- Authors:
- Chuine, I.
- Regniere, J.
- Crespo-Perez, V.
- Rebaudo, F.
- Dangles, O.
- Source: GLOBAL CHANGE BIOLOGY
- Volume: 21
- Issue: 1
- Year: 2015
- Summary: Climate induced species range shifts might create novel interactions among species that may outweigh direct climatic effects. In an agricultural context, climate change might alter the intensity of competition or facilitation interactions among pests with, potentially, negative consequences on the levels of damage to crop. This could threaten the productivity of agricultural systems and have negative impacts on food security, but has yet been poorly considered in studies. In this contribution, we constructed and evaluated process-based species distribution models for three invasive potato pests in the Tropical Andean Region. These three species have been found to co-occur and interact within the same potato tuber, causing different levels of damage to crop. Our models allowed us to predict the current and future distribution of the species and therefore, to assess how damage to crop might change in the future due to novel interactions. In general, our study revealed the main challenges related to distribution modeling of invasive pests in highly heterogeneous regions. It yielded different results for the three species, both in terms of accuracy and distribution, with one species surviving best at lower altitudes and the other two performing better at higher altitudes. As to future distributions our results suggested that the three species will show different responses to climate change, with one of them expanding to higher altitudes, another contracting its range and the other shifting its distribution to higher altitudes. These changes will result in novel areas of co-occurrence and hence, interactions of the pests, which will cause different levels of damage to crop. Combining population dynamics and species distribution models that incorporate interspecific trade-off relationships in different environments revealed a powerful approach to provide predictions about the response of an assemblage of interacting species to future environmental changes and their impact on process rates.
- Authors:
- Cayambe,J.
- Iglesias,A.
- de Jalón,S. G.
- Chuquillanqui,C.
- Riga,P.
- Source: ITEA
- Volume: 111
- Issue: 2
- Year: 2015
- Summary: The temperature rise of the planet associated with anthropogenic greenhouse gas emissions promotes interest for strategies to mitigate them. Since agriculture is a sector responsible for nearly a fifth of global emissions, it is necessary to identify measures to be applied, what is their mitigation potential and the estimated cost of implementing each measure. Our study addresses these questions by comparing the production of potato in two distinct production systems and with actual field data. In a first step, this paper calculates in a modern agricultural system the carbon footprint of mechanization and energy use for irrigation (located in Spain) and in less productive systems that integrate less technologies (located in Peru) . The results show that in the case studies in both countries the nitrogen cycle represents the primary source of greenhouse gas emissions, followed by energy fuel for irrigation and mechanization. Subsequently this study evaluates economically the mitigation actions through Marginal Abatement Cost Curves. These results demonstrate that the management of nitrogen fertilizer is the best alternative to reduce the carbon footprint because of their greater potential to reduce greenhouse gas emissions and their lower equivalent mitigation costs. Finally, the study provides a methodological framework that can be easily applied to other crops. © 2015, Asociacion Interprofesional para el Desarrollo Agrario. All rights reserved.
- 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:
- Source: Climatic Change
- Volume: 133
- Issue: 3
- Year: 2015
- Summary: It is banal to say that different beliefs provide the basis for different conceptions of the good and diverse ways of life, the protection of which will seem to many to be paramount as a matter of justice. But what happens when those beliefs are about global processes of the magnitude of those involved in climate change, with the scale of their implications? How, and to what extent, should the diversity of local beliefs about factors relevant to climate change be factored into a normative response to the challenges it poses? This article is framed in response to the companion piece 'Local perceptions in climate change debates', which presents detailed contrasts between such beliefs in Peru and the South Tyrol. Focusing on perceptions of the nature/culture relationship as an example, I contrast 'globalist' and 'localist' normative responses to evidence of such diversity in belief. Both are limited, to the extent that they dwell on the fair treatment of beliefs. I argue that normatively speaking, what is crucial is not accommodating diversity in belief - as if beliefs about the factors implicated in climate change were on a par with other beliefs about the nature of the good - but acknowledging the requirement to make 'thick' commitments about which such beliefs are most adequate. Alongside their fascinating contributions in other respects, anthropological findings can be crucial in this one. They will help furnish the kind of understanding of human/nature relations on which a political philosophy of climate change must depend.
- Authors:
- Cisz, M.
- Galdos, M.
- Hilbert, J.
- Rod, K.
- Ferreira, A.
- Leite, L.
- Kaczmarek, D.
- Chimner, R.
- Resh, S.
- Asbjornsen, H.
- Scott, D.
- Titus, B.
- Gollany, H.
- Source: Environmental Management
- Volume: 56
- Issue: 6
- Year: 2015
- Summary: Rapid expansion in biomass production for biofuels and bioenergy in the Americas is increasing demand on the ecosystem resources required to sustain soil and site productivity. We review the current state of knowledge and highlight gaps in research on biogeochemical processes and ecosystem sustainability related to biomass production. Biomass production systems incrementally remove greater quantities of organic matter, which in turn affects soil organic matter and associated carbon and nutrient storage (and hence long-term soil productivity) and off-site impacts. While these consequences have been extensively studied for some crops and sites, the ongoing and impending impacts of biomass removal require management strategies for ensuring that soil properties and functions are sustained for all combinations of crops, soils, sites, climates, and management systems, and that impacts of biomass management (including off-site impacts) are environmentally acceptable. In a changing global environment, knowledge of cumulative impacts will also become increasingly important. Long-term experiments are essential for key crops, soils, and management systems because short-term results do not necessarily reflect long-term impacts, although improved modeling capability may help to predict these impacts. Identification and validation of soil sustainability indicators for both site prescriptions and spatial applications would better inform commercial and policy decisions. In an increasingly inter-related but constrained global context, researchers should engage across inter-disciplinary, inter-agency, and international lines to better ensure the long-term soil productivity across a range of scales, from site to landscape.
- Authors:
- Botello, R.
- Barrera, V.
- Alwang, J.
- Delgado, J. A.
- Escudero, L.
- Saavedra, A. K.
- Monar, C.
- Source: Journal of Soil and Water Conservation
- Volume: 68
- Issue: 1
- Year: 2013
- Authors:
- Source: Acta Horticulturae
- Issue: 947
- Year: 2012
- Summary: Hydroponics has been used during years for research in the field of plant mineral nutrition and related topics. Today the soilless culture method is the most intensive horticulture production and is being applied with success in developed countries for commercial purposes. The growing and future of hydroponics in Latin America will much depend of the developing and adaptation of less sophisticated commercial systems. These have to be cost competitive with respect to the high sophisticated technology generated and used in developed countries, using natural and local substrates, developing native or endemic crops of the Region with economical potential for its high feed or medicinal value, among others. Meanwhile, as there is a considerable decreasing of agricultural soils in the world, soilless culture would be an important production alternative in urban and peri-urban areas, mainly in undeveloped countries. Inside the context of urban agriculture, hydroponics could be applied in the cities with more simple and low cost of technologies, mainly in extreme poverty areas, as a way to spread vegetables for self-consumption and to support the family or community income. Also to create micro-companies that will generate employments. There are no official statistics on the evolution of the state of the hydroponic cultures in Latin America. The main hydroponic systems used are the drip irrigation and NFT system. According with their profits, the main hydroponic crops are lettuce, tomato, pepper and strawberry. In Andean countries like Peru, Bolivia, Colombia and Ecuador, aeroponics is being developing to obtain basic potato tuber seed, free of virus. In relation to the media used in soilless culture, there is no ideal or optimum substrate, because a great diversity in media could be used, as pure or as mix form. Among the inorganic substrates it is possible to use quarry, river and quartz sand, gravel, pumice and tezontle. Husk rice, coco fiber, peat moss and sawdust are used as organic media. The use of rock wool is not generalized in the Region, but in countries like Mexico and Chile it is mainly used in tomato crop with drip irrigation system. Brazil and Mexico are the more representative hydroponic countries in Latin America. The area of soilless culture is increasing in the Region and every day there is much interest to learn and to dominate this technique of plants production without using soil. A great number of international courses, seminaries, congresses and symposia organized in countries like Peru, Mexico, Brazil, Costa Rica and Chile demonstrate this affirmation. Finally, it is necessary to obtain a hydroponic certification, as well as the organic products, to support the hydroponic growers in our countries.
- Authors:
- Kreuzer, M.
- Wettstein, H.
- Gomez, C.
- Gamarra, J.
- Bartl, K.
- Hess, H.
- Source: Grass and Forage Science
- Volume: 64
- Issue: 2
- Year: 2009
- Summary: The agronomic performance and nutritive value of twelve annual and perennial grasses and legumes were analysed in order to define alternatives to local forages for dry-season feeding of ruminants in the Peruvian Andes. There were twelve species and two fertilizer treatments (no fertilizer and a N;P;K fertilizer mainly applied at sowing) in an experiment with a randomized complete block design with three replicates at each of two sites. Plant height, soil cover by forage and weed species, frost damage, dry matter (DM) yield and nutritive value of herbage were evaluated in 2005 and 2006. Among the annual species, Hordeum vulgare L. cv. UNA 80 and * Triticosecale Wittm. had the highest DM yields when fertilized (8226 and 6934 kg ha -1 respectively). Without fertilizer the alternative cultivars had similar DM yields to that of the local forages. Cultivars of Avena sativa L. had lower concentrations of neutral-detergent fibre (NDF) (557 g kg -1 DM) and higher concentrations of predicted net energy for lactation (5.86 MJ kg -1 DM) than the other annual grass species (625 g kg -1 DM and 5.01 MJ kg -1 DM respectively), while the legumes were superior in concentrations of crude protein (277 g kg -1 DM) and NDF (362 g kg -1 DM). Considering the low agronomic performance of the perennial forages, a mixture of fertilized annual grasses and legumes appears the most appropriate approach to meeting the demand for forage of high nutritive value in the Peruvian highlands.
- Authors:
- Hairiah, K.
- Weise, S.
- Sonwa, D.
- Mbile, P.
- Agus, F.
- Edadinata, A.
- Meadu, V.
- Robiglio, V.
- Budidarsono, S.
- Hyman, G.
- Gockowski, J.
- White, D.
- Murdiyarso, D.
- Dewi, S.
- Van Noordwijk, M.
- Swallow, B.
- Year: 2007
- Authors:
- Moreira, A.
- Martins, G.
- Mccann, J.
- German, L.
- Kern, D.
- Lehmann, J.
- Source: Amazonian Dark Earths
- Volume: Part 2
- Year: 2004