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5 resultados encontrados para: AUTOR: Naeem, Shahid
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1.
- Artículo con arbitraje
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Smallholder response to environmental change: impacts of coffee leaf rust in a forest frontier in Mexico
Valencia, Vivian ; García Barrios, Luis Enrique (coaut.) ; Sterling, Eleanor J. (coaut.) ; West, Paige (coaut.) ; Meza Jiménez, Amayrani (coaut.) ; Naeem, Shahid (coaut.) ;
Contenido en: Land Use Policy Vol. 79 (December 2018), p. 463-474 ISSN: 0264-8377
Nota: Solicítelo con su bibliotecario/a
Resumen en: Inglés |
Resumen en inglés

Coffee agroforestry systems are a promising approach to the challenge of sustaining both biodiversity and livelihoods in tropical landscapes. However, coffee farmers' response to the unrelenting coffee leaf rust (CLR) outbreak may have repercussions for the potential of coffee agroforestry systems to contribute to biodiversity conservation. Adaptations in management practices could affect the extent to which farmers rely on ecological processes vs. external inputs (e.g., agrochemicals) to support production. This study investigates farmers' response to CLR outbreak through a study in a forest frontier in a Biosphere Reserve in Chiapas, Mexico. We conducted household surveys and fieldwork before the CLR outbreak in 2011-2012 (n = 59), and follow-up surveys after the outbreak in 2016 (n = 48). Before CLR outbreak, farmers were cultivating Arabica coffee varieties in agroforestry systems and generally following agroecological approaches. Most farmers (82%) were certified organic and did not employ synthetic agrochemicals. Farmers (66%) had plans to expand their Arabica coffee agroforests either into forest (35%) or fallow (31%) in response to high farm gate prices. After CLR outbreak, 94% of farmers had CLR-resistant hybrid coffee varieties (HCV) in their possession and were either incorporating them by substituting affected Arabica coffee plants in existing fields, or by establishing new coffee fields with HCV at lower elevations. In attempts to control CLR, farmers (54%) also applied agrochemicals at least once and, to a lesser extent (19%), removed shade trees. Among the farmers (63%) who were planning on expanding coffee production with HCV, more farmers were planning on expanding on fallow (46%) than forest (17%) compared to the period before CLR outbreak (p-value < 0.05). Public and private actors promoted and distributed saplings of HCV and agrochemicals along with technical assistance.

The promotion of HCV along with fertilizers may result in a substitution of ecosystem functions with agrochemicals, and the need to acquire seeds and saplings outside of farmers’ own resource base and networks. This shift in management strategies generates new instabilities and risks by introducing a new market for HCV about which little is known and by making external agents the holders of productive resources and knowledge.


2.
- Artículo con arbitraje
Conservation of tree species of late succession and conservation concern in coffee agroforestry systems
Valencia, Vivian ; Naeem, Shahid (coaut.) ; García Barrios, Luis Enrique (coaut.) ; West, Paige (coaut.) ; Sterling, Eleanor J. (coaut.) ;
Contenido en: Agriculture, Ecosystems & Environment Vol. 219 (March 2016), p. 32–41 ISSN: 0167-8809
Resumen en: Inglés |
Resumen en inglés

Shade-grown, montane coffee agroforestry systems have the potential to conserve native tree species of conservation concern (CC) and typical of old growth or late succession (LS) forests in montane cloud forests. However, it remains unclear how preferential selection by farmers for or against certain tree species and diameter sizes affects CC and LS trees distribution and abundance. To address this issue, we investigated how management practices may inadvertently compromise the potential of agroforestry systems to serve as reservoirs for CC and LS trees. We sampled tree diversity in 31 coffee farms and 10 forest sites in La Sepultura Biosphere Reserve in Chiapas, Mexico and assessed the relative importance of shade tree density, basal area, proportion of Inga spp. trees, previous land use, and age of fallow (for farms established on land with an agricultural history) on the proportions of CC and LS trees. We then examined if tree size distributions differed between farms and forests, and whether land use legacies mediated the impact of the explanatory variables of interest. These analyses found that management practices that sought to increase the proportion of Inga spp. trees had the largest negative impact on the proportions of trees of LS and CC, but the magnitude of the effects were dependent on land-use legacy. We also found that tree size distributions differed between farms and forests among smaller trees (5–20 cm diameter at breast height, (DBH)), but not among larger trees (>30 cm DBH). These findings suggest that in order to increase the conservation potential of coffee agroforestry systems, particularly for farms established on land with an agricultural history, it is important to promote farmers’ tolerance of tree species other than Inga spp. and preferred tree species.


3.
- Artículo con arbitraje
The role of coffee agroforestry in the conservation of tree diversity and community composition of native forests in a Biosphere Reserve
Valencia, Vivian ; García Barrios, Luis Enrique (coaut.) ; West, Paige (coaut.) ; Sterling, Eleanor J. (coaut.) ; Naeem, Shahid (coaut.) ;
Contenido en: Agriculture, Ecosystems and Environment Vol. 189, (May 2014), p. 154–163 ISSN: 0167-8809
Resumen en: Inglés |
Resumen en inglés

Agroforestry is considered a promising alternative to conventional agriculture that can both conserve biodiversity and support local livelihoods. Coffee agroforestry may be particularly important for sustaining trees of conservation concern and late-successional stage, but this possibility remains unclear. Here, we examined whether coffee agroforestry systems can serve as conservation reservoirs of tree species native to nearby forests. We compared tree diversity, composition and structure between coffee agroforests and forests in La Sepultura Biosphere Reserve in Chiapas, Mexico. We found that, although at the landscape level the full set of coffee agroforests appears to conserve comparable tree species richness to nearby native forests, the species composition that is being conserved is different. Coffee agroforests had a lower proportion of trees of conservation concern, a higher proportion of pioneer trees, were dominated by Inga spp., harbored lower tree species diversity at the plot level, and were composed of different tree species compared to native forests. We suggest that conservation practitioners and policy makers seeking to promote coffee agroforestry as a conservation strategy should consider how such agroforestry systems differ in species diversity and composition from the native forests of conservation interest. Further, promoting different coffee agroforest management strategies, such as discouraging the replacement of diverse agroforest canopies with Inga-dominated canopies, would help improve the conservation value of coffee agroforests through more sustainable practices.


4.
Libro
Biodiversity, ecosystem functioning, and human wellbeing: an ecological and economic perspective / edited by Shahid Naeem, ... [et al.]
Naeem, Shahid (ed.) ; Bunker, Daniel E. (coed.) ;
Oxford : Oxford University Press , 2009
Clasificación: 333.95 / B54
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
ECO010014837 (Disponible)
Disponibles para prestamo: 1

5.
Libro
Biodiversity and ecosystem functioning: synthesis and perspectives / edited by Michel Loreau, Shahid Naeem, Pablo Inchausti
Loreau, Michel (ed.) ; Naeem, Shahid (coed.) ; Inchausti, Pablo (coed.) ;
Oxford : Oxford University Press , c2002
Clasificación: 574.5248 / B56
Bibliotecas: Campeche
Cerrar
SIBE Campeche
ECO040003894 (Disponible)
Disponibles para prestamo: 1
Resumen en: Inglés |
Resumen en inglés

The relationship between biodiversity and ecosystem functioning has emerged as one of the most exciting and dynamic areas in contemporary ecology. Increasing domination of ecosystems by humans is steadily transforming them into depauperate systems. How will this loss of biodiversity affect the functioning and stability of natural and managed ecosystems? This volume provides the first comprehensive and balanced coverage of recent empirical and theoretical research on this question. It reviews the evidence, provides bases for the resolution of the debate that has divided scientists on these issues, and offers perspectives on how current knowledge can be extended to other ecosystems, other organisms and other spatial and temporal scales. It cuts across the traditional division between community ecology and ecosystem ecology, and announces a new ecological synthesis in which the dynamics of biological diversity and the biogeochemical functioning of the earth system are merged.