Global climate change and environmental degradation highlight the need for institutions of sustainability. In particular, there is increased interest in the potential of payments for environmental services (PES) to improve incentives for sustainable land management. Although smallholder land users can be efficient producers of environmental services of value to larger communities and societies, experience shows that the international and national institutions that govern PES are often designed in ways that entail transaction costs that cannot be feasibly met by individual smallholders. This chapter presents a conceptual framework to examine the inter-linkages between property rights, collective action, payment for environmental services, and the welfare of smallholder land users, examining how these play out in the contexts of carbon sequestration, biodiversity, and watershed functions. Greater consideration of the linkages between PES and other rural institutions can lead to more equitable outcomes, particularly by (1) suggesting how collective action can be used to overcome transaction costs and barriers to participation by smallholders and (2) identifying mechanisms through which managers of small private parcels or areas of common property can be rewarded for environmental stewardship through PES.
Tag: Carbon sequestration
Quantifying tree biomass carbon stocks and fluxes in agricultural landscapes
This chapter presents methods to quantify carbon stocks and carbon stock changes in biomass of trees in agricultural landscapes. Specifically it assesses approaches for their applicability to smallholder farms and other tree enterprises in agricultural landscapes. Measurement techniques are evaluated across three criteria: accuracy, cost, and scale. We then recommend techniques appropriate for users looking to quantify carbon in tree biomass at the whole-farm and landscape scales. A basic understanding of the carbon cycle and the concepts of biomass assessment is assumed.
Methods for environment: productivity trade-off analysis in agricultural systems
Trade-off analysis has become an increasingly important approach for evaluating system level outcomes of agricultural production and for prioritising and targeting management interventions in multi-functional agricultural landscapes. We review the strengths and weakness of different techniques available for performing trade-off analysis. These techniques, including mathematical programming and participatory approaches, have developed substantially in recent years aided by mathematical advancement, increased computing power, and emerging insights into systems behaviour. The strengths and weaknesses of the different approaches are identified and discussed, and we make suggestions for a tiered approach for situations with different data availability. This chapter is a modified and extended version of Klapwijk et al. (2014).
Grazing lands in Sub-Saharan Africa and their potential role in climate change mitigation: What we do and don’t know
In 2014, the USAID project ‘Grazing lands, livestock and climate resilient mitigation in Sub-Saharan Africa’ held twoworkshops, hosted by the Colorado State University, which brought together experts from around the world. Two reportsresulted from these workshops, one an assessment of the state of the science, and the other an inventory of related activitiesin the region to date.. In this short communication we summarize the main points of the first report – The state of thescience (Milne and Williams, 2015). A second report is in preparation.
Estimation of wet aggregation indices using soil properties and diffuse reflectance near infrared spectroscopy: An application of classification and regression tree analysis
Soil aggregation is critical for assessing soil health; however, conventional aggregation measurement is laborious and expensive. The performance of near infrared diffuse reflectance spectroscopy (NIR) and basic soil properties for estimation of wet aggregation indices was investigated. Two samples sets representing different soils from across Lake Victoria Basin in Kenya were used for the study. A model calibration set (n = 136) was obtained following a conditioned Latin hypercube sampling, and validation set (n = 120) using a spatially stratified random sampling strategy. Spectral measurements were obtained for air-dried (<2 mm) soil using a Fourier-transform NIR spectrometer. Soil laboratory reference data were also obtained for wet aggregation indices (WSA): macro, micro and unstable fractions using two different wet-sieving pretreatments. Soil properties were screened as candidate predictors of WSA using Classification and Regression Tree (CART regression) analysis. WSA were calibrated to soil predictors and to smoothed first derivative NIR spectra using partial least squares (PLS) regression. Key soil predictors were: soil organic carbon and pH water (macro), water dispersible clay (WDC) (micro) and exchangeable sodium (unstable). Full cross validation of NIR PLS prediction of stable macro, micro, unstable aggregates, and for WDC gave RPD (ratio of prediction deviation) of 1.4–2.0. Independent testing of NIR PLS gave RPD = 1.4 for macro and RPD = 1.2–1.0 for unstable and soil predictors. NIR could estimate macro and unstable fractions with moderate reliability, and; NIR was superior over soil properties for stability pedotransfer purposes. Further efforts should widely test performance for a wider range of soil types and calibration strategies for improved geographic transferability of models. © 2016 IAgrE
Linking climate change research with food security and poverty reduction in the tropics
Climate change is a reality and will affect the poor in developing countries in many ways. The effectiveness of global change research could be substantially improved by linking International Geosphere-Biosphere Programme (IGBP) study with Consultative Group on International Agricultural Research (CGIAR) centres based in the tropics. These centres are carrying interdisciplinary research and development on how to achieve food security and reduce rural poverty through the innovative management of natural resources. A CGIAR intercentre working group on climate change (ICWG-CC) identified joint opportunities that take advantage of the comparative advantages of both institutions. CGIAR centres will focus on adaptation and mitigation research in developing countries. A natural resource management research approach is suggested, which consists of six steps: (1) identifying and quantifying the extent of food insecurity, rural poverty and resource degradation; (2) conducting technological and policy research on economic and environmental functions; (3) optimising the trade-offs between global environmental benefits and private farmer benefits; (4) extrapolating and disseminating results, including research on policy implementation; (5) assessing impact and (6) providing feedback.Two examples of current CGIAR research illustrate this approach. Agroforestry alternatives to slash and burn (ASB) agriculture at tropical forest margins were identified and the trade-offs between carbon sequestration and farmer profitability provided options to policy makers. Land tenure problems were resolved with participatory policy research. Agroforestry practices sequester an additional 57 Mg C per ha, three times that of croplands or grasslands are able to do. Soil nutrient capital is being replenished in subhumid tropical Africa through improved leguminous tree fallows, rock phosphate and biomass transfers of Tithonia diversifolia, helping farmers to attain food security. Afterwards, when farmers shift to high-value tree or vegetable crop production, poverty is reduced. The transformation of low productivity croplands to sequential agroforestry is estimated to triple system carbon stocks in 20 years.
Carbon sequestration in tropical agroforestry systems
Removing atmospheric carbon (C) and storing it in the terrestrial biosphere is one of the options, which have been proposed to compensate greenhouse gas (GHG) emissions. Agricultural lands are believed to be a major potential sink and could absorb large quantities of C if trees are reintroduced to these systems and judiciously managed together with crops and/or animals. Thus, the importance of agroforestry as a land-use system is receiving wider recognition not only in terms of agricultural sustainability but also in issues related to climate change. The objective of this paper was to analyse C storage data in some tropical agroforestry systems and to discuss the role they can play in reducing the concentration of CO2 in the atmosphere. The Csequestration potential of agroforestry systems is estimated between 12 and 228Mgha-1 with amedian value of 95Mgha-1. Therefore, based on the earth’s area that is suitable for the practice (585-1215 × 106 ha), 1.1-2.2 Pg C could be stored in the terrestrial ecosystems over the next 50 years. Long rotation systems such as agroforests, homegardens and boundary plantings can sequester sizeable quantities of C in plant biomass and in long-lasting wood products. Soil C sequestration constitutes another realistic option achievable in many agroforestry systems. In conclusion, the potential of agroforestry for CO2 mitigation is well recognised. However, there are a number of shortcomings that need to be emphasised. These include the uncertainties related to future shifts in global climate, land-use and land cover, the poor performance of trees and crops on substandard soils and dry environments, pests and diseases such as nematodes. In addition, more efforts are needed to improve methods for estimating C stocks and trace gas balances such as nitrous oxide (N2O) and methane (CH4) to determine net benefits of agroforestry on the atmosphere
Carbon and economic benefits of community management of dry forests in Tigray, Ethiopia
Community management of forests may help meet human subsistence needs and mitigate climate change. The study was conducted to quantify the potential of community managed forests to accumulate carbon and simultaneous increase income. Twenty-four plots were randomly selected from managed natural forest, disturbed natural forest, exclosure and grazing land to quantify biomass and carbon. Tree and shrub biomass was estimated using a regression model while herbaceous biomass was determined using a total harvest. The impact of community forest on total income of the community was studied by taking landless sample households. A Propensity Score Matching (PSM) was conducted to measure the impact of the community forest on total income of the users. The estimated total biomass for managed natural forest, disturbed natural forest, exclosure and grazing land were 92.9 Mg ha-1, 33.4 Mg ha-1, 33.8 Mg ha-1 and 12.5 Mg ha-1, respectively. There was a significant difference in total biomass between the community forests and the grazing land (P<0.05). The carbon content of the living biomass for managed natural forest, disturbed natural forest and exclosure were estimated as, 43.6 Mg ha-1, 15.7 Mg ha-1, 15.9 Mg ha-1, while for open grazing the estimated carbon were 5.8 Mg ha-1. The carbon trading potential for managed natural forest, disturbed natural forest and exclosure was US
Carbon finance in extensively managed rangelands: issues in project, programmatic and sectoral approached
Considering their vast geographic area and the documented carbon (C) sequestration effects of a variety of rangeland management practices, there is considerable interest in the potential of C finance in rangelands, where it is still very much in its early stages. Pilot projects are essential to exploring this potential in practice. Ex ante assessments at the project level show areas of positive potential, but have identified several areas where documentation is insufficient, and critical constraints that exist in some contexts. This chapter summarizes these potentials and constraints, and then discusses opportunities and challenges in view of the major options currently being considered for a post-Kyoto agreement that includes agricultural land use: project, programmatic and sectoral approaches (including unilateral mitigation actions, supported mitigation actions and sectoral crediting approaches). The paper describes this emerging architecture for future mitigation options, and analyses the requirements for developing project, programmatic and sectoral approaches. It concludes by highlighting key actions required to promote the development of project, programmatic and sectoral approaches to rangeland-based mitigation
Effects of enclosure management on carbon sequestration, soil properties and vegetation attributes in East African rangelands
The use of enclosures has globally gained popularity as an effective strategy to enhance soil carbon sequestration, but empirical evidence is lacking particularly in arid and semi-arid rangelands of Africa. This study addressed the effectiveness of long-term (15–37 years old) enclosures in enhancing soil carbon sequestration in a semi-arid rangeland of Southern Ethiopia. We tested for differences in soil properties and vegetation characteristics between enclosures and adjacent open-grazed areas, while accounting for effects of age of enclosures and soil depths. Three enclosures age categories ( 30 years) each paired with adjacent open-grazed areas were selected. We collected soil samples at three soil depths (0–5 cm, 5–15 cm and 15–30 cm), and vegetation attributes from 90 plots within 9 enclosures and adjacent open grazing sites. The results showed that soil properties did not differ significantly (P > 0.05) between the two management systems across the three soil depths. However, relatively higher soil organic carbon content and stock was recorded in the enclosures than open-grazed lands. We recorded an overall mean of soil organic carbon stock of 39.6 ± 3.5 Mg ha 1 in enclosures of 30 years old. The soil organic carbon stock for the adjacent open-grazed areas ranged from 34.4 ± 2.5 to 47.9 ± 5.1 Mg ha 1. The age of enclosures did not show any significant effect on soil organic carbon stocks. However, enclosure management had a significant (P 0.05) effect on vegetation attributes. We concluded that enclosure had a significant role in terms of soil carbon sequestration and adaptation to climate change. © 2017 Elsevier B.V.