Recent progresses in mangrove conservation,restoration and research in China

Aims In this paper,we highlighted some key progresses in mangrove conservation,restoration and research in China during last two decades.Methods Based on intensive literature review,we compared the distribution and areas of existing mangroves among selected provinces of China,discussed the issues associated with mangrove conservation and restoration and highlighted major progresses on mangrove research conducted by key institutions or universities in China's Mainland,Hong Kong,Taiwan and Macao.Important findings The population boom and rapid economic developments have greatly reduced mangrove areas in China since 1980s,leaving only 22700 ha mangroves in China's Mainland in 2001.Chinese government has launched a series of programs to protect mangroves since 1980s and has established mangrove ecosystems as high-priority areas for improving environmental and living resource management.During last three decades,a total of 34 natural mangrove conservation areas have been established,which accounts for 80%of the total existing mangroves areas in China.Mangrove restoration areas in China' Mainland accounted for<7%of the total mangroves areas in 2002.A great deal of research papers on Chinese mangroves has been published in international journals.However,more systematic protection strategies and active restoration measurements are still urgently needed in order to preserve these valuable resources in China.

Linkages of flow regime and micro-topography:prediction for non-native mangrove invasion under sea-level rise

Flow regime is a key driver of invasive aquatic organisms,and the invasiveness of mangrove species may be simultaneously attributed to plant traits and flowing hydrological conditions at the estuary scale.We focused on hydrological and topographic conditions for a non-native mangrove species,Sonneratia apetala,in Zhangjiang Estuary of Fujian,China.A hydrological model and a micro-topographic model were used to predict its dispersal and early establishment,and field surveys and simulated experiments were integrated to estimate its future dispersal patterns.The mesohaline mudflat with a salinity of 8~10 PSU at the mangrove seaward edge was the most likely colonization area for S.apetala under current conditions.The south-western region of the estuary with native mangroves was the most likely area for its colonization according to the unstructured-grid finite-volume community ocean model(FVCOM)in September,when the largest tidal currents within a year and the maximum fruit maturity period occur.Approximately 42%of the mudflats throughout the whole estuary may be available for seedling establishment under the future sea-level rise RCP 4.5 scenarios compared with 44%for current establishment;however,the RCP 8.5 scenarios would significantly decrease seedling establishment by 2100 due to serious tidal inundation according to the micro-topographical model.

Blue carbon sequestration following mangrove restoration:evidence from a carbon neutral case in China

Sequestration of blue carbon(C)in mangrove plantations depends on site characteristics and plantation management.This study evaluated the effects of plantation management on C sequestration at a C-neutral site in Xiamen,China.A field study was conducted on 10-year-old Sonneratia apetala and Kandelia obovata plantations(mono-Sa,mono-Ko)and a 15-year-old mixed plantation-.We found that mono-Ko had a significantly higher ecosystem C sequestration rate(3.32±0.62 kg C m^(-2)yr^(-1))than others when planted in the indirect shade of pioneer species.As a non-native species,Sonneratia performed better(0.57±0.01 kg C m^(-2)yr^(-1))when planted with Kandelia than in monotypic plantations.The temporary and long-term certified emission reduction(tCER and lCER)of the 12.98 ha mono-Ko was 4103.89 and 3693.50 net CO_(2)-e within 10 years,respectively.A literature review was conducted to show the compatibility of this study with other natural and plantation sites of China and Bangladesh(the native habitat for Sonneratia).The C sequestration of Sonneratia plantation sites in China is comparable with those in Bangladesh.However,the soil C accumulation rate for a Sonneratia monotypic plantation in Bangladesh decreased with age,yet the same did not occur in the plantations of China.