The Importance of Phytogenic Mounds (Nebkhas) for Restoration of Arid Degraded Rangelands in Northern Sinai

El-Bana, M. I., et al., 2003. Restoration Ecology

Original research (primary data)
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Natural accumulation of wind-borne sediments within or around the canopies of plants plays an important role in the ecological and evolutionary dynamics of many coastal and desert ecosystems. The formation of such phytogenic mounds (nebkhas) creates patches that can strongly influence the spatial distribution of plant and soil resources. In land restoration of arid and semiarid environments it is important to study the potential role of such biological patchiness that may provide sites for coexistence of species with different life and growth forms. Our main objective was to test whether the nebkhas of a leguminous shrub, Retama raetam (white broom), promote restoration of herbaceous vegetation and soil in the degraded rangelands of northern Sinai. Vegetation and microclimatic and edaphic characteristics within the nebkhas, as well as within internebkha spaces, were compared for ungrazed and grazed sites. Abundance and richness of herbaceous plants were positively related to nebkha area, which explained more of the variance of abundance and richness in the grazed site than in the ungrazed one. Protection from grazing, especially on nebkhas, was associated with an increase in abundance and richness of herbaceous plants, improved soil microclimate, and increased soil fine particles and nutrient concentrations. The results suggest that management (in casu protection from grazing) of nebkhas of woody perennial shrubs changes rangeland conditions and improves the resource regulatory processes. Furthermore, nebkhas of unpalatable plants have the potential to preserve plant diversity in overgrazed plant communities, because they are effective in capturing and retaining water, soil materials, and propagules within and from nearby areas, resources that would otherwise be lost.

Case studies

Basic information

  • Case ID: INT-127-1
  • Intervention type: Combination
  • Intervention description:

    Mixed: protection and restoration Inhibition and protection of livestock grazing (occurring within a broader protected area "wetland nature reserve under the International Ramsar, Iran Wetland Convention in 1988" but this larger scale intervention is not what is being investigated. it is the other action that just happens to be occurring within the protected area)

  • Landscape/sea scape ecosystem management: No
  • Climate change impacts Effect of Nbs on CCI Effect measures
    Reduced soil quality  Positive % sand, % silt and clay, Electric conductivity, organic matter, total N, Na, K
    Reduced water availability  Positive Soil moisture (%)
    Biomass cover loss  Positive Abundance of herbaceous vegetation
  • Approach implemented in the field: Yes
  • Specific location:

    Zaranik Nature Reserve located on the eastern part of Lake Bardawil (31 03 N and 33 30 E) on the Mediterranean coast of the Sinai Peninsula --> two com- parable sandy islands, namely El Fusiyat [restored site] and El Malty [control/overgrazed site].

  • Country: Egypt, Arab Rep.
  • Habitat/Biome type: Deserts and xeric shrublands |
  • Issue specific term: Not applicable


  • Notes on intervention effectivness: effectiveness determined by comparing to unrestored/overgrazed plots
  • Is the assessment original?: Yes
  • Broadtype of intervention considered: Not applicable
  • Compare effectivness?: No
  • Compared to the non-NBS approach: Not applicable
  • Report greenhouse gas mitigation?: No
  • Impacts on GHG: Not applicable
  • Assess outcomes of the intervention on natural ecosystems: Yes
  • Impacts for the ecosystem: Positive
  • Ecosystem measures: • number of herbaceous plant species on the nebkha patches and the other two in the internebkha spaces • mean abundance and frequency of presence per species in nebkha and internebkha patches • Species richness • proportion of species recorded on the site that were found only on R. raetam nebkha patches and the proportion found only in internebkha spaces at both grazed and ungrazed sites
  • Assess outcomes of the intervention on people: No
  • Impacts for people: Not reported
  • People measures:
  • Considers economic costs: No
  • Economic appraisal conducted: No
  • Economic appraisal described:
  • Economic costs of alternative considered: No
  • Compared to an alternative: Not reported

Evaluation methodology

  • Type of data: Quantitative
  • Is it experimental: Yes
  • Experimental evalution done: In-situ/field
  • Non-experimental evalution done: Not applicable
  • Study is systematic: