Can silvo-pastoral agroforestry systems contribute to Scotland’s emission reduction targets? (original) (raw)
Related papers
Afforestation: Replacing livestock emissions with carbon sequestration
Journal of Environmental Management, 2020
In Ireland, agriculture accounts for 33% of national greenhouse gas (GHG) emissions. Ireland faces significant challenges in terms of emissions reduction and is well off course in terms of meeting binding European Union targets. Flexibility mechanisms will allow Ireland to offset 5.6% of its commitment via sequestration in biomass and soils and land use change. Agricultural emissions in Ireland are largely driven by livestock production. As such, the purpose of this research is to estimate the net GHG emission benefit resulting from a land use change with forest replacing livestock systems (dairy, beef cattle and sheep). We estimate the total carbon sequestration in biomass and harvested wood products, along with the total emissions avoided from each livestock system on a per hectare basis. In addition, the paper compares the social cost of carbon to the average income per hectare of each livestock system. Finally, a hypothetical national planting scenario is modelled using plausible planting rates. Results indicate that the greatest carbon benefit is achieved when forest replaces dairy production. This is due to high emissions per hectare from dairy systems, and greater sequestration potential in higher-yielding forests planted on better quality soils associated with dairy production. The inclusion of harvested wood products in subsequent rotations has the potential to enhance GHG mitigation and offset terrestrial carbon loss. A hypothetical national planting scenario, afforesting 100,000 ha substituting dairy, beef cattle and sheep livestock systems could abate 13.91 Mt CO 2 e after 10 years, and 150.14 Mt CO 2 e (unthinned plantations) or 125.89 Mt CO 2 e (thinned plantations) over the course of the rotation. These results highlight the critical role for forest land use change in meeting the urgent need to tackle rising agricultural emissions.
fao.org
This research aims at identifying pasture and silvo-pastoral systems that provide economically attractive solutions to farmers and offer environmental services, particularly the recovery of degraded areas and C sequestration, in four ecosystems of Tropical America vulnerable to climate change. Soil C stocks, C contents in biomass, and socio-economic indicators were evaluated in a wide range of pasture and silvo-pastoral systems under grazing, in commercial farms under conservation management practices. At each ecosystem and site, C evaluations were also performed for native forest (positive reference) and degraded soil (negative reference). Results of 5 years of research (2002)(2003)(2004)(2005)(2006)(2007) show that improved and well-managed pasture and silvo-pastoral systems can contribute to the recovery of degraded areas as C-improved systems.
Agriculture, Ecosystems & Environment, 2013
Shrub cover has increased in semi-arid regions worldwide. This change has generally been viewed as land degradation, due to shrub-induced declines in pastoral productivity. As a consequence, widespread management treatments to reduce shrub density have been applied in many pastoral areas. These treatments, however, often do not have long-term positive benefits for forage production. Alternative uses for shrub-encroached lands have received little consideration, but a recent move towards economic incentives for carbon (C) storage could lead to financially viable alternative land management strategies. We examined changes in above-and belowground C storage following 20 years of factorial land management treatments (grazing/no grazing and shrub removal/no removal) in an Australian semi-arid woodland. Disturbance by shrub removal (root ploughing) and/or livestock grazing significantly reduced the amount of soil organic carbon (SOC). The most disturbed treatment (grazed and ploughed) contained the least SOC (15.30 Mg C ha −1) while protection from grazing and shrub removal led to the greatest SOC (28.49 Mg C ha −1). Declines in SOC in shrub removal treatments (with and without grazing) were compensated, in part, by enhanced aboveground C accumulation, derived mainly from woody plants. Destocking currently grazed shrublands for two decades resulted in a net C accretion, over 20 years, in the order of 6.5 Mg ha −1 , almost entirely through increasing belowground C. At the current price for C in Australia, the economic benefit for C accumulation from removing livestock grazing would be similar to the economic benefit of grazing. The results suggest that C farming in this semi-arid woodland system may offer an economically viable alternative management strategy to grazing, although uncertainties in future climate, C credit value, and assessment protocols present hurdles for implementing alternative management aimed at C farming.
Land Use Policy, 2019
Agroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in northwestern France, Denmark, Central Spain, north and southwestern Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha −1 a −1. Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a −1 (7.78 and 234.85 million t CO 2eq a −1) depending on the type of agroforestry. This corresponds to between 1.4 and 43.4% of European agricultural greenhouse gas (GHG) emissions. Moreover, promoting agroforestry in the Priority Areas would contribute to mitigate the environmental pressures identified there. We conclude that the strategic and spatially targeted establishment of agroforestry systems could provide an effective means of meeting EU policy objectives on GHG emissions whilst providing a range of other important benefits.
Agroforestry in Scotland – potential benefits in a changing climate
2018
The Scottish Government has set statutory targets for the reduction of GHG emissions in Scotland through the Climate Change (Scotland) Act 2009. One of the ways in which it aims to meet this target is through increased woodland cover from around 18% to 21% by 2032 (Scottish Government, Climate Change Plan, 2018, p18). Increased use of agroforestry in Scotland is one option that could help achieve these targets, while also supporting sustainable adaptation to a changing climate.
International Journal of Climate Change Strategies and Management, 2018
Purpose This paper aims at providing the evidence about how carbon sequestration in terrestrial ecosystems could contribute to the decrease of atmospheric CO2 rates through the adoption of appropriate cropping systems such as agroforestry. Design/methodology/approach Stratified randomly selected plots were used to collect data on tree diameter at breast height (DBH). Composite soil samples were collected from three soil depths for soil carbon analysis. Above ground biomass estimation was made using an allometric equation. The spectral signature of each plot was extracted to study the statistical relationship between carbon stock and selected vegetation indices. Findings There was a significant difference in vegetation and soil carbon stocks among the different land use/land cover types (P < 0.05). The potential carbon stock was highest in the vegetation found in sparsely cultivated land (13.13 ± 1.84 tons ha−1) and in soil in bushland (19.21 ± 3.79 tons ha−1). Carbon sequestratio...
Optimising carbon sequestration in arid and semiarid rangelands
Ecological Engineering, 2015
Destocking degraded rangeland can potentially help climate change mitigation by re-sequestering emitted carbon. Broad-scale implementation has been limited by uncertainties in the magnitude, duration and location of sequestration and the profitability relative to the existing grazing land use. This paper employs a novel methodology to assess potential rangeland sequestration and its profitability, using 31 Mha of rangeland in New South Wales, Australia as a case-study. This approach combines remotely sensed data and modelled estimates of various components. Remotely sensed, synthetic aperture radar data were used to determine woody biomass of minimally degraded forest (benchmarks) and neighbouring more-degraded forest, followed by sequestration modelling using non-linear growth rates based on woody thickening and slow-growing plantations, scaled to the benchmarks. Livestock concentration and livestock-based farm profits were modelled. We compared sequestration and grazing net profits, for a carbon price of AUD$10 Mg À1 CO 2-e, at different growth stages for different levels of forest attrition. We found that broad-scale destocking with subsequent C re-sequestration was initially unprofitable compared with grazing. However, after 50 years, with full costing of C emissions, the returns were similar for the two alternatives of continued grazing or re-sequestration, for areas with biomass below benchmark levels. Reforestation of recently deforested land represents the most profitable option with profitability increasing with growth rate. Emissions of soil organic carbon, set in motion by climate change over the next century, were calculated to be the largest of all sources. Emissions from biomass, induced by climate change, will be higher where vegetation cannot adapt. The secondary effects of climate change will reduce re-sequestration and grazing profits, possibly limiting the carbon stored by re-sequestration projects. 2014 Elsevier B.V. All rights reserved.
Soil Carbon Sequestration in Grazing Lands: Societal Benefits and Policy Implications
Rangeland Ecology & Management, 2010
This forum manuscript examines the importance of grazing lands for sequestering soil organic carbon (SOC), providing societal benefits, and potential influences on them of emerging policies and legislation. Global estimates are that grazing lands occupy , 3.6 billion ha and account for about one-fourth of potential carbon (C) sequestration in world soils. They remove the equivalent of , 20% of the carbon dioxide (CO 2 ) released annually into the earth's atmosphere from global deforestation and land-use changes. Atmospheric CO 2 enters grazing lands soils through photosynthetic assimilation by green plants, subsequent cycling, and sequestration of some of that C as SOC to in turn contribute to the ability of grazing lands to provide societal (environmental and economic) benefits in every country where they exist. Environmental benefits provided include maintenance and well-being of immediate and surrounding soil and water resources, air quality, human and wildlife habitat, and esthetics. Grazing lands contribute to the economic well-being of those living on the land, to trade, and to exchange of goods and services derived from them at local, regional, or national levels. Rates of SOC sequestration vary with climate, soil, and management; examples and conditions selected from US literature illustrate the SOC sequestration that might be achieved. Public efforts, policy considerations, and research in the United States illustrate possible alternatives that impact grazing lands. Discussion of US policy issues related to SOC sequestration and global climate change reflect the importance attached to these topics and of pending legislative initiatives in the United States. Addressing primarily US policy does not lessen the importance of such issues in other countries, but allows an in-depth analysis of legislation, US Department of Agriculture program efforts, soil C credits in greenhouse gas markets, and research needs.
As result of increased emission of green house gases, especially increased emission of Co2, Climate change is the main global challenges that many countries are facing. Increasing carbon sequestration through a forestation, reforestation and appropriate land use practices are considered as means to sink the atmospheric Co2 in terrestrial ecosystem. Agroforestry is recognized as a strategy for soil carbon sequestration (SCS) under the afforestation/reforestation activities in different parts of the world.However, little information is available on soil carbon dynamics under agroforestry systems. This study was aimed to determine the soil organic carbon pool under silvopastoral agroforestry system. The study was conducted at Henfeas research center in the north Wales, UK where Sycamore (Acer pseudoplatanus L.) and Red alder (Alnus rubra) were planted in 1992 in integration with the grasslands. The soil samples were collected to the depth of 30cm at different depth intervals (0-10, 10-20 and 20-30cm) under five treatments: under and outside the canopy of both Sycamore (Acer pseudoplatanus L.) and Red alder (Alnus rubra) and under the control grassland. The concentration of soil organic carbon (SOC %) under each treatment were analyzed using LOI (loss on ignition method) where soil samples were burned at 450 oc. The regression formula (Y= 0.458X-0.4 Where, Y= SOC (%) and X= SOM (%)) developed by Ball, 1964, was used to convert soil organic matter to SOC. It was identified that SOC concentration were significantly different at (P<0.05) between the treatments and along the soil profile.