiss birds tracking climate change? Detecting elevational shifts using response curve shapes

Journal Articles & Books
December, 2011
Switzerland

Climate change is affecting biodiversity worldwide inducing species to either “move, adapt or die”. In this paper we propose a conceptual framework for analysing range shifts, namely a catalogue of the possible patterns of change in the distribution of a species along elevational or other environmental gradients and an improved quantitative methodology to identify and objectively describe these patterns.

On the extent of fire-induced forest degradation in Mato Grosso, Brazilian Amazon, in 2000, 2005 and 2010

Journal Articles & Books
December, 2016
Brazil

In this paper we analyse the extent of fire-induced forest degradation in Mato Grosso State, Brazil. We utilise a sample based approach used in a previous pan-tropical deforestation survey to derive information on land cover and burned areas in the two major biomes of Mato Grosso: Amazon and Cerrado. Land cover and burned area are mapped for three years (2000–2005–2010) over 77 sample sites (10000ha each) distributed systematically throughout the state which covers 90.337 Mha.

Landscape Composition Weakly Affects Home Range Size in Blanding's Turtles (Emydoidea blandingii)

Journal Articles & Books
December, 2012

Landscape composition and habitat quality influence the abundance, population structure, and movements of animals. Understanding how an animal interacts with elements of the landscape helps predict its response to habitat loss and changes in land cover. We tested the hypothesis that the extent of movement depends on landscape composition in a threatened freshwater turtle, Emydoidea blandingii. We measured habitat composition at multiple spatial scales, ranging from the home range to the landscape scale.

Global‐scale mapping of changes in ecosystem functioning from earth observation‐based trends in total and recurrent vegetation

Journal Articles & Books
December, 2015
Africa
Global
South America

AIM: To evaluate trend analysis of earth observation (EO) dense time series as a new way of describing and mapping changes in ecosystem functioning at regional to global scales. Spatio‐temporal patterns of change covering 1982–2011 are discussed in the context of changes in land use and land cover (LULCC). LOCATION: Global.

Development and mapping of fuel characteristics and associated fire potentials for South America

Journal Articles & Books
December, 2014
South America

The characteristics and spatial distribution of fuels are critical for assessing fire hazard, fuel consumption, greenhouse gas emissions and other fire effects. However, fuel maps are difficult to generate and update, because many regions of the world lack fuel descriptions or adequate mapped vegetation attributes to assign these fuelbeds spatially across the landscape. This paper presents a process to generate fuel maps for large areas using remotely sensed information and ancillary fuel characteristic data.

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

Journal Articles & Books
December, 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
December, 2015
Switzerland
Norway
Europe

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
December, 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
December, 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
December, 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
December, 2013
United States of America

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).