摘要
Nebkhas are often extensively distributed in arid and semi-arid areas, and play an important role in the stabilization of ecological environment in these areas. This paper reviews the following aspects, including formation and succession, spatial distribution, shape and surface airflow characteristics, balance between erosion and deposition, ecological and physiological characteristics of vegetation, response to precipitation and groundwater, soil properties as well as the protection measures. We found that nebkhas were studied without differentiation of succession periods, and shape characteristics, surface airflow, soil proper- ties as well as vegetation dynamics in different succession periods were not fully understood, which made it difficult to explain the succession dynamics of nebkhas and its affecting factors. Previous studies of nebkhas were over-emphasized for its role as an indicator of land deg- radation, while its ecological functions in degraded ecosystems were neglected, which was unfavorable for the ecological restorations in arid and semi-arid areas. Future studies should pay more attention to the variation of vegetation, soil as well as hydrological process in the succession of nebkhas and its interaction between different influencing factors. In addition, positive role of nebkhas in degraded ecosystems in arid and semi-arid areas should be fully discussed. According to the data got from the above, effective protection measures of nebkhas should be explored.
Nebkhas are often extensively distributed in arid and semi-arid areas, and play an important role in the stabilization of ecological environment in these areas. This paper reviews the following aspects, including formation and succession, spatial distribution, shape and surface airflow characteristics, balance between erosion and deposition, ecological and physiological characteristics of vegetation, response to precipitation and groundwater, soil properties as well as the protection measures. We found that nebkhas were studied without differentiation of succession periods, and shape characteristics, surface airflow, soil proper- ties as well as vegetation dynamics in different succession periods were not fully understood, which made it difficult to explain the succession dynamics of nebkhas and its affecting factors. Previous studies of nebkhas were over-emphasized for its role as an indicator of land deg- radation, while its ecological functions in degraded ecosystems were neglected, which was unfavorable for the ecological restorations in arid and semi-arid areas. Future studies should pay more attention to the variation of vegetation, soil as well as hydrological process in the succession of nebkhas and its interaction between different influencing factors. In addition, positive role of nebkhas in degraded ecosystems in arid and semi-arid areas should be fully discussed. According to the data got from the above, effective protection measures of nebkhas should be explored.
基金
State Key Laboratory of Earth Surface Processes and Resource Ecology,No.2008-ZZ-02
Open Fund Program by Gansu Key Laboratory of Desertification Combating,No.KD200602
Financial Supporting Plan of Initial Study for Young Teacher in 2009 in Sun Yat-Sen University,No.37000-3126171
