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Fire and overgrazing reduce aboveground biomass, leading to land degradation and potential impacts on soil organic carbon (SOC) and total nitrogen (TN) dynamics. However, empirical data are lacking on how prescribed burning and livestock exclusion impact SOC in the long-term. Here we analyse the effects of 19 years of prescribed annual burning and livestock exclusion on tree density, SOC and TN concentrations in the Sudanian savanna ecoregion at two sites (Tiogo and Laba) in Burkina Faso. Results revealed that neither livestock exclusion nor prescribed burning had significant impact on SOC and TN concentrations. The results at both sites indicate that 19 years of livestock and fire exclusion did not result in a significant increase in tree density compared to grazing and annual prescribed burning. The overall mean (± SEM) of SOC stocks in the 0–50 cm depth increment in the unburnt (53.5 ± 4.7 Mg C ha−1) and annually burnt (56.4 ± 4.3 Mg C ha−1) plots at Tiogo were not statistically different. Similarly, at Laba there was no significant difference between the corresponding figures in the unburnt (37.9 ± 2.6 Mg ha−1) and in the annually burnt plots (38.6 ± 1.9 Mg ha−1). Increases in belowground inputs from root turnover may have countered changes in aboveground biomass, resulting in no net change in SOC and TN. We conclude that, contrary to our expectation and current policy recommendations, restricting burning or grazing did not result in increase in SOC stocks in this dry savanna ecosystem. [ABSTRACT FROM AUTHOR]

Agricultural landscapes are increasingly being managed with the aim of enhancing the provisioning of multiple ecosystem services and sustainability of production systems. However, agricultural management that maximizes provisioning ecosystem services can often reduce both regulating and maintenance services. We hypothesized that agroforestry reduces trade-offs between provisioning and regulating/maintenance services. We conducted a quantitative synthesis of studies carried out in sub-Saharan Africa focusing on crop yield (as an indicator of provisioning services), soil fertility, erosion control, and water regulation (as indicators of regulating/maintenance services). A total of 1106 observations were extracted from 126 peer-reviewed publications that fulfilled the selection criteria for meta-analysis of studies comparing agroforestry and non-agroforestry practices (hereafter control) in sub-Saharan Africa. Across ecological conditions, agroforestry significantly increased crop yield, total soil nitrogen, soil organic carbon, and available phosphorus compared to the control. Agroforestry practices also reduced runoff and soil loss and improved infiltration rates and soil moisture content. No significant differences were detected between the different ecological conditions, management regimes, and types of woody perennials for any of the ecosystem services. Main trade-offs included low available phosphorus and low soil moisture against higher crop yield. This is the first meta-analysis that shows that, on average, agroforestry systems in sub-Saharan Africa increase crop yield while maintaining delivery of regulating/maintenance ecosystem services. We also demonstrate how woody perennials have been managed in agricultural landscapes to provide multiple ecosystem services without sacrificing crop productivity. This is important in rural livelihoods where the range of ecosystem services conveys benefits in terms of food security and resilience to environmental shocks. [ABSTRACT FROM AUTHOR]

Floodplain forests serve a critical function in flood regulation and the global carbon (C) cycle due to their important role in C sink management. Barringtonia acutangula , a tree species adapted to floodplains has been managed traditionally over millennia as family and community forest in North East India. Prevailing traditional management of the Barringtonia forest restricts felling of trees while promoting uses of tree branches in fishery management and fuel wood production. Such management systems might have helped in sustaining floodplain family forests with a steady stock of biomass. However, our knowledge of their role in biomass stocks and C storage is still scanty. Therefore, the present study was undertaken to estimate the biomass and carbon stocks of Barringtonia forests and to understand their role in carbon sink management. The floodplain forest at the study site was stocked with 3204 trees ha −1 of Barringtonia . Allometric models were developed using harvested tree, and these were used for estimation of biomass and vegetation carbon stocks. Among the various models tested the power model using diameter at breast height (DBH) as an independent variable fitted tree biomass in different tree components (bole, sprout, branch and leaves) adequately. Total dry above ground biomass (AGB) estimated at 552 ± 23 Mg ha −1 in the Barringtonia floodplain forests was much larger than AGB reported for various forest types and agroforestry systems in North East India. Biomass allocation patterns revealed that out of the total biomass, the bole contributed the highest proportion (45%) followed by sprouts (27%), branches (24%) and leaves (4%). The above-ground carbon stock was estimated at 263 ± 11 Mg ha −1 . The quantity of biomass stock and the carbon storage in vegetation cover of Barringtonia forest suggest its direct influence on local, regional and even global climate. [ABSTRACT FROM AUTHOR]

Indigenous agroforestry systems are important reservoirs of biodiversity, and ecosystem services with a potential contribution for conservation of biodiversity while sustaining the livelihood of the rural populace. Pineapple (Ananas comosus) agroforestry systems (PAFS) form an essential constituent of the rural landscape in the Indian Eastern Himalayas and other parts of Asia. The traditional PAFS management in southern Assam is unique in that it involves shifting cultivation transitioning from native forests to a PAFS. Scarcity of information on the functioning and services in terms of species diversity and carbon storage potential in the traditional PAFS has restricted the opportunities for consideration under the nature-based solutions of climate action including REDD+. Therefore, the present study assessed the tree diversity and ecosystem carbon storage in a chronosequence from swidden agriculture through different phases of PAFS establishment. The result demonstrated that basal area in the PAFS increased with age. The most dominant species in the native forests was Palaquium polyanthum , while agricultural land use and PAFS aged <5, 11–15 and > 15 years old were dominated by Gmelina arborea , Albizia procera , Areca catechu and Hevea brasiliensis , respectively. The highest value of Shannon-Wiener diversity index (H) was recorded in native forests (2.71), and lowest in 5–10 years old PAFS. The ecosystem carbon storage declined from 261.43 Mg ha−1 in native forests to 181.07 Mg ha−1 in <5-years old PAFS. In <5 years old PAFS, the ecosystem carbon storage was 30 % lower than the native forest; while at >15 years it was merely 5 % less than the native forests. The traditional PAFS maintains a steady ecosystem carbon stock while reducing land use related carbon emission and providing additional co-benefits to the communities. Therefore, the traditional PAFS constitute a good opportunity for REDD+. [Display omitted] • The Shannon-Wiener diversity index (H) was the highest in native forests (2.71), and the least in 5–10 years PAFS. • Forest clearing and burning prior to the establishment of PAFS caused a decline of 30 % of the ecosystem C. • The bush density of the pineapple increased with the increase in the PAFS age. • At >15 years of PAFS ecosystem carbon loss was merely 5 % compared to native forests. [ABSTRACT FROM AUTHOR]