Studi mengenai jasa lingkungan karbon pada berbagai sistem penggunaan lahan di Kabupaten Labuhanbatu Utara memberikan pemahaman mengenai kontribusi setiap sistem terhadap penyerapan dan penyimpanan karbon.
Brief ini menyajikan temuan penelitian dengan pendekatan ilmiah, menghubungkan data dengan isu perubahan iklim dan kebijakan pengelolaan lahan. Mengetahui cadangan karbon dari beragam sistem lahan penting untuk mendukung tata kelola berkelanjutan dan strategi mitigasi iklim. Informasi ini dapat menjadi dasar dalam perencanaan tata guna lahan, khususnya untuk menjaga kawasan dengan cadangan karbon tinggi agar tidak dialihfungsikan secara intensif. Hasil studi ini diharapkan dapat memperkuat pengambilan keputusan berbasis bukti dalam pengelolaan lanskap, sekaligus mendorong keseimbangan antara produksi, konservasi, dan ketahanan iklim.
Tag: Carbon sequestration
Integrating dendrochronology and satellite NDVI to assess climate sensitivity and canopy resilience along a disturbance gradient in tropical moist forests
Stem radial growth is driven by the interaction between environmental conditions and tree physiological processes. As a result, tree rings serve as valuable natural archives, recording environmental information over time. In tropical forests, data on past climate variability and historical canopy greenness—an important indicator of forest health—are often limited in duration. Studying tree rings can thus provide essential insights into historical climate dynamics and canopy condition, helping us better predict the responses of tropical forests to global environmental changes. Here we present the first ring-width index chronologies (RWI) and normalized difference vegetation index (NDVI) (as a proxy of canopy greenness) time series of Zanthoxylum rhetsa (Roxb.) DC. from three moist forest sites in Bangladesh aligned along a gradient of increasing human disturbance. We compared historical annual radial growth rates with monthly, seasonal and annual climate data and seasonal NDVI values derived from high resolution satellite images. Our analyses showed that the growth of Z. rhetsa is primarily influenced by pre-monsoon temperatures and monsoon precipitation, with pre-monsoon climate signals becoming stronger in recent decades. The signal strength of the RWI chronologies, however, varied across study sites along the disturbance gradient, with stronger signals in the sites with low disturbance intensity. At the ecosystem level, canopy greenness (NDVI) was highly correlated with tree growth rates over the past two decades. NDVI showed high sensitivity to drought, particularly at drier sites. Global warming and drought are detrimental to forest health and thus limiting the carbon sequestration potential of moist tropical forests. By taking Zanthoxylum rhetsa as a model tree species in three Bangladeshi moist tropical forests we demonstrate how tree-ring analysis can be combined with remote sensing to reconstruct canopy dynamics for periods preceding the availability of satellite imagery for NDVI calculations that could be replicable to other tropical forests.
Prunus africana: From extractive trade to a regenerative medicinal tree-powered bioeconomy in Africa
- Prunus africana (African cherry) is a highly valuable medicinal tree species distributed across more than 22 African countries where it provides a wide variety of ecosystem services including biodiversity conservation, watershed protection, carbon sequestration in montane forest ecosystems, as well as many products of socioeconomic interest collected from its bark, roots, wood and leaves.
- The anti-inflammatory and anti-androgenic properties of its bark extract are used in traditional and conventional medicine for treating benign prostatic hyperplasia (BPH), prostate cancer and other urinary ailments affecting older men worldwide. Moreover, recent advances in phytochemistry have revealed novel bioactive fractions with potential applications in gastrointestinal oncology, dermatological regeneration, cosmeceuticals and functional food preservatives, thereby broadening opportunities for P. africana-based biopharmaceutical development.
- Europe remains the largest importer of P. africana bark products, while Asia is rapidly expanding its pharmaceutical and herbal integration markets. North America maintains stable demand through supplements and over-the-counter prostate formulations. African markets for P. africana based-medicinal and pharmaceutical products remain very poorly developed.
- To align with the African Union strategy for driving circular nature-based industrialization, some African countries, including South Africa, Ghana, Nigeria, Cameroon, Uganda and Kenya are promoting medicinal herbal-based bioeconomy frameworks and biopharmaceutical companies. Such developments are expected to catalyse the African perspectives on a P. africana powered bioeconomy.
- The global market for P. africana products is projected to grow from USD 150 million in 2024 to USD 250 million by 2033, driven by rising demand for herbal medicines and aging populations. The projected innovations in its medicinal applications will certainly add to the current growing trend.
- Due to international trade regulations imposed by the inclusion of the species under CITES Appendix II since 1995, Cameroon has contributed to the development of sustainability measures through institutionalization of Non-Detriment Findings (NDFs), supported by scientific evidence on improved bark harvesting techniques and standards, existing harvestable tree potential, and inclusive management plans. Moreover, domestication and integration into agroforestry, restoration and climate agendas, offer an opportunity to move from a compliance-driven model to a genuinely regenerative bioeconomy.
- The trend in global dry bark exports shows distinct phases tied to trade traffic and regulations as well as CITES quota realignments, with Rwanda, Cameroon, Tanzania, Democratic Republic of the Congo (DRC) and Burundi supporting nearly 90 percent of the global bark export market.
- Despite persistent challenges, including weak governance, inequitable benefit sharing, climate change, habitat degradation, informal trade and limited local processing capacity, P. africana could become a flagship species for Africa’s regenerative circular bioeconomy if backed by equitable governance, restoration efforts, innovation-driven biopharmaceutical development and community-centred sustainable management.
Development of aboveground biomass allometric equations for seven agroforestry tree species in northern Uganda
Accurate estimating aboveground biomass (AGB) is essential for quantifying carbon stocks and assessing the climate-mitigation potential of agroforestry systems. However, many existing biomass models in Uganda and other eastern African countries were developed for natural forests, rely on limited sample sizes, or employ generalized equations that may not adequately represent trees grown under smallholder agroforestry setting This study developed species-specific allometric equations to estimate AGB for seven agroforestry tree species in northern Uganda: Acacia polyacantha, Albizia lebbeck, Gmelina arborea, Maesopsis eminii, Markhamia lutea, Melia volkensii, and Senna siamea. Destructive sampling was conducted on 36–44 trees per species across a range of diameter classes and management regimes in Gulu, Amuru, Nwoya, and Oyam districts. Diameter at breast height (D), tree height (H), and crown radius (CR) were fitted as predictors of AGB using nonlinear maximum-likelihood regression models. Model performance was assessed using coefficient of determination (R2), root mean square error (SE), prediction error (PE%), Akaike Information Criterion (AIC), and repeated k-fold cross-validation. The selected models explained most of the variation in AGB (R2 = 0.90–0.99) and PE% below 3.5%. Model structure varied among species: for M. eminii and S. siamea, D alone adequately explained AGB variation, whereas other species required combinations of D with H or CR. Comparison with previously developed models revealed that generalised or pantropical equations produced biased estimates. Therefore, the developed species-specific equations provide reliable tools for estimating AGB and carbon stocks in smallholder agroforestry systems and woodlots in northern Uganda, supporting carbon accounting and restoration monitoring.
Coupling of soil carbon and water dynamics in two agroforestry systems in Malawi
This study evaluated the effects of Gliricidia sepium-maize agroforestry systems on carbon dynamics, soil properties, and water fluxes in Malawi as a strategy for enhancing climate change adaptation and sustainable agricultural production. The research was conducted at two long-term experimental sites managed by World Agroforestry (ICRAF), representing agroforestry systems established for more than 10 and more than 30 years. Soil carbon content, organic matter stability, soil physical characteristics, hydraulic properties, soil moisture, matric potential, and responses to rainfall events were assessed and compared with maize monoculture systems. Results showed that the incorporation of Gliricidia sepium increased soil carbon stocks and enhanced carbon stabilization, particularly at sites with lower initial soil carbon content. While changes in basic soil physical properties such as porosity and bulk density were limited, agroforestry plots exhibited improved saturated hydraulic conductivity and greater soil water storage capacity. The agroforestry systems generally retained more water and provided protection against soil drying below the topsoil, likely through enhanced infiltration into deeper soil layers. The findings demonstrate that agroforestry impacts on water dynamics are strongly influenced by local soil conditions and require direct field-based measurements for accurate assessment. Overall, integrating Gliricidia sepium into maize production can improve nutrient cycling, enhance soil carbon sequestration, increase water-use efficiency, and support climate-resilient and sustainable agricultural systems in Malawi.
Drivers of tree species diversity and aboveground carbon stocks in smallholder agroforestry systems in Laikipia East, Central Kenya
Agroforestry is highly valued for its role in carbon sequestration and biodiversity enhancement, yet empirical knowledge on how tree diversity and carbon stocks relate to environmental, farm-level, and household factors remain limited. This study combined whole-farm tree inventories and household surveys across 55 farms in Laikipia East Sub-County to assess patterns and drivers of woody species diversity and aboveground carbon stocks. A total of 108 woody species (6,756 individuals) across 38 families were recorded. Native species accounted for 56% of all species but only 40% of individuals, indicating dominance by a few exotic species. Species richness was highest in croplands (70 species) and boundary areas (59 species), which together accounted for 65% of all recorded trees. Young trees dominated the farms (>50%), mature trees made up about one-third, while large trees (<10%) were mostly confined to boundaries and croplands. Aboveground carbon stocks varied widely (mean: 16.5±7.1 t C/ha), with highest densities in woodlots (40.0±12.7 t C/ha) and homegardens (20.0±9.5 t C/ha). Multivariate analyses showed that plant density and average tree size were the strongest predictors of aboveground carbon (p< 0.01), while species richness was influenced primarily by the diversity of agroforestry practices and selected household characteristics, including respondent’s gender and household size (p < 0.05). Species diversity showed a weak relationship with aboveground carbon stocks (r < 0.20). These findings highlight both the ecological value and structural limitations of smallholder agroforestry. We recommend promoting tree conservation, native regeneration, and diversified agroforestry practices as strategies to enhance carbon storage and biodiversity outcomes in the region.
Global literature review and survey of implementation constraints on natural climate solutions
Natural Climate Solutions – protection, restoration, and improved management of lands and waters that reduce greenhouse gasses – have large climate change mitigation potential. However, lack of comprehensive information on implementation challenges hinders the adoption of Natural Climate Solutions and the delivery of near-term mitigation. Using a global survey of Natural Climate Solutions projects and a systematic review of recent studies, we map 46 constraints in eight categories, yielding 15,572 geo-referenced pathway-constraint observations from 501 studies and projects in 137 countries covering 20 of 22 United Nations subregions. Social-behavioral, Knowledge, and Government-Organizational are the most-reported constraint categories, and lack of policy coordination or implementation capacity the most-observed constraint and most frequently top-ranking constraint for pathways and subregions. Despite broad congruence, top constraint and category rankings vary among subregions and pathways, respectively. We find that projects generally encounter diverse sets of challenges. Without enabling efforts, near-term mitigation from Natural Climate Solutions may remain well below its biophysical potential.
Species-specific allometric models for estimating aboveground biomass and carbon stocks of plantation forests in northcentral Ethiopia
Plantation forests are crucial for landscape rehabilitation and carbon sequestration. However, the efficacy of these plantations in carbon sequestration in Ethiopia remains uncertain due to a lack of robust, species- and site-specific biomass estimation models. This study addresses this gap by developing and validating allometric models for estimating aboveground biomass (AGB) and carbon (C) stocks of plantation forests. Allometric models were developed using data from 69 harvested trees of three species: Eucalyptus globulus, Cupressus lusitanica, and Pinus patula. AGB was regressed against diameter at breast height (DBH) as the sole predictor, with stepwise inclusion of height (H), crown area and wood density. Model performance was evaluated using fit statistics, including Pseudo-R2 and mean prediction error (MPE). The model that incorporated both DBH and H as predictors provided the best fit (Pseudo-R2 > 0.90, p < 0.001) and achieved the lowest MPE (1.47–5.67%) across all species. The findings indicated a mean C stock of 121.6 Mg C ha−1 in the plantations studied. Our models provide valuable insights for forest management and improve the accuracy of AGB and C stock estimations in the study area and similar ecosystems. The estimated C stocks can serve as a benchmark for assessing future C dynamics.
Allometric models for estimating fuelwood and above-ground wood dry mass of pruned Faidherbia albida trees in northern Cameroon
In Cameroon’s Sudano-Sahelian zone, rising fuelwood demand is jeopardising Faidherbia albida agroforestry parklands. Faced with these alarming pressures and ongoing climate challenges, evaluating sustainable management practices and the contribution of F. albida agroforestry parklands to climate change mitigation has become a pressing priority. In these agro-ecosystems, total and rotational crown pruning are common practices, traditionally aimed at fuelwood and livestock feed collection. However, its impact on the trade-off between leaf removal and pod production remains poorly documented, particularly regarding long-term fuelwood yield potential. This research aims to develop tools for estimating the above-ground wood dry mass of F. albida components in the context of their use as renewable fuelwood and their carbon storage potential. Allometric equations for the different tree components were developed using data from the most recent pruning event (2023) of F. albida trees that had undergone three complete crown-pruning cycles over the past two decades. The predictors used to estimate fuelwood and above-ground wood dry mass were diameter at breast height (D, in cm), crown area (Ca, in m²), and total tree height (H, in m). The best-performing equations for each tree components relied on structurally meaningful combinations of these variables: (i) D²Ca, capturing the combined influence of stem size and crown development for estimating fuelwood obtained after pruning (DWpr, R²adj = 0.84) and the total above-ground wood dry mass of F. albida (TDWb, R²adj = 0.85), corresponding to the sum of DWpr and the post-pruning wood dry mass remaining after pruning (DWUpr); and (ii) D, reflecting the effect of stem diameter for predicting DWUpr, (R²adj = 0.76). The best crown area-only models for predicting DWpr and TDWb showed strong explanatory power, with adjusted R² values of 0.82 and 0.64, respectively. The integration of structural characteristics visible from space, such as the tree crown area, provides promising prospects for large-scale bio-mass mapping using satellite images and remote sensing methods.
Building the Great Green Wall supports the three Rio Conventions: And trees are the mortar
Key messages
- Enabling land users to regenerate trees and shrubs on farmland and common land helps support implementation of the three Rio Conventions – the UNFCCC, UNCCD and CBD, and simultaneously helps achieve many of the UN Sustainable Development Goals.
- Sahelian farmers who protect and manage woody species provide a service to polluting companies and countries across the world by sequestering more carbon than they emit.
- More trees and shrubs mean more leaf litter, which helps maintain and improve soil fertility, as well as reducing erosion, thus preventing land degradation and desertification.
- Increasing the number of trees and shrubs over millions of hectares provides additional shelter and food for tens of millions of migratory insect-eating birds overwintering in the Sahel.