Non-native mangrove can accelerate carbon sequestration in both soil and biomass
Ziming Zhang¹, Zhangcai Qin^{1,2 *
1}School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519000
²Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000
*Correspondence: qinzhangcai@mail.sysu.edu.cn; qinzc@hotmail.com
Abstract: Mangrove ecosystem can help mitigate climate change by sequestering and storing significant amounts of carbon (C) from the atmosphere and oceans. However, it is still unclear whether the non-native species introduced in coastal wetland can function as an efficient carbon sink. By examining two mangrove species, native Kandelia obovata and exotic Sonneratia apetala Buch.-Ham., at the Qi’ao Island, China, we quantified and compared ecosystem carbon storage, sequestration rate and source of soil organic carbon (SOC) under different vegetation cover. Our results showed that both species acted as strong carbon sinks, with total ecosystem carbon storage being similar under Kandelia obovata and old Sonneratia apetala. It should be noted, however, prior land use history, stand age, and vegetation growth can all affect the magnitude of carbon sequestration rate. Generally, Sonneratia apetala had a higher rate than Kandelia obovata, especially those with longer stand age (20 or 22 years) and higher primary production, or that have just matured after rapid growth (11 years). The input of autochthonous source (mangrove tissues) decreased with the decrease of tidal gradient and the increase of soil depth. More autochthonous input leads to larger and more stable SOC storage. This study shows that appropriate mangrove species can effectively increase the carbon storage of coastal wetlands. However, other potential ecological, environmental and economic impacts should be further examined as whether non-native mangrove can be introduced.
Keywords: mangrove, non-native species, ecosystem carbon storage, SOC sources
 

mangrove, non-native species, ecosystem carbon storage, SOC sources