Spatial patterns and driving factors of carbon stocks in mangrove forests on Hainan Island, China

Abstract

Aim Mangrove forests are important coastal wetlands for the blue carbon budget and play a significant role in mitigating global climate change. However, spatial patterns of carbon stocks in mangrove forests on an island scale have not been quantified owing to methodological limitations and lack of understanding of controlling factors. We took the entire Hainan Island as a case study and aimed to carry out a comprehensive investigation of the spatial patterns and driving factors of carbon stocks in mangrove forests. Location Southern China. Time period 2017–2020. Major taxa studied Mangrove forest. Methods The upscaling method combined with field surveys and Sentinel‐2 imagery analysis were used to compare different models for optimization of mangrove ecosystem carbon stock estimations. We also used structural equation modelling (SEM) to evaluate the factors driving the distributional patterns of mangrove carbon stocks on an island scale. Results The current total mangrove carbon stock of the entire Hainan Island was estimated to be 703,181 Mg C (with a mean density of 192 Mg C/ha), with the above‐ and below‐ground carbon stocks averaging at 44.7 and 147.3 Mg C/ha, respectively. The mangrove carbon storage in the north‐eastern region of the island was the highest and in the west region the lowest. Sediment nitrogen content and plant species diversity had the most positive driving effects on the distribution of total carbon stock for Hainan Island mangroves. Main conclusions The combination of field surveys and Sentinel‐2 imagery analysis can be applied to regional‐scale estimations of carbon stocks for mangrove forests. Spatial pattens of mangrove carbon stocks vary among locations on Hainan Island, and soil nutrient (especially nitrogen) availability is the dominant factor regulating carbon stock variations along the land‐to‐sea gradient. Our findings have significant implications for better understanding the distribution of mangrove carbon stocks and quantification of the global blue carbon budget.

Biomass Estimation of Subtropical Arboreal Forest at Single Tree Scale Based on Feature Fusion of Airborne LiDAR Data and Aerial Images

“…In the study of biomass estimation based on multi-source remote sensing, the traditional linear parameter model has problems of nonlinearity and multicollinearity due to its limited statistical assumptions. As a result, non-parametric modeling methods are widely used in biomass estimation research, which solves the problems of high dimensionality, high redundancy, and small sample sizes in multi-source remote sensing data [28][29][30]. Coeli M. Hoover et al (2018) [31] compared random forest (RF) with the traditional biomass estimation methods and proved that the estimate from RF was better than the general estimate by using the average canopy height and cross-sectional area, as proposed by G.P.…”

Distribution of black carbon in sediments from mangrove wetlands in China

“…Since BC content is affected by mangrove tree species (Guo et al, 2018), this might be the driving factor of a higher accumulation of BC in Hainan province. In addition, mangrove cover, climate factors and anthropogenic disturbances also had impact on BC content in sediments (Charles et al, 2020;Meng et al, 2022). Therefore, these factors mentioned above should be considered in the future researches.…”

Assessment of mangrove ecosystem conditions in Sepulu District, Bangkalan

“…The chemical function of mangroves is that mangroves can absorb and store five times more carbon than terrestrial plants and produce twice as much oxygen. For instance [8] elucidated that with an average density of 192 mg C/ha, the current total mangrove carbon store of the entire island of Hainan was calculated to be 703,181 mg C, with an average of 44.7 mg C/ha for the above-and 147.3 mg C/ha for the below-ground carbon stocks. The island's north-eastern and western regions have the largest and lowest levels of mangrove carbon storage, respectively.…”