In the Nanliu River Estuary of Guangxi, China, the naturally expanding process of a mangrove swamp（primarily consist of Aegiceras corniculatum） over past decades is studied by satellite images. From 1988 to2013, the...In the Nanliu River Estuary of Guangxi, China, the naturally expanding process of a mangrove swamp（primarily consist of Aegiceras corniculatum） over past decades is studied by satellite images. From 1988 to2013, the area of studied mangrove swamp increased significantly from 60 hm2 to 134 hm2. The expanding process is not gradual and the significant expansion only took place in some special periods. To reveal the dynamic of mangrove swamp expansion, the evolution of tidal flat elevation and the climate change in past decades are studied respectively. The hydrodynamic condition and nutrient supply are also analysed. The study results show that the climate factors of typhoon intensity and annual minimum temperature are crucial for controlling mangrove expansion. A large number of mangrove seedlings on bare tidal flats can survive only in special climate optimum periods, which are continuous years of low typhoon intensity and high annual minimum temperature. In past decades, the scarcity of climate optimum periods resulted in a non-gradual process of mangrove expanding and a time lag of 30 years between the elevation reaching the low threshold for mangrove seedling survival and the eventual emergance of the mangrove. Compared with the climate factors,the hydrodynamic condition and nutrient supply are not important factors affecting mangrove expansion. In the future, combined with global warming, the enhanced frequency and energy of landing typhoons will most likely restrain the further expansion of this mangrove swamp.展开更多
基金The National Natural Science Foundation of China under contract No.41306075the Natural Science Foundation of Guangxi Province under contract No.2014GXNSFBA118222the Foundation of Guangxi Academy of Sciences under contract No.12YJ25HS16
文摘In the Nanliu River Estuary of Guangxi, China, the naturally expanding process of a mangrove swamp（primarily consist of Aegiceras corniculatum） over past decades is studied by satellite images. From 1988 to2013, the area of studied mangrove swamp increased significantly from 60 hm2 to 134 hm2. The expanding process is not gradual and the significant expansion only took place in some special periods. To reveal the dynamic of mangrove swamp expansion, the evolution of tidal flat elevation and the climate change in past decades are studied respectively. The hydrodynamic condition and nutrient supply are also analysed. The study results show that the climate factors of typhoon intensity and annual minimum temperature are crucial for controlling mangrove expansion. A large number of mangrove seedlings on bare tidal flats can survive only in special climate optimum periods, which are continuous years of low typhoon intensity and high annual minimum temperature. In past decades, the scarcity of climate optimum periods resulted in a non-gradual process of mangrove expanding and a time lag of 30 years between the elevation reaching the low threshold for mangrove seedling survival and the eventual emergance of the mangrove. Compared with the climate factors,the hydrodynamic condition and nutrient supply are not important factors affecting mangrove expansion. In the future, combined with global warming, the enhanced frequency and energy of landing typhoons will most likely restrain the further expansion of this mangrove swamp.
