Résultats de la recherche | Land Portal

Résultats de la recherche

Showing items 1 through 9 of 21.
  1. Library Resource
    Articles et Livres
    décembre, 2015

    Organic carbon (OC) sequestration in degraded semi‐arid environments by improved soil management is assumed to contribute substantially to climate change mitigation. However, information about the soil organic carbon (SOC) sequestration potential in steppe soils and their current saturation status remains unknown. In this study, we estimated the OC storage capacity of semi‐arid grassland soils on the basis of remote, natural steppe fragments in northern China. Based on the maximum OC saturation of silt and clay particles

  2. Library Resource
    Articles et Livres
    décembre, 2009

    The industrialization of agriculture in western societies has often led to either intensified use or abandonment of farmland and open pastures, but experimental evidence on how the dynamics of farmed ecosystems affect space use by large herbivores is limited. We experimentally manipulated farmland patches with cutting and (early summer) low- and high-intensity domestic sheep Ovis aries grazing according to traditional use in north Norway.

  3. Library Resource
    Articles et Livres
    décembre, 2015
    Irlande, Europe

    We present quantitative reconstructions of regional vegetation cover in north‐western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling.

  4. Library Resource
    Articles et Livres
    décembre, 2014

    Low rainfall, water scarcity and land degradation severely intimidate the production capacities of the rangelands in the arid environments. Water harvesting focuses on improving the productive use of rainwater on the local scale (field to subcatchment scale) before the runoff water leaves the geographical unit in question. The aim is to mitigate the effects of temporal water shortages to cover both domestic and agricultural needs.

  5. Library Resource
    Articles et Livres
    décembre, 2009
    République-Unie de Tanzanie

    This paper examines the changes in land use/cover types in the degraded environment of central Tanzania over the last 45 years, and how such changes have influenced agricultural and livelihoods sustainability, especially in the Irangi Hills. Changes of land use/cover were measured through aerial photographs interpretations, while local perceptions and description of change were addressed through household interviews and field observations. The results of this study show that there have been variations over the years in terms of both the areas and spatial distribution of cultivated fields.

  6. Library Resource
    Articles et Livres
    décembre, 2012

    Development of accurate classification methods for rapidly changing catchments like that of Lake Basaka is fundamental to better understanding the catchment dynamics, which were not addressed in previous studies. Thus, the aim of this study was to map the decadal land use/cover (LUC) regimes of the Lake Basaka catchment, utilizing time series of LANDSAT images and to analyse the changes that occurred at different time periods. Both unsupervised and supervised image classification systems were utilized in Earth Resources Data Analysis System (ERDAS) Imagine (9.1).

  7. Library Resource
    Articles et Livres
    décembre, 2000
    France, Irlande, Espagne

    The relationship between vegetation and environment was investigated for calcareous grasslands in a region in the west of Spain, France, Britain and Ireland defined by climatic criteria. Vegetation was sampled using objective methods and data collected on soils, land cover, location and management. Climate data were obtained from an available database. Examination of the first axis of vegetation variation as defined by Detrended Correspondence Analysis (DCA) showed a gradient from the Irish and British samples to those from France.

  8. Library Resource
    Articles et Livres
    décembre, 2014

    The vegetation of semi‐arid and arid landscapes is often comprised of mixtures of herbaceous and woody vegetation. Since the early 1900s, shifts from herbaceous to woody plant dominance, termed woody plant encroachment and widely regarded as a state change, have occurred world‐wide. This shift presents challenges to the conservation of grassland and savanna ecosystems and to animal production in commercial ranching systems and pastoral societies.

  9. Library Resource
    Articles et Livres
    décembre, 2008

    In the last 100 years or so, desertification, degradation, and woody plant encroachment have altered huge tracts of semiarid rangelands. It is expected that the changes thus brought about significantly affect water balance in these regions; and in fact, at the headwater-catchment and smaller scales, such effects are reasonably well documented. For larger scales, however, there is surprisingly little documentation of hydrological change.

  10. Library Resource
    Articles et Livres
    décembre, 2016

    Vast areas of forests in North‐eastern Ethiopia have been replaced by cropland, shrub land or grazing areas. Thus, information about how vegetation composition and structure varies with disturbance is fundamental to conservation of such areas. This study aimed to investigate the effects of disturbance on the population structure and regeneration potential of five dominant woody species within forest where local communities harvest wood and graze livestock. Vegetation structure and environmental variables were assessed in 50 quadrats (20 m × 20 m).

Rechercher dans la bibliothèque foncière

Grâce à notre moteur de recherche robuste, vous pouvez rechercher n'importe quel document parmi les plus de 64 800 ressources hautement conservées dans la bibliothèque du foncier.

Si vous souhaitez avoir un aperçu de ce qui est possible, n'hésitez pas à consulter le guide de recherche.


Partagez cette page