Mangroves on the islands along the Java Sea play a crucial role in supporting biodiversity, protecting coastlines, and sequestering carbon. However, there is a lack of information on mangrove structure and biomass in the area. This study aimed to assess the mangrove structures and biomass on Desa Daun, located on the Bawean Islands, and Kemujan Island, located on the Karimunjawa Islands, respectively. The study utilized a combination of line transect and quadrant plot methods with a size plot of 10×10 m. We established 7 line transects and 28 quadrant plots in the mangrove forest of Desa Daun and similarly set up 7 line transects and 21 quadrant plots on Kemujan Island. Within each quadrant, the mangrove species were identified, and their diameters at breast height (DBH) were recorded. To assess the relative significance of each species, the importance value index (IVI) was calculated, and allometric equations were applied to estimate biomass and carbon storage in the trees. PlanetScope imagery was also used to quantify the carbon stock of mangroves on those islands. In Desa Daun, 13 mangrove species were identified, while 12 species were recorded on Kemujan Island. The species Nypa fruticans and Excoecaria agallocha exhibited the highest IVI in Desa Daun and Kemujan Island, respectively. Notably, Rhizophora apiculata demonstrated the greatest biomass in both locations, with measurements of 43.08 Mg B/ha in Desa Daun and 102.22 Mg B/ha in Kemujan Island. Overall, mangrove stands on Desa Daun stored biomass of 113.60 Mg B/ha and carbon of 50.98 Mg C/ha, whereas mangrove stands on Kemujan Island stored biomass of 295.04 Mg B/ha and carbon of 131.95 Mg C/ha. Mangrove stands of the whole Bawean Islands sequestered 22,941 Mg C, while Karimunjawa Islands hold much higher C stocks, 79,451 Mg C. Despite being smaller in size, the Karimunjawa Islands have more extensive mangrove coverage compared to the Bawean Islands due to their geomorphological characteristics, which in turn influence their mangrove structures and carbon stocks. However, the loss of mangroves in the Karimunjawa Islands due to aquaculture expansions could increase carbon loss in the islands.
Tag: Carbon stock
Characterization and ecological importance of cocoa and oil palm agroforestry systems on the outskirts of a forest concession in southern Cameroon
Traditional production systems, agroforestry systems (SAFs) in southern Cameroon combine various types of trees of socio-economic interest which can contribute to the conservation of biodiversity. The objective of this work is to analyze the contribution of these agroforestry systems based on cocoa and oil palms in the sustainable management of peripheral resources of a forest concession in southern Cameroon. The methodological approach adopted consisted of carrying out socio-demographic surveys with 66 SAF operators using survey forms. A sampling rate of 10% was applied in seven villages in the Commune of Djoum. These interviews were supplemented by floristic inventories carried out on 69 plots of 40 × 60 m for a total area of 15.84 ha. The data collected allowed us to calculate various diversity and ecological indices, woody biomass and carbon stock, to which various statistical tests and Analyzes of variance were applied. The floristic potential is made up of 8,355 individuals divided into 177 species, 153 genera, 47 families, and classified into 3 woody groups, namely introduced, preserved and perennial species. The Shannon index between land use types varies from 2.15 bits in palm agroforests to 3.9 bits in forests while it is 2.81 bits in cocoa agroforests. The forests of the UFA and the peripheral SAFs share 42 forest species out of 63 inventoried species, ie 66.7% of forest species preserved in cocoa agroforests, proof of the effectiveness of the conservation potential of these SAFs in the region. The largest diameter class is [10–20] cm while the largest height class is the stratum of [5–10] m. Tree density and basal areas are highest in forests with 110.51 stems/ha and 42.08 m2/ha. Three types of architectural profiles for cocoa-based SAFs and two types of architectural profiles for oil palm-based SAFs were identified with a typology that shows 4 groups of TUTs based on ecological interactions. Forests are the type of land use that stores the most carbon (115.81 tC/ha) compared to 93.54 tC/ha for palm agroforest and 58.8 tC/ha for cocoa agroforests. Gradients of diversity, density and complexity vary with proximity to the forest concession. These results could be considered as effective and quantifiable tools for the certification of numerous cash crops such as cocoa and oil palm, which will make it possible to promote this endogenous knowledge scientifically and in the development of various programs and publications. technical notes.
Towards comprehensive blue carbon accounting in Vietnam
Key messages
- The Government of Vietnam pays great attention to protecting mangrove ecosystems as they play a vital role in climate change mitigation. In 2024, the government issued Technical Guidelines for Biomass and Carbon Stock Estimation of Mangrove Forests (Decision No. 316/QD-LN-SXLN). These Guidelines aim to standardize estimates for biomass and carbon stock, and increase carbon storage from their restoration. This brief looks at required improvements to the Guidelines to help Vietnam join the blue carbon market.
- Better estimates of greenhouse gas (GHG) emissions from converted mangroves are needed to understand baseline emissions from anthropogenic disturbances in mangrove forests, as well as the impact of ending conversion of mangroves to other uses like aquaculture. To that end, better information on conversion and land-management practices is needed. This includes excavation depth for construction of aquaculture ponds and infrastructure development, nitrogen inputs for aquaculture production, and knowledge on crop types, drainage depth, and GHG budgets in mangroves converted to agriculture.
- More refined estimates of GHG emissions from converted mangroves can help shed light on baseline emissions from anthropogenic disturbances in mangrove forests, as well as the impact of ending conversion of mangroves to other uses like aquaculture.
- Strategic alignment with established blue carbon standards—such as the Verified Carbon Standard (VCS) and the Gold Standard (GS) Framework—would enable Vietnam to harness the full potential of its mangrove ecosystems for high-integrity blue carbon crediting.
- Integrating remote sensing and machine learning techniques with species-level classification data can significantly enhance the accuracy and robustness of blue carbon accounting in mangrove ecosystems.
Multispecies allometric models for estimating aboveground biomass in plantation and natural dry Afromontane forests in northcentral Ethiopia
Dry Afromontane forests in Ethiopia are vital carbon sinks, yet accurate biomass and carbon stock assessments have been hindered by the lack of site-specific models. This study developed and validated multispecies allometric equations for Wof-Washa plantation and natural forests using biometric data from 127 trees across seven dominant species. Models incorporating diameter at breast height (DBH) and total height (H) explained up to 95% of aboveground biomass variation and outperformed pan-tropical models in accuracy and bias reduction. These findings provide robust tools for national carbon accounting and support sustainable forest management, contributing to climate mitigation and improved land-use planning in Ethiopia’s highland ecosystems.
Assessment of C-stock and earthworm population for a forest-to-coffee conversion in Sumberjaya, West Lampung
The purpose of this poster is to asses above-ground C-stock and Earthworm pupulation density of Monocultural and multistrata coffee based system
Potential of Alnus acuminata based agroforestry for carbon sequestration and other ecosystem services in Rwanda
Alnus acuminata Kunth. (alnus) is widely used in agroforestry systems across the globe and is believed to provide multiple ecosystem services; however, evidence is lacking in agroforestry literature to support the perceived benefits, particularly in Rwanda. To understand carbon sequestration potential and other benefits of alnus, a household survey, tree inventory and destructive sampling were conducted in north-western Rwanda. Over 75% of the respondents had alnus trees in their farms. The trees provide stakes for climbing beans, firewood and timber. They also improve soil fertility and control soil erosion. Farmers had between 130 and 161 alnus trees per hectare with an average height of 7.7 ± 0.59 m and diameter at breast height of 16.3 ± 1.39 cm. The largest biomass proportion was found in stems (70.5%) while branches and leaves stock about 16.5 and 13% of the total biomass, respectively. At farm level, aboveground biomass of alnus trees was estimated to be 27.2 ± 0.7 Mg ha−1 representing 13.6 Mg of carbon (C) per hectare. Biomass carbon increased with tree size, from 7.1 ± 0.2 Mg C ha−1 in 3 years old trees to 34.4 ± 2.2 Mg C ha−1 in 10 years old trees. The converse was observed with elevation; biomass carbon decreased with increasing elevation from 21.4 ± 1.29 Mg C ha−1 at low (2011–2110 m) to 9.6 ± 0.75 Mg C ha−1 in the high elevation (> 2510 m). In conclusion, alnus agroforestry significantly contributes to carbon sequestration, although the magnitude of these benefits varies with tree age and elevation. Planting alnus trees on farms can meet local needs for stakes for climbing beans, wood and soil fertility improvement, as well as the global need for regulation of climate change.