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Biosphere Reserve (biosphere + reserve)
Selected AbstractsA female Lucifer Hummingbird (Calothorax lucifer) with iridescent chin feathersJOURNAL OF FIELD ORNITHOLOGY, Issue 1 2006Raúl Ortiz-Pulido ABSTRACT We report an observation of a female Lucifer Hummingbird (Calothorax lucifer) with iridescent feathers on the chin, resembling the plumage of the juvenile male. The female and nest were found in a xeric shrubland in Barranca de Metztitlán Biosphere Reserve, Hidalgo State, Mexico. This is the first definitive report of a breeding female with such plumage, supporting a previous observation in which sex was not confirmed by behavior. Although this condition appears be rare in female Lucifer Hummingbirds, females in other species of hummingbirds exhibit much variation in the amount of iridescent plumage on the chin and in some, such as Costa's Hummingbirds (Calypte costae), females commonly exhibit colored feathers on the chin. SINOPSIS Reportamos una observacion de una hembra de colibrí Lucifer (Calothorax lucifer) con plumas iridiscentes en el babero, parecidas al plumaje de un macho juvenil. La hembra, la cual estaba incubando, fue encontrada en un área arbustiva xerofítica en la Reserva Biosférica Barranca de Metztitlan, en Hidalgo, México. Este es el primer informe definitivo de una hembra reproductora con este tipo de plumaje, en apoyo a una observación previa en donde el sexo no fue confirmado. Esta condición parece ser rara en estas aves en contraste con otras especies de zumbadores como Calypte costae, pero común en otras especies dimórficas de México y de los Estados Unidos. [source] Disentangling the proximate factors of deforestation: The case of the Monarch butterfly Biosphere Reserve in MexicoLAND DEGRADATION AND DEVELOPMENT, Issue 1 2009J. Honey-Rosés Abstract Understanding the causes of environmental degradation can lead to more effective forest management. Often, the discussion about the causes of deforestation confuses issues across spatial and temporal scales. Such is the case in the Monarch Butterfly Biosphere Reserve (MBBR) in Mexico where various hypotheses compete to explain the deforestation observed there. This paper analyzes these hypotheses using the analytical approaches developed by the literature on environmental degradation and biodiversity loss. This paper first distinguishes between proximate factors and underlying socioeconomic forces. It then reviews recent deforestation studies to evaluate the relative impact of each proximate factor observed in the MBBR. Illegal logging stands out as the factor with the most empirical support. In contrast, agricultural clearing, while frequently cited as major driver of forest loss, has much less empirical backing. These conclusions update the deforestation diagnosis for this protected area and suggest that more attention should be directed at understanding the illicit timber trade. Copyright © 2008 John Wiley & Sons, Ltd. [source] The Low-Wage Conservationist: Biodiversity and Perversities of Value in MadagascarAMERICAN ANTHROPOLOGIST, Issue 4 2009Genese Sodikoff ABSTRACT In the early 1990s, donors began to implement "integrated conservation and development projects" (ICDPs) in Madagascar to stem deforestation, develop ecotourism, and promote forest conservation practices in rural areas. ICDPs recruited agrarian labor to groom and police parks and disseminate rules. In this article, I present a Marxian analysis of biodiversity's value in the global north, focusing on the role of manual workers in a Biosphere Reserve. I argue that ICDP's reliance on cheap local labor has maintained the historical interdependency of "slash-and-burn" agriculture, wage work, and forest conservation. By facilitating the discovery of species while unintentionally perpetuating the conditions of habitat endangerment, the conservation labor process creates forms of rain forest value. [source] Winning back more than words?THE CANADIAN GEOGRAPHER/LE GEOGRAPHE CANADIEN, Issue 1 2005Power, discourse, quarrying on the Niagara Escarpment This paper explores the controversy and public hearing on the proposed extension of the largest limestone quarry in Canada, operated by Dufferin Aggregates at Milton, Ontario. The quarry constitutes an important source of construction material for the nearby Greater Toronto Area. However, the quarry is protected by the provincial Niagara Escarpment Planning and Development Act and located inside the UNESCO-designated Niagara Escarpment Biosphere Reserve. The proposal has therefore attracted considerable opposition from the public institution charged with its protection, the Niagara Escarpment Commission, as well as environmental groups and local residents. To make sense of the tensions, conflicts and outcome of the Dufferin case, we consult and apply several critical literatures. We see the conflict as part of a transformation of the countryside from a space of production to a space of consumption, where there is a shift in emphasis from resource extractive to scenic and ecological landscape values, and the displacement of productive classes, farmers and workers, in favour of a service class of professionals and retirees. Within this transformation, we identify a ,power geometry' of actor networks of different coalition groups that form allegiances and engage in struggles at different geographic scales. These actor networks operate within the set frames of a dominant development discourse and a popular environmentalist discourse that both include and exclude other ways of seeing and managing the escarpment. Cet article examine la controverse et l'audience publique sur l'aggrandissement projetée de la plus vaste carrière de calcaire au Canada, operée par Dufferin Aggregates à Milton, Ontario. La carrière constitue une source importante de matériaux de construction pour la région métropolitaine de Toronto. Toutefois, cette carrière est non seulement protégée par la loi du développement et de l'aménagment de l'Escarpement du Niagara, mais elle est également située dans la Réserve Biosphère désignée par l'UNESCO. Cette proposition d'aggrandissement de la carrière a donc suscité l'opposition de la Commission de l'Escarpement du Niagara, institution publique désignée pour la protection, ainsi que de certains groupes environnementaux et résidents locaux. Afin d'examiner les tensions, conflits et résultat du cas de la carrière Dufferin, nous avons consulté et appliqué plusieurs littératures critiques. Nous considérons d'abord ce conflit comme faisant partie de la transformation de la campagne d'un site de production en un site de consommation, où l'emphase passe de l'extraction d'une resource à la revalorisation aesthétique et écologique du paysage, accompagnée par le déplacement des classes productives, agriculteurs et ouvriers, en faveur de la classe de services professionnels et retraités. Émergeant de cette transformation, nous identifions une ,géométrie de pouvoir , des réseaux d'acteurs issus de différentes coalitions formant des allégeances et s'engageant dans des formes de résistances à différentes échelles géographiques. Ces réseaux d'acteurs opèrent dans les paramètres d'un discours dominant de développement et d'un discours populaire d'environnementalisme qui tout à la fois inclus et exclus d'autres façons de voir et de gérer l'escarpement. [source] Impact of landscape spatial pattern on liana communities in tropical rainforests at Los Tuxtlas, MexicoAPPLIED VEGETATION SCIENCE, Issue 3 2009Víctor Arroyo-Rodríguez Abstract Questions: What are the species composition and species and stem densities of liana communities in tropical landscapes of different deforestation levels? Which spatial attributes (forest cover, patch area, shape and isolation) have the strongest influence on liana communities in these landscapes? Location: Forty-five rainforest patches in Los Tuxtlas Biosphere Reserve, Mexico. Methods: In three landscapes with different deforestation levels (HDL=4%; IDL=11%; and LDL=24% of remaining forest cover) liana communities (DBH ,2.5 cm) were characterized in 15 randomly selected patches per landscape (10 50 m × 2 m transects per patch=0.1 ha), and evaluated the effects of patch area, shape and isolation on liana species and stem density (number of species and stems per 0.1 ha). Results: A total of 64 taxa and 24 families were sampled. Species composition differed highly among landscapes, with HDL being the most dissimilar landscape. The response of lianas to landscape spatial pattern differed significantly among landscapes. Proximity to villages had a strong positive effect on species and stem densities in LDL and IDL. There was a sharp decrease in liana stem density in HDL, with four patches (27%) found to be unoccupied by lianas. Conclusions: Fragmentation may have a positive effect on lianas, partly because of edge effects. This positive effect seems to be limited by the proportion of remaining forest cover in the landscape, as the liana communities had collapsed in the most deforested landscape. [source] Habitat protection, cattle grazing and density-dependent reproduction in a desert treeAUSTRAL ECOLOGY, Issue 8 2009VALERIA ASCHERO Abstract Anthropogenic activities usually trigger changes in the population density of plants. Thus, land management practices can influence density-dependent demographic parameters and species interactions. We investigated plant-pollinator interactions and reproduction in Prosopis flexuosa, the largest tree species in the Central Monte desert of Argentina, an important economic and cultural resource for humans and a functionally prominent species. We hypothesized that reproductive output of P. flexuosa would be limited at low densities, and that exclusion of catle grazing would enhance population density and consequently interaction frequency with pollinators and reproductive success. The study was conducted in and around Ñacuñán Biosphere Reserve (Mendoza, Argentina), where cattle grazing has been excluded for over 35 years. Working in five pairs of protected and cattle grazed 1-ha plots, we recorded density of adult trees, pollinator visitation frequency to inflorescences and seeds per inflorescence in focal trees. Adult tree density was higher in protected plots than in cattle grazed plots. Density of reproductive trees was positively correlated with seed production, suggesting positive density dependence for reproduction (Allee effect). Pollinator visitation to inflorescences and seed production was higher in protected plots compared with plots under cattle grazing. Suppression of anthropogenic degradation has resulted in higher adult tree density in protected plots, indirectly higher pollinator visitation to inflorescences and higher reproductive success of trees. Increased frequency of plant-pollinator interactions and tree reproduction suggest success of management practices aimed at protecting P. flexuosa woodlands. [source] Phyllostomid Bat Community Structure and Abundance in Two Contrasting Tropical Dry Forests,BIOTROPICA, Issue 4 2005Kathryn E. Stoner ABSTRACT Although tropical wet forests are generally more diverse than dry forests for many faunal groups, few studies have compared bat diversity among dry forests. I compared ground level phyllostomid bat community structure between two tropical dry forests with different precipitation regimes. Parque National Palo Verde in northwestern Costa Rica represents one of the wettest tropical dry forests (rainfall 1.5 m/yr), whereas the Chamela-Cuixmala Biosphere Reserve on the Pacific coast of central Mexico represents one of the driest (750 mm/yr). Mist net sampling was conducted at the two study sites to compare changes in ground level phyllostomid bat community structure between regions and seasons. Palo Verde was more diverse than Chamela and phyllostomid species showed low similarity between sites (Classic Jaccard = 0.263). The distinct phyllostomid communities observed at these two dry forest sites demonstrates that variants of tropical dry forest can be sufficiently different in structure and composition to affect phyllostomid communities. At both dry forest sites, abundance of the two most common foraging guilds (frugivores and nectarivores) differed between seasons, with greatest numbers of individuals captured coinciding with highest chiropterophilic resource abundance. RESUMEN A pesar de que los bosques tropicales húmedos, en general, son más diversos que los bosques tropicales secos para muchos grupos de fauna, pocos estudios han comparado la diversidad de murciélogos en los bosques tropicales secos. El presente estudio compara la estructura de la comunidad de los murciélagos filostómidos a nivel del suelo entre dos tipos de bosque tropical seco con diferentes regimenes de precipitación. El parque Nacional Palo Verde esta localizado en el Noroeste de Costa Rica y representa uno de los bosques tropicales secos mas húmedos (con una precipitación de 1.5 m/año), mientras que la Reserva de la Biosfera Chamela-Cuixmala esta localizada en la costa oeste del pacífico de México y representa uno de los bosques más secos (750 mm/año). Se realizó un muestreo con redes de niebla en los dos sitios para comparar los cambios en la estructura de la comunidad de murciélagos filostómidos a nivel de suelo. Palo Verde fue más diverso que Chamela y se encontró la simultud de las especies filostomidos entre los dos sitio fue bajo (Classic Jaccard = 0.263). Las comunidades distintas de filostomidos observado en estos dos sitios de bosque seco demuestra que las variantes en el bosque tropical seco pueden ser suficientemente diferentes en estructura y composición para poder afectar la comunidad de filostomidos. En ambos bosques secos la abundancia de lo dos gremios tróficos más comunes (frugívoros y nectarívoros) fue diferente en las estaciones, con un mayor número de individuos capturados coincidiendo con una mayor abundancia de recursos quiropterofílicos. [source] Landscape Heterogeneity and Diurnal Raptor Diversity in Honduras: The Role of Indigenous Shifting Cultivation,BIOTROPICA, Issue 3 2001David L. Anderson ABSTRACT I studied the relationship between diurnal raptor diversity, density, and richness, and landscape heterogeneity in continuous primary forests and forests farmed by native Amerindians in the Río Plátano Biosphere Reserve of northeastern Honduras from January to June 1996 and 1997. I estimated landscape heterogeneity,the variability in naturally occurring and/or anthropogenic habitat mosaics,by mapping the extent and distribution of five human-modified and natural habitats in 24 1 km2 survey plots. I used the Shannon index to calculate landscape heterogeneity values for the respective plots based on the proportion of total area of each habitat within each plot. Diurnal raptor surveys from canopy-emergent viewpoints in these plots resulted in 137 observations of 18 species of raptors. Four species (Coragyps atratus, Ictinia plumbea, Leucopternis albicollis, and Buteo magnirostris) differed significantly in abundance among heterogeneity classes. Raptor diversity, density, and richness all increased directly with increasing landscape heterogeneity. Landscape heterogeneity was more important in explaining differences in raptor species diversity than the presence or extent of any single habitat or combination of habitats. In contrast to previous studies, my results indicate the importance of indigenous shifting cultivation in altering the naturally occurring patterns of habitat mosaics in lowland rain forest and its effect on bird species abundance and diversity in a rain forest ecosystem. RESUMES Estudié la relación entre la diversidad, densidad y la riqueza de especies de rapaces diurnas con la heterogeinidad de paisajes en bosques primaries contínues y bosques donde practican la agricultura migratoria indígenas de la Reserva de Biósfera del Río Plátano al noreste de Honduras entre los meses de enero a junio de 1996 y 1997. Evalué la heterogeneidad de paisajes-la variabilidad en mosaicos de hábitats naturales o antropogínicos-con mapas de cinco hábitats en 24 parcelas de 1 km2. Usé el Indice de Shannon para calcular valores de la heterogeneidad de cada parcela, basado en la proporción de cada hábitat. Desde el dosel, hice conteos de rapaces en las 24 parcelas que resukaron en 137 observaciones de 18 especies. Cuatro especies (Coragyps atratus, Ictinia plumbea, Leocopternis albicollis, y Buteo magnirostris) difirieron significativamente en abundancia entre los grupos de heterogeneidad del paisaje. La diversidad, densidad y riqueza de especies aumentaron conjuntamente con la heterogeneidad del paisaje. La heterogeneidad del paisaje rue mas importante para explicar la diversidad de rapaces que la presencia o el área de cualquier hábitat o combinación de hábitats. En contraste con estudios anteriores, mis resultados sugieron la importancia de la agricultura migratoria indigena en la alteracíon de mosaicos de hábitats naturales en los bosques hiimedos bajos, y su efecto en la abundancia y diversidad de aves de un ecosistema forestal. [source] Aerobic Heterotrophic Bacterial and Fungal Communities in the Topsoil of Omo Biosphere Reserve in Southwestern Nigeria,BIOTROPICA, Issue 2 2000A. I. Okoh ABSTRACT As a part of the surveillance effort to monitor the ecological status of Omo Biosphere Reserve in the southwestern region of Nigeria, the aerobic heterotrophic bacterial and fungal communities of the topsoil were investigated in March 1995 and April 1996, before the onset of the rainy season. Four distinct wood-tree plantations, a core strict nature reserve (SNR) area, and a buffer zone were sampled. The topsoil samples (7.5 cm depth), including the litter, were taken with an auger (8 cm diameter) and transported to the laboratory in polyethylene bags. One-gram dry weight equivalent of sample was suspended in 10 ml sterile water, and serial dilutions from it were used for the estimation of bacterial and fungal densities. The bacterial and fungal densities ranged in the order of 106 and 103 cfu/g, respectively. Out of the 18 bacterial and 16 fungal species that were obtained, 13 and 12, respectively, were isolated from the core SNR. About 46 to 69 percent of the bacteria and 50 to 83 percent of the fungi species found in the SNR were absent in different combinations in the plantations and the buffer zone; these variations were significant among the sites monitored. The bacterial and fungal species compositions were significantly different between the SNR and each of the other sites. Proportional distributions within the sites were significant only for the bacterial communities. It would appear that plantation and human activities have caused significant changes in the distribution and species richness of the heterotrophic bacterial and fungal communities relative to the undisturbed SNR area of the Omo Biosphere Reserve. [source] Invasive Africanized honey bee impact on native solitary bees: a pollen resource and trap nest analysisBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009DAVID W. ROUBIK Little is known of the potential coevolution of flowers and bees in changing, biodiverse environments. Female solitary bees, megachilids and Centris, and their nest pollen provisions were monitored with trap nests over a 17-year period in a tropical Mexican biosphere reserve. Invasion by feral Apis (i.e. Africanized honey bees) occurred after the study began, and major droughts and hurricanes occurred throughout. Honey bee competition, and ostensibly pollination of native plants, caused changes in local pollination ecology. Shifts in floral hosts by native bees were common and driven by plant phylogenetics, whereby plants of the same families or higher taxa were substituted for those dominated by honey bees or lost as a result of natural processes. Two important plant families, Anacardiaceae and Euphorbiaceae, were lost to competing honey bees, but compensated for by greater use of Fabaceae, Rubiaceae, and Sapotaceae among native bees. Natural disasters made a large negative impact on native bee populations, but the sustained presence of Africanized honey bees did not. Over 171 plant species comprised the pollen diets of the honey bees, including those most important to Centris and megachilids (72 and 28 species, respectively). Honey bee pollination of Pouteria (Sapotaceae) plausibly augmented the native bees' primary pollen resource and prevented their decline. Invasive generalist pollinators may, however, cause specialized competitors to fail, especially in less biodiverse environments. No claim to original US government works. Journal compilation © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 152,160. [source] | ||||||||||||||||