Carbon Sequestration Opportunities Research Articles

Prosopis juliflora management and grassland restoration in Baringo County, Kenya: Opportunities for soil carbon sequestration and local livelihoods

Abstract Climate change, land degradation and invasive alien species (IAS) threaten grassland ecosystems worldwide. IAS clearing and grassland restoration would help to reduce the negative effects of IAS, restore the original vegetation cover and sustain livelihoods while contributing to climate change mitigation, but uncertain financial benefits to local stakeholders hamper such efforts. This study assessed where and when net financial benefit could be realized from Prosopis juliflora management and subsequent grassland restoration by combining ecological, social and financial information. Impacts of Prosopis invasion and grassland degradation on soil organic carbon (SOC) in nine sublocations in Baringo County, Kenya, were evaluated. Then the financial impacts of Prosopis removal and grassland restoration in the area were calculated and spatially explicit management scenarios for each sublocation modelled, combining geographical information derived from satellite images taken in different years of the invasion with SOC data and socio‐economic data collected in the sublocations. The expanding Prosopis distribution and density since 1995 have increased cumulated SOC storage on former bare land or degraded grasslands. On former pristine or restored grasslands, however, Prosopis invasion has reduced total SOC storage. Prosopis removal and grassland restoration are predicted to yield financial benefits through charcoal made from removed trees, increased cattle numbers and carbon credits. However, a trade‐off between increased SOC and net financial benefit was found. The predicted net SOC increase would contribute around one‐tenth, at most, to the net financial benefit. The available budget, based on Baringo households’ average willingness to pay, would enable removal, on average, of one‐fifth of Prosopis per sublocation in a single year. A larger area can be cleared if Prosopis is sparse than if it is dense. The analyses show that in some sublocations, households’ annual investments could result in restoration of all former grassland areas. Synthesis and applications. This study shows how integrating and linking detailed ecological, social and financial geodata to develop accurate and realistic invasive alien species management scenarios can illustrate costs and benefits of management interventions in a spatial context. Such scenarios should be used more extensively to support land management decisions.

Ecosystem service pattern of Fuzhou City based on ecosystem service bundles.

Based on InVEST model, recreational opportunity spectrum, factor analysis, cold and hot spot analysis, SOFM neural network, relief degree of land surface (RDLS) methods, we evalua-ted six kinds of ecosystem service in Fuzhou City and analyzed the trade-offs and synergies among them, with the aim to clarify the dominant services and the spatial pattern of service bundles in different topographical regions. The results showed substantial spatial heterogeneity in different ecosystem services of Fuzhou City. Water yield, carbon sequestration, habitat quality, and recreational opportunities were totally high, whereas the supply of agricultural products and soil and water conservation were low and substantial differences. The interaction between water yield and cultural servi-ces were synergies, but trade-offs occurred among regulating service, supporting service and agricultural products service. There were spatial aggregations for both trade-offs and synergies. Ecosystem service bundles could be divided into suburban recreation bundle, water conservation bundle, agricultural products bundle, urban life bundle, and forest ecological conservation bundle. The composition of service bundles clusters was different under different RDLS, with obvious spatial heterogeneity.

Hydroponic fodder and greenhouse gas emissions: a potential avenue for climate mitigation strategy and policy development

This research explores the potential hydroponic systems have for contributing to climate mitigation in fodder agriculture. Using British Columbia (BC) and Alberta as case studies, the study compares greenhouse gas (GHG) emissions and carbon sequestration potential of hydroponically grown sprouted barley fodder to conventional barley grain fodder. GHG emissions were examined through scenarios that assumed Alberta to be the main barley producer, while exploring different situations of BC and Alberta as consumers, distributed/centralized hydroponic systems, and renewable/nonrenewable energy. Carbon sequestration opportunities were examined through scenarios that explored the land sparing potential of transitioning from conventional to hydroponic barley and shifts from tillage to no-tillage practices. Sensitivity analyses were done to examine how changes in hydroponic seed-to-fodder output and energy consumption affect the systems’ climate mitigation potential. The results indicated that incorporating hydroponic systems into barley production has the potential to reduce GHG emissions, given seed-to-fodder output and energy consumption are maintained at certain levels and the systems are powered by renewable energy. Results also showed that hydroponic farming can provide greater carbon sequestration opportunities than simply shifting to no-tillage farming. The research indicates that hydroponic fodder farming could contribute to climate mitigation objectives if complemented with effective energy and land use policies.

Preliminary Assessment of Carbon and Nitrogen Sequestration Potential of Wildfire-Derived Sediments Stored by Erosion Control Structures in Forest Ecosystems, Southwest USA

The role of pyrogenic carbon (PyC) in the global carbon cycle is still incompletely characterized. Much work has been done to characterize PyC on landforms and in soils where it originates or in “terminal” reservoirs such as marine sediments. Less is known about intermediate reservoirs such as streams and rivers, and few studies have characterized hillslope and in-stream erosion control structures (ECS) designed to capture soils and sediments destabilized by wildfire. In this preliminary study, organic carbon (OC), total nitrogen (N), and stable isotope parameters, δ13C and δ15N, were compared to assess opportunities for carbon and nitrogen sequestration in postwildfire sediments (fluvents) deposited upgradient of ECS in ephemeral- and intermittent-stream channels. The variability of OC, N, δ13C, and δ15N were analyzed in conjunction with fire history, age of captured sediments, topographic position, and land cover. Comparison of samples in 2 watersheds indicates higher OC and N in ECS with more recently captured sediments located downstream of areas with higher burn severity. This is likely a consequence of (1) higher burn severity causing greater runoff, erosion, and transport of OC (organic matter) to ECS and (2) greater cumulative loss of OC and N in older sediments stored behind older ECS. In addition, C/N, δ13C, and δ15N results suggest that organic matter in sediments stored at older ECS are enriched in microbially processed biomass relative to those at newer ECS. We conservatively estimated the potential mean annual capture of OC by ECS, using values from the watershed with lower levels of OC, to be 3 to 4 metric tons, with a total potential storage of 293 to 368 metric tons in a watershed of 7.7 km2 and total area of 2000 ECS estimated at 2.6 ha (203-255 metric tons/ha). We extrapolated the OC results to the regional level (southwest USA) to estimate the potential for carbon sequestration using these practices. We estimated a potential of 0.01 Pg, which is significant in terms of ecosystem services and regional efforts to promote carbon storage.

A review on steel slag valorisation via mineral carbonation

Alkaline slags, a waste product of steel industry, provide an opportunity for carbon sequestration and creation of value at the same time. This requires an understanding of the mechanisms of leaching and carbonation.

Environmental control on carbon exchange of natural and planted forests in Western Himalayan foothills of India

India has committed to increase carbon sequestration by forests under the Nationally Determined Contributions (NDC). However, the CO2 carbon exchange characteristics (Gross Primary Productivity, Net Ecosystem Exchange, and Ecosystem respiration) of Indian forests are poorly understood. Immense carbon sequestration opportunities exist with the natural as well as planted forests. Therefore, it becomes vital to assess the potential of existing forests (natural and planted) by means of the most accurate and reliable methods of eddy covariance (EC). It is also important to know the eco-physiological response of the forests towards diurnal, seasonal, and yearly changes in the prevailing environmental conditions. We analyzed CO2 carbon exchange characteristics of a mature moist deciduous forest and a young mixed deciduous plantation located in the sub-tropical climate regime in the western Himalayan foothills of India with the help of co-located EC measurements (2016 to 2018). The study reveals that both the mature forest (− 719.43 gCm− 2year− 1) and young plantation (− 467.49 gC m− 2 year− 1) are absorbing a significant amount of atmospheric CO2 carbon. The maximum uptake of atmospheric CO2 occurred during the post-monsoon season in both the forests. The minimum NEE of the mixed deciduous plantation was observed during the leaf fall period while the NEE of the moist deciduous forest was the lowest in monsoon due to a higher respiration rate during monsoon. Among the environmental factors, soil moisture showed maximum control on the productivity of both the forest ecosystems. The value reported in this study can help Forest Survey of India in establishing/assessing emission factor for these particular forest types. This study can also help forest managers in carbon assessment of plantation under NDC.

Assessing land-based mitigation implications for biodiversity

The Paris Agreement to keep global temperature increase to well-below 2 °C and to pursue efforts to limit it to 1.5 °C requires to formulate ambitious climate-change mitigation scenarios to reduce CO2 emissions and to enhance carbon sequestration. These scenarios likely require significant land-use change. Failing to mitigate climate change will result in an unprecedented warming with significant biodiversity loss. The mitigation potential on land is high. However, how land-based mitigation options potentially affect biodiversity is poorly understood. Some land-based mitigation options could also counter the biodiversity loss. Here we reviewed the recently scientific literature to assess twenty land-based mitigation options that are implemented in different mitigation pathways to comply with the Paris Agreement for their biodiversity impacts by using the Mean Species Abundance (MSALU) indicator for land use. We showed the likely land-use transition and potential MSALU changes for each option, compared their carbon sequestration opportunities (tC per ha) and assessed the resulting biodiversity change in two case scenarios. Our results showed that most options benefit biodiversity. Reforestation of cultivated and managed areas together with restoration of wetlands deliver the largest MSALU increases, if land is allowed to reach a mature state over time. A quarter of the assessed options, including intensification of agricultural areas and bioenergy with carbon capture and storage, decreased MSALU. Options, such as afforestation and reduced deforestation, either positively or negatively affected MSALU. This depends on their local implementation and adopted forest-conservation schemes. Comparing the different options showed that avoiding deforestation by implementing agroforestry at the expense of pastures delivered both the largest MSALU increases and the highest carbon sequestration opportunities. However, agroforestry that leads to deforestation, enhanced carbon sequestration slightly but with a marginal MSALU increase. This stresses the importance of avoiding forest conversion. Our study advances the understanding on current and future benefits and adverse effects of land-based mitigation options on biodiversity. This certainly helps biodiversity conservation and determines the regions with large land-based mitigation potential.

From Farms to Forests: Landscape Carbon Balance after 50 Years of Afforestation, Harvesting, and Prescribed Fire

Establishing reliable carbon baselines for landowners desiring to sustain carbon sequestration and identify opportunities to mitigate land management impacts on carbon balance is important; however, national and regional assessments are not designed to support individual landowners. Such baselines become increasingly valuable when landowners convert land use, change management, or when disturbance occurs. We used forest inventories to quantify carbon stocks, estimate annual carbon fluxes, and determine net biome production (NBP) over a 50-year period coinciding with a massive afforestation effort across ~80,000 ha of land in the South Carolina Coastal Plain. Forested land increased from 48,714 ha to 73,824 ha between 1951 and 2001. Total forest biomass increased from 1.73–3.03 Gg to 17.8–18.3 Gg, corresponding to biomass density increases from 35.6–62.2 Mg ha−1 to 231.4–240.0 Mg ha−1. Harvesting removed 1340.3 Gg C between 1955 and 2001, but annual removals were variable. Fire consumed 527.1 Gg C between 1952 and 2001. Carbon exported by streams was <0.5% of total export. Carbon from roots and other harvested material that remained in-use or in landfills comprised 49.3% of total harvested carbon. Mineral soil carbon accounted for 41.6 to 50% of 2001 carbon stocks when considering depths of 1.0 or 1.5 m, respectively, and was disproportionately concentrated in wetlands. Moreover, we identified a soil carbon deficit of 19–20 Mg C ha−1, suggesting opportunities for future soil carbon sequestration in post-agricultural soils. Our results provide a robust baseline for this site that can be used to understand how land conversion, forest management, and disturbance impacts carbon balance of this landscape and highlight the value of these baseline data for other sites. Our work also identifies the need to manage forests for multiple purposes, especially promotion of soil carbon accumulation in low-density pine savannas that are managed for red-cockaded woodpeckers and therefore demand low aboveground carbon stocks.

Guiding carbon farming using interdisciplinary mixed methods mapping

Abstract In recognition of the need to address complex environmental problems, some ecological studies have adopted social research methods to better understand the complexity of social‐ecological systems management. The overwhelming majority of these studies stop short of fully embracing qualitative methodologies. The lack of integrative social and natural science data for a topic such as soil carbon farming is problematic as theoretical carbon sequestration opportunities identified through soil mapping and process‐based models can fail to deliver the sequestration levels promised when introduced on‐the‐ground. Such mapping needs to account for the human factors involved in delivering increased soil carbon on‐farm. Here, we develop a mixed methods mapping approach to explore the potential for increasing soil carbon stocks on upland farms in the UK. Our approach considers ecological and social complexity through application of soil science, ecology, participant observation, interviews and a focus group. Our maps revealed landscapes that are full of carbon farming opportunity, but contain previously hidden barriers to the delivery of increased soil carbon. For example, they revealed that carbon farming can be considered by farmers to work in opposition to perceived ‘good farming’ practices and be correlated with increased incidents of livestock disease. We also discovered that the use of maps in research can be problematic as they can close down discussion and exclude local representation of an area. Trialling an interdisciplinary mixed methods approach produced new, deeper and more richly‐textured understandings about how soil carbon management is produced socially as well as ecologically on upland livestock farms. Our findings have potential to improve the success of future carbon farming initiatives by incorporating farmer knowledge and social drivers of implementation. A plain language summary is available for this article.

Biochar from residual biomass as a concrete filler for improved thermal and acoustic properties

The current imbalance of carbon in the atmosphere is stimulating the search for carbon sequestration opportunities and for alternative processes and products with a reduced carbon footprint. Biochar, produced from residual biomass of the bio-ethanol industry (Dry Distillers Grains), was added as filler to a standard concrete, aiming at finding potential solutions for simultaneous carbon sequestration and improved properties and performance of the concrete. The addition of biochar resulted in a linear decrease in concrete density, with a concrete density of 1454 kg/m3 for 15 wt% biochar. The addition of biochar also considerably increased the sound absorption coefficient of concrete across the range of 200–2000 Hz, as it created pore networks within the concrete. The thermal conductivity of the concrete showed the largest reductions with 2 wt% of biochar, reaching lows of 0.192 W/(m·K). Finally, the incorporation of biochar showed a detrimental effect on the compressive strength of the concrete, which would put bio-enhanced concretes in the low-strength concrete classification category.

The Impact of Biochar Incorporation on Inorganic Nitrogen Fertilizer Plant Uptake; An Opportunity for Carbon Sequestration in Temperate Agriculture

Field studies of biochar addition to soil and nutrient cycling using 15N fertilizers in temperate agriculture are scant. These data are required in order to make evidence based assessments. This study was conducted to test the hypothesis that biochar application can increase crop yields through improving the nitrogen uptake and utilization of added inorganic fertilizer, whilst sequestering significant quantities of carbon. Results showed that although biochar addition led to significant spring barley grain yield increases in the first year of biochar application, an unusually dry year; this was possibly not solely the result of improved nitrogen uptake, as total crop N was similar in both treatments. Results suggested it was improved water utilization, indicated by the crop carbon isotope values and soil moisture characteristics. In the second year, there were no significant effects of the previous year’s biochar addition on the sunflower yield, N status, fertilizer recovery or any signs of improved water utilization. These data add to a growing body of evidence, suggesting that biochar addition has only slightly positive or neutral effects on crop growth and fertilizer retention but has the potential to sequester vast amounts of carbon in the soil with minimal yield losses in temperate agriculture.

An approach to estimating forest biomass change over a coniferous forest landscape based on tree-level analysis from repeated lidar surveys

ABSTRACTForests represent a significant opportunity for carbon sequestration, but quantifying biomass change at the landscape scale and larger remains a challenge. Here we develop an approach based on repeated tree-level analysis using high-resolution airborne lidar (around 8 pulses/m2). The study area was 53 km2 of actively managed coniferous forestland in the Coast Range Mountains in western Oregon. The study interval was 2006–2012. Tree heights and crown areas were determined from the lidar data using point cloud clustering. Biomass per tree was estimated with allometry. Tree-level data (N = 14,709) from local USDA Forest Service Forest Inventory and Analysis plots provided the basis for the allometry. Estimated biomass change over the 6-year interval averaged −1.3 kg m−2 year−1, with the average gain in undisturbed areas of 1.0 kg m−2 year−1. Full harvest occurred on 3% of the area per year. For surviving trees, the mean change in height was 0.5 m year−1 (SD = 0.3) and the mean change in biomass was 45.3 kg year−1 (SD = 6.7). The maximum bin-average increase in biomass per tree (57.3 kg year−1) was observed in trees of intermediate height (35–40 m). In addition to high spatially resolved tracking of forest biomass change, potential applications of repeated tree-level surveys include analysis of mortality. In this relatively productive forest landscape, an interval of 6 years between lidar acquisitions was adequate to resolve significant changes in tree height and area-wide biomass.

Increased CO2 fluxes from a sandy Cambisol under agricultural use in the Wendland region, Northern Germany, three years after biochar substrates application

AbstractIn recent years, biochar has been discussed as an opportunity for carbon sequestration in arable soils. Field experiments under realistic conditions investigating the CO2 emission from soil after biochar combined with fertilizer additions are scarce. Therefore, we investigated the CO2 emission and its 13C signature after addition of compost, biogas digestate (originating from C4 feedstock) and mineral fertilizer with and without biochar (0, 3, 10, 40 Mg biochar/ha) to a sandy Cambisol in Northern Germany. Biomass residues were pyrolized at ~650°C to obtain biochar with C3 signature. Gas samples were taken biweekly during the growing season using static chambers three years after biochar substrate addition. The CO2 concentration and its δ13C isotope signature were measured using a gas chromatograph coupled to an isotope ratio mass spectrometer. Results showed increased CO2 emission (30%–60%) when high biochar amount (40 Mg/ha) was applied three years ago together with mineral fertilizer and biogas digestate. On average, 59% of the emitted CO2 had a C3 signature (thus, deriving from biochar and/or soil organic matter), independent of the amount of biochar added. In addition, our results clearly demonstrated that only a small amount of released CO2 derived from biochar. The results of this field experiment suggest that biochar most likely stimulates microbial activity in soil leading to increased CO2 emissions derived from soil organic matter and fertilizers mineralization rather than from biochar. Nevertheless, compared to the amount of carbon added by biochar, additional CO2 emission is marginal corroborating the C sequestration potential of biochar.

Soil organic carbon stocks and their determining factors in the Dano catchment (Southwest Burkina Faso)

Although the evaluation of soil organic carbon (SOC) stocks across different types of land use and major reference soil groups is essential for mitigating climate change, there remains, to date, limited comprehensive understanding of whole tropical soil profiles. Therefore, this study aimed to explain the amount of SOC stocks in different land-use systems and across various soil groups, as well as its spatial pattern in the topsoil (0–30 cm) and subsoil (30–100 cm) within the savannah zone of Burkina Faso. Roughly 70 soil profiles were considered along with additional auger sampling to account for spatial variation in both cropland (CR) and savannah (SA). The machine learning technique random forest regression (RFR) and multiple linear regression (MLR) were used for modeling the surface and subsurface SOC stocks. For model calibration, covariates including land use, topographic, texture, and climatic data were considered as surrogate for soil forming factors. The prediction maps produced by the calibrated models were validated by an independent dataset. The results indicated that about 53% of the SOC stock over 1 m depth was held in the upper 30 cm. Only a marginal difference was recorded between the topsoil SOC stock in SA (41.4 t C ha−1) and CR (39.1 t C ha−1) soils. For the subsoil, a significant difference (p < 0.05) was observed between the SOC stock of CR soils recording about 40.2 t C ha−1 and SA soils with 26.3 t C ha−1. Among the reference soil groups, the Gleysols located at lower elevation positions revealed the highest SOC stocks over 0–30 cm (44 t C ha−1) and 100 cm depth (86.6 t C ha−1). The Stagnosols (45.2 t C ha−1) followed by the Gleysols (42.7 t C ha−1) recorded the highest SOC stocks over 30–100 cm. The variability of SOC stock in the topsoil was primarily related to site-specific elements, such as particle-size fraction and wetness index, while its distribution in the subsoil was mainly associated with the topographical orientation represented by the slope aspect. Compared to the MLR, RFR estimated mean top- and subsoil SOC stocks of the catchment fairly well, along with lower statistical error metrics, though extreme values were not covered. Nevertheless, the findings on SOC stocks reinforce the view that the semi-arid ecosystems of West Africa still offer a significant opportunity for carbon sequestration for both topsoil and subsoil, and these results represent a baseline for future modeling of SOC dynamics in the region.

Introduction to special section: Characterization of hydrocarbon and geothermal resource potential and carbon sequestration opportunities of the Pannonian Basin

Introduction to special section: Characterization of hydrocarbon and geothermal resource potential and carbon sequestration opportunities of the Pannonian Basin

A sustainability framework for engineering carbon capture soil in transport infrastructure

Recent research has demonstrated considerable potential for artificial soils to be designed for carbon capture. The incorporation of quarry fines enables the accumulation of atmospheric CO2 in newly formed carbonate minerals. However, the rate and trajectory of carbon accumulation has been little studied. The relative contribution of biotic (e.g. vegetation, micro-organisms) and abiotic (water, light, temperature) factors to the carbonation process is also unknown. This article presents a sustainability framework which aims to determine the multi-functionality of soils to which fines have been added not only in their role as carbon sinks but also in their role of providing additional opportunities for improvement to ecosystem services. Such frameworks are required specifically where land designed for CO2 capture must also provide other ecosystem services, such as flood mitigation and biodiversity conservation. land within linear transport infrastructure provides a case study, focusing on 238,000 ha of vegetated land associated with roadside verges in the UK. Hypothetically this area could remove 2.5 t CO2 per year from the atmosphere, equivalent to 1% 2011 total UK emissions or 2% of current transport emissions and saving an equivalent of £1.1 billion in non-traded mitigation values. roadside verges should be designed to minimize flooding onto the highway and perform other important functions such as removal of dust and suspended solids from surface waters. Vegetation on 30,000 ha of railway land also provides opportunities for carbon sequestration, but management of this vegetation is subject to similar constraints to protect the rail tracks from debris extending from autumn leaves to fallen trees.

Delta‐Flux: An Eddy Covariance Network for a Climate‐Smart Lower Mississippi Basin

Core Ideas The Lower Mississippi River Basin (LMRB) is agriculturally important and ecologically unique. The Delta‐Flux network will coordinate the activities of 17 eddy covariance towers. The network addresses the need for scaled C and water cycle observations. The network aims to promote sustainable, climate‐smart land management. Delta‐Flux is open to collaborators from strategic sites and relevant disciplines. Networks of remotely monitored research sites are increasingly the tool used to study regional agricultural impacts on carbon and water fluxes. However, key national networks such as the National Ecological Observatory Network and AmeriFlux lack contributions from the Lower Mississippi River Basin (LMRB), a highly productive agricultural area with opportunities for soil carbon sequestration through conservation practices. The authors describe the rationale to create the new Delta‐Flux network, which will coordinate efforts to quantify carbon and water budgets at seventeen eddy covariance flux tower sites in the LMRB. The network structure will facilitate climate‐smart management strategies based on production‐scale and continuous measurements of carbon and water fluxes from the landscape to the atmosphere under different soil and water management conditions. The seventeen instrumented field sites are expected to monitor fluxes within the most characteristic landscapes of the target area: row‐crop fields, pasture, grasslands, forests, and marshes. The network participants are committed to open collaboration and efficient regionalization of site‐level findings to support sustainable agricultural and forestry management and conservation of natural resources.

Greenhouse gas mitigation potential of shelterbelts: estimating farm-scale emission reductions using the Holos model

Shelterbelts provide an opportunity for carbon (C) sequestration and have the potential to mitigate agricultural greenhouse gas (GHG) emissions. However, the influence of shelterbelts on GHG emissi...

Revegetation in China’s Loess Plateau is approaching sustainable water resource limits

Revegetation of degraded ecosystems provides opportunities for carbon sequestration and bioenergy production(1,2). However, vegetation expansion inwater-limited areas creates potentially conflicting demands for water between the ecosystem and humans(3). Current understanding of these competing demands is still limited(4). Here, we study the semi-arid Loess Plateau in China, where the 'Grain to Green' large-scale revegetation programme has been in operation since 1999. As expected, we found that the new planting has caused both net primary productivity (NPP) and evapotranspiration (ET) to increase. Also the increase of ET has induced a significant (p < 0.001) decrease in the ratio of river runoff to annual precipitation across hydrological catchments. From currently revegetated areas and human water demand, we estimate a threshold of NPP of 400 +/- 5 g C m(-2) yr(-1) above which the population will suffer water shortages. NPP in this region is found to be already close to this limit. The threshold of NPP could change by 36% in the worst case of climate drying and high human withdrawals, to C 43% in the best case. Our results develop a new conceptual framework to determine the critical carbon sequestration that is sustainable in terms of both ecological and socio-economic resource demands in a coupled anthropogenic-biological system.

Modelling the forest and woodland-irrigation nexus in tropical Africa: A case study in Benin

Major increases in food production are needed to feed the rapidly growing population of sub-Saharan Africa. Increased application of irrigation has often been identified as one of the main pathways to agricultural intensification. However, water flows, in particular during the dry season, often depend upon the water regulation services provided by forests and woodlands which are increasingly subject to land conversion as well as degradation from the overexploitation of wood resources. Insight in the trade-off between land conversion in sub-Saharan African uplands and sustaining water flows is, therefore, urgently needed. In this paper, we develop a general modelling approach for analysing the effects of deforestation on the availability of water for irrigation at the watershed level, and we apply the approach to the Upper Ouémé watershed in Benin. We use controlled modelling experiments based on the Soil and Water Assessment Tool (SWAT) in addition to copula functions to quantify surface water availability and irrigation potential under prevailing forest and woodland cover as well as varying forest and woodland extents. We undertake these comparative analyses for two irrigation development scenarios that are defined based on different levels of sustained water flows in the Upper Ouémé river network. Our analyses show that conservation of prevailing forests and woodlands in the Upper Ouémé watershed is needed to allow the development of 80% (15,000ha) or 71% (20,000ha) of the irrigation potential in the dry season depending on the scenario. At the prevailing forest and woodland extent, the loss of around 40ha of forest and woodland area reduces the irrigation potential by 1ha depending on the scenario. Our irrigation potential calculations are based on the water requirements of rice which is the most water intensive crop grown in the study area. For other crops, the ratio will be lower (i.e. less forest and woodland area is required to sustain 1ha of irrigated crop production). The relation between forest and woodland extent and irrigation potential is, however, not linear, and more hectares of forest and woodland are needed to support 1ha of irrigated crop production with increasing deforestation. This is relevant for trade-off analysis, where it needs to be noted that the forests and woodlands not only generate water regulation services but also provide other ecosystem services including fuelwood, timber, opportunities for livestock grazing and carbon sequestration.