Pasar al contenido principal

page search

Issuescobertura de suelosLandLibrary Resource
There are 2, 238 content items of different types and languages related to cobertura de suelos on the Land Portal.

cobertura de suelos

AGROVOC URI:

Displaying 1501 - 1512 of 1964

Influence of hydrological regime and land cover on traits and potential export capacity of adult aquatic insects from river channels

Journal Articles & Books
Diciembre, 2016

Despite many studies highlighting the widespread occurrence and effects of resource movement between ecosystems, comparatively little is known about how anthropogenic alterations to ecosystems affect the strength, direction and importance of such fluxes. Hydrological regime and riparian land use cause well-documented changes in riverine larval invertebrate communities.

Impact of habitat alteration on endemic Afromontane chameleons: evidence for historical population declines using hierarchical spatial modelling

Journal Articles & Books
Diciembre, 2014
Tanzania

AIM: We map estimated historical population declines resulting from species‐specific models of sensitivity to habitat fragmentation for three forest‐dependent chameleons. LOCATION: East Usambara Mountains, Eastern Arc Mountains, Tanzania. METHODS: We surveyed three chameleon species (Rhampholeon spinosus, Rhampholeon temporalis and Trioceros deremensis) along 32.2� km of transects and used a hierarchical, distance‐sampling model to estimate densities. The model included habitat characteristics at the landscape (patch) and local (transect) scales while accounting for detectability.

Natural and human-induced environmental changes in Eastern Europe during the Holocene: a multi-proxy palaeolimnological study of a small Latvian lake in a humid temperate zone

Journal Articles & Books
Diciembre, 2013
Letonia
Europa oriental

This study uses the Holocene lake sediment of Lake Ķūži (Latvia, Vidzeme Heights) for environmental reconstruction with multi-proxy records including lithology, computerised axial tomography scan, grain-size analysis, geochemistry, diatoms and macrofossils, supported by AMS radiocarbon dating. Numerical analyses (PCA; CONISS) reveal three main phases in the development of the lake. Response to the Lateglacial–Holocene transition in Lake Ķūži took place around 11,300 cal. BP.

Maximizing water yield with indigenous non‐forest vegetation: a New Zealand perspective

Journal Articles & Books
Diciembre, 2008
Sudáfrica
Nueva Zelandia
África austral

Provision of clean freshwater is an essential ecosystem service that is under increasing pressure worldwide from a variety of conflicting demands. Water yields differ in relation to land‐cover type. Successful resource management therefore requires accurate information on yields from alternative vegetation types to adequately address concerns regarding water production. Of particular importance are upper watersheds/catchments, regardless of where water is extracted.

Does estuarine health relate to catchment land-cover in the East Kleinemonde system, South Africa?

Journal Articles & Books
Diciembre, 2014
Sudáfrica
África austral

Temporarily open/closed estuaries in South Africa are being subjected to varying degrees of catchment land-cover transformation. Natural landscapes and hydrological functions are integral to the functioning of estuaries. The relationship between catchment land-cover and the health of the East Kleinemonde Estuary was investigated between 2011 and 2013, using geographic information system (GIS) techniques to delineate and quantify land-cover in the whole catchment, in the lower section of the catchment, and in the 1 km and 100 m buffer zones surrounding the estuary.

Pollinator body size mediates the scale at which land use drives crop pollination services

Journal Articles & Books
Diciembre, 2014

Ecosystem services to agriculture, such as pollination, rely on natural areas adjacent to farmland to support organisms that provide services. Native insect pollinators depend on natural or semi‐natural land surrounding farms for nesting and alternative foraging resources. Despite interest in conserving pollinators through habitat restoration, the scale at which land use affects pollinators and thus crop pollination services is not well understood. We measured abundance of native, wild bee pollinators and the pollination services they provided to highbush blueberry Vaccinium corymbosum L.

Antarctic land-cover classification using IKONOS and Hyperion data at Terra Nova Bay

Journal Articles & Books
Diciembre, 2012
Antártida

Low or medium spatial resolution satellite images are used for environmental monitoring in remote, extremely cold areas such as Antarctica. However, they cannot provide detailed spatial and spectral information over Antarctic areas. For obtaining this information, we propose an Antarctic land-cover classification method using IKONOS and Hyperion data over Terra Nova Bay, Antarctica. High spatial resolution IKONOS imagery enabled the detection of detailed, accurate boundaries between areas of snow, ice, vegetation, water and rock.

Landsat-comparable land cover maps using ASTER and SPOT images: a case study for large-area mapping programmes

Journal Articles & Books
Diciembre, 2011

The long-term record of global Landsat data is an important resource for studying Earth's system. Given the identified gaps in Landsat data and the undetermined future status of Landsat data availability, alternatives to Landsat imagery need to be tested in an operational environment. In this study, forest land cover and crown closure maps generated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and System Pour 1'Observation de la Terre (SPOT) data were compared to Landsat-based map products currently in use by the grizzly bear habitat-mapping program.

cost effective stratified two-stage sampling design to estimate the forest land area of southern Chile

Journal Articles & Books
Diciembre, 2011
Chile

There is a growing demand for improving the measurement of forest resources, with more frequent updating and better information on environmental variables. We explore the cost efficiency of a stratified two-stage design using area sampling to estimate the forest plantation and native forest areas in southern Chile. Analytical expressions for the approximate mean square error of combined and separate ratio estimators are derived applying Taylor linearization.

Segmented canonical discriminant analysis of in situ hyperspectral data for identifying 13 urban tree species

Journal Articles & Books
Diciembre, 2011
Estados Unidos de América

A total of 458 in situ hyperspectral data were collected from 13 urban tree species in the City of Tampa, FL, USA using a spectrometer. The 13 species include 11 broadleaf and two conifer species. Three different techniques, segmented canonical discriminant analysis (CDA), segmented principal component analysis (PCA) and segmented stepwise discriminate analysis (SDA), were applied and compared for dimension reduction and feature extraction.

Implications of land-cover types for soil erosion on semiarid mountain slopes: Towards sustainable land use in problematic landscapes

Journal Articles & Books
Diciembre, 2013
España

The impact of land-cover types on soil erosion and runoff, as well as on physico-chemical soil properties, was monitored. The study area, an agroforestry landscape was located in Sierra Nevada Mountains in south-eastern Spain. Eight land-cover types were investigated: farmland planted with olive, almond, and cereals; forest with P. halepensis and P. sylvestris; shrubland; grassland; and abandoned farmland. The erosion plots replicated twice were located on hillslopes, where erosion and runoff were measured after 22 storm events.

Modern pollen and land-use relationships in the Taihang mountains, Hebei province, northern China—a first step towards quantitative reconstruction of human-induced land cover changes

Journal Articles & Books
Diciembre, 2013
China

Studies of the modern relationship between pollen, vegetation and land-use are essential to infer past human impact on vegetation from pollen records. Nevertheless, such investigations are relatively few in China. We present here a study of pollen assemblages from sediment samples collected from irrigation pools in the Tuoliang and Qipanshan catchments in northern China.