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Xu, Y.; Liao, B.; Jiang, Z.; Xin, K.; Xiong, Y., and Zhang, Y., 2021. Examining the differences between invasive Sonneratia apetala and native Kandelia obovata for mangrove restoration: Soil organic carbon, nitrogen, and phosphorus content and pools. Journal of Coastal Research, 37(4), 708–715. Coconut Creek (Florida), ISSN 0749-0208. Mangroves play an important role in enhancing soil organic carbon (SOC) and nutrient pools. The exotic Sonneratia apetala is widely used for the restoration of mangroves in China because of its fast growth. However, it is not clear whether S. apetala increases SOC, nitrogen, and phosphorus pools compared with the native mangrove species. Thus, the aims of this study were to determine whether Kandelia obovata and the fast-growing mangrove species S. apetala have advantages with regard to the SOC, nitrogen, and phosphorus content and pools and whether restored mangroves have SOC, nitrogen, and phosphorus content and pools similar to those of original mangroves. Four sites in the Qi'ao-Dangan Provincial Nature Reserve were selected: a 15-year-old planted S. apetala forest, a 15-year-old planted K. obovata forest, a native K. obovata forest, and an unvegetated mudflat. The content and pools of organic carbon, nitrogen, and phosphorus in the soil were compared. Compared with mudflats, the content and pools of SOC, nitrogen, and phosphorus were significantly increased by planting S. apetala. However, compared with the 15-year-old planted K. obovata, the fast-growing S. apetala showed no advantage. The content and pools of SOC and nitrogen in the 15-year-old planted S. apetala site were lower than those of native K. obovata forests. It is recommended that more native mangrove species be used for future mangrove restoration to increase the content and pools of SOC, nitrogen, and phosphorus. [ABSTRACT FROM AUTHOR]

Xu, Y.; Liao, B.; Jiang, Z.; Xin, K.; Xiong, Y., and Guan, W., 2021. Emission of greenhouse gases (CH4 and CO2) into the atmosphere from restored mangrove soil in South China. Journal of Coastal Research, 37(1), 52–58. Coconut Creek (Florida), ISSN 0749-0208. Mangroves are a special ecosystem in tropical and subtropical coastal areas. Currently, it is not adequately understood whether soils in restored mangroves are a substantial source of greenhouse gases. The objectives of this study were to determine whether restored mangrove soils are a substantial source of carbon dioxide (CO2) and methane (CH4) and to identify environmental factors affecting soil CO2 and CH4 fluxes in mangrove sites. From August 2019 to January 2020, CO2 and CH4 flux surveys were conducted in soils at four planted mangrove sites, dominated by Excoecaria agallocha, Kandelia obovata, Bruguiera gymnorrhiza, and Hymenocallis littoralis, respectively, in a mangrove reserve in southern China. The results showed that the CO2 and CH4 flux ranges of the four mangrove sites were 0.9432–1.7892 mmol m–2 h–1 and –0.104 to 0.845 µmol m–2 h–1, respectively. Soil CO2 flux was strongly positively (p < 0.01) correlated with soil organic carbon content and positively correlated (p < 0.05) with soil total N content, temperature, and redox potential. CH4 flux was positively correlated with soil temperature. The results confirm that these restored mangrove soils are only a small greenhouse gases source to the atmosphere. [ABSTRACT FROM AUTHOR]