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53 resultados encontrados para: TEMA: Bosques tropicales secos
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1.
Artículo
Combining LiDAR data and airborne imagery of very high resolution to improve aboveground biomass estimates in tropical dry forests
Reyes Palomeque, Gabriela (autora) ; Manuel Dupuy, Juan (autor) ; Johnson, Kristofer D. (autor) ; Castillo Santiago, Miguel Ángel (autor) ; Hernández Stefanoni, José Luis (autor) ;
Disponible en línea
Contenido en: Forestry An International Journal of Forest Research Volume 92, número 5 (October 2019), p. 599–615 ISSN: 1464-3626
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Resumen en: Inglés |
Resumen en inglés

Knowledge of the spatial distribution of aboveground biomass (AGB) is crucial to guide forest conservation and management to maintain carbon stocks. LiDAR has been highly successful for this purpose, but has limited availability. Very-high resolution (<1 m) orthophotos can also be used to estimate AGB because they allow a fine distinction of forest canopy grain. We evaluated the separate and joint performance of orthophotos and LiDAR data to estimate AGB in two types of tropical dry forests in the Yucatan Peninsula. Woody plants were surveyed in twenty 0.1 ha plots in a semideciduous forest at Kaxil Kiuic Biocultural Reserve (RBKK) and 28 plots in a semievergreen forest at Felipe Carrillo Puerto (FCP). We fitted three regression models: one based on LiDAR data, another based on orthophoto variables calculated for forest canopy and canopy opening fractions, and a third model that combined both sets of variables. Variation in AGB was decomposed into LiDAR, orthophotos and joint components using variation-partitioning analyses. In FCP, regression models using LiDAR data only showed higher fit (R2 = 0.82) than orthophoto variables only (R² = 0.70). In contrast, orthophotos had a slightly higher fit (R² = 0.91) than LiDAR (R2 = 0.88) in RBKK, because orthophoto variables characterize very well the horizontal structure of canopies on this site. The model that combined both data sets showed a better fit (R2 = 0.85) only in FCP, which has a more complex forest structure. The largest percentage of AGB variation (88 per cent in RBKK and 67 per cent in FCP) was explained by the joint contribution of LiDAR and orthophotos. We conclude that both LiDAR and orthophotos provide accurate estimation of AGB, but their relative performance varies with forest type and structural complexity. Combining the two sets of variables can further improve the accuracy of AGB estimation, particularly in forests with complex vegeta


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Resumen en: Inglés |
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The role of invasive species in ecosystem functioning represents one of the mainchallenges in ecology.Pteridium aquilinumis a successful cosmopolitan invasive specieswith negative effects on the ecological mechanisms that allow secondary succession. Inthis study, we evaluated the influence of P. aquilinumon secondary succession underdifferent disturbances in a seasonal dry forest of the Yucatán Peninsula. We determined species richness, composition and the relative importance value in four sampling units. Fabaceae followed by Asteraceae, Meliaceae, Rubiaceae, Sapindaceae and Verbenaceaewere the most species rich families. A dissimilarity analysis determined significant differences in beta diversity between sampling units. With a generalized linear model wefound that species richness was best explained by site conditions, followed by calciumand soil organic matter. Also, the generalized linear model showed that abundanceresulted in a strong correlation with site conditions and soil characteristics. Specific soil conditions related to phosphoro and calcium were also detected as beneficiary tothe successional processes. Our results suggest that applying fire restriction and periodiccutting of the bracken fern, this can increase a higher diversity of species.


3.
Artículo
*Solicítelo con su bibliotecario/a
Succession and the relationship between vegetation and soil in the Marl Quarries of the Yucatan Peninsula, Mexico
Valdéz Hernández, Mirna ; Gil Medina, Rossana (coaut.) ; López Martínez, Jorge Omar (coaut.) ; Torrescano Valle, Nuria (coaut.) ; Cabanillas Terán, Nancy (coaut.) ; Islebe, Gerald A. (coaut.) ;
Contenido en: Forests Vol. 10, no. 116 (2019), p. 1-13 ISSN: 1999-4907
Nota: Solicítelo con su bibliotecario/a
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4.
- Artículo con arbitraje
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Effects of long-term inter-annual rainfall variation on the dynamics of regenerative communities during the old-field succession of a neotropical dry forest
Martínez Ramos, Miguel ; Balvanera, Patricia (coaut.) ; Arreola Villa, Felipe (coaut.) ; Mora, Francisco (coaut.) ; Maass, José Manuel (coaut.) ; Maza Villalobos Méndez, Susana (coaut.) ;
Contenido en: Forest Ecology and Management Vol. 426, (October 2018), p. 91-100 ISSN: 0378-1127
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Resumen en: Inglés |
Resumen en inglés

Effects of long-term rainfall inter-annual variation on regeneration dynamics of tropical dry forests (TDF) are still poorly understood. Such understanding is particularly important to assess the regeneration potential of TDF in landscapes subjected to slash-and-burn farming management. Here, we studied from 2004 to 2016 the effects of inter-annual rainfall variation on the dynamics of regenerative communities of woody species during the old-field succession of a TDF in Western Mexico. Over the study period a severe drought, caused by an El Niño Southern Oscillation (ENSO) event in 2005, and two hurricanes (Jova, 2011, magnitude 2; Patricia, 2015, magnitude 4) were experienced. In 2004, we established a chronosequence of abandoned cattle pastures and old-growth forest sites, which were assigned to four successional categories, each one with three sites: Pasture (0–3 years fallow age), Early (3–5 years), Intermediate (8–12 years), and Old-Growth Forest (without any human disturbance). At each site, seedlings, saplings and resprouts 10–100 cm height of shrub and tree species were tagged, taxonomically identified, measured in height and monitored over 12 continuous year intervals. At each year, all new plants reaching 10 cm height were recorded and considered as recruits. Community rates (recruitment, relative growth rate in height, mortality, species gain and species loss) were calculated per year, considering all plants combined and separating shrub from tree species. All community rates varied notoriously in response to temporal rainfall variability, with almost null interaction with successional category. As expected, mortality and species loss rates declined as the amount of rainfall increased, especially when precipitation of the current and the previous year were taken into account; these rates peaked in the ENSO year and were still high in the following year.

Unexpectedly, recruitment and species gain rates also declined with the increase in rainfall, especially with the amount of rainfall in the current year. Overall, community rates of tree species were more responsive than those of shrub species to temporal rainfall variation. The ENSO-related drought event produced a short and transient instability in the plant density and species density of regenerative communities. However, ENSO effects were smoothed out by subsequent rainy years, leading to a net increase in plant density and species density in all successional categories, especially in the younger one. Overall, our study shows that global (e.g. ENSO) and regional (e.g. storms, hurricanes) climate factors play a key role on forest succession, modulating the speed of the TDF regeneration dynamics. We conclude that low impact agricultural land use and the presence of good levels of remnant forest cover in the landscape confers a high potential for regeneration in abandoned agricultural fields, even under the impact of severe droughts and severe hurricanes.


5.
- Artículo con arbitraje
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Resumen en: Inglés |
Resumen en inglés

Accurate estimates of above ground biomass (AGB) are needed for monitoring carbon in tropical forests. LiDAR data can provide precise AGB estimations because it can capture the horizontal and vertical structure of vegetation. However, the accuracy of AGB estimations from LiDAR is affected by a co-registration error between LiDAR data and field plots resulting in spatial discrepancies between LiDAR and field plot data. Here, we evaluated the impacts of plot location error and plot size on the accuracy of AGB estimations predicted from LiDAR data in two types of tropical dry forests in Yucatán, México. We sampled woody plants of three size classes in 29 nested plots (80 m², 400 m² and 1000 m²) in a semi-deciduous forest (Kiuic) and 28 plots in a semi-evergreen forest (FCP) and estimated AGB using local allometric equations. We calculated several LiDAR metrics from airborne data and used a Monte Carlo simulation approach to assess the influence of plot location errors (2 to 10 m) and plot size on ABG estimations from LiDAR using regression analysis. Our results showed that the precision of AGB estimations improved as plot size increased from 80 m² to 1000 m² (R² = 0.33 to 0.75 and 0.23 to 0.67 for Kiuic and FCP respectively). We also found that increasing GPS location errors resulted in higher AGB estimation errors, especially in the smallest sample plots. In contrast, the largest plots showed consistently lower estimation errors that varied little with plot location error. We conclude that larger plots are less affected by co-registration error and vegetation conditions, highlighting the importance of selecting an appropriate plot size for field forest inventories used for estimating biomass.


6.
- Artículo con arbitraje
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Resumen en: Inglés |
Resumen en inglés

We document the first record of Imantodes gemmistratus for Zacatecas state, Mexico. In August 2016, one adult male was found in a dry forest and oak forest ecotone in the Municipality of Valparaiso. This new record extends known distribution of the species 166 km to the northeast from the nearest previous record in Nayarit state.


7.
Artículo
Resumen en: Inglés |
Resumen en inglés

The tropical dry forest (BTS) of Yucatan Peninsula has been managed for centuries, but the relationship between these management efforts and their effects on trees diversity has not been fully understood. The aim of this study was to evaluate the effect of forest management (thinning, harvesting and enrichment of species), in the structure of secondary vegetation derived from dry tropical forests, in two communities in Calakmul, Campeche, Southeast Mexico. We analyzed changes in the composition, species richness, species diversity, and structure in secondary vegetation subject to following types of management: (1) secondary vegetation with beekeeping management (MA), secondary vegetation with forest management (MF), natural secondary vegetation (SM) and tropical dry forest (BTS). The species composition was similar between secondary vegetation managed and unmanaged. On the other hand, between managed secondary vegetation and BTS there were differences in species composition. Species richness was not different between all conditions. MA showed the lowest species diversity and presented higher average density (5 413±770.26 ind.ha-1).MF had lowest average density (3 289 ± 1 183.60 ind.ha-1). BTS showed the highest average basal area (24.89 ± 1.56 m2.ha-1) regarding the other conditions. We concluded that is necessary to keep monitoring the managed areas to detect effects of management that may be adverse or favorable to conservation of floristic diversity of BTS.


8.
Tesis - Maestría
Producción sustentable de leña y carbón, una vía para luchar contra la pobreza / Vitza Cabrera Manrique
Cabrera Manrique, Vitza ; Valdéz Hernández, Mirna (tutora) ; Macario Mendoza, Pedro A. (evaluador) ;
Chetumal, Quintana Roo, México : El Colegio de la Frontera Sur :: Université de Sherbrooke , 2017
Clasificación: TE/333.953970972 / C3
Cerrar
SIBE Campeche
ECO040006719 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
ECO030008644 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
ECO010019154 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
ECO020013727 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
ECO050006328 (Disponible)
Disponibles para prestamo: 1
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Índice | Resumen en: Español | Frances |
Resumen en español

Los bosques son ecosistemas que se encuentran distribuidos en todas las regiones del planeta. Intervienen en diversos ciclos biogeoquímicos y actúan como sumideros de carbono, lo que ayuda en la regulación del clima y ofrecen una gran cantidad de productos de necesidad básica. La leña y el carbón forman parte de estos productos, los cuales son la principal fuente de energía para millones de personas, sobre todo en países en desarrollo. Además, esta industria genera gran cantidad de empleos a lo largo de la cadena productiva. A pesar de su relevancia, esta industria se ha mantenido en el sector informal por ser considerada una fuente de energía para pobres. Hasta hoy, existe una gran ignorancia sobre la cantidad de leña y carbón que es suministrada y consumida, así como del funcionamiento y la dinámica de la cadena productiva. Asimismo, no existen leyes que regularicen la actividad, ni un interés de los gobiernos por desarrollarla. Este ensayo evalúa la contribución y sustentabilidad de la industria de la leña y producción de carbón en la lucha contra la pobreza. Los estudios de caso presentados muestran los vacios de información que existen a lo largo de la cadena y una deficiencia en la ejecución de políticas públicas; situación que demerita su sustentabilidad y uso como mecanismo para luchar contra la pobreza. Para lograr la sustentabilidad es imprescindible implementar políticas públicas que reconozcan su valor y formalicen y regularicen la actividad, así como estudios que permitan cubrir dichos vacios. Es necesario desarrollar, junto con las comunidades, planes de manejo forestal sustentable y aplicar tecnología que eficientice el uso de leña iv y la producción de carbón. Sólo así, esta industria podría llegar a ser una vía contra la pobreza.

Resumen en frances

Les forêts sont reparties dans toutes les régions de la planète. Ils jouent un rôle important dans les différents cycles biogéochimiques et comme puits de carbone, ce qu'aide à réguler le climat. Ainsi, ils offrent de nombreux produits de base. Le bois de chauffage et le charbon forme partie de ces produits, lesquels sont la principale source d’énergie pour des millions de personnes, en particulier dans les pays en développement. Aussi, cette industrie crée un grand nombre des emplois, tout au long la chaîne productive. Malgré son importance, elle demeure dans le secteur informel, car elle est considérée comme l'énergie des pauvres. Jusqu'à aujourd'hui, il y a une grande ignorance sur la quantité de bois de chauffage et de charbon qui est fournie et consommée, ainsi comme du fonctionnement et de la dynamique de la chaîne de production. D'ailleurs, il n’y a aucune loi qui le régularise ou un réel intérêt des gouvernements pour le développer. Cet essai a pour objective d'évaluer la contribution et la durabilité de l'industrie de bois énergie et la production de bois de chauffage dans la lutte contre la pauvreté. Les études de cas présentés montrent qu'il y a une absence d'information, tout au long la chaîne productive et un manque des politiques publiques. Cela porte atteinte sa durabilité et sa utilisation comme un mécanisme dans la lutte de la pauvreté. Pour atteindre la durabilité, il est essentiel de mettre en oeuvre des politiques publiques qui reconnaissent sa valeur, ce qui permette de formaliser et réglementer l'activité. De plus, il est nécessaire de développer, avec des communautés, des plans d'aménagement forestier durable et employer des technologies qu'améliore l'utilisation vi du bois de chauffage et la production du charbon. Cela serait la seule manière pour que cette industrie puisse être un mécanisme dans la lutte contre la pauvreté.

Índice

Agradecimientos
Resumen
Résumé
Lista de Tablas
Lista de Figuras
Glosario
Abreviaturas y Acrónimos
Introducción
Capítulo 1: Sustentabilidad en la extracción de la leña y carbón
1.1 Los bosques como sumideros de carbono
1.1.1 Los bosques el día de hoy
1.1.2 ¿Qué va a pasar con los bosques?
1.2 La leña y el carbón como fuente de energía
1.2.1 El uso actual de la leña y prospecciones
1.2.2 Factores que influyen en el uso de leña y carbón
1.2.3 Efectos de la extracción de la leña y producción del carbón
1.3 Manejo de los bosques y uso eficiente de la leña para mitigar las concentraciones de CO2 atmosférico
1.3.1 Manejo sustentable de los bosques
1.3.2 Uso y producción eficiente de leña y carbón
Capítulo 2: La industria de la leña y el carbón, ¿una medida para luchar contra la pobreza?
2.1 Un vistazo a la industria de la leña y el carbón
2.1.1 Eslabones de la cadena de producción y sus actores principales
2.2 Importancia socioeconómica de la industria de la leña y carbón
2.2.1 La industria como una herramienta para luchar contra la pobreza
2.3 Estrategias para lograr una reducción de la pobreza
2.3.1 Acciones en cada eslabón
Capítulo 3: Uso de la leña en los bosques tropicales secos
3.1 Los bosques tropicales secos
3.2 Importancia socioeconómica y ambiental de los bosques tropicales secos
3.3 Estudios de caso
3.3.1 Región Norte de Camerún, la sabana
3.3.2 Región del sureste de México, la selva seca en Yucatán
Conclusión
Referencias


9.
Artículo
*En hemeroteca, SIBE-San Cristóbal
Diversidad, estructura y regeneración de la selva tropical estacionalmente seca de la Península de Yucatán, México
Hernández Ramírez, Angélica María ; García Méndez, Socorro (coaut.) ;
Contenido en: Revista de Biología Tropical Vol. 63, no. 3 (setiembre 2015), p. 603-616 ISSN: 0034-7744
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
56572-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal
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Resumen en: Español | Inglés |
Resumen en español

Las selvas tropicales estacionalmente secas son consideradas como uno de los ecosistemas más amenazados en las tierras bajas de la región tropical. El objetivo de este estudio fue caracterizar la composición florística, riqueza, diversidad, estructura y regeneración de una selva tropical estacionalmente seca constituida por selva mediana, vegetación secundaria y selva baja inundable localizada en el noroeste de la Península de Yucatán, México. Se utilizó el protocolo de muestreo estandarizado propuesto por Gentry(0.1 ha por tipo de vegetación en 2007) con la finalidad de comprar los resultados obtenidos en este estudio con respecto a otras selvas estacionalmente secas en Mesoamérica. Se registraron un total de 77 especies pertenecientes a 32 familias de plantas. Fabaceae y Euphorbiaceae fueron lasfamilias con el mayor número de especies observadas en los tres tipos de vegetación estudiados. Se observó un alto recambio de especies a nivel del paisaje (Índice de Similitud de Sorensen; 0.19- 0.40). Las especies no-regenerativas fueron dominantes (50-51 %), seguida de las especies regenerativas (30-28 %) y colonizadoras (14-21 %) en los tres tipos de vegetación estudiados.

Zoocoria fue el modo de dispersión comúnmente observado en el área de estudio. El 88 % de las especies observadas en el área de estudio se distribuyen en Centro América. La selva del noroeste de la Península de Yucatán compartió diversos atributos florísticos a los observados en otras selvas estacionalmente secas de Meosoamérica. Las características estructuralesde la vegetación (número de individuos y área basal), así como el número de especies de lianas registradas en este estudio se asociaron a los eventos de alteración natural ocurridos recientemente en el área de estudio. Los resultados obtenidos en este estudio sugieren que la selva del noroeste de la Península de Yucatán ha sido resiliente a los eventos de alteración natural (huracanes), lo que le ha permitido mantener los valores de riqueza específica dentro del rango considerado como común para las selvas estacionalmente secas de Mesoamérica. Sin embargo, la recuperación y regeneración de la vegetación a largo plazo depende de los animales dispersores de semillas. Este estudio enfatiza en la importancia de establecer una red de áreas naturales protegidas con la finalidad de conservar tanto a la diversidad como a la diversidad en las selvas estacionalmente secas de Mesoamérica.

Resumen en inglés

Diversity, structure and regeneration of the seasonally dry tropical forest of Yucatán Península, Mexico. Seasonally dry tropical forests are considered as the most endangered ecosystem in lowland tropics. The aim of this study was to characterize the floristic composition, richness, diversity, structure and regeneration of a seasonally dry tropical forest landscape constituted by mature forest, secondary forest and seasonally inundated forest located in the Northeastern part of the Yucatán Península, Mexico. We used the Gentry’s standard inventory plot methodology (0.1 ha per forest type in 2007) for facilitating comparison with other Mesoamerican seasonally dry tropical forests. A total of 77 species belonging to 32 families were observed in the study area. Fabaceae and Euphorbiaceae were the families with the largest taxonomic richness in the three forest types. Low levels of β diversity were observed among forest types (0.19-0.40), suggesting a high turnover of species at landscape level. The non-regenerative species were dominant (50-51 %), followed by regenerative species (30- 28 %), and colonizer species (14-21 %) in the three forest types.

Zoochory was the most common dispersal type in the study area. The 88 % of the observed species in the study area were distributed in Central America. Some floristic attributes of the seasonally dry tropical forest of the Yucatán Península, fall into the values reported for Mesoamerican seasonally dry tropical forests. Natural disturbances contributed to explain the high number of individuals, the low number of liana species, as well as the low values of basal area observed in this study. Our results suggested that the seasonally dry tropical forest of Yucatán Península seems to be resilient to natural disturbances (hurricane) in terms of the observed number of species and families, when compared with the reported values in Mesoamerican seasonally dry tropical forests. Nonetheless, the recovery and regeneration of vegetation in long-term depends on animal-dispersed species. This study highlights the importance of establishing multiple protected areas throughout the Mesoamerican seasonally dry tropical forest in order to conserve both ∝- and β- diversity.


10.
- Capítulo de libro con arbitraje
Physiological ecology of vascular plants
Valdéz Hernández, Mirna ; González Salvatierra, Claudia (coaut.) ; Reyes García, Casandra (coaut.) ; Jackson, Paula C. (coaut.) ; Andrade, José Luis (coaut.) ;
Contenido en: Biodiversity and conservation of the Yucatan Peninsula New York : Springer International Publishing Switzerland, 2015 p. 97-129 ISBN:978-3-319-06528-1
Resumen en: Inglés |
Resumen en inglés

The Yucatán Peninsula has opposing gradients of precipitation and evaporation from north to south: as precipitation increases, evaporation rates decrease. Also, due to bedrock composed primarily of limestone, the area presents high porosity and rainfall infiltrates quickly, resulting in no superficial runoff. Natural disturbances such as hurricanes and fires are also common. The interaction of these factors has created a mosaic of environmental conditions that has given rise to a series of physiological adaptations in the plant species of the area. This chapter focuses mainly on the morphophysiological responses and adaptations of native plant species of the Yucatán to natural conditions, and on how plants respond to environmental factors at the level of the individual, species, population and/or functional groups. In this chapter, species were grouped according to their metabolic pathway (C3 species or crassulacean acid metabolism species (CAM)), and discussed based on adaptations to limiting resources: water, nutrients, temperature, and light. For C3 species only trees were included, and studies incorporated in this section spanned from plant establishment, growth, water use and water relations, alternative water sources, and carbon and nutrient flow. For the section on CAM the focus was on the factors that affect CAM plants in the microenvironments in which they occur. Other issues analyzed include plant physiological responses to natural disturbances, the potential impact of climate change on plant populations, and gaps in information as well as additional perspectives of study.