Appearance can be deceptive: shrubby native mangrove species contributes more to soil carbon sequestration than fast-growing exotic species

Effects of Invasive Spartina alterniflora Loisel. and Subsequent Ecological Replacement by Sonneratia apetala Buch.-Ham. on Soil Organic Carbon Fractions and Stock

“…Similar results were reported in Australian salt marshes encroached by mangroves: belowground carbon was not enhanced in 0-14-year mangroves, while the total carbon storage increased when the mangrove ages exceeded 30 years [51]. The carbon stock of the mangroves in Qi'ao Island fell within the range that was previously reported for soil carbon stocks of mangrove ecosystems worldwide, ranging from 72 Mg C/ha in Saudi Arabia [52], to 126.14-657.61 Mg C/ha in South China [53], to the highest 2063.6 Mg C/ha in Sulawesi [54]. Although the soil carbon stocks were related to various environmental factors, such as degree of carbon inputs and export, biotic controls, and human pressures, the age of the ecosystem might be more significant in modulating mangrove carbon stocks [51].…”

“…In China, the fast growing exotic mangrove S. apetala has shown no advantages for carbon storage potential when compared to the native mangrove forests [7,27,54]. In contrast, the native mangrove K. obovata not only controlled the growth of S. alterniflora, but it also had a larger soil carbon pool than the invasive S. alterniflora and gradually restored the food web complexity after 14 years of restoration [10,20,21].…”

Improved estimates on global carbon stock and carbon pools in tidal wetlands

“…There are other estimates of global mangrove area (e.g., 137,600 km 2 in 2010 35 ), which may result in the variation of total mangrove ecosystem carbon stock. Nonetheless, mangrove area is a poor constraint on carbon densities or other mangrove functions 36 , as canopy height 20 and species identity 9,37 could also result in large variation in carbon densities, as do salinity categories, forest conditions and mangrove types, as found in this study. Sediments account for the largest proportion (60.4%) of ecosystem carbon stock.…”

Colonisation by native shrubby species enhances the carbon storage capacity of exotic mangrove monocultures

“…Thus, carbon stock in these compartments determines the carbon accumulation capacity of mangrove ecosystem. In contrast to terrestrial forests, mangroves allocate a high proportion of their biomass to belowground components, contributing more than half of the total standing biomass [20,21] Carbon stored in belowground biomass varied among mangrove species and more than 50% of mangroves soil carbon derived from plant [20,22,23,24,25]. The amount of soil organic carbon of mangrove forests dominated by different species varies greatly, from less than 0.5% to 40%, with a global mean value of 2.2% [26].…”

“…Even when successfully established, planting programs often lack adequate cost-bene t evaluation at the ecosystem level [30]. Sonneratia apetala was native to Bangladesh that introduced to China in 1985 and has been planted extensively in mangrove afforestation programmes [31,32] In China, the extent of S. apetala forests is estimated at > 50% (3,800 ha) of the total mangrove plantations area [24,33,34], while Kandelia obovata, a native mangrove species with the widest natural distribution and dominant along the southeast Chinese coastline, has also been widely planted for mangrove afforestation. Ren et al [33] suggested that the fast-growing S. apetala had great potential on carbon sequestration than most of the native species, and should be preferred in afforestation [18,33].…”