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6 resultados encontrados para: AUTOR: Casanoves, Fernando
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1.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees.


2.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

Forest ecosystems are major providers of high quality water and contribute to maintain a better distribution of base flows during the year. However, these environmental services have been adversely affected by human pressure due to the decline and deterioration of forested areas and the inadequate management of water resources. To better understand the relations between human population, forest area and water quality and yield, at a regional level, we studied six catchments located in the upper Grijalva river basin in the border between Guatemala and Mexico. Measurements of twelve water quality parameters and water yield from nine sampling periods during 2011–2013 were analyzed through PLS (partial least squares) regression, ANOVA and linear mixed models to assess the season effect on water quality and the forest cover effect on water yield. An ordination by PCA (principal components analysis) and Pearson's pair-wise correlations were used to identify association between hydrological and social catchment features (forest cover, protection of riparian buffer strips, population density and urban areas). Our results suggest that overall water quality is higher during the dry season (higher values of dissolved oxygen and lower levels of total dissolved solids, total suspended solids, total phosphorus, chemical oxygen demand and temperature were observed). Water yield is positively related to forest cover and riparian buffer strips, becoming essential in maintaining water security for local populations. Major threats to water flux and their quality are related to human pressures and untreated wastewater discharges, which reduce water quality of the receiving rivers.


3.
- Artículo con arbitraje
Concepts and a methodology for evaluating environmental services from trees of small farms in Chiapas, Mexico
Marinidou, Eleni ; Finegan, Bryan (coaut.) ; Jiménez Ferrer, Guillermo (coaut.) ; Delgado, Diego (coaut.) ; Casanoves, Fernando (coaut.) ;
Contenido en: Journal of Environmental Management Vol. 114 (January 2013), p. 115-124 ISSN: 0301-4797
Resumen en: Inglés |
Resumen en inglés

We propose a methodology to estimate the environmental service (ES) value of small farms in Chiapas, Mexico, involving trained farmers-promoters in field sampling. We considered the ways in which the landscape's principal organisms, the trees, contribute to ES. We proposed a species functional value (FV) index based on their functional traits and key ecological characteristics, and estimated each site's ES value using FV weighted by the dimensions and abundance of individuals in different land uses (LU). Tree contribution to carbon storage (C) was defined using species wood density and biodiversity conservation value (BD) using food and habitat provision for wildlife and species existence (non-use) value (EX). Many species and individuals had high C, as wind-dispersed species with dense wood were common, but low BD prevailed, with high BD species common only in riparian forests. Few species and fewer individuals had high EX conferred by dense wood, large size, harvesting pressure and animal dispersal, among others. High variance in value within LU types, suggested that LU is a poor estimator of ES value, and that the measurement of species FV and tree dimensions is essential. This tool accurately reflects the ecological values of farm tree cover, allowing negotiation of compensation for environmental services. This methodology could be implemented combining open-access regional traits databases and field sampling by local people, and can easily be adapted for the measurement of other ES, and to other ecological and cultural contexts. The functional ecology approach was adapted to assess environmental services. Existence (non use) value of trees was used in biodiversity service estimation. Environmental services valuation based only on land use category is questioned. Outside forest, carbon service value was high but biodiversity value low. We recognize complexity to accurately estimate environmental service supply.


4.
Capítulo de libro
*Solicítelo con su bibliotecario/a
Estimación de los servicios ecosistémicos con índices funcionales específicos
Marinidou, Eleni ; Finegan, Bryan (coaut.) ; Jiménez Ferrer, Guillermo (coaut.) ; Casanoves, Fernando (coaut.) ; Delgado, Diego (coaut.) ;
Contenido en: Valoración y análisis de la diversidad funcional y su relación con los servicios ecosistémicos Turrialba, Costa Rica : Centro Agronómico Tropical de Investigación y Enseñanza, 2011 p. 75-105 ISBN:978-997-7575-39-1
Nota: Solicítelo con su bibliotecario/a

5.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Efecto del ancho del bosque ribereño en la calidad del agua en la microcuenca del río Sesesmiles, Copán, Honduras: uso de comunidades de macroinvertebrados bentónicos como organismos indicadores
Arcos, Inty ; Jiménez Otárola, Francisco (coaut.) ; Harvey, Celia (coaut.) ; Campos, José Juaquín (coaut.) ; Casanoves, Fernando (coaut.) ; León, Josué Anibal (coaut.) ;
Contenido en: Recursos Naturales y Ambiente No. 48 (agosto 2006), p. 29-34 ISSN: 1659-1216
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
B10879 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal

6.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Manejo de recursos hídricos y vulnerabilidad a la contaminación del acuífero Guaraní en la Cuenca del Arroyo Capiibary, Paraguay
Laino Guanes, Rafaela María ; Jiménez Otárola, Francisco (coaut.) ; Páez, Gilberto (coaut.) ; Casanoves, Fernando (coaut.) ; Velásquez, Sergio (coaut.) ;
Contenido en: Recursos Naturales y Ambiente No. 48 (agosto 2006), p. 65-74 ISSN: 1659-1216
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
B10890 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal