40 research outputs found

    Estudio del comportamiento que presenta la enzima poligalacturonasa en cuatro materailes experimentales de toamate

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    El fruto del toamte (Lycopersicon esculentum), durante su proceso de maduración, sufre numerosos cambios en las sustancias péicas que conforman la paredd celular produciendo una pérdida de lozanía y firmeza que ocasiona su senescencia debido al incremento de la actividad de las enzimas péticas entre las cuales se encuntra la poligalacturonasa (PG). En la Facultad de Ciencias de la Pontificia Universidad Jveriana, en 1996, mediante el uso de la Metodología del Heteroinjerto Bernal (HIB) se obtuvieron cuatro materiales experimentales de tomate denominados experimentalmente T1(Tomate Marglobe X Tomate de Árbol), T2 (Tomate Milano X Altamiza), T3 (Tomate Milano X Maciega) y T4 (Tomate Milano X Altrmuz). Se ha observado que estos tomates tienen la característica de presentar un período de poscosecha más largo al comprarlo con los aprentales maternos. El objetivo de este estudio fue determinar la velocidad enzimática de la poligalacturosa (PG) de los heteroinjertos de toamte y y un tomate comercial (TC) como control en el estado de la maduración rojo. Para la extracción de la enzima PG se empleó el método de Redenbaugh (1993).Los cristales de enzima obtenidos se resuspendieron y las proteínas se cuantificaron espectrofotométricamente a 280 nm por el método Stosheck (1990) hallando valores promedio de 0.850 mg/ml, 0.781 mg/ml,0.747mg/ml, o.750 mg/ml y 0.329 mg/ml para T1, T2, T3, T4 y TC respectivamente. A partir de los extractos de cada heteroinjerto se realizó una electroforesis SDS-PAGE del 12% en donde se observaron cuatro bandas, una de ellas con peso molecular de 44,7 KD que posiblemente corresponde a la isoenzima endo-PG. Posteriormente se midió la actividad enzimática de la PG en los materiales de tomate objeto de estudio espectrofotométricamente por el método de Gross (1982) el cual fue modificado, se halló que una disminusión de actividad del 44.5%, 46%, 28% y 37% respecivamente para T1, T2 T3 y T4 con relación al control TC. Para caracterizar los productos de la relación enzimática de la PG se realizó una cromatografía en capa fina que mostró en los heteroinjertos un monómero correspondiente al ácido galactutónico con mayor intensidad y otros complejos coloreados muy débiles de mayor peso molecular que pueden corresponder a dímeros, trímetros, tetrámetros, etc., esto se debe a que la PG presente en los materiales experimentales no hidrolizó el ácido poligalacturónico en un 100% a diferencia de la PG del tomate control

    Spatial similarities between European agroforestry systems and ecosystem services at the landscape scale

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    Agroforestry systems are known to provide ecosystem services which differ in quantity and quality from conventional agricultural practices and could enhance rural landscapes. In this study we compared ecosystem services provision of agroforestry and non-agroforestry landscapes in case study regions from three European biogeographical regions: Mediterranean (montado and dehesa), Continental (orchards and wooded pasture) and Atlantic agroforestry systems (chestnut soutos and hedgerows systems). Seven ecosystem service indicators (two provisioning and five regulating services) were mapped, modelled and assessed. Clear variations in amount and provision of ecosystem services were found between different types of agroforestry systems. Nonetheless regulating ecosystems services were improved in all agroforestry landscapes, with reduced nitrate losses, higher carbon sequestration, reduced soil losses, higher functional biodiversity focussed on pollination and greater habitat diversity reflected in a high proportion of semi-natural habitats. The results for provisioning services were inconsistent. While the annual biomass yield and the groundwater recharge rate tended to be higher in agricultural landscapes without agroforestry systems, the total biomass stock was reduced. These broad relationships were observed within and across the case study regions regardless of the agroforestry type or biogeographical region. Overall our study underlines the positive influence of agroforestry systems on the supply of regulating services and their role to enhance landscape structure

    Spatial similarities between European agroforestry systems and ecosystem services at the landscape scale

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    This is a post-peer-review, pre-copyedit version of an article published in Agroforestry Systems. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10457-017-0132-3Agroforestry systems are known to provide ecosystem services which differ in quantity and quality from conventional agricultural practices and could enhance rural landscapes. In this study we compared ecosystem services provision of agroforestry and non-agroforestry landscapes in case study regions from three European biogeographical regions: Mediterranean (montado and dehesa), Continental (orchards and wooded pasture) and Atlantic agroforestry systems (chestnut soutos and hedgerows systems). Seven ecosystem service indicators (two provisioning and five regulating services) were mapped, modelled and assessed. Clear variations in amount and provision of ecosystem services were found between different types of agroforestry systems. Nonetheless regulating ecosystems services were improved in all agroforestry landscapes, with reduced nitrate losses, higher carbon sequestration, reduced soil losses, higher functional biodiversity focussed on pollination and greater habitat diversity reflected in a high proportion of semi-natural habitats. The results for provisioning services were inconsistent. While the annual biomass yield and the groundwater recharge rate tended to be higher in agricultural landscapes without agroforestry systems, the total biomass stock was reduced. These broad relationships were observed within and across the case study regions regardless of the agroforestry type or biogeographical region. Overall our study underlines the positive influence of agroforestry systems on the supply of regulating services and their role to enhance landscape structureWe acknowledge funding through Grant 613520 from the European Commission (Project AGFORWARD, 7th Framework Program), the Xunta de Galicia, Consellería de Cultura, Educación e Ordenación Universitaria (“Programa de axudas á etapa posdoutoral DOG no. 122, 29/06/2016 p.27443, exp: ED481B 2016/071-0”), the Forest Research Center strategic project (PEst OE/AGR/UI0239/2014) and the Portuguese Foundation for Science and Technology through the contract SFRH/BD/52691/2014S

    Dry deposition of air pollutants on trees at regional scale: a case study in the Basque Country

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    There is increased interest in the role of trees to reduce air pollution and thereby improve human health and well-being. This study determined the removal of air pollutants by dry deposition of trees across the Basque Country and estimated its annual economic value. A model that calculates the hourly dry deposition of NO2, O3, SO2, CO and PM10 on trees at a 1 km x 1 km resolution at a regional scale was developed. The calculated mean annual rates of removal of air pollution across various land uses were 12.9 kg O3 ha−1, 12.7 kg PM10 ha−1, 3.0 kg NO2 ha−1, 0.8 kg SO2 ha−1 and 0.2 kg CO ha−1. The results were then categorised according to land use in order to determine how much each land use category contributed to reducing air pollution and to determine to what extent trees provided pollution reduction benefits to society. Despite not being located in the areas of highest pollutions, coniferous forests, which cover 25% of the land, were calculated to absorb 21% of the air pollution. Compared to other land uses, coniferous forests were particularly effective in removing air pollution because of their high tree cover density and the duration of leaf life-span. The total economic value provided by the trees in reducing these pollutants in terms of health benefits was estimated to be €60 million yr−1 which represented around 0.09% of the Gross Domestic Product of the Basque Country in 2016. Whilst most health impacts from air pollution are in urban areas the results indicate that most air pollution is removed in rural areas

    Whole system valuation of arable, agroforestry and tree-only systems at three case study sites in Europe

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    There is an increasing demand to study the long-term effects of land use from both local farm and wider societal and environmental perspectives. This study applied an approach to evaluate both the financial profitability of arable, agroforestry, and tree-only systems and the wider societal benefits over a period of 30-60 years. The biophysical inputs and yields from the three systems were modelled for three case study sites in the United Kingdom, Spain, and Switzerland, using a tree and crop simulation model called Yield-SAFE. A bio-economic model called Farm-SAFE was then used to compare the financial (EAVF) and economic (or societal) equivalent annual values (EAVE) by including monetary values for five environmental externalities: carbon dioxide emissions, carbon sequestration, soil erosion by water, and nitrogen and phosphorus balances. Across the three case studies, arable farming generated higher farm incomes than the agroforestry or tree-only systems, but the arable systems also created the greatest environmental costs. By comparison the agroforestry and tree-only systems generated lower CO2 emissions and sequestered more carbon. Applying monetary values to the environmental externalities meant that the EAVE of the agroforestry and tree-only systems were greater or similar to that for the arable system in the UK case study. In Spain, the slow predicted growth of the trees meant that, even after including the environmental externalities, the arable system created greater societal benefit than the agroforestry and tree-only systems. In Switzerland, including the environmental externalities increased the attraction of the tree-only system, but the high subsidies for arable and agroforestry systems meant that the EAVE for the agroforestry and arable systems were the most attractive from a farmer’s perspective. A breakeven analysis was used to determine the environmental externality values at which the agroforestry and tree-only systems produced the same societal return as the arable system in each case study. In the UK, a carbon price of ₠16 (t CO2)-1 allowed the EAVE of the agroforestry system to attain parity with the arable EAVE. In both the UK and Spain, an environmental nitrogen cost of ₠3-6 (kg N)-1 was sufficient for the EAVE of the agroforestry and tree-only systems to match those of arable farming. Because trees on farms provide ‘‘economies of multifunction’’ for environmental benefits, the breakeven values will be less if environmental benefits are considered together as packages. The described approach provides a method for governments and others to examine the cost effectiveness of new agri-environment measure

    Current extent and stratification of agroforestry in the European Union

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    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

    Agroforestry is paying off – Economic evaluation of ecosystem services in European landscapes with and without agroforestry systems

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    The study assessed the economic performance of marketable ecosystem services (ES) (biomass production) and non-marketable ecosystem services and dis-services (groundwater, nutrient loss, soil loss, carbon sequestration, pollination deficit) in 11 contrasting European landscapes dominated by agroforestry land use compared to business as usual agricultural practice. The productivity and profitability of the farming activities and the associated ES were quantified using environmental modelling and economic valuation. After accounting for labour and machinery costs the financial value of the outputs of Mediterranean agroforestry systems tended to be greater than the corresponding agricultural system; but in Atlantic and Continental regions the agricultural system tended to be more profitable. However, when economic values for the associated ES were included, the relative profitability of agroforestry increased. Agroforestry landscapes: (i) were associated to reduced externalities of pollution from nutrient and soil losses, and (ii) generated additional benefits from carbon capture and storage and thus generated an overall higher economic gain. Our findings underline how a market system that includes the values of broader ES would result in land use change favouring multifunctional agroforestry. Imposing penalties for dis-services or payments for services would reflect their real world prices and would make agroforestry a more financially profitable system

    Cross-site analysis of perceived ecosystem service benefits in multifunctional landscapes

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    Rural development policies in many Organization for Economic Co-operation and Development (OECD) member countries promote sustainable landscape management with the intention of providing multiple ecosystem services (ES). Yet, it remains unclear which ES benefits are perceived in different landscapes and by different people. We present an assessment of ES benefits perceived and mapped by residents (n = 2,301) across 13 multifunctional (deep rural to peri-urban) landscapes in Europe. We identify the most intensively perceived ES benefits, their spatial patterns, and the respondent and landscape characteristics that determine ES benefit perception. We find outdoor recreation, aesthetic values and social interactions are the key ES benefits at local scales. Settlement areas are ES benefit hotspots but many benefits are also related to forests, waters and mosaic landscapes. We find some ES benefits (e.g. culture and heritage values) are spatially clustered, while many others (e.g. aesthetic values) are dispersed. ES benefit perception is linked to people’s relationship with and accessibility to a landscape. Our study discusses how a local perspective can contribute to the development of contextualized and socially acceptable policies for sustainable ES management. We also address conceptual confusion in ES framework and present argumentation regarding the links from services to benefits, and from benefits to different types of values.</p

    Cross-site analysis of perceived ecosystem service benefits in multifunctional landscapes

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    Rural development policies in many Organization for Economic Co-operation and Development (OECD) member countries promote sustainable landscape management with the intention of providing multiple ecosystem services (ES). Yet, it remains unclear which ES benefits are perceived in different landscapes and by different people. We present an assessment of ES benefits perceived and mapped by residents (n = 2,301) across 13 multifunctional (deep rural to peri-urban) landscapes in Europe. We identify the most intensively perceived ES benefits, their spatial patterns, and the respondent and landscape characteristics that determine ES benefit perception. We find outdoor recreation, aesthetic values and social interactions are the key ES benefits at local scales. Settlement areas are ES benefit hotspots but many benefits are also related to forests, waters and mosaic landscapes. We find some ES benefits (e.g. culture and heritage values) are spatially clustered, while many others (e.g. aesthetic values) are dispersed. ES benefit perception is linked to people’s relationship with and accessibility to a landscape. Our study discusses how a local perspective can contribute to the development of contextualized and socially acceptable policies for sustainable ES management. We also address conceptual confusion in ES framework and present argumentation regarding the links from services to benefits, and from benefits to different types of values
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