Effects of tree species diversity and stand structure on carbon stocks of homestead forests in Maheshkhali Island, Southern Bangladesh

Abstract

Background The homestead forests of Bangladesh occupy 0.27 million hectares (10% of the total forested area) and have potential to store carbon (C) and conserve biodiversity. Small scale forestry practices, however, are lacking reliable estimation of C stocks and tree species diversity. This may hinder successful implementation of REDD + and similar mechanisms as they concentrate on large-scale forests. This study aimed to estimate the above- and below-ground carbon stocks in homestead forests of Maheshkhali Island in Bangladesh and how tree species diversity and stand structural variation affect these C stocks. We randomly surveyed a total of 239 homestead forests in the hillside, beachside, and inland in 2019. Results Tree biomass C stocks were 48–67% greater in the inland and hillside forests than in the beachside due to significantly greater stand density, basal area, tree diameter. In total we found 52 tree species, but most abundant species in the inland and hillside forests, Mangifera indica, Samanea saman, and Artocarpus heterophyllus stored the most C in tree biomass. Greater tree species richness and diversity index in the inland and hillside forests indicated greater above- and below-ground tree biomass C stocks. An increase in tree species richness and diversity index by one unit was found to increase the tree biomass C stock by 22 and 30 Mg C ha−1, respectively. The total soil C stock was also affected by tree species diversity, stand density, and their interaction with soil properties. Total soil C stocks were greatest (51 Mg ha−1) in the inland forests, having also the greatest stand density and tree species richness. C stock in soil surface was greatest in the hillside forests due to the greatest litterfall, but the average share of litterfall from the total biomass C was only 0.1%. Conclusions Homestead forest ecosystems could store 96 Mg C ha−1 in total, which can contribute to climate change mitigation by generating C credits for small-scale homestead forests owners. Above- and below-ground tree biomass C stocks were found to correlate with tree species diversity, which may also contribute to biodiversity conservation in the REDD + in Bangladesh and countries alike.

Climate resilient traditional agroforestry systems in Silite district, Southern Ethiopia

“…However, the result in this study was opposite to the above claim proving that parkland AFS accounts for a high amount of carbon stock compared to the other studied AFS having a lower number of individual trees with less diversity. Therefore, the result indicated that the stand structure and number of individual trees in the study area have a greater impact on increasing the carbon stock than the species diversity (Baul et al 2021). This study also indicated that the species diversity has a significant positive relationship with aboveground carbon.…”

Balancing Livestock Environmental Footprints with Forestry-Based Solutions: A Review

“…Hence, even though livestock farming emits greenhouse gases all year round, these gases can be offset through carbon sequestration (Figure 2). The sequestration concept is very complex [130] and requires details in terms of compositions, as diversity in the forest ecosystem has a significant effect on carbon sequestration [131][132][133][134]. For instance, aged trees store more atmospheric carbon than young trees [135][136][137].…”

“…Therefore, the biophysical effects of forests on soil and water cycle promote, erosion control, water conservation, and nutrient cycling, making forests essential components of resilient and sustainable landscapes. The sequestration concept is very complex [130] and requires details in terms of compositions, as diversity in the forest ecosystem has a significant effect on carbon sequestration [131][132][133][134]. For instance, aged trees store more atmospheric carbon than young trees [135][136][137].…”

Study of Phytosociological Parameters and Carbon Stock between Two Community Forest of Different Ecological Regions of Udaypur District of Nepal

“…Despite the significant number of community forests in Nepal, there is often a lack of detailed information regarding essential technical aspects such as species diversity, stand structure, and carbon stocks (Anup, 2017;Poudyal et al, 2019). These metrics are critical for understanding the role of forests in providing ecosystem services such as carbon sequestration, soil conservation, and biodiversity conservation (Mandal et al, 2013;Bhandari et al, 2021;Baul et al, 2021). Therefore, there is a growing need for assessments studies in community forests in different regions that can provide detailed information about these technical aspects and their implications for ecosystem services (Paudyal et al, 2017).…”