Blue carbon is increasingly being considered in global carbon budgets; however, there is poor understanding of how carbon stocks vary within mangrove forests with heterogeneous growth forms and in areas where mangroves are showing rapid changes in distribution. Here, field measurements and LiDAR data were used to estimate aboveground carbon stocks and economic benefits of Avicennia marina in the Auckland Region, New Zealand, where the mangrove area has increased at an annual rate of 3.2% since 1940. Multiple allometric equations were explored to determine best fits for different growth forms (tall and dwarf mangroves) that minimised uncertainty in conversions of tree size to aboveground carbon stock estimates. Across the Auckland Region, the mean total aboveground carbon stock (including trees, seedling, pneumatophores and woody debris) was 40.2 Mg C ha⁻¹ with over 75% contained in tree biomass. Total aboveground carbon stocks varied considerably between mangrove growth form (tall and dwarf mangroves) and hydrodynamic conditions (estuarine, riverine and delta mangroves). Total aboveground carbon storage across the Auckland Region amounted to 384,451 Mg C with an economic value of US$ 70 million. This study demonstrates that LiDAR data can be used to produce reliable and high-resolution tree carbon stock estimates in estuaries characterised by spatially variable distributions of dwarf mangroves. These estimates are critical for the incorporation of mangroves into national blue carbon accounting schemes.

中文翻译：

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新西兰快速扩张的红树林中的地上碳储量：蓝碳的区域评估和经济评估

全球碳预算中越来越多地考虑使用蓝碳。但是，人们对具有不同生长方式的红树林和红树林分布迅速变化的地区的碳储量如何变化知之甚少。在这里，现场测量和LiDAR数据被用来估算地上碳储量和Avicennia码头的经济效益。自1940年以来，新西兰奥克兰地区的红树林面积以每年3.2％的速度增长。探索了多种异速方程，以确定不同生长形式（矮矮红树林）的最佳拟合，从而最大程度地减少了树木转换的不确定性地上碳储量估算的大小。在整个奥克兰地区，地上的平均总碳储量（包括树木，幼苗，气穴和木屑）为40.2 Mg C ha ^-1树木生物量中含有超过75％。在红树林的生长形式（矮红树林和矮红树林）和水动力条件（河口，河流和三角洲红树林）之间，地上总碳储量差异很大。整个奥克兰地区的地下总碳储量为384,451 Mg C，经济价值为7,000万美元。这项研究表明，LiDAR数据可用于在以矮红树林的空间变量分布为特征的河口中生成可靠的高分辨率树木碳储量估算值。这些估计对于将红树林纳入国家蓝色碳核算计划至关重要。