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Résumé :
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Coastal dunes are highly vulnerable to disturbances. We characterized changes in the plant distribution, soil properties, and topology of a coastal dune field during the monsoon period. We selected a 600 x 300 m rectangular area of Dadaepo in the Nakdong River estuary and measured variables at 40 sampling points. A field survey was performed over two periods (pre- and post-monsoon) in 2009. Soil, topological features, and vegetation were surveyed at each point, and canonical correspondence analysis was used to identify relationships among the variables during the monsoon. The volumetric net change in the study site was 33,104 m(3) during the monsoon. When topographic and edaphic variables were compared, topological variables were found to be the dominant factors in dune vegetation zonation; however, their influence on vegetation change during the monsoon was less prominent than that of edaphic variables. Inland exotic species (Oenothera odorata and Conyza canadensis) and Cynodon dactylon replaced most of the Carex pumila distribution (54 % decrease) after the monsoon. Phragmites australis expanded its distribution and replaced the adjacent community after the monsoon. The area of Suaeda japonica decreased by more than 85 %, and this area was also replaced by P. australis. This knowledge of the dynamics of dune vegetation and environmental variables will be important for predicting the impacts of climate change, such as sea level rise and increased rainfall frequency.
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