Resumen Introducción: El integumento de los moluscos terrestres es susceptible a desecación, por eso la selección de microhábitats, la estacionalidad y el comportamiento a lo largo del día son cruciales para su sobrevivencia. No obstante, es poco lo que se ha investigado al respecto, en especial para moluscos tropicales de arbustos del sotobosque en bosques húmedos de montaña. Objetivo: Analizar los patrones de actividad y de la selección de microhábitats del caracol terrestre Tikoconus costarricanus según la estación del año, la hora del día y el clima. Métodos: El trabajo lo realicé en un bosque tropical húmedo de montaña cerca de la represa hidrológica “El Llano”, Costa Rica. Analicé la actividad diaria de especímenes de T.costarricanus en un trayecto de 2 km: observé 167 especímenes e hice 781 observaciones. Tomé nota de: estación del año, hora, actividad, parte de la hoja donde estaba el caracol, altura en la planta, clima y humedad relativa y temperatura dentro del bosque. Consideré que un espécimen estaba activo cuando los tentáculos ópticos estaban extendidos. Analicé la precipitación pluvial por horas con datos de una estación meteorológica cercana. Resultados: Encontré caracoles principalmente en las hojas de arbustos entre 1.1 y 2 m sobre el suelo; encontré individuos activos a todas horas y en cualquier época del año. Solo el 24 % de los individuos estaban en el haz, de esos el 92 % estaban activos. Encontré variación estacional en el patrón de actividad, la selección del lado de la hoja de acuerdo a la hora del día y el clima, la cantidad de especímenes estivando, y la distribución vertical. En la época seca encontré más caracoles activos con clima húmedo, por el contrario, en la estación lluviosa encontré más caracoles activos con clima seco. Durante las horas de luz de la estación lluviosa, la cantidad de caracoles activos sobre el haz de las hojas disminuyó con el aumento de precipitación pluvial, en tanto que en la estación seca disminuyó con el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas nocturnas de ambas estaciones, la cantidad de caracoles sobre el haz de las hojas disminuyó considerablemente en relación a los caracoles activos, especialmente en la época lluviosa. Este caracol estivó principalmente a mediodía y en las tardes de la época seca en el envés de las hojas por periodos inferiores a 21 h seguidas. La elevada humedad del bosque tropical húmedo de montaña permite que estos caracoles estén activos en cualquier momento. Sin embargo, la estivación les permite protegerse de la desecación durante los periodos más secos. El patrón de lluvias durante las horas de luz de la época lluviosa explica la disminución de especímenes presentes en el haz de las hojas, pero en la época seca lo explica mejor el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas oscuras, la casi ausencia de caracoles en el haz de las hojas durante la estación lluviosa se explica si al patrón de lluvia se le agrega el efecto del goteo foliar producido por la lluvia y el rocío que se condensa sobre las hojas. La situación es un poco diferente en las horas oscuras de la estación seca, en este caso, la disminución de caracoles en el haz, se explica por el goteo foliar derivado del rocío y de la precipitación de neblina. Es posible que la diferencia en la preferencia vertical se deba a que evitan la lluvia y la salpicadura de la lluvia al caer en el suelo. Conclusiones: La humedad, la temperatura, la lluvia y el goteo foliar derivado de rocío, neblina y lluvia, afectan el comportamiento y la selección de sustrato de moluscos terrestres pequeños que habitan en arbustos de bosques tropicales húmedos de montaña.

Abstract Introduction: The integument of terrestrial mollusks is highly susceptible to dehydration; therefore, microhabitat selection, seasonality and behavior around the day are crucial to their survival. However, they are still poorly understood, especially for tropical montane wet forest species. Objetive: To analyze activity patterns and microhabitat selection on shrubs of the land snail Tikoconus costarricanus, according to season, daytime and weather. Methods: I conducted the study near “El llano” water dam in a tropical montane wet forest in Costa Rica. I observed daily activity of T. costarricanus, during the rainy and the dry season on a 2 km long trail. I observed 167 specimens and made 781 observations in total. I took note of: season, time, activity, weather, temperature and relative humidity inside the forest, and part of the leaf and height where snails were. Active snails had optical tentacles extended. I analysed daily rainfall data from a nearby meteorological station. Results: This species can be found mainly on understory leaves between 1.1 and 2 m above the floor. They are active the day around during the whole year. Only 24 % of the snails were on the upper side of leaves, but 92 % of them were active. The following behaviors were season dependent: activity peaks, leaf side selection according to daytime and weather, quantity of snails aestivating and vertical distribution. During the dry season, I found more active snails in rainy and cloudy days. During the rainy season I found more active snails in sunny days. During rainy season light hours, active snail percentage on the upper side of leaves decreased with rainfall increase, while in the dry season decreased with temperature increase and relative humidity decrease. During night hours of both seasons, the number of snails on the upper side of leaves decreased considerably in relation to active snails, especially in the rainy season. This snail aestivated on the underside of leaves during periods shorter than 21 h, mainly around noon and afternoons during the dry season. High humidity in this forest allowed snail activity around the day at any season. However, this species aestivated when moisture reached the lowest values, mainly, around noon and in the afternoons in the dry season. The rainfall pattern during the rainy season light hours explains the specimen decrease on the upper side of leaves, but in the dry season it is better explained by the temperature increase and the decrease in relative humidity. During dark hours, the almost complete snail absence on the upper side of leaves during the rainy season is explained if the effect of canopy drip produced by rain and dew condensed on leaves is added to the rain pattern. The situation is slightly different in dark hours of the dry season, in this case, snail decrease on the upper side of leaves is explained by canopy drip from dew and fog precipitation. Seasonal difference in vertical distribution may be a way to avoid rain and rain splash out on the soil. Conclusions: Moisture, temperature, rain, and canopy drip from dew, fog and rain, affect behavior and substrate selection of small terrestrial mollusks that inhabit shrubs in wet tropical rainforests.

Resumo A Mata Atlântica (MA) é considerada um dos hotspots de biodiversidade do mundo, sendo o bioma mais degradado no Brasil. Este bioma compreende muitas fitofisionomias, como floresta ombrófila, semidecidual, e campos de altitude. Esta complexidade, aliada à enorme variação latitudinal e altitudinal, disponibiliza habitats e condições diversas à especiação dos anfíbios. Como resultado, atualmente são conhecidas mais de 600 espécies de anfíbios que ocorrem na MA. Dentro deste bioma o Parque Nacional do Caparaó (PNC) é relevante, pois inclui o ponto mais alto da Mata Atlântica, o Pico da Bandeira com cerca de 3000 m de elevação, assim como diferentes fitofisionomias, como campos rupestres e florestas úmidas. Apesar disso, sua fauna de anfíbios é ainda pobremente descrita. Realizamos inventários de anfíbios no PNC e entorno de 2016 a 2018 e registramos 47 espécies de anuros, das quais duas são endêmicas e pelo menos seis ainda não foram descritas. Adicionalmente, compilamos dados de coletas anteriores (2004 a 2008) e dados secundários de coleções científicas. Ao juntar todos os dados registramos um total de 61 espécies de anuros de 12 famílias para o PNC e arredores, colocando esta área entre as 10 áreas mais ricas em anfíbios da MA. Algumas destas espécies estão representadas apenas por um ou dois exemplares em coleções e não foram registradas no PNC desde a década de 1980, como Thoropa lutzi e Hylodes vanzolinii. Estas espécies podem ser exemplos de declínios populacionais ou mesmo de extinções locais, destacando a necessidade de maiores esforços amostrais neste local altamente biodiverso.

Abstract The Atlantic Forest (AF) is one of the biodiversity hotspots of the world, and the most fragmented biome of Brazil. This biome includes different phytophysiognomies, as riparian, slope, cloudy forests, and grasslands. Such complexity, allied to huge latitudinal and high elevational range, provides diverse habitats and conditions for amphibian speciation. As a result, there are over 600 amphibian species known to occur in the AF. Within this biome the Caparaó National Park (CNP) is relevant, as it includes the highest peak of the biome, the Pico da Bandeira at almost 3,000 m above sea level, as well as different phytophysiognomies as rocky fields and humid forests. In spite of that, its amphibian fauna is still poorly described. We inventoried amphibians at the CNP and surrounding areas from 2016 to 2018 and recorded 47 anuran species, of which two are locally endemic and at least six have not been described yet. Additionally, we compiled data from previous surveys (2004 to 2008) and secondary data from scientific collections. All together, we registered a total of 61 anuran species from 12 families for the CNP and surroundings, placing this area among the 10 amphibian richest sites in the AF. Some of these species are represented by only one or two collected specimens and have not been registered in the CNP since the 1980’s, such as Thoropa lutzi and Hylodes vanzolinii. These species could be examples of population declines or even past local extinctions, highlighting the need of further sampling efforts in that highly biodiverse site.

Abstract Leaf spots caused by Phoma and Alternaria are common symptoms in algarrobo blanco [whitemezquite] (Prosopis alba Griseb.) seedlings in nurseries, when weather conditions (cool, cloudy and drizzling days) are favorable for the emergence of these fungi. In view of this problem, it was hypothesized whether or not two selected fungicides were effective in controlling said disease. With this purpose in mind, a completely randomized experimental design consisting of three treatments and five repetitions was carried out. One of the treatments was the control, another one was the application of Azoxistrobina + Difenoconazole, and the third one involved the application of Carbendazim. Upon applying the fungicides, the incidence of the disease on each seedling as well as the effectiveness of the fungicides was determined. The results of the variable “incidence” were subjected to analysis of a mixed generalized linear model. Of statistical analysis showed significant differences among treatments, thus leading to the conclusion that the application of fungicides caused a reduction in the disease while Azoxistrobina + Difenoconazole exhibited the greatest effect. It was further determined that Azoxistrobina + Difenoconazole is about 13% more effective in controlling the disease.

Resumen Las manchas foliares causadas por Phoma y Alternaria, son síntomas comunes en cultivos de algarrobo blanco (Prosopis alba Griseb.) en vivero, cuando las condiciones meteorológicas (días frescos, nublados y con lloviznas) son propicias para la aparición de estos hongos. En vista de este problema, se dispuso investigar la eficacia de dos fungicidas para controlar dicha enfermedad. Para ello se realizó un diseño experimental completamente aleatorizado con 3 tratamientos y 5 repeticiones. Uno de los tratamientos fue el control; otro, la aplicación de Azoxistrobina + Difenoconazole, y el tercero, la aplicación de Carbendazim. Efectuadas las aplicaciones de los fungicidas, se determinó la incidencia de la enfermedad en cada plantín y la eficacia de los fungicidas. Los resultados de la variable “incidencia” se analizaron estadísti-camente a través de un modelo lineal generalizado mixto. Del análisis estadístico se obtuvieron diferencias significativas entre los tratamientos, y se concluyó que la aplicación de los fungicidas provocó una disminución notable de la incidencia de la enfermedad, y que Azoxistrobina + Difenoconazole fue el fungici-da más efectivo. A partir del análisis de eficacia, se determinó que Azoxistrobina + Difenoconazole muestra un valor mayor, superando a Carbendazim en un 13 % aproximadamente, lo que demuestra que es más efectivo para controlar la enfermedad.

RESUMEN La familia Asteraceae es una de las más ricas en Venezuela. Pentacalia es el género con mayor cantidad de especies dentro de la misma y su principal área de distribución corresponde a los estados Mérida, Táchira y Trujillo. A pesar de su importancia, son pocos los estudios de anatomía xilemática para Pentacalia. El objetivo de este trabajo es la descripción anatómica de la madera de ocho especies de Pentacalia: P. cachacoensis, P. greenmaniana, P. imbricatifolia, P. mason-halei, P. pachypus, P. quirorana, P. reflexa y P. venezuelensis con el fin de encontrar caracteres útiles para su identificación. Las muestras fueron colectadas en los páramos de los estados Táchira y Mérida y en selva nublada de Mérida. La preparación del material se hizo utilizando los procedimientos de microtecnia xilemática y la descripción se realizó de acuerdo a lo estipulado por la asociación internacional de anatomistas de la madera. Las especies se pueden separar en dos grupos de acuerdo a la presencia o ausencia de estructura estratificada y dentro de cada grupo se pueden establecer diferencias con base en caracteres cualitativos y, en algunos casos, es necesario separar con base en caracteres cuantitativos. Sólo P. pachypus y P. venezuelensis no se pudieron separar utilizando características anatómicas de la madera.

ABSTRACT The family Asteraceae is one of the most diverse in Venezuela. Pentacalia is the genus with the highest number of species in the family and its principal distribution area is in Mérida, Táchira and Trujillo states. In spite of its importance, there are few studies about wood anatomy for Pentacalia. The aim of this research was describe the wood anatomy of eight species of Pentacalia: P. cachacoensis, P. greenmaniana, P. imbricatifolia, P. mason-halei, P. pachypus, P. quirorana, P. reflexa and P. venezuelensis to find useful features for identification. Samples were collected in andean paramos of Mérida and Táchira states and cloudy forest in Mérida state. Samples were prepared using standard procedures of xylem microtechnique and description was made according international association of wood anatomists. Species studied can be separated in two groups according the presence or absence of storied structure and in each group, we found differences in qualitative features and, in some cases, is necessary the separation using quantitative features. Only P. pachypus and P. venezuelensis can not be separated using wood anatomical features.

Resumo Ipê amarelo é uma árvore nativa da floresta Atlântica brasileira, encontrada em uma ampla distribuição latitudinal. Neste estudo, nós investigamos os efeitos potenciais de alterações de curto prazo nas condições micro-climáticas sobre características estruturais, proteína e carboidratos histoquimicamente marcados, de folhas de ipê amarelo, usando estratégias de análise estrutural e histoquímicas. As folhas foram marcadas em quatro condições microclimáticas distintas: 1. Tarde, após um dia quente e ensolarado; 2. Amanhecer, após um dia quente e ensolarado; 3. Ao meio-dia, de um dia quente e ensolarado; e 4. Ao meio-dia, de um dia frio e nublado. Folíolos expostos à baixa irradiância luminosa apresentaram cloroplastos achatados, uniformemente distribuídos no interior das células, por todo o parênquima paliçádico, enquanto que folíolos expostos à alta irradiância apresentaram cloroplastos achatados e arredondados, nas células superiores e inferiores do parênquima paliçádico, respectivamente. A marcação mais intensa para proteína foi observada para folhas coletadas no momento mais frio de coleta, enquanto que a marcação mais fraca foi observada para folhas coletadas após um dia quente e ensolarado. Os grãos de amido maiores e mais numerosos foram observados em folhas coletadas durante a tarde de dia quente e ensolarado, enquanto que os menores e menos numerosos grãos de amido foram observados em folhas coletadas ao amanhecer.

Abstract Golden trumpet, Tabebuia chrysotricha, is a native tree from the Brazilian Atlantic rain forest, with a broad latitudinal distribution. In this study, we investigated the potential effects of short-term changes in micro-weather conditions on structural features, and total protein and carbohydrate content of golden trumpet leaves, using structural and histochemical approaches. Leaves were harvested in four different micro-weather conditions: 1. Afternoon, after a hot, sunny day; 2. at dawn, after a previously hot, sunny day; 3. at noon, of a hot, sunny day; and 4. at noon, of a cold, cloudy day. Leaflets exposed to low light irradiance showed flattened chloroplasts, uniformly distributed within the cells, throughout the palisade parenchyma. Conversely, leaflets exposed to high light irradiance presented flattened and rounded chloroplasts, in the upper and lower palisade parenchyma cells, respectively. The strongest protein staining was found for leaves harvested at the coldest period, whereas the weakest protein staining was found for leaves harvested after a hot, sunny day. The largest and most numerous starch grains were found for leaves harvested in the afternoon, after a hot, sunny day. Conversely, the smallest and less numerous starch grains were found for leaves harvested at dawn. Analysis of the data reported herein suggests that the leaflet responses to transient changes in micro-weather conditions are likely to contribute to the golden trumpet successful establishment in the broad latitudinal distribution in which the species is found.

Los escarabajos coprófagos son un grupo de insectos ampliamente reconocido como indicador ecológico de perturbación antrópica, por lo cual cuentan con una gran cantidad de información a nivel de los ensamblajes. En contraste, aún son escasos los estudios a nivel poblacional y apenas se ha empezado a entender cómo la fragmentación y transformación de sus hábitats afecta la estructura y dinámica de las poblaciones de Scarabaeinae. En este trabajo se examinaron algunos aspectos sobre la estructura poblacional de dos especies de Scarabaeinae típicas del paisaje cafetero en los Andes occidentales de Colombia (Dichotomius cf. satanas y D. cf. alyattes). Entre agosto de 2010 y febrero de 2011, en dos localidades cafeteras de Risaralda, se instalaron seis transectos de ecotono cada uno compuesto por 15 trampas de caída no letales cebadas con una mezcla de excremento humano y cerdo. Cada mes las trampas estuvieron activas durante 48 horas, con revisión cada 24 horas. En cada revisión los especímenes de ambas especies se marcaron con el método de perforaciones en los élitros. Se marcaron 1723 individuos, de los cuales 73 fueron recapturados (43 de D. cf. alyattes y 30 de D. cf. satanas). El tamaño poblacional estimado fue diferente entre especies y localidades, así como la densidad promedio osciló entre 26,4 y 172,2 ind/km². Ambas especies presentaron una proporción de los sexos similar (∼1:1) y mostraron diferencias en sus preferencias de hábitat: D. cf. satanas tendió a mantenerse en el interior del bosque; mientras que D. cf. alyattes usa de forma extensiva el ecotono bosque - café de sol.

Dung beetles are a group of insects widely recognized as ecological indicators of anthropic disturbance, reason why they count with a lot of information at the level of the assemblies. In contrast, population-based studies are still scarce and little has been understood on how fragmentation and transformation of their habitats affect the structure and dynamics of Scarabaeinae populations. Some aspects of the population structure of two typical Scarabaeinae species (Dichotomius cf. satanas and D. cf. alyattes) of the coffee landscape in the Western Andes of Colombia are examined in this paper. Between August 2010 and February 2011, six ecotone transects, each one consisting of 15 non-lethal pitfall traps, primed with a mixture of human and pig excrement, were installed in two coffee growing locations of Risaralda. Each month the traps were active for 48 hours and were inspected every 24 hours. Specimens of both species were labeled with the elytron drilling method in each inspection. A total of 1723 individuals were marked of which 73 were recaptured (43 D. cf. alyattes and 30 D. cf. satanas). The estimated population size differed between species and locations, and the average density ranged between 26.4 and 172.2 ind/km². Both species had similar gender ratio (∼1:1) and showed differences in their habitat preferences: D. cf. satanas tended to stay inside the forest, while D. cf. alyattes used extensively ecotone forest - sun coffee.

Un nuevo registro, Falco columbarius (Falconidae), y cuatro nuevas extensiones de distribución: Vireo altiloquus (Vireonidae), Chloroceryle aenea (Alcedinidae), Calliphlox amethystina (Trochilidae), Elaenia chiriquensis ( Tyrannidae), son señalados para el estado Sucre. El Halcón Migratorio , F. columbarius , fue fotografiado en manglares de la laguna de Chacopata, al NE de la península de Araya; V. altiloquus (Julián Chiví Bigotinegro) fue identificada por un ejemplar capturado, en matorral acantoxeromorfo costero, al NO de la Península de Araya; previamente había sido registrado en un bosque deciduo basimontano, en la base SO de la Península de Paria. El Martín Pescador Pigmeo , Chaenea, fue observado y capturado en un bosque de galería basimontano, al sur de la laguna de Buena Vista, al centro-oeste del estado; su distribución anterior se circunscribía al SE del estado. El Tucusito Amatista, C. amethystina, fue observado y capturado en un bosque montano nublado, en el cerro Las Melenas (810 msnm), en la vertiente sur de la Península de Paria, al este del estado; su registro anterior había sido en el macizo Turimiquire, al SO del estado. El Fiofio Belicoso, E. chiriquensis, fue capturado en un bosque montano nublado, en el cerro La Cerbatana (764 msnm), en la vertiente norte de la Península de Paria, al norte del estado; su registro anterior había sido en las estribaciones del macizo Turimiquire, al SO del estado.

The first record of Falco columbarius (Falconidae) is made for Sucre State , and Vireo altiloquus (Vireonidae), Chloroceryle aenea (Alcedinidae), Calliphlox amethystina (Trochilidae) and Elaenia chiriquensis (Tyrannidae) extend their distribution range inside this State. An individual of F. columbarius (Mer lin) was photographed in Chacopata lagoon mangroves, in northeastern Sucre S tate. An individual of V. altiloquus (Black - whiskered Vireo) was captured in northwestern Araya Peninsula in a coastal xeric habitat; previously, this species had been recorded in foothill deciduous forest s of southwestern Paria Peninsula. The American Pygmy Kingfisher , C. aenea , was identified and captured in gallery forest near Campoma - Vista lagoon - fluvial complex sited to the center - western of Sucre State; previously, this species was recorded from the eastern Sucre State. The Amethyst Woodstar , C. amethystine, was observed and captured in a cloudy montane forest, in Las Melenas hill (810 masl); previously, this species was recorded in Turimiquire Ser rania, from southwestern of Sucre S tate . The lesser elaenia , E. chiriquensis , was captured in a cloudy montane forest, in La Cerbatana hill (764 masl), in the northern slope of Paria Peninsula, in northern Sucre State; previously, this species was recorded from the Turimiquire serrania, at southwestern Sucre State.

Here we provide the first analysis of activity patterns exhibited by spotted and melanistic colour morphs of the vulnerable guiña Leopardus guigna, in a forest landscape of southern Chile. Camera traps showed guiñas were mainly active at night (64% of photos). Melanistic guiñas were more nocturnal (82% of photos) than the more common spotted cats (57%). Spotted guiñas were more active on cloudy and moonless nights. Our study provides novel findings about the behavioural plasticity of guiña in different ambient conditions, and the relative advantage to each colour morph to persist in an increasingly human-dominated landscape.

Entregamos el primer análisis de patrones de actividad exhibidos por morfos moteados y melánicos de la vulnerable güiña Leopardus guigna, en un paisaje de bosque del sur de Chile. Cámaras trampas mostraron que las güiñas estuvieron mayoritariamente activas en la noche (64% de fotos). Las güiñas melánicas fueron más nocturnas (82% de fotos) que las moteadas más comunes (57%). Las güiñas moteadas estuvieron más activas en noches nubosas y oscuras. Nuestro estudio provee nuevos resultados sobre la plasticidad conductual de la guiña en diferentes condiciones ambientales, y la ventaja relativa de cada morfo para persistir en un paisaje cada vez más dominado por el ser humano.

We describe the species composition of the subfamily Ophioninae (Hymenoptera: Ichneumonidae) along an altitudinal gradient in the cloudy forest Monteseco, Cajamarca, Peru collected in 2009 and 2010. Eighteen species were recorded in three genera of Ophioninae: Alophophion, Enicospilus y Ophion. Five species are recorded for the first time in Peru: Ophion polyhymniae Gauld, 1988; Enicospilus cubensis (Norton, 1863); E. guatemalensis (Cameron, 1886); E. cressoni Hooker, 1912 y E. mexicanus (Cresson, 1874). Subfamily composition varies with the elevation. The highest species richness (S=11) was found at 2150 m and the lowest (S=3) at 3116 m. Enicospilus is more diverse from low to mid elevation, Ophion from mid to high elevation and Alophophion occurs predominantly at high elevation.

Se describe la composición de especies de la subfamilia Ophioninae (Hymenoptera: Ichneumonidae) a lo largo de una gradiente altitudinal en el bosque nublado Monteseco, Cajamarca, Perú; colectados en los años 2009 y 2010. Se encontraron 18 especies en tres géneros de Ophioninae: Alophophion, Enicospilus y Ophion. Cinco especies son registradas por primera vez para Perú: Ophion polyhymniae Gauld, 1988, Enicospilus cubensis (Norton, 1863), E. guatemalensis (Cameron, 1886), E. cressoni Hooker, 1912 y E. mexicanus (Cresson, 1874). La composición de la subfamilia Ophioninae varía según la elevación. La mayor riqueza de Ophioninae se encontró a 2150 m (S=11) y la menor a 3116 m (S=3). Enicospilus es más diverso en zonas de baja a mediana altitud, Ophion es más diverso en zonas de mediana a elevada altitud y Alophophion ocurre predominantemente a elevada altitud.

No Pantanal, existem diversas comunidades de espécies monodominantes, que servem como indicadores de mudanças ambientais. O estudo da dinâmica das trocas de CO2 entre essas comunidades e a atmosfera contribui para avaliar o funcionamento desses ecossistemas. Dessa forma, o objetivo deste trabalho foi determinar o fluxo de CO2 (Acf) de uma área monodominante de Cambará (Vochysia divergens Pohl) no norte do Pantanal. O fluxo de CO2 foi determinado por meio do método da razão de Bowen modificada. Para isso, utilizaram-se medidas de saldo de radiação, fluxo de calor no solo e gradientes de temperatura, umidade relativa e concentração de CO2 do ar realizadas em uma torre de 32 m, em uma área monodominante de Cambará. A concentração de CO2 ao longo do perfil vertical do dossel, durante o período noturno, foi maior nos dias de céu limpo. O Acf no dossel do Cambarazal foi positivo no período noturno e negativo no período diurno. Os maiores valores de Acf foram medidos nos dias de céu limpo, os quais foram 75% maiores do que em dias de céu parcialmente nublados.

In the Brazilian Pantanal region, there are some monodominant species which are suited as environmental changes indicators. The study of the dynamics of CO2 exchange between those plants communities and the atmosphere contributes to evaluate those ecosystems behavior. Therefore, the purpose of this study was to determine the CO2 flux (Acf) of Vochysia divergens Pohl mono species forest in northern Pantanal. The CO2 flux was estimated by the modified Bowen ratio method. For this, net solar radiation, surface heat flux and soil temperature and air humidity data and CO2 concentration profiles, collected at a 32m high tower installed in this area were used. The CO2 concentrations along the canopy profiles ware greater during clear sky conditions in nighttime periods. The Acf over Vochysia divergens Pohl canopy was positive in nighttime period and negative during daytime. The highest Acf values ware collected during clear sky conditions, 75% higher than partly cloudy sky conditions.

La sobrevivencia de las plantas epífitas a su ambiente depende de las adaptaciones vegetativas que les permiten afrontar diferentes tipos de estrés. Basado en la diversidad estructural de las Orchidaceae, el presente estudio tiene por objetivo relatar la estructura anatómica de Dichaea cogniauxiana y Epidendrum secundum con relación a los distintos ambientes donde viven. Hojas y raíces fueron recolectados en un bosque nuboso de un campo rupestre en la Serra da Piedade, Brasil. Dichaea cogniauxiana está adherida a los troncos, en sitios con alta humedad atmosférica y sombra, mientras que E. secundum está localizada en el margen del bosque nebular, en sitios más iluminados. Las hojas de E. secundum tienen una cutícula más gruesa y un mayor número de estomas por área que las de D. cogniauxiana, características coherentes con los diferentes patrones de exhibición a la luz del sol. Las cámaras supraestomáticas formadas por la cutícula pueden funcionar como una barrera de resistencia a la evaporación del agua. La suculencia de las hojas de E. secundum propicia el almacenamiento de ácidos orgánicos por la noche, y el almacenamiento de almidón puede estar implícito en el metabolismo de la PEP-carboxilasa. Las raíces con mayor velamen y especializadas paredes gruesas de las células corticales (ambas en E. secundum) ayudan a la absorción e indican una mejor adaptación al ambiente con intensa radiación solar y probable alto déficit de agua. El engrosamiento de la pared celular en la exodermis de E. secundum puede conferir una protección más eficaz contra el exceso de transpiración en el margen del bosque nebular. Por otra parte, D. cogniauxiana además de ser epífita, está en una posición baja, en un ambiente sombreado y con una alta humedad relativa. Su velamen delgado permite la entrada de la baja luz disponible y la fotosíntesis, produciendo oxígeno que ayuda a evitar la condición hipóxica.

The survival of plants in epiphytic environments depends on vegetative adaptations capable to defraud different stresses. Based on the structural diversity of the Orchidaceae, the current study has the objective of relating the anatomical structure of Dichaea cogniauxiana and Epidendrum secundum with the distinct environments where they live. It was expected that, despite structural similarities as strategies for resource acquisition, some peculiar variations related to the distinct light microenvironments (inside or in the edge of the nebular forest, near to “campo rupestre” area) might be found. Leaves and roots of both species were collected in a nebular forest located at a “campo rupestre” area at Serra da Piedade, Brazil), in January and February 2005. D. cogniauxiana is adhered to trunks, in sites with high atmospheric humidity and shaded, while E. secundum is located at the edge of the nebular forest, in more luminous sites. The leaves of E. secundum had thicker cuticle and higher number of stomata per area than those of D. cogniauxiana, characteristics coherent with their distinct pattern of exhibition to sun light. The suprastomatic chambers formed by the thicker cuticle may function as a barrier of resistance to water evaporation. The succulence of the leaves of E. secundum propitiates organic acids storage at night, and the storage of starch may be involved in PEP-carboxylase metabolism, both propitiating CAM mechanism. Roots with larger number of cell layers of the velamen, and specialized thick walled cortical cells (both in E. secundum) help water absorption and indicate better adaptation to an environment with intense solar radiation and a probable higher water deficit. The remarkable cell wall thickening of E. secundum exodermis can confer more efficient protection against the excess of transpiration at the border of the nebular forest. On the other hand, besides D. cogniauxiana be epiphyte, it is in a low position - in a shaded environment and with high relative humidity. Its thin thickened velamen permits the entrance of the low available light, and photosynthesis, producing oxygen and helping to avoid hypoxia condition. As features registered for D. cogniauxiana and E. secundum roots, we can depict the velamen, distinct exodermis and endodermis, and specialized thick walled cortical cells as characteristic of epiphytic plants.

A influência do desmatamento da Mata Atlântica sobre o microclima da Serra da Mantiqueira ainda não é totalmente compreendida. Para conhecer as consequências do desmatamento sobre o clima serrano é necessário realizar estudos sobre o balanço de radiação na superfície. A falta de dados possibilita conjugar imagens de satélite com dados meteorológicos em um Sistema de Informação Geográfica na determinação do balanço de radiação. O presente estudo teve por objetivo avaliar o modelo MTCLIM em dias de céu claro ou nublado para simular o balanço de radiação na Serra da Mantiqueira, divisa entre os estados de São Paulo, Minas Gerais e Rio de Janeiro, Brasil. Imagens diárias, semanais e dezesseis dias do sensor MODIS disponíveis em 2003 foram utilizadas em rotinas específicas do MTCLIM. Alvos específicos foram selecionados para avaliar o comportamento do balanço de radiação. Observou-se que o balanço de radiação acompanhou a topografia local e é influenciado pelo tipo de uso da terra. Conclui-se que a temperatura da superfície contribui para aumentar a temperatura do ar implicando em diminuição do balanço de radiação sobre pastagem. O modelo MTCLIM demonstrou boa correlação para a temperatura do ar (R² = 0,82) e para a radiação solar global (R² = 0,71).

The influence of deforestation of the Atlantic Forest on the microclimate of the mountain Mantiqueira is not yet fully understood. To understand the consequences of deforestation on the highland climate research is needed about the surface radiation balance. The lack of data allows combining satellite images with meteorological data in a Geographic Information System in determining the radiation balance. The study aimed to evaluate the MTCLIM model in cloudless days or cloudy sky and simulate the radiation balance in the Mantiqueira mountain, between São Paulo, Minas Gerais and Rio de Janeiro, Brazil. Daily images, weekly and sixteen days MODIS available in 2003 were used in specific routines from MTCLIM. Specific targets were selected to evaluate the behavior of the radiation balance. It was observed that the radiation balance followed the local topography and is influenced by the type of land use. It follows that the surface temperature contributes to elevate the air temperature, resulting in lesser radiation balance on pasture. The MTCLIM model showed good correlation for air temperature (R² = 0.82) and solar radiation (R² = 0.71).

The species of the genus Elaphomyces are scarcely known in Mexico in spite of its ecological and traditional importance. In this paper Elaphomyces aculeatus and E. maculatus are cited for the first time to Mexico and E. muricatus from Michoacan State. The specimens were colected from pine-oak forests, oak forest and mesophic cloudy forest. The species were associated with Quercus spp., except E. aculeatus that was collected under Carpinus caroliniana.

Las especies del género Elaphomyces son poco conocidas en México a pesar de su importancia ecológica y tradicional. En este trabajo se citan por primera vez para México Elaphomyces aculeatus y E. maculatus y para el Estado de Michoacán, E. muricatus. Los especímenes fueron colectados de bosques de pino-encino, encino y bosque mesófilo de montaña. Las especies estaban asociadas a Quercus spp., con excepción de E. aculeatus que se colectó bajo Carpinus caroliniana.

The generation of allometric equations is important to determine biomass and carbon in tree species. This information is useful in climate change studies. In this paper, allometric equations were generated for two species of ecological importance in the cloud forest: Clethra mexicana DC and Alnus arguta (Schltdl) Spach. Equations determined are of the form Y= bXk; where: Y= biomass or carbon content (kg); and X= normal diameter (ND) in centimeters. To estimate model values of b and k for each species, a sampling was performed in fifteen Clethra mexicana and 22 of Alnus arguta trees. In Clethra mexicana the highest percentage of biomass 45.2% was found in the trunk including the stump, while branches and foliage had 36.3% and 18.6% respectively. With the biomass and ND of the tress, b and k parameters were determined from the proposed model (B= 0.4632 DN1.8168, R²= 0.946). For Alnus arguta the highest percentage of biomass (60.6%) was found in the trunk including the stump, while branches and foliage had 27.4 and 12% respectively. Like the previous case with biomass and ND, b and k parameters were obtained from the proposed model (B= 0.1649 DN2.2755, R²= 0.968). After analyzing carbon content in each species samples, equations were adjusted for Clethra mexicana C= 22.49DN1.8168, with R²= 0.946, whereas for Alnus arguta C= 0.0809DN2.2782 with R² = 0.968.

La generación de ecuaciones alométricas es importante para determinar la biomasa y el carbono en las especies arbóreas. Esta información es útil en los estudios de cambio climático. En el presente estudio se generaron ecuaciones alométricas para dos especies de importancia ecológica en el bosque mesófilo de montaña: Clethra mexicana DC y Alnus arguta (Schltdl) Spach. Las ecuaciones que se determinaron son de la forma Y= bXk; donde: Y= contenido de biomasa o de carbono (kg); y X= diámetro normal (DN) en centímetros. Para estimar los valores b y k del modelo para cada especie, se realizó un muestreo de quince árboles de Clethra mexicana y 22 de Alnus arguta. En Clethra mexicana el mayor porcentaje de biomasa 45.2 % se encontró en el fuste incluido el tocón, mientras que en las ramas y el follaje estaba 36.3% y 18.6%, respectivamente. Con la biomasa y el DN de los árboles se determinaron los parámetros b y k del modelo propuesto (B= 0.4632 DN1.8168, R²= 0.946). Para Alnus arguta el mayor porcentaje de biomasa (60.6%), se encontró en el fuste incluido el tocón, mientras que en las ramas y el follaje presentó 27.4 y 12%, respectivamente. Al igual que el caso anterior con la biomasa y el DN, se obtuvieron los parámetros b y k del modelo propuesto (B= 0.1649 DN2.2755, R²= 0.968). Después de analizar el contenido de carbono en las muestra de cada especie, se ajustaron las ecuaciones para Clethra mexicana C= 22.49DN1.8168, con R²= 0.946, mientras que para Alnus arguta C= 0.0809DN2.2782 con R²= 0.968.

La biología reproductiva de Crotalaria micans fue estudiada en áreas perturbadas del remanente de bosque nublado de Altos de Pipe (IVIC), estado Miranda, Venezuela. Las flores abren progresivamente desde las 6:00 h hasta las 10:00 h con una longevidad de cuatro días. El número promedio de flores abiertas por inflorescencia es de 3 (1-6). La secreción de néctar se inicia entre las 14:30 y 15:00 h, el volumen máximo producido es de 1 μl/h. Las flores son visitadas por abejas carpinteras (Xylocopa sp.), Apis melifera, y hormigas (Solenopsis sp.). La actividad de los visitantes fue diurna y Xylocopa sp. estableció contacto directo con el estigma. Más del 50% de la biomasa floral es asignada a la corola y por tanto a la atracción. La relación biomasa reproductiva/biomasa vegetativa fue de 0,28 indicando un desbalance entre el perianto y las partes reproductivas. Los cruces controlados indican que C. micans es autógama, sin embargo, las características de inversión de biomasa y la relación Polen/Óvulo sugieren un sistema reproductivo xenógamo. El comportamiento autógamo se explica como una conducta consecuente con la historia de vida de la planta y su supervivencia en ambientes perturbados. La comparación de los rasgos reproductivos de C. micans en el área estudiada no difiere de los expresados en un estudio similar realizado previamente en una zona templada suramericana, lo cual indica que la variación geográfica no representa un factor que condicione el comportamiento reproductivo de la especie.

The reproductive biology of Crotalaria micans was studied in disturbed areas of the remainder of cloudy forest of Altos de Pipe (IVIC), Miranda State, Venezuela. The flowers open progressively from the 6:00 h until the 10:00 h with a longevity of four days. The average number of flowers opened by inflorescence were 3 (1-6). The secretion of nectar begins between the 14:30 and 15:00 h, the maximum volume is 1 μl/h. The flowers are visited by carpenter bees (Xylocopa sp.), Apis melifera, and ants (Solenopsis sp.). The activity of the visitors occur during the morning and afternoon. Xylocopa sp. was the visitor that established direct contact with the stigma. More than 50% of floral biomass is allocated to the corolla, and therefore to attraction. Reproductive/vegetative biomass ratio was 0,28, which indicate an unbalanced biomass allocation between perianth and reproductive parts. However, the characteristics of investment of biomass and the Pollen/Ovule ratio do not coincide with the results of the controlled crossings and they suggest a xenogamous reproductive system. The autogamous behavior is explained as consequent with the history of life of the plant and its survival in perturbed atmospheres. The comparison of the reproductive trait of C. micans in the studied area does not differ of the features expressed in a similar study carried out previously in a temperate South American area; this indicates that the geographical variation does not represent a factor that influences the reproductive behavior of the species.