Résultats de la recherche | Land Portal

Résultats de la recherche

Showing items 1 through 9 of 21.
  1. Library Resource
    Articles et Livres
    décembre, 2009
    Norvège

    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.

  2. 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).

  3. Library Resource
    Articles et Livres
    décembre, 2015
    Chine

    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

  4. Library Resource
    Articles et Livres
    décembre, 2015

    The resilience, diversity and stability of mountain ecosystems are threatened by climatic as well as land‐use changes, but the combined effects of these drivers are only poorly understood. We combine two high‐resolution sediment records from Iffigsee (2065 m a.s.l.) and Lauenensee (1382 m a.s.l.) at different elevations in the Northern Swiss Alps to provide a detailed history of vegetational changes during the period of first pastoralism (ca. 7000–5000 cal. BP, 5000–3000 BC) in order to understand ongoing and future changes in mountain ecosystems.

  5. 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.

  6. Library Resource
    Articles et Livres
    décembre, 2016
    Éthiopie

    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).

  7. Library Resource
    Articles et Livres
    décembre, 2015
    Chine

    Most of China's 24–28 primate species are threatened with extinction. Habitat reduction and fragmentation are perhaps the greatest threats. We used published data from a conservation genetics study of 5 endangered primates in China (Rhinopithecus roxellana, R. bieti, R. brelichi, Trachypithecus francoisi, and T. leucocephalus); distribution data on these species; and the distribution, area, and location of protected areas to inform conservation strategies for these primates. All 5 species were separated into subpopulations with unique genetic components.

  8. Library Resource
    Articles et Livres
    décembre, 2009
    Nouvelle-Zélande

    1. The distribution and abundance of invasive species can be driven by both environmental variables and land management decisions. However, understanding these relationships can be complicated by interactions between management actions and environmental variability, and differences in scale among these variables. The resulting 'context-dependence' of management actions may be well-appreciated by ecologists and land managers, but can frustrate attempts to apply general management principles. 2.

  9. Library Resource
    Articles et Livres
    décembre, 2012
    États-Unis d'Amérique

    Although common disturbances of grazing lands like plant defoliation are expected to affect their sensitivity to increasing atmospheric CO2 concentration, almost no research has been conducted to evaluate how important such effects might be on the direct responses of rangelands to CO2. This growth chamber experiment subjected intact plant–soil cylinders from a Wyoming, USA, prairie to a 3‐way factorial of CO2 (370 vs. 720 μL L−1), defoliation (non‐clipped vs. clipped) and soil nitrogen (control vs. 10 g m−2 added N) under simulated natural climatic conditions.

  10. Library Resource
    Articles et Livres
    décembre, 2012
    États-Unis d'Amérique

    Although common disturbances of grazing lands like plant defoliation are expected to affect their sensitivity to increasing atmospheric CO2 concentration, almost no research has been conducted to evaluate how important such effects might be on the direct responses of rangelands to CO2. This growth chamber experiment subjected intact plant–soil cylinders from a Wyoming, USA, prairie to a 3‐way factorial of CO2 (370 vs. 720 μL L−1), defoliation (non‐clipped vs. clipped) and soil nitrogen (control vs. 10 g m−2 added N) under simulated natural climatic conditions.

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