• Authors:
    • Zhang,K.
    • Castanho,A. D. de A.
    • Galbraith,D. R.
    • Moghim,S.
    • Levine,N. M.
    • Bras,R. L.
    • Coe,M. T.
    • Costa,M. H.
    • Malhi,Y.
    • Longo,M.
    • Knox,R. G.
    • McKnight,S.
    • Wang,J. F.
    • Moorcroft,P. R.
  • Source: Global Change Biology
  • Volume: 21
  • Issue: 7
  • Year: 2015
  • Summary: There is considerable interest in understanding the fate of the Amazon over the coming century in the face of climate change, rising atmospheric CO 2 levels, ongoing land transformation, and changing fire regimes within the region. In this analysis, we explore the fate of Amazonian ecosystems under the combined impact of these four environmental forcings using three terrestrial biosphere models (ED2, IBIS, and JULES) forced by three bias-corrected IPCC AR4 climate projections (PCM1, CCSM3, and HadCM3) under two land-use change scenarios. We assess the relative roles of climate change, CO 2 fertilization, land-use change, and fire in driving the projected changes in Amazonian biomass and forest extent. Our results indicate that the impacts of climate change are primarily determined by the direction and severity of projected changes in regional precipitation: under the driest climate projection, climate change alone is predicted to reduce Amazonian forest cover by an average of 14%. However, the models predict that CO 2 fertilization will enhance vegetation productivity and alleviate climate-induced increases in plant water stress, and, as a result, sustain high biomass forests, even under the driest climate scenario. Land-use change and climate-driven changes in fire frequency are predicted to cause additional aboveground biomass loss and reductions in forest extent. The relative impact of land use and fire dynamics compared to climate and CO 2 impacts varies considerably, depending on both the climate and land-use scenario, and on the terrestrial biosphere model used, highlighting the importance of improved quantitative understanding of all four factors - climate change, CO 2 fertilization effects, fire, and land use - to the fate of the Amazon over the coming century.
  • Authors:
    • Tran,T.
    • Da,G.
    • Moreno-Santander,M. A.
    • Velez-Hernandez,G. A.
    • Giraldo-Toro,A.
    • Piyachomkwan,K.
    • Sriroth,K.
    • Dufour,D.
  • Source: Resources, Conservation & Recycling
  • Volume: 100
  • Year: 2015
  • Summary: Energy use, water use and greenhouse gas (GHG) emissions were assessed for the transformation of cassava roots into starch by two small-scale (ST1, ST2: 1-2 t starch per day) and one large-scale (VLT: 100-200 t starch per day) technologies. The goal of the study was to identify hotspots of energy use and GHG emissions, as well as sustainable practices, with a view to uncover opportunities to improve the environmental performance of cassava starch production. VLT required 2527 MJ/t starch, mainly (77%) from biogas used to dry starch, but was the most efficient in terms of water use (10 m 3/t starch) due to the practice of water recycling between unit operations. ST1 and ST2 were similar in terms of electricity use (212 MJ/t starch), and were able to rely on solar energy to dry starch, due to the small volumes of production. In contrast, water use varied from 21 to 62 m 3/t starch due to differences in the design of the rasping and starch recovery (extraction) operations. GHG emissions were 149, 93 and 105 kg CO 2eq/t starch for VLT, ST1 and ST2 respectively. For ST1 and ST2, methane emissions from untreated wastewater were the main contribution to GHG emissions. For VLT, methane was captured to produce biogas and to dry starch, and the main contribution to GHG emissions was the use of non-renewable grid electricity. Biogas technology was adopted in the past 12 years in the case of VLT. Previously fuel oil was used instead of biogas, which resulted in GHG emissions of 539 kg CO 2eq/t starch. VLT used markedly more electricity than ST1 and ST2, which was necessary to ensure the high output and consistent starch quality. Strategies to reduce the impacts of cassava starch production could focus on (1) increasing the energy efficiency of the drying operation, in order to make more biogas available for other uses such as production of renewable electricity; (2) improving the design of some unit operations with regards to water and energy efficiency; and (3) promoting the transfer and adoption of water recycling practices.
  • Authors:
    • Tzanopoulos, J.
    • Bravo-Monroy, L.
    • Potts, S. G.
  • Source: Article
  • Volume: 211
  • Year: 2015
  • Summary: Bees and other insects provide pollination services that are key to determining the fruit set on coffee plantations. These pollination services are influenced by local ecology as well as human factors, both social and economic. To better understand these different factors, we assessed their effect on pollinators and coffee pollination services in Santander, Colombia. We quantified the effect of key ecological drivers on pollinator community composition, such as the method of farm management (either conventional or organic) and the surrounding landscape composition, specifically the proximity to forest. We found that ambient levels of pollination services provided by the local pollinator fauna (open pollination) accounted for a 10.52.0% increase in final coffee fruit set, and that the various pollinators are affected differently by the differing factors. For example, our findings indicate that conventional farm management, using synthetic inputs, can promote pollinators, especially if they are in close proximity to natural forest fragments. This is particularly true for stingless bees. Honeybee visitation to coffee is also positively influenced by the conventional management of farms. Factors associated with greater numbers of stingless bees on farms include greater shade cover, lower tree densities, smaller numbers and types of trees in bloom, and younger coffee plantations. A forested landscape close to farms appears to enhance these factors, giving increased stability and resilience to the pollinating bees and insects. However we found that organic farms also support diverse pollinator communities, even if distant from forest fragments. The contribution of honeybees to pollination value (US$129.6/ha of coffee) is greater than that of stingless bees (US$16.5/ha of coffee). Since the method of farm management has a major impact on the numbers and types of pollinators attracted to farms, we have analysed the statistically significant social factors that influence farmers' decisions on whether to adopt organic or conventional practices. These include the availability of technology, the type of landowner (whether married couples or individual owners), the number of years of farmers' formal education, the role of institutions, membership of community organizations, farm size, coffee productivity and the number of coffee plots per farm. It is hoped that the use of our holistic approach, which combines investigation of the social as well as the ecological drivers of pollination, will help provide evidence to underpin the development of best practices for integrating the management of pollination into sustainable agricultural practices.
  • Authors:
    • De Prager, M. S.
    • Rodrígues, B. A. S.
    • Reyes, O. E. S.
  • Source: Acta Agronomica, Universidad Nacional de Colombia
  • Volume: 63
  • Issue: 4
  • Year: 2014
  • Summary: This study provided knowledge about the agro-ecosystem N dynamics mediated by the use of agroecological practices such as GM. GM is established as legume its symbiotic action with soil rhizobia and arbuscular mycorrhiza formation, allows the cycling of nitrogen and phosphorus, among others. This study aimed at evaluating the influence of GM in the nitrogen dynamics of a Typic Haplustert located in the municipality of Candelaria (Colombia). In completely randomized blocks design with six replications, the GM coming from the intercropping Mucuna pruriens var utilis - Zea mays L. var. ICA 305 was established as T1 treatment and the native arvense Rottboellia cochinchinensis L. as T2, during the second half of year 2011. During the stage of preflowering of M. pruriens the content of organic C (OC) was evaluated as well as total N (TN), nitrate, ammonium, number of copies of amoA gene of ammoniaoxidizing bacteria, total porosity filled with water (TPW), temperature, flow of greenhouse gases: methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O), as well as the dry matter (DM) and the contents of C, N and P in plant tissues. Significantly higher concentrations (p <0.05) of CO, NT, ammonium and nitrate, were recorded in T2. The number of oxidizing bacteria of ammonium was significantly higher in T1 which coincided with the higher TPW and the lower soil temperature. The emission of atmospheric CO2 was significantly lower in T1, in contrast to the CH4 and N2O which scored the highest values. At the end of the trial, the GM in T1 provided about 4 t MS / ha, 1668.3 kg C / ha, 78.7 kg N / ha and 11.0 kg P / ha, with social economic benefit of 9.2 t corn/ha.
  • Authors:
    • Cardona Alzate, C. A.
    • Rincón-Pérez, L. E.
    • Valencia-Botero, M. J.
  • Source: Ingeniería y Universidad
  • Volume: 18
  • Issue: 1
  • Year: 2014
  • Summary: The bioenergy (especially biofuels) production and use has been worldly encouraged as a possible solution for the energy crisis caused by fossil fuel extraction and burnt. However, some intrinsic features of the biofuels supply chain generate notable uncertainties. The land use change can be considered a key issue of the feedstock production stage. In this work, the carbon replacement time was calculated for the cases of the oil palm growing in soils for forest, degraded lands and marginal lands. Most cultivated lands are required to increase the biodiesel production in Colombia. Additionally, the greenhouse gas emission from the land use change was calculated, when the palm crops are extended to achieve B20 blends. The results indicated that the palm crop growing on degraded and marginal lands, as well as palm cultivated in Eastern zone, do not generate carbon debt. Moreover, oil palm growing under these conditions helps to increase the carbon captures of these lands. The Eastern zone shows the highest carbon capture power.
  • Authors:
    • Acevedo, H.
    • Castanheira, E. G.
    • Freire, F.
  • Source: Applied Energy
  • Volume: 114
  • Year: 2014
  • Summary: The main goal of this article is to assess the life-cycle greenhouse gas (GHG) intensity of palm oil produced in a specific plantation and mill in Colombia. A comprehensive evaluation of the implications of alternative land use change (LUC) scenarios (forest, shrubland, savanna and cropland conversion) and fertilization schemes (four synthetic and one organic nitrogen-fertilizer) was performed. A sensitivity analysis to field nitrous oxide emission calculation, biogas management options at mill, time horizon considered for global warming and multifunctionality approach were also performed. The results showed that the GHG intensity of palm oil greatly depends on the LUC scenario. Significant differences were observed between the LUC scenarios (-3.0 to 5.3 kg CO(2)eq kg(-1) palm oil). The highest result is obtained if tropical rainforest is converted and the lowest if palm is planted on previous cropland, savanna and shrubland, in which almost all LUC from Colombian oil palm area expansion occurred between 1990 and 2009. Concerning plantation and oil extraction, it was shown that field nitrous oxide emissions and biogas management options have a high influence on GHG emissions.
  • Authors:
    • Sanabria, C.
    • Rodriguez, E.
    • Xiomara Pullido, S.
    • Loaiza, S.
    • del Pilar Hurtado, M.
    • Gutierrez, A.
    • Gomez, Y.
    • Chaparro, P.
    • Botero, C.
    • Bernal, J.
    • Arguello, O.
    • Rodriguez, N.
    • Lavelle, P.
    • Velasquez, E.
    • Fonte, S.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 185
  • Year: 2014
  • Summary: In the Orinoco River Basin of eastern Colombia large scale and rapid conversion of natural savannas into commercial agriculture exists as a critical threat for the ecological integrity of this fragile region. The highly acidic and compacted soils inherent to this region require thorough physical and chemical conditioning in order for intensive cropping systems to be established. Assessing the impact of this dramatic soil perturbation on biodiversity, ecosystem services and other elements of the natural capital is an urgent task for designing sustainable management options in the region. To address this need, we evaluated soil macro invertebrate communities and soil-based ecosystem services (climate regulation, hydrologic functions, soil stability provided by macro aggregation and nutrient provision potential) in four major production systems: improved pastures, annual crops (rice, corn and soy bean), oil palm and rubber plantations, and compared them to the original savanna. Fifteen plots of each system were sampled along a 200 km natural gradient of soil and climatic conditions. In each plot, we assessed climate regulation by measuring green house gas emissions (N2O, CH4 and CO2) and C storage in aboveground plant biomass and soil (0-20 cm). Soil biodiversity (macro invertebrate communities) and three other soil-based ecosystem services, were assessed using sets of 12-20 relevant variables associated with each service and synthesized via multivariate analyses into a single indicator for each ecosystem function, adjusted in a range of 0.1-1.0. Savannas yielded intermediate values for most indicators, while each production system appeared to improve at least one ecosystem service. For example, nutrient provision (chemical fertility) was highest in annual cropping systems (0.78 +/- 0.03) due to relatively high concentrations of Ca, Mg, N, K, and available P and low Al saturation. Hydrological functions and climate regulation (C storage and GHG emissions) were generally improved by perennial crops (oil palm and rubber), while indicators for macro invertebrate biodiversity and activity (0.73 +/- 0.05) and soil macro aggregation (0.76 +/- 0.02) were highest within improved pastures. High variability within each system indicates the potential to make improvements in fields with lowest indicator values, while differences among systems suggest the potential to mitigate negative impacts by combining plots with contrasted functions in a strategically designed landscape mosaic. (C) 2014 Elsevier B.V. All rights reserved.
  • Authors:
    • Jair Andrade, H.
    • Alvarado, J.
    • Segura, M.
  • Source: Revista Colombia Forestal
  • Volume: 16
  • Issue: 1
  • Year: 2013
  • Summary: The increase in greenhouse gas emissions from anthropogenic sources has resulted in climate change, which affects all living beings. Coffee (Coffea arabica L.) plantations, in monoculture or together with timber species such as salmwood (Cordia alliodora), mitigate climate change due to fixation of atmospheric CO 2 that is deposited in biomass and soils. This study was carried out in the municipality of Libano, Tolima, Colombia with the objective of defining which of the following coffee production systems store more soil organic carbon (SOC): (1) monoculture, (2) agroforestry systems (AFS) with salmwood, and (3) AFS with plantain. Farms with those systems that are the most dominant in the study zone were selected. From each system, five repetitions were identified to be analyzed with a completely randomized design. In each plot or repetition, five samples for bulk density (BD) using the cylinder method and a composite sample for concentration of SOC were taken and analyzed using the Walkley and Black approach. The systems of production did not significantly (p >0.05) affect either the BD or the concentration of SOC. However, AFS with plantain tended to have less BD than monoculture and AFS with salmwood (0.830.03 vs 0.880.03 vs 0.920.04 g.cm -3, respectively). These systems of production stored between 50 and 54 t.ha -1 of SOC in the top 30 cm, which indicates their capacity for climate change mitigation.
  • Authors:
    • Gonzalez, A.
    • Tapasco, J.
    • Graefe, S.
  • Source: Fruits
  • Volume: 68
  • Issue: 4
  • Year: 2013
  • Summary: Introduction. The cultivation of high-value fruit species is a profitable agricultural activity in many tropical countries; however, intensive fruit cultivation may depend on high amounts of external inputs. The objective of our study was to quantify and compare the resource use during the cultivation of eight tropical fruit species (Rubus glaucus, Solanum quitoense, Passiflora edulis, Cyphomandra betacea, Physalis peruviana, Ananas comosus, Persea americana and Mangifera indica) commonly cultivated in Colombia. It further aimed to identify greenhouse gas (GHG) emissions in the selected production systems and to highlight the potential to contribute to climate change mitigation efforts. Materials and methods. The analysis was based on data from agricultural databases and applied a life-cycle assessment with energy use and GHG emissions as impact categories. Furthermore, economic indicators were taken into account with the aim of integrating the environmental and economic goals of production systems. Results and discussion. Among the eight fruit species studied, mango (Mangifera indica) was found to have the lowest and tree tomato (Cyphomandra betacea) the highest emission profile. The variability in resource use among growers of the same species was high, indicating the need to improve management abilities at the farm level. Mineral fertilizer production was the highest contributor to GHG emissions. GHG- and energy-efficient management alternatives would have a high potential to reduce the carbon footprint of fruit cultivation.
  • Authors:
    • Murgueitio Restrepo, E.
    • Ibrahim, M.
    • Montagnini, F.
  • Source: BOIS ET FORETS DES TROPIQUES
  • Issue: 316
  • Year: 2013
  • Summary: Cattle production is part of people's cultures and is important for human nutrition and welfare. However, conventional cattle ranching is a source of greenhouse gas (GHG) emissions. Carbon sequestration in vegetation and soils can be enhanced and GHG emissions reduced with controlled grazing, appropriate pasture species, and the use of silvopastoral systems (SPS), which combine trees and shrubs with pastures. In addition, SPS contribute to climate change adaptation thanks to the ameliorating effects of trees on air temperatures that dry out pastures, as well as improving animal well-being and productivity. Several types of SPS are commonly found in the agricultural landscapes of Latin America. Intensive SPS (ISPS), where fodder banks are combined with woody species planted at high density, produce better yields than conventional ranching thanks to higher cattle density and better weight gain by the animals. Research in Colombia, Nicaragua and Costa Rica shows that SPS have more carbon in aboveground biomass and in soils than degraded pastures. In SPS, the timber or fruit trees, either planted or from natural forest regeneration, increases carbon stocks and sequestration rates. Native tree species can be used in SPS with good results in terms of productivity, soil restoration, carbon sequestration, and biodiversity conservation. The use of SPS contributes to carbon sequestration in trees and in soils, while establishing forest plantations and conserving secondary forests increase carbon sequestration and storage at the landscape level. SPS and especially ISPS can contribute to climate change mitigation because their net GHG emissions can be negative. In Latin America, successful ISPS are being scaled up to regional levels. Incentives such as Payments for Environmental Services along with technical assistance can stimulate the adoption of SPS, thus contributing to climate change mitigation while preserving rural livelihoods.