Browsing by Author "Paulo, Joana A."

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    Assessing food sustainable intensification potential of agroforestry using a carbon balance method
    (Italian Society of Silviculture and Forest Ecology (SISEF), 2019-01-24) Crous-Duran, Josep; Graves, Anil; García de Jalón, Silvestre; Paulo, Joana A.; Tomé, Margarida; Palma, João H. N.
    Food security, climate change mitigation, and land use challenges are interlinked and need to be considered simultaneously. One possible solution is sustainable intensification, which is the practice of increasing food production per area of land whilst also reducing the environmental impacts associated with this. Agroforestry has been stated to be a practice that meets this definition. In this study, a new methodology is presented to assess the potential of different management options as sustainable intensification practices. The methodology is based on comparing the carbon emissions associated with the production of food and the carbon sequestered for that same activity for a particular quantity of food produced over a specific area and over a specific time. The resulting indicator, the “carbon balance” is the difference between the greenhouse gasses emitted (considered as negative values) and carbon sequestered (positive values) estimated in Mg CO2eq per Mg of food produced on one hectare of land for one year. The carbon balance quantifies the global warming potential associated with sustainable intensification by integrating a process-based model with life cycle analysis and is able to estimate above- and below-ground biomass and soil carbon content. This methodology is tested in Portugal for wheat production under crop monoculture and agroforestry systems. The results show agroforestry to be a suitable practice for sustainable intensification compared to a crop monoculture as it just slightly decreased wheat yields whilst providing a positive carbon balance from year 50 onwards of approximately 1 Mg of CO2eq sequestered per Mg of wheat produced.
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    Current extent and stratification of agroforestry in the European Union
    (Elsevier, 2017-03-20) den Herder, Michael; Moreno, Gerardo; Mosquera-Losada, María Rosa; Palma, João H. N.; Sidiropoulou, Anna; Santiago-Freijanes, Jose Javier; Crous-Duran, Josep; Paulo, Joana A.; Tomé, Margarida; Pantera, Anastasia; Papanastasis, Vasilios P.; Mantzanas, Kostas; Pachana, Przemko; Papadopoulos, Andreas; Plieninger, Tobias; Burgess, Paul J.
    An accurate and objective estimate on the extent of agroforestry in Europe is critical for the development of supporting policies. For this reason, a more harmonised and uniform Pan-European estimate is needed. The aim of this study was to quantify and map the distribution of agroforestry in the European Union. We classified agroforestry into three main types of agroforestry systems: arable agroforestry, livestock agroforestry and high value tree agroforestry. These three classes are partly overlapping as high value tree agroforestry can be part of either arable or livestock agroforestry. Agroforestry areas were mapped using LUCAS Land Use and Land Cover data (Eurostat, 2015). By identifying certain combinations of primary and secondary land cover and/or land management it was possible to identify agroforestry points and stratify them in the three different systems. According to our estimate using the LUCAS database the total area under agroforestry in the EU 27 is about 15.4 million ha which is equivalent to about 3.6% of the territorial area and 8.8% of the utilised agricultural area. Of our three studied systems, livestock agroforestry covers about 15.1 million ha which is by far the largest area. High value tree agroforestry and arable agroforestry cover 1.1 and 0.3 million ha respectively. Spain (5.6 million ha), France (1.6 million ha), Greece (1.6 million ha), Italy (1.4 million ha), Portugal (1.2 million ha), Romania (0.9 million ha) and Bulgaria (0.9 million ha) have the largest absolute area of agroforestry. However the extent of agroforestry, expressed as a proportion of the utilised agricultural area (UAA), is greatest in countries like Cyprus (40% of UAA), Portugal (32% of UAA) and Greece (31% of UAA). A cluster analysis revealed that a high abundance of agroforestry areas can be found in the south-west quadrat of the Iberian Peninsula, the south of France, Sardinia, south and central Italy, central and north-east Greece, south and central Bulgaria, and central Romania. Since the data were collected and analysed in a uniform manner it is now possible to make comparisons between countries and identify regions in Europe where agroforestry is already widely practiced and areas where there are opportunities for practicing agroforestry on a larger area and introducing novel practices. In addition, with this method it is possible to make more precise estimates on the extent of agroforestry in Europe and changes over time. Because agroforestry covers a considerable part of the agricultural land in the EU, it is crucial that it gets a more prominent and clearer place in EU statistical reporting in order to provide decision makers with more reliable information on the extent and nature of agroforestry. Reliable information, in turn, should help to guide policy development and implementation, and the evaluation of the impact of agricultural and other policies on agroforestry.
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    How is agroforestry perceived in Europe? An assessment of positive and negative aspects by stakeholders
    (Springer, 2017-08-24) Garcia de Jalon, Silvestre; Burgess, Paul J.; Graves, Anil; Moreno, Gerardo; McAdam, Jim; Pottier, Eric; Novak, Sandra; Bondesan, Valerio; Mosquera-Losada, Rosa; Crous-Duran, Josep; Palma, João H. N.; Paulo, Joana A.; Oliveira, Tania S.; Cirou, Eric; Hannachi, Yousri; Pantera, Anastasia; Wartelle, Regis; Kay, Sonja; Malignier, Nina; van Lerberghe, Philippe; Tsonkova, Penka; Mirck, Jaconette; Rois, Mercedes; Kongsted, Anne Grete; Thenail, Claudine; Luske, Boki; Berg, Staffan; Gosme, Marie; Vityi, Andrea
    Whilst the benefits of agroforestry are widely recognised in tropical latitudes few studies have assessed how agroforestry is perceived in temperate latitudes. This study evaluates how stakeholders and key actors including farmers, landowners, agricultural advisors, researchers and environmentalists perceive the implementation and expansion of agroforestry in Europe. Meetings were held with 30 stakeholder groups covering different agroforestry systems in 2014 in eleven EU countries (Denmark, France, Germany, Greece, Hungary, Italy, Netherlands, Portugal, Spain, Sweden and the United Kingdom). In total 344 valid responses were received to a questionnaire where stakeholders were asked to rank the positive and negative aspects of implementing agroforestry in their region. Improved biodiversity and wildlife habitats, animal health and welfare, and landscape aesthetics were seen as the main positive aspects of agroforestry. By contrast, increased labour, complexity of work, management costs and administrative burden were seen as the most important negative aspects. Overall, improving the environmental value of agriculture was seen as the main benefit of agroforestry, whilst management and socio-economic issues were seen as the greatest barriers. The great variability in the opportunities and barriers of the systems suggests enhanced adoption of agroforestry across Europe will be most likely to occur with specific initiatives for each type of system.
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    Integrating belowground carbon dynamics into Yield-SAFE, a parameter sparse agroforestry model
    (Springer, 2017-09-16) Palma, João H. N.; Crous-Duran, Josep; Graves, Anil; García de Jalón, Silvestre; Upson, Matthew; Oliveira, Tania S.; Paulo, Joana A.; Ferreiro-Domínguez, N.; Moreno, Gerardo; Burgess, Paul
    Agroforestry combines perennial woody elements (e.g. trees) with an agricultural understory (e.g. wheat, pasture) which can also potentially be used by a livestock component. In recent decades, modern agroforestry systems have been proposed at European level as land use alternatives for conventional agricultural systems. The potential range of benefits that modern agroforestry systems can provide includes farm product diversification (food and timber), soil and biodiversity conservation and carbon sequestration, both in woody biomass and the soil. Whilst typically these include benefits such as food and timber provision, potentially, there are benefits in the form of carbon sequestration, both in woody biomass and in the soil. Quantifying the effect of agroforestry systems on soil carbon is important because it is one means by which atmospheric carbon can be sequestered in order to reduce global warming. However, experimental systems that can combine the different alternative features of agroforestry systems are difficult to implement and long-term. For this reason, models are needed to explore these alternatives, in order to determine what benefits different combinations of trees and understory might provide in agroforestry systems. This paper describes the integration of the widely used soil carbon model RothC, a model simulating soil organic carbon turnover, into Yield-SAFE, a parameter sparse model to estimate aboveground biomass in agroforestry systems. The improvement of the Yield-SAFE model focused on the estimation of input plant material into soil (i.e. leaf fall and root mortality) while maintaining the original aspiration for a simple conceptualization of agroforestry modeling, but allowing to feed inputs to a soil carbon module based on RothC. Validation simulations show that the combined model gives predictions consistent with observed data for both SOC dynamics and tree leaf fall. Two case study systems are examined: a cork oak system in South Portugal and a poplar system in the UK, in current and future climate.
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    Modelling tree density effects on provisioning ecosystem services in Europe
    (2018-10-20) Crous-Duran, Josep; Graves, Anil R.; Paulo, Joana A.; Mirck, Jaconette; Oliveira, Tania S.; Kay, Sonja; García de Jalón, Silvestre; Palma, João H. N.
    Agroforestry systems, in which trees are integrated in arable or pasture land, can be used to enable sustainable food, material, and energy production (i.e. provide provisioning ecosystem services) whilst reducing the negative environmental impacts associated with farming. However, one constraint on the uptake of agroforestry in Europe is a lack of knowledge on how specific agroforestry designs affect productivity. A process-based biophysical model, called Yield-SAFE, was used: (1) to quantify the food, material and biomass energy production of four contrasting case study systems in Europe in a common energy unit (MJ ha−1), and (2) to quantify how tree density determined the supply of provisioning ecosystem services. The Yield-SAFE model was calibrated so that simulated tree and crop growth fitted observed growth data for reference monoculture forestry, pasture, and arable systems. The modelled results showed that including trees in pasture or arable systems increased the overall accumulated energy of the system in comparison with monoculture forestry, pasture, and arable systems, but that the accumulated energy per tree was reduced as tree density increased. The greatest accumulated energy occurred in the highest tree density agroforestry system at all the case study sites. This suggests that the capture of environmental resources, such as light and water, for obtaining provisioning services is most effective in high density agroforestry systems. Further modelling should include tree canopy effects on micro-climatic and the impact this has on pasture, crop, and livestock yields, as well as the impact of tree density on the economic value and management of the different systems.