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There are 2, 238 content items of different types and languages related to cobertura do solo on the Land Portal.

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Ecosystem functional units characterized by satellite observed phenology and productivity gradients: A case study for Europe

Journal Articles & Books
Dezembro, 2013
Europa

The present study demonstrates remote sensing derived phenological and productivity indicators of ecosystem functional dynamism. The indices were derived from SPOT VEGETATION NDVI data on 1km spatial resolution across the pan-European continent using the Phenolo approach. The phenological and productivity indices explained 78% of the variance in the European ecosystem gradient measured by bio-climatic zones. Along this gradient climatic predictors could only explain 57% of the variance in the satellite metrics.

Land Use Effects on Mangrove Nutrient Status in Phang Nga Bay, Thailand

Journal Articles & Books
Dezembro, 2016
Tailândia

Tropical mangrove forests can play an important role in the functioning of adjacent marine ecosystems, by protecting them from an excess in land‐derived sediment and nutrients. The strength of this interaction may however depend on the nutrient status of the mangrove forest. This study related the nutrient status of eight mangrove forests in Phang Nga Bay (Thailand) to the land‐cover distributions in the upstream catchment areas.

synthesis of rates and controls on elemental mercury evasion in the Great Lakes Basin

Journal Articles & Books
Dezembro, 2012

Rates of surface-air elemental mercury (Hg⁰) fluxes in the literature were synthesized for the Great Lakes Basin (GLB). For the majority of surfaces, fluxes were net positive (evasion). Digital land-cover data were combined with representative evasion rates and used to estimate annual Hg⁰ evasion for the GLB (7.7 Mg/yr). This value is less than our estimate of total Hg deposition to the area (15.9 Mg/yr), suggesting the GLB is a net sink for atmospheric Hg.

Modelling sandgrouse (Pterocles spp.) distributions and large-scale habitat requirements in Spain: implications for conservation

Journal Articles & Books
Dezembro, 2014
Espanha
Europa

Knowledge of the factors determining species distributions is essential for developing conservation strategies. Sandgrouse Pterocles alchata and P. orientalis are threatened in Spain, the stronghold of European populations. Spatial modelling was used to: (1) assess the relative importance of abiotic, anthropogenic and geographical factors in the distribution of both sandgrouse species, (2) determine the most important anthropogenic predictors for each species occurrence, and (3) identify areas where conservation efforts should be prioritized.

Piospheres and Pastoralists: Vegetation and Degradation in Steppe Grasslands

Journal Articles & Books
Dezembro, 2012
China
Mongólia
Ásia Oriental

The Mongolian plateau in East Asia is part of a new hotspot of land cover change. Recent human activity and natural forces have degraded grasslands in northern China with the southern Mongolia steppe similarly vulnerable. Investigating vegetation patterns at piospheres (the area around water points) can identify herder influence on pasture conditions. Through fieldwork and remote sensing this paper examines plant density and species richness at water sources to establish land cover patterns in two Mongolian provinces where overgrazing is thought to be the major cause of degradation.

Meta‐analysis of flow modeling performances—to build a matching system between catchment complexity and model types

Journal Articles & Books
Dezembro, 2015

Hydrological models play a significant role in modelling river flow for decision making support in water resource management. In the past decades, many researchers have made a great deal of efforts in calibrating and validating various models, with each study being focused on one or two models. As a result, there is a lack of comparative analysis on the performance of those models to guide hydrologists to choose appropriate models for the individual climate and physical conditions.

Patterns and trends in land-use land-cover change research explored using self-organizing map

Journal Articles & Books
Dezembro, 2011

Research on land change has a long history, has generated numerous publications and continues to receive international research attention. To facilitate the understanding of the patterns and trends of land-change research, this article uses a content-based text-retrieval approach and self-organizing map to analyse more than 700 peer-reviewed remote-sensing and natural-science papers on land-use/cover change (LUCC) from the past two decades. We present the results in map-like displays and discuss papers within the identified clusters to examine the research activities.

Changing Landscapes for Forest Commons: Linking Land Tenure with Forest Cover Change Following Mexico’s 1992 Agrarian Counter-Reforms

Journal Articles & Books
Dezembro, 2013
México

Mexico’s 1992 agrarian counter-reforms opened up the country’s vast network of common property regimes, known as ejidos, to the possibility of privatization. This study investigates the relationship between dynamic common property regimes and deforestation in the wake of policy reform among eight ejidos in southeastern Mexico. Using institutional analyses, land use/land cover change (LULCC) analyses and a Forest Dependency Index, we examine how land tenure arrangements relate to land use and forest cover change patterns.

Environmental effects on species richness of macrophytes in Slovak streams

Journal Articles & Books
Dezembro, 2012

The effect of 19 environmental variables on species richness of macrophytes was studied in 39 Slovak streams. The studied streams were poor in species; in total, 88 macrophyte taxa were found and the average number of macrophytes per sampling site was 4, ranging from 0 to15. The most frequently occurring macrophytes were filamentous algae (occurrence at 38.6% of sampling sites), followed by Rhynchostegium riparioides (28.4%) and Phalaris arundinacea (19.3%).

Influence of urbanization on riparian forest diversity and structure in the Georgia Piedmont, US

Journal Articles & Books
Dezembro, 2008

Riparian forests are increasingly threatened by urban expansion and land use change worldwide. This study examined the relationships between landscape characteristics and woody plant diversity, structure, and composition of small order riparian corridors along an urban-rural land use gradient in the Georgia Piedmont, US. Riparian plant diversity, structure, and composition were related to landscape metrics and land use. Species richness was negatively associated with impervious surfaces and landscape diversity, and positively associated with forest cover and largest forest patch index.

Algorithms of Expert Classification Applied in Quickbird Satellite Images for Land Use Mapping

Journal Articles & Books
Dezembro, 2009
Espanha

The objective of this paper was the development of a methodology for the classification of digital aerial images, which, with the aid of object-based classification and the Normalized Difference Vegetation Index (NDVI), can quantify agricultural areas, by using algorithms of expert classification, with the aim of improving the final results of thematic classifications.

Spatial and temporal patterns of range expansion of white‐winged doves in the USA from 1979 to 2007

Journal Articles & Books
Dezembro, 2014
Estados Unidos
América do Norte

AIM: The geographical expansion of white‐winged doves (Zenaida asiatica) in North America has attracted the attention of biologists and sportsmen because of their recreational and aesthetic value; however, data on factors driving the spatial spread of this species are lacking. We examined spatial and temporal patterns of range expansion for white‐winged doves along the northern edge of their geographical range from 1979 to 2007 and used a dynamic occupancy model to estimate when and where doves would be found along an expansion gradient. LOCATION: Southern half of the USA.