Résultats de la recherche | Land Portal

Résultats de la recherche

Showing items 1 through 9 of 372.
  1. Library Resource
    Articles et Livres
    août, 2018
    Afrique australe, Afrique

    Empirical scientific evidence indicates that there is still room for increasing food production by improving land productivity. This study aimed at identifying the key determinants that govern farmers’ decisions to adopt multiple components of integrated soil fertility management (ISFM) in a maize mixed cropping system of the Chinyanja Triangle, Southern Africa.

  2. Library Resource
    Articles et Livres
    décembre, 2017

    Wetlands are important providers of ecosystem services and key regulators of climate change. They positively contribute to global warming through their greenhouse gas emissions, and negatively through the accumulation of organic material in histosols, particularly in peatlands. Our understanding of wetlands’ services is currently constrained by limited knowledge on their distribution, extent, volume, interannual flood variability and disturbance levels.

  3. Library Resource
    Articles et Livres
    avril, 2017

    Although REDD+ is approaching its 10th anniversary, major impacts in terms of reduced forest loss are hard to document. Conservation practitioners and scholars are therefore increasingly asking why REDD+ has not delivered more tangible results. A recent Comment in Conservation Biology by Fletcher et al. (2016) addresses this question. We agree with Fletcher et al. that REDD+ has been hyped in some circles, which has created unrealistic expectations among policy makers and forest dwellers alike. Yet, we argue that Fletcher et al.

  4. Library Resource
    Articles et Livres
    décembre, 2012

    The thesis of this article is that the now extensive contemporary literature on the economics of property rights has generated more heat than light. Economists have invoked at least five distinct theories of ownership or property rights in their work. Unfortunately, authors frequently fail to acknowledge the existence of competing theories of property rights that stand as conceptual rivals to the theory that they, often implicitly, invoke.

  5. Library Resource
    Articles et Livres
    décembre, 2009
    Éthiopie

    We investigated six different bush encroachment control treatments on the responses of 29 woody species in southern Ethiopia. During the post-treatments (i.e. between June 2004 and 2005), we monitored tree stump total kill, partial kill and the responses of woody species to disturbances, in terms of coppicing and seedling regeneration. Protection from disturbance promoted seedling regeneration by 4.6%. The effects of tree cutting and fire greatly reduced woody species regeneration, while tree cutting and fire combined with grazing treatment was more effective in reducing coppicing.

  6. Library Resource
    Articles et Livres
    décembre, 2006
    Porto Rico

    We studied the ecological characteristics of 45-50-yr-old subtropical dry forest stands in Puerto Rico that were growing on sites that had been deforested and used intensively for up to 128 yr. The study took place in the Guánica Commonwealth Forest. Our objective was to assess the long-term effects of previous land use on this forest--i.e., its species composition, structure, and functioning. Previous land-use types included houses, farmlands, and charcoal pits. Stands with these land uses were compared with a nearby mature forest stand.

  7. Library Resource
    Articles et Livres
    décembre, 2016

    Bumble bee (Bombus) species are ecologically and economically important pollinators, and many species are in decline. In this article, we develop a mechanistic model to analyse growth trajectories of Bombus vosnesenskii colonies in relation to floral resources and land use. Queen production increased with floral resources and was higher in semi‐natural areas than on conventional farms. However, the most important parameter for queen production was the colony growth rate per flower, as opposed to the average number of available flowers.

  8. Library Resource
    Articles et Livres
    décembre, 2016
    Argentine

    We analysed coexistence patterns between two mesocarnivores, Geoffroy's cat (Leopardus geoffroyi: Felidae) and culpeo fox (Pseudalopex culpaeus: Canidae), in northern Patagonia, Argentina. We examined spatial distribution influenced by land cover, anthropogenic disturbance and invasive hare presence, and analysed temporal activity patterns and dietary composition. If competitive exclusion accounts for carnivore coexistence in this system, we predicted segregation would occur in one or more of these aspects as a mechanism for coexistence.

  9. Library Resource
    Articles et Livres
    décembre, 2006
    Finlande

    We explored the relative contributions of climatic and land-cover factors in explaining the distribution patterns of butterflies in a boreal region. Finland, northern Europe. Data from a national butterfly atlas survey carried out during 1991-2003, with a 10-km grain grid system, were used in these analyses. We used generalized additive models (GAM) and hierarchical partitioning (HP) to explore the main environmental correlates (climate and land-cover) of the realized niches of 98 butterfly species.

  10. Library Resource
    Articles et Livres
    décembre, 2014

    Agroecosystems are increasingly recognized as both sources and sinks of non‐native weedy plant species as well as of native plant species, thus management of these systems has important implications for the composition of plant communities and landscape diversity. We quantified the distribution and abundance of both native and non‐native plant species along a habitat gradient representing four management zones: managed agroecosystem, the agroecosystem boundary, ecotone, and neighbouring native forest for two land uses: kiwifruit orchards and neighbouring grassland agroecosystems.

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