Résultats de la recherche | Land Portal

Résultats de la recherche

Showing items 1 through 9 of 43.
  1. Library Resource
    Articles et Livres
    décembre, 2016
    Argentine, Burkina Faso, République centrafricaine, Chine, Cameroun, Algérie, Érythrée, Éthiopie, Mali, Mauritanie, Niger, Nigéria, Soudan, Sénégal, Soudan du Sud, Tchad, Asie central

    It took scientists more than three decades to transform a perceived desertification crisis in the Sahel into a non-event. Looking beyond the Sahel, the chapters in this book provide case studies from around the world that examine the use and relevance of the desertification concept.

  2. Library Resource
    Articles et Livres
    avril, 2017
    Chine, Asie orientale

    Context: Recent conceptual developments in ecosystem services research have revealed the need to elucidate the complex and unintended relationships between humans and the environment if we are to better understand and manage ecosystem services in practice.

    Objectives: This study aimed to develop a model that spatially represents a complex human–environment (H–E) system consisting of heterogeneous social–ecological components and feedback mechanisms at multiple scales, in order to assess multi-dimensional (spatial, temporal, and social) trade-offs in ecosystem services.

  3. Library Resource
    Articles et Livres
    décembre, 2014
    Chine

    The Huajiang and Hongfenghu demonstration areas represent typical karst landforms and rocky desertification landscapes in Guizhou, China. These were selected for a comparison of rocky desertification and land use cover. Based mainly on 5� m resolution Spot 5, remote sensing images, topographic maps (1:10,000) and land use maps, the intensity and extent of rocky desertification, and slope characteristics of the two areas were interpreted. Spatial overlay analysis was used to compare the land use/land cover (LULC) and rocky desertification within each.

  4. Library Resource
    Articles et Livres
    décembre, 2014
    Chine

    To protect biodiversity and improve environmental conditions, China has invested billions of dollars in reforestation and payments for ecosystem service programs. Here, we examine the Sloping Land Conversion Program, the largest such program in the world and found that after 13� years of implementation at our study site, it has had negative impacts on natural tropical forests. GIS and remote sensing techniques revealed that both natural forests and natural shrub and grasslands were replaced by non-native monocultural plantations on Hainan Island, China, a key tropical biodiversity hotspot.

  5. Library Resource
    Articles et Livres
    décembre, 2010
    Chine

    Artemisia sphaerocephala and A. ordosica are two dominant shrub species in Mu Us sandy land (Inner Mongolia, China) and are widely used for vegetation restoration. However, there are two different conclusions about the effect of light on their germination: light promotes germination versus light inhibits germination. The aim of this study was to evaluate these two conclusions and relate the results to instances of failure of these two species to germinate well when air-dispersed in revegetation projects.

  6. Library Resource
    Articles et Livres
    décembre, 2015
    Chine

    Desertification is one of the major obstacles to the development and utilization of oases in arid and semi-arid regions of China. Revegetation of oases is an effective means of protecting oases from sand invasion (the main cause of desertification) and enhancing the ecological stability of oasis. In order to assess the effects of revegetated plant communities, 21-year-old Haloxylon ammodendron shrubland (Shrubland), 28-year-old Populus simonii Carr. land (Poplar land) and 33-year-old Pinus sylvestris var. mongolica Litv land (Pine land) were selected as study objects.

  7. Library Resource
    Articles et Livres
    décembre, 2006
    Mongolie

    Steppe desertification due to vehicle travel is a severe environmental issue in Mongolia. We studied natural vegetation recovery on abandoned vehicle tracks in the central Mongolia steppe through vegetation surveys and stable isotopic techniques. The following issues were addressed: (i) invasion of pioneering plant species, (ii) alteration of soil surface features, and (iii) contribution of revegetated plants to soil organic matter (SOM).

  8. Library Resource
    Articles et Livres
    décembre, 2013
    Chine, États-Unis d'Amérique, Europe

    The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The western Europe has a longer history of agricultural land development than the eastern United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century.

  9. Library Resource
    Articles et Livres
    décembre, 2013
    Chine, Mongolie

    In order to understand the genetic diversity of wild Ussurian pears in China, chloroplast DNA (cpDNA) of 186 wild accessions from 12 populations in Inner Mongolia, Heilongjiang and Jilin Provinces and 51 Chinese and European pear cultivars including Pyrus ussuriensis, Pyrus pyrifolia, Pyrus bretschneideri, Pyrus sinkiangensis and Pyrus communis were investigated. Each accession was classified into one of three types (types A, B and C) based on two large deletions in the hypervariable regions between the accD–psaI and rps16–trnQ genes.

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