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
    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.

  2. Library Resource
    Articles et Livres
    décembre, 2014
    Australie

    AIM: Improving our understanding of the drivers of forest fragmentation is fundamental to mitigating the consequences of anthropogenic fragmentation for biodiversity. Moreover, the impacts of fragmentation on biodiversity depend on the spatial scale at which fragmentation occurs. Therefore, understanding how the effect of land use on fragmentation patterns varies across scales is critical to ensure that fragmentation is managed at scales relevant to the ecology of target species or to land management.

  3. 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.

  4. Library Resource
    Articles et Livres
    décembre, 2006

    To mitigate the adverse effects of reduced access to public forage, ranchers may require financial or other forms of "compensation." In this paper, we use results from a survey of Nevada ranchers to examine their willingness to sell grazing permits and participate in other schemes that enable them to continue ranching in spite of declining access to public forage.

  5. Library Resource
    Articles et Livres
    décembre, 2016
    Botswana

    Dual‐scale analyses assessing farm‐scale patterns of ecological change and landscape‐scale patterns of change in vegetation cover and animal distribution are presented from ecological transect studies away from waterpoints, regional remotely sensed analysis of vegetation cover and animal numbers across the southern Kalahari, Botswana. Bush encroachment is prevalent in semi‐arid sites where Acacia mellifera Benth. is widespread in communal areas and private ranches, showing that land tenure changes over the last 40 years have not avoided rangeland degradation.

  6. 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.

  7. 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.

  8. 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.

  9. Library Resource
    Articles et Livres
    décembre, 2013
    Europe

    The livestock sector contributes considerably to global greenhouse gas emissions (GHG). Here, for the year 2007 we examined GHG emissions in the EU27 livestock sector and estimated GHG emissions from production and consumption of livestock products; including imports, exports and wastage. We also reviewed available mitigation options and estimated their potential. The focus of this review is on the beef and dairy sector since these contribute 60% of all livestock production emissions.

  10. Library Resource
    Articles et Livres
    décembre, 2014

    Understanding how vegetation composition varies with season and interannual climate variability is important for any ecological research that uses vegetation data derived from surveys for the basis of inference. Misunderstanding this variation can influence land management and planning decisions, leading to poor implementation of biodiversity offsetting mechanisms, for example. We monitored plots (400 m²) grazed by livestock paired with adjacent ungrazed plots in derived native pastures four times a year over 2.5 years on the North‐West Slopes of New South Wales.

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