RESUMO
Los hongos del género Marasmius Fr. son i mportantes degradadores de hojarasca y se reportan como los más abundantes en los trópicos. La Ecorregión Lachuá es uno de los remanentes más importantes de selvas tropicales en Guatemala, y de los más amenazados por la pérdida de hábitat debido al avance de la frontera agrícola. Se ha determinado que durante los últimos 5 años se ha perdido el 75% de cobertura original fuera de las áreas protegidas de la ecorregión, debido principalmente al aumento de la agricultura. Estos cambios ocasionados por la pérdida de cobertura vegetal influyen en las condiciones microclimáticas de las cuales los hongos dependen para poder reproducirse. Este estudio constituye el primer acercamiento para comprender como responde este grupo de hongos a las fluctuaciones causadas por el cambio en condiciones climáticas y su vulnerabilidad a la pérdida de hábitat. Se evaluó la producción de cuerpos fructíferos del género Marasmius en respuesta a los factores climáticos temperatura, humedad relativa, precipitación, temporalidad y tamaño de remanente en la en época de lluvias durante 2010 y 2011 en ocho remanentes boscosos en la Ecorregión Lachuá. Se recolectaron 98 ejemplares pertenecientes a 56 morfoespecies y 2 especies. Las mayores riquezas (r) y frecuencias acumuladas (a) de cuerpos fructíferos se presentaron en junio (r=16, a=21) y en la localidad de Santa Lucía Lachuá (r =15, a=16). Los rangos de las variables climáticas donde se presentó mayor frecuencia acumulada fue T°= 26°C27°C; Precipitación= 812 mm y 40mm y H%= 8890%. La composición de Marasmius está influenciada por la temporalidad que de junio a agosto presenta mayor número de especies compartidas, disminuyéndose considerablemente en octubre y noviembre. No se observó un cambio en la composición de Marasmius en relación al tamaño de remanente, sin embargo espacialmente es posible diferenciar entre remanentes rodeados por áreas con cobertura y remanentes rodeados por áreas abiertas, determinando que este género responde a los cambios de hábitat. Estos cambios en riqueza y abundancia acumulada de hongos en el tiempo y el espacio, pueden ser utilizados como indicadores de estas perturbaciones. La información generada permite proponer el monitoreo de este género a través del tiempo p ara generar planes de manejo adecuados para el área
Fungi of genus Marasmius Fr. are important litter decomposers and reported as abundant in tropics. Lachuá Ecoregion is the largest remaining tropical forests in Guatemala, and the most threatened by habitat loss due to the agricultural advance. It has been determined that over the past five years 75% of the original coverage outside protected areas in the ecoregion has been lost. This loss is mainly attributed to increased agriculture activity. These changes caused by the loss of plant cover influence the microclimatic conditions that depend on fungi to reproduce. This study is the first approach to understand how this group of fungi respond to currency fluctuations caused by changes in climatic conditions and vulnerability to habitat loss. Relationship of temperature, relative humidity, precipitation, temporality and patch size with Marasmius fruit bodies production were evaluated. The study was carried out in eight forest patches in the rainy season in 2010 and 2011 in Lachuá Ecoregion. 98 specimens of 56 morphospecies and 2 species were colected. The highest cumulative richness (r) and cumulative frequency (a) of fruit bodies were presented in June (r =16, a = 21) and Santa Lucia Lachuá locality (r =15, a = 16). Marasmius composition is influenced by temporality. June to August were the months with higher number of shared species, decreasing considerably in October and November. No change was observed in Marasmius composition allied to patch size, however spatially there is a difference between patches surrounded by coverage areas and patches surrounded by open areas. This shows that genera responds to changes in habitat. These changes in cumulative richness and abundance of fungi over time and space, can be used as disturbance indicators. This information allows proposed monitoring of this genera over time to produce a management plan for the area
Assuntos
Humanos , Marasmius , Fungos/classificação , Mudança ClimáticaRESUMO
The interruption of vectorial transmission of Chagas disease by Triatoma dimidiata in central America is a public health challenge that cannot be resolved by insecticide application alone. In this study, we collected information on previously known household risk factors for infestation in 11 villages and more than 2,000 houses in Guatemala, Honduras, and El Salvador, and we constructed multivariate models and used multimodel inference to evaluate their importance as predictors of infestation in the region. The models had moderate ability to predict infested houses (sensitivity, 0.32-0.54) and excellent ability to predict noninfested houses (specificity higher than 0.90). Predictive ability was improved by including random village effects and presence of signs of infestation (insect feces, eggs, and exuviae) as fixed effects. Multimodel inference results varied depending on factors included, but house wall materials (adobe, bajareque, and palopique) and signs of infestation were among the most important predictive factors. Reduced models were not supported suggesting that all factors contributed to predictions. Previous knowledge and information from this study show that we have evidence to prioritize rural households for improvement to prevent house infestation with Triatoma dimidiata in Central America. House improvement will most likely have other health co-benefits.