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DocumentOther documentBiomass estimation in mangrove forests: a comparison of allometric models incorporating species and structural information
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Improved estimates of aboveground biomass are required to improve our understanding of the productivity of mangrove forests to support the long-term conservation of these fragile ecosystems which are under threat from many natural and anthropogenic pressures. To understand how individual species affects biomass estimates in mangrove forests, five species-specific and four genus-specific allometric models were developed. Independent tree inventory data were collected from 140 sample plots to compare the aboveground biomass (AGB) among the species-specific models and seven existing frequently used pan-tropical and Sundarbans-specific generic models. The effect of individual tree species was also evaluated using model parameters for wood densities (from individual trees to the whole Sundarbans) and tree heights (individual, plot average and plot top height). All nine species-specific models explained a high percentage of the variance in tree AGB (R2 = 0.97 to 0.99) with the diameter at breast height (DBH) and total height (H). At the individual tree level, the generic allometric models overestimated AGB from 22% to 167% compared to the species-specific models. At the plot level, mean AGB varied from 111.36 Mg ha-1 to 299.48 Mg ha-1, where AGB significantly differed in all generic models compared to the species-specific models (p < 0.05). Using measured species wood density (WD) in the allometric model showed 4.5% to 9.7% less biomass than WD from a published database and other sources. When using plot top height and plot average height rather than measured individual tree height, the AGB was overestimated by 19.5 % and underestimated by 8.3% (p < 0.05). The study demonstrates that species-specific allometric models and individual tree measurements benefit biomass estimation in mangrove forests. Tree level measurement from the inventory plots, if available, should be included in allometric models to improve the accuracy of forest biomass estimates, particularly when upscaling individual trees up to the ecosystem level. Keywords: Climate change, Monitoring and data collection, Sustainable forest management ID: 3621710 -
DocumentOther documentThe effects of ignoring clustered data structure in allometric biomass models on large forest area biomass estimation
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.The aim of this study was to assess the effects of ignoring the clustered data structure on large area biomass estimation, when model uncertainty is included or not in the biomass prediction process. We used a Monte Carlo error propagation procedure to combine the uncertainty from allometric model predictions with the uncertainty from plot-to-plot variation, to produce estimates of mean AGB per hectare and standard error of the mean. An alternative procedure that ignores model prediction uncertainty was also used, therefore, showing only uncertainty due to differences between plots. Ignoring the clustered data structure, (i.e., fitting allometric models using ordinary least squares), the estimates of mean biomass per hectare were approximately 11% less than the estimates based on mixed effects models (that accounted for the clustered data structure), regardless of including or not the model prediction uncertainty. The estimates of uncertainty were also affected by ignoring the clustered data structure. When including model prediction uncertainty, ignoring the clustered data structure resulted in underestimation of standard error by 30%, whereas when model uncertainty was not included, the underestimation was 13%. Therefore, ignoring the clustered data structure, may affect both, the accuracy and the precision of biomass estimations over large forest areas. Keywords: Monitoring and data collection, Climate change ID: 3616826 -
ArticleJournal articleVolume yield, tree species diversity and carbon storage of sacred groves in Southwestern Nigeria
XV World Forestry Congress, 2-6 May 2022
2022Also available in:
No results found.Recently, the role of sacred groves in biodiversity conservation and provision of ecosystem goods and services has been a subjected to scientific investigation. In this study, data were collected from four sacred groves (Osun‐Osogbo, Igbo‐Olodumare, Idanre Hills and Ogun‐Onire) in southwestern, Nigeria to investigate their volume yield, tree species diversity, biomass and carbon storage potentials. Data were collected from 32 sample plots of 20 m x 40 m, established across the four sacred groves. In each plot, all woody plants with dbh ≥10cm were identified and their growth variables (dbh and height) measured. Non‐destructive allometric equation method was adopted for the estimation of volume, biomass and carbon stock production. The number of families and tree species encountered in the groves (understory and overstory layers) ranged from 22 to 32 and 41 to 85, respectively. The four groves had high Shannon‐Wiener diversity index (2.63 ‐ 3.55). They had high volume yield (244.99 m3 ha‐1 to 343.08 m3 ha‐1), biomass production (87.8 t ha‐1 to 231.86 t ha‐1) and carbon stock (43.9 t ha‐1 to 115.9 t ha‐1), with potentials for continuous growth as evidenced by the presence of young trees in the lower canopy. Thus, besides being good biodiversity conservation method, sacred groves act as sink of atmospheric CO2 considering their high biomass and carbon accumulation. The use and protection of sacred groves by indigenous people has enhanced tree species diversity, improved carbon sequestration and production of other forests ecosystem goods and services, thereby mitigating climate change and its effects. Keywords: Biomass, Climate change, Carbon stock, Carbon sequestration, sacred forest and Traditional methods ID: 3605244
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Brochure, flyer, fact-sheetBrochureManeio Integrado da Lagarta do Funil do Milho
Guião para as Escolas na Machamba do Camponês em África
2019Also available in:
No results found.Este guião foi elaborado com base nos resultados de um seminário de redação intensiva realizado de 21 a 25 de Julho de 2017 em Acra, Gana, organizado pela Organização das Nações Unidas para a Alimentação e Agricultura (FAO). O seminário juntou pesquisadores e profissionais de metodologia Escola na Machamba do Camponês da África Ocidental, Central, Oriental e Austral e entomologistas e pesquisadores da América com experiência sólida de gestão da Lagarta do Funil do Milho. -
Book (stand-alone)Manual / guideFood safety risk analysis: A guide for national food safety authorities 2006Ensuring food safety to protect public health and promote economic development remains a significant challenge in both developing and developed countries. Considerable progress to strengthen food safety systems has been achieved in many countries, highlighting the opportunities to reduce and prevent food-borne disease. However, unacceptable rates of foodborne illness still remain and new hazards continue to enter the food supply.
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Book (series)Technical reportFood safety risk management: Evidence-informed policies and decisions, considering multiple factors
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2017Also available in:
No results found.These FAO guidance materials were developed to support food safety risk managers and policy-makers in applying structured, evidence-informed processes to decisionmaking. Food safety issues can have widespread impacts beyond public health. They may contribute to, or detract from the achievement of goals in areas including nutrition, food security, food trade and market access, economic and rural development. The risk analysis paradigm guides risk managers to ensure their decisions are based on an assessment of risks to health, and consideration of other factors in choosing the preferred risk management decision. The materials assist decision-makers in applying a multi-factor approach and is applied to two key decision areas – setting food safety priorities, and selecting risk management options. The principles and approaches can be applied to all food safety decisions. Case studies are included as examples of how to apply this decision-making process. Using this guidance will lead to improved food safety decisions, where decision-makers can demonstrate how evidence was used and any trade-offs made. It also facilitates stakeholder engagement, transparency and accountability throughout the decision-making process.