Quantifying Local-scale Forest Degradation Intensity from Charcoal Production Using a Fusion of GEDI and Landsat Data

2021 ◽  
Author(s):  
Mengyu Liang ◽  
Laura Duncanson ◽  
Fernando Sedano
Keyword(s):  
Forest Structure ◽  
Vegetation Indices ◽  
Forest Degradation ◽  
Local Scale ◽  
Ecosystem Dynamics ◽  
Sub Saharan Africa ◽  
Optical Remote Sensing ◽  
Degraded Forest ◽  
Charcoal Production ◽  
Sub Saharan

<p>Deforestation and degradation are two major threats to the global forest that jeopardize their functions to store carbon and mitigate climate change. Forest degradation undermines the health and functions of the forest to perform ecosystem services and is a stepping stone to deforestation. However, forest degradation has not been sufficiently monitored and quantified due to the varying intensity of disturbance and usually inconsistent spectral signals reflected in optical remote sensing. Drivers of forest degradation can be natural and/or human-related, and charcoal production is a key driver of forest degradation in sub-Saharan Africa due to the high demands for charcoal for energy consumption and the increasing rate of population growth and urbanization. In this study, we focus on charcoal production-driven forest degradation that occurred at the Mabalane district in Southern Mozambique from 2008 to 2018. We intend to demonstrate the potential of combining Global Ecosystem Dynamics Investigation (GEDI) data and Landsat time stacks for inspecting the changes in forest structure and aboveground biomass (AGB). To do so, we categorize the degraded forest by the year of disturbance based on a disturbance map produced for the study area for 2008-2018 by Sedano et al. (2019) and analyze the first year of publicly-released GEDI data to characterize forest structure and AGB at different disturbance classes. We also compare the GEDI L4A biomass with three other global and continental AGB products to understand the pre-disturbance biomass storage and the degradation patterns. Lastly, we build an empirical model between GEDI biomass and Landsat spectral bands and vegetation indices to quantify the biomass removal and regrowth from 10-year charcoal production. Uncertainties from the GEDI-Landsat models are estimated using Monte Carlo Simulations to propagate errors. The study improves the current understanding of forest degradation and carbon dynamics associated with it in tropical dry forests of sub-Saharan Africa. It also demonstrates the potential of combining spaceborne lidar missions and Landsat archives to facilitate accurate mapping of forest structural and AGB change in the degraded forest at a local scale. </p>

The Impact of Charcoal Production for Energy on Tropical Rainforest Resources in Nigeria

2020 ◽  
Author(s):  
Angelique Lansu ◽  
Jaap Bos ◽  
Wilfried Ivens
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Population Growth ◽  
Open Data ◽  
Forest Degradation ◽  
Sub Saharan Africa ◽  
Charcoal Production ◽  
Household Energy ◽  
Sub Saharan ◽  
The Impact

<p>In Sub Saharan Africa, many people depend on biomass for their household energy. Charcoal production is a common technique for converting biomass into a useful energy source. Nigeria is the biggest charcoal producer in Sub Saharan Africa. A large amount of wood is harvested from Nigerian forests for this charcoal production for energy. The Nexus of charcoal-land use change-energy imposes a considerable burden on the amount of wood that must be extracted from the forest for charcoal production. Therefore, charcoal production is linked to deforestation and forest degradation. However, it is not clear to what extent the demand for charcoal in Nigeria contributes to deforestation by land use change, and degradation of forests by selected wood logging. In this study, an attempt was made to provide an answer to this and to state which situation could occur by 2030, following the expected population growth in Nigeria. To achieve this, literature and open data on charcoal production, deforestation, forest degradation and population growth in Nigeria have been collected and analysed. Subsequently, calculations were carried out to determine to what extent charcoal production contributed to deforestation in the period 1990-2015. In this period, the share of deforestation due to charcoal production increased from 6% to 14%. If the expected charcoal production in 2030 were to apply to the current situation, this share would be around 20%. The quantity of wood required can also be expressed in numbers of hectares with biomass. In that case, around 80,000 ha would be required in 2030. To validate the findings, further research is needed on the amount of biomass per hectare in Nigerian forests, and on the amount of charcoal exported, not only as source of household energy but also globally as barbecue fuel. A more extensive analysis of open data on the nexus charcoal-land use change-energy at multiple scales will help to project future interlinkages.</p>

scholarly journals The Sub-Saharan Africa carbon balance, an overview

2009 ◽  
Vol 6 (1) ◽  
pp. 2085-2123 ◽  
Author(s):  
A. Bombelli ◽  
M. Henry ◽  
S. Castaldi ◽  
S. Adu-Bredu ◽  
A. Arneth ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Agricultural Sector ◽  
Fire Regime ◽  
Carbon Sink ◽  
Forest Degradation ◽  
Sub Saharan Africa ◽  
Cycle System ◽  
First Results ◽  
Sub Saharan ◽  
The Impact

Abstract. This study presents a summary overview of the carbon balance of Sub-Saharan Africa (SSA) by synthesizing the available data from national communications to UNFCCC and first results from the project CarboAfrica (net ecosystem productivity and emissions from fires, deforestation and forest degradation, by field and model estimates). According to these preliminary estimates the overall carbon balance of SSA varies from 0.43 Pg C y−1 (using in situ measurements for savanna NEP) to a much higher sink of 2.53 Pg C y−1 (using model estimates for savanna NEP). UNFCCC estimates lead to a moderate carbon sink of 0.58 Pg C y−1. Excluding anthropogenic disturbance and intrinsic episodic events, the carbon uptake by forests (0.98 Pg C y−1) and savannas (from 1.38 to 3.48 Pg C y−1, depending on the used methodology) are the main components of the SSA sink effect. Fires (0.72 Pg C y−1), deforestation (0.25 Pg C y−1) and forest degradation (0.77 Pg C y−1) are the main contributors to the SSA carbon emissions, while the agricultural sector contributes only with 0.12 Pg C y−1. Notably, the impact of forest degradation is higher than that caused by deforestation, and the SSA forest net carbon balance is close to equilibrium. Savannas play a major role in shaping the SSA carbon balance, due to their large areal extent, their fire regime, and their strong interannual NEP variability, but they are also a major uncertainty in the overall budget. This paper shows that Africa plays a key role in the global carbon cycle system and probably could have a potential for carbon sequestration higher than expected, even if still highly uncertain. Further investigations are needed, particularly to better address the role of savannas and tropical forests. The current CarboAfrica network of carbon measurements could provide future unique data sets for better estimating the African carbon balance.

scholarly journals Implementation of REDD+ in sub-Saharan Africa: state of knowledge, challenges and opportunities

2011 ◽  
Vol 16 (4) ◽  
pp. 381-404 ◽  
Author(s):  
MATIEU HENRY ◽  
DANAE MANIATIS ◽  
VINCENT GITZ ◽  
DAVID HUBERMAN ◽  
RICCARDO VALENTINI
Keyword(s):  
Land Use ◽  
Carbon Stock ◽  
Forest Cover ◽  
Carbon Sink ◽  
Forest Degradation ◽  
Forest Carbon ◽  
Sub Saharan Africa ◽  
Forest Cover Change ◽  
Forest Carbon Stock ◽  
Sub Saharan

ABSTRACTDeforestation and forest degradation represent an important part of global CO2 emissions. The identification of the multiple drivers of land-use change, past and present forest cover change and associated carbon budget, and the presence of locally adapted systems to allow for proper monitoring are particularly lacking in sub-Saharan Africa (SSA). Any incentive system to reduce emissions from deforestation and forest degradation (REDD+) will have to overcome those limits. This paper reviews the main challenges to implementing effective REDD+ mitigation activities in SSA. We estimate that SSA is currently a net carbon sink of approximately 319 TgCO2 yr−1. Forest degradation and deforestation put the forest carbon stock at risk (mean forest carbon stock is 57,679 TgC). Our results highlight the importance of looking beyond the forest sector to ensure that REDD+ efforts are aligned with agricultural and land-use policies.

scholarly journals Woody encroachment and forest degradation in sub-Saharan Africa's woodlands and savannas 1982–2006

2013 ◽  
Vol 368 (1625) ◽  
pp. 20120406 ◽  
Author(s):  
Edward T. A. Mitchard ◽  
Clara M. Flintrop
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Forest Degradation ◽  
Dry Season ◽  
Congo Basin ◽  
Sub Saharan Africa ◽  
Woody Encroachment ◽  
Small Scale ◽  
The North ◽  
Sub Saharan

We review the literature and find 16 studies from across Africa's savannas and woodlands where woody encroachment dominates. These small-scale studies are supplemented by an analysis of long-term continent-wide satellite data, specifically the Normalized Difference Vegetation Index (NDVI) time series from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset. Using dry-season data to separate the tree and grass signals, we find 4.0% of non-rainforest woody vegetation in sub-Saharan Africa (excluding West Africa) significantly increased in NDVI from 1982 to 2006, whereas 3.52% decreased. The increases in NDVI were found predominantly to the north of the Congo Basin, with decreases concentrated in the Miombo woodland belt. We hypothesize that areas of increasing dry-season NDVI are undergoing woody encroachment, but the coarse resolution of the study and uncertain relationship between NDVI and woody cover mean that the results should be interpreted with caution; certainly, these results do not contradict studies finding widespread deforestation throughout the continent. However, woody encroachment could be widespread, and warrants further investigation as it has important consequences for the global carbon cycle and land–climate interactions.

scholarly journals Efficiency of charcoal production in Sub-Saharan Africa: solutions beyond the kiln

2019 ◽  
Vol 340 ◽  
Author(s):  
Jolien Schure ◽  
François Pinta ◽  
Paolo Omar Cerutti ◽  
Lwanga Kasereka-Muvatsi
Keyword(s):  
Present Article ◽  
Sub Saharan Africa ◽  
Charcoal Production ◽  
Afrique Subsaharienne ◽  
Renforcement Des Capacités ◽  
Du Bois ◽  
République Démocratique Du Congo ◽  
Sub Saharan

Le charbon de bois restera une source d’énergie importante en Afrique subsaharienne dans un avenir prévisible, le présent article se concentre sur l’amélioration de l’efficacité de la carbonisation comme contribution à des chaînes de valeur plus durables du charbon de bois. Alors que l’efficacité de la conversion du bois en charbon est souvent considérée comme une question technique de performance des fours, cette étude vise à mettre en lumière le rôle d’un contexte institutionnel favorable et les capacités des acteurs impliqués. Sont d’abord passées en revue les initiatives visant à améliorer la production de charbon de bois dans différents pays d’Afrique subsaharienne. Nous comparons ensuite les données sur les processus de carbonisation dans deux zones en République démocratique du Congo : Yangambi et le Plateau de Bateke. Les principales conclusions sont les suivantes : 1) l’amélioration des techniques de carbonisation permet de réaliser d’importants gains en termes de taux de conversion du bois en charbon, mais le succès dépend en grande partie de l’adéquation des solutions de four en fonction du contexte, de la capacité et de la sensibilisation des producteurs et du contexte institutionnel favorable ; 2) le renforcement des capacités des opérateurs et des autres parties prenantes nécessite des techniques de four efficaces, mais aussi une sensibilisation accrue aux avantages et aux options d’approvisionnement durable, le renforcement des compétences financières et de gestion des organisations de producteurs et l’amélioration du transport, de la manutention et de la commercialisation ; 3) le statut illégal ou informel des producteurs de charbon de bois en Afrique subsaharienne nuit à l’efficacité des processus de production du charbon, tandis qu’un cadre institutionnel adéquat facilite l’accès des producteurs aux permis et au financement, fournit une fiscalité claire avec des incitations pour des pratiques plus durables et relie les exigences techniques en termes de carbonisation aux sources et utilisations finales durables. Le succès ou l’échec des techniques de carbonisation améliorées et les résultats socio-écologiques connexes sont déterminés conjointement par les solutions qui incluent les aspects de renforcement des capacités, d’acceptabilité et d’institutions favorables identifiés dans cet article. La poursuite du développement de ces solutions en partenariat avec les producteurs accroît le potentiel de chaînes de valeur plus durables pour le bois-énergie.

scholarly journals Improving operational land surface model canopy evapotranspiration in Africa using a direct remote sensing approach

2013 ◽  
Vol 17 (3) ◽  
pp. 1079-1091 ◽  
Author(s):  
M. Marshall ◽  
K. Tu ◽  
C. Funk ◽  
J. Michaelsen ◽  
P. Williams ◽  
...  
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Time Series ◽  
Hybrid Model ◽  
Land Surface ◽  
Vegetation Indices ◽  
Land Surface Model ◽  
Sub Saharan Africa ◽  
Surface Model ◽  
Sub Saharan

Abstract. Climate change is expected to have the greatest impact on the world's economically poor. In the Sahel, a climatically sensitive region where rain-fed agriculture is the primary livelihood, expected decreases in water supply will increase food insecurity. Studies on climate change and the intensification of the water cycle in sub-Saharan Africa are few. This is due in part to poor calibration of modeled evapotranspiration (ET), a key input in continental-scale hydrologic models. In this study, a remote sensing model of transpiration (the primary component of ET), driven by a time series of vegetation indices, was used to substitute transpiration from the Global Land Data Assimilation System realization of the National Centers for Environmental Prediction, Oregon State University, Air Force, and Hydrology Research Laboratory at National Weather Service Land Surface Model (GNOAH) to improve total ET model estimates for monitoring purposes in sub-Saharan Africa. The performance of the hybrid model was compared against GNOAH ET and the remote sensing method using eight eddy flux towers representing major biomes of sub-Saharan Africa. The greatest improvements in model performance were at humid sites with dense vegetation, while performance at semi-arid sites was poor, but better than the models before hybridization. The reduction in errors using the hybrid model can be attributed to the integration of a simple canopy scheme that depends primarily on low bias surface climate reanalysis data and is driven primarily by a time series of vegetation indices.

scholarly journals An outlook on the Sub-Saharan Africa carbon balance

2009 ◽  
Vol 6 (10) ◽  
pp. 2193-2205 ◽  
Author(s):  
A. Bombelli ◽  
M. Henry ◽  
S. Castaldi ◽  
S. Adu-Bredu ◽  
A. Arneth ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Agricultural Sector ◽  
Fire Regime ◽  
Forest Degradation ◽  
Sub Saharan Africa ◽  
Data Sets ◽  
Cycle System ◽  
Biogeochemical Models ◽  
Biogenic Carbon ◽  
Sub Saharan

Abstract. This study gives an outlook on the carbon balance of Sub-Saharan Africa (SSA) by presenting a summary of currently available results from the project CarboAfrica (namely net ecosystem productivity and emissions from fires, deforestation and forest degradation, by field and model estimates) supplemented by bibliographic data and compared with a new synthesis of the data from national communications to UNFCCC. According to these preliminary estimates the biogenic carbon balance of SSA varies from 0.16 Pg C y−1 to a much higher sink of 1.00 Pg C y−1 (depending on the source data). Models estimates would give an unrealistic sink of 3.23 Pg C y−1, confirming their current inadequacy when applied to Africa. The carbon uptake by forests and savannas (0.34 and 1.89 Pg C y−1, respectively,) are the main contributors to the resulting sink. Fires (0.72 Pg C y−1) and deforestation (0.25 Pg C y−1) are the main contributors to the SSA carbon emissions, while the agricultural sector and forest degradation contributes only with 0.12 and 0.08 Pg C y−1, respectively. Savannas play a major role in shaping the SSA carbon balance, due to their large extension, their fire regime, and their strong interannual NEP variability, but they are also a major uncertainty in the overall budget. Even if fossil fuel emissions from SSA are relative low, they can be crucial in defining the sign of the overall SSA carbon balance by reducing the natural sink potential, especially in the future. This paper shows that Africa plays a key role in the global carbon cycle system and probably could have a potential for carbon sequestration higher than expected, even if still highly uncertain. Further investigations are needed, particularly to better address the role of savannas and tropical forests and to improve biogeochemical models. The CarboAfrica network of carbon measurements could provide future unique data sets for better estimating the African carbon balance.

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