Mangrove ecosystems store large quantities of organic carbon for long periods of time. This study explores organic carbon stock change through the first comparative study of radiometric analysis and repeat field measures over a multi-decadal period in a mangrove system. Examining one tall gallery forest of Avicennia marina, and an adjacent interior scrub mangrove of mixed Avicennia marina and Aegiceras corniculatum, radiometric analysis estimated a soil organic carbon accumulation rate of 4.3 ± 0.6 Mg C ha⁻¹ y⁻¹ in the tall gallery forest and 2.2 ± 0.5 Mg C ha⁻¹ y⁻¹ in a stunted mangrove. Repeat measures of root carbon separated by 30 years estimated an increase of 5.06 Mg C ha⁻¹ y⁻¹ in the tall forest and 6.63 Mg C ha⁻¹ y⁻¹ in the stunted forest—suggesting an underestimate of carbon accumulation by radiometric dating of 15% and 67% in the tall and stunted forest, respectively. A higher carbon stock in the interior forest was attributed to root mass increase, associated with landward mangrove encroachment. Extrapolated to the entire region of NSW we estimate that mangrove encroachment has contributed at least about 1.8 Tg C sequestration over the 70 years for which this has been observed in New South Wales, Australia.

红树林生态系统可长时间存储大量有机碳。这项研究通过对辐射分析的首次比较研究和在红树林系统中数十年的重复田间测量方法，探索了有机碳库的变化。检查的一种妥尔库林白骨壤，和混合的相邻内部擦洗红树白骨壤和桐花树，辐射分析估计的4.3±0.6的MgÇ公顷土壤有机碳积累速率^-1  ý ^-1在高大库林和2.2±0.5 Mg C ha ^-1  y ^-1在发育不良的红树林中。重复测量根系碳的时间间隔为30年，估计高大森林中的根系碳增加了5.06 Mg C ha ^-1  y ^-1，发育不良的森林中根系碳增加了6.63 Mg C ha ^-1  y ^-1，这表明通过放射性测年法低估了碳的积累在高大和发育不良的森林中分别占15％和67％。内陆森林中较高的碳储量归因于根系质量增加，这与陆上红树林的入侵有关。推断到新南威尔士州的整个地区，在澳大利亚新南威尔士州观察到的70年中，红树林的入侵至少贡献了约1.8 Tg C的固存。