Altitudinal distribution of the functional feeding groups of aquatic macroinvertebrates using an ecological network in Andean streams / Distribución altitudinal de los grupos funcionales de alimentación de macroinvertebrados acuáticos utilizando una red ecológica en arroyos andinos

Abstract Introduction: Analysis of functional feeding groups (FFG) in aquatic macroinvertebrates is important in understanding the structure, function, and dynamics of ecological processes in ecosystems. Modularity refers to the degree of compartmentalization of food webs and varies between -1 and 1. A network with a modularity value close to 1 is resilient to disturbances and can be interpreted as an indicating factor for the stability of communities. Objective: In this study, we analyzed the trophic structure of benthic macroinvertebrates in La Nitrera stream, the San Juan River, and the Cauca River in the Colombian Andes. Methods: The study was supported by ecological networking techniques using Gephi software. We studied nine sites in dry, rainy, and transition seasons in 2017 and 2018, monitoring changes in the altitude gradient. At each of the sites, the organisms were captured and determined, and physicochemical and hydraulic information was obtained. Results: The variance component analysis allowed to explain the variability of the data by relating the following environmental variables: FFG, diversity, richness, modularity, season, and time. Simple multifactorial ANOVA indicated that significant changes in FFG were associated with altitude, and modularity to time. The allocation of the FFG was done by stomach analysis and secondary information. Conclusion: The transition season had the highest modularity, possibly due to the recolonization of some biotopes caused by the decrease in the velocity of water currents. La Nitrera and San Juan presented higher values than the Cauca, which may indicate that the altitudinal change and velocity of water currents affects the compartmentalization of the network.

Resumen Introducción: El análisis de grupos funcionales de alimentación (GFA) en macroinvertebrados acuáticos es importante para comprender la estructura, función y dinámica de los ecosistemas de procesos ecológicos. La modularidad se refiere al grado de compartimentación de las redes alimentarias y varía entre -1 y 1. Una red con un valor de modularidad cercano a 1 es resistente a las alteraciones y puede interpretarse como un factor indicativo para la estabilidad de las comunidades. Objetivo: En este estudio se analizó la estructura trófica de los macroinvertebrados bentónicos, un elemento importante en la calidad ambiental, en el arroyo La Nitrera, el río San Juan y el río Cauca. Métodos: El estudio contó con el apoyo de técnicas de redes ecológicas utilizando el software Gephi. En 2017 y 2018, estudiamos nueve sitios en estaciones secas, lluviosas y de transición, monitoreando cambios en el gradiente de altitud. En cada uno de los sitios se capturaron y determinaron los organismos y se recogió información fisicoquímica e hidráulica. Resultados: El análisis de componentes de varianza permitió explicar la variabilidad de los datos relacionando las siguientes variables ambientales: GFA, diversidad, riqueza, modularidad, estación y tiempo. La ANOVA simple multifactorial indicó que existen cambios significativos en los GFA en relación con la altitud, y la modularidad con el tiempo. La asignación de los GFA se realizó mediante análisis estomacal e información secundaria. Conclusión: La temporada de transición tuvo la mayor modularidad, posiblemente debido a la recolonización de algunos biotopos provocada por la disminución de la velocidad del cauce. La Nitrera y San Juan presentaron valores superiores a los del Cauca, lo que puede indicar que el cambio altitudinal y la velocidad de las corrientes de agua influyen en la compartimentación de la red.

DNA content and cytogenetic characteristics of Gymnocalycium quehlianum (Cactaceae) along an altitudinal gradient / Contenido de ADN y características citogenéticas de Gymnocalycium quehlianum (Cactaceae) a lo largo de un gradiente altitudinal

ABSTRACT Important changes in vegetation types occur along elevational gradients. The genus Gymnocalycium is endemic to southern South America, and its species are distributed along elevational gradients. In particular, Gymnocalycium quehlianum is a globular cactus endemic to the Sierras de Córdoba. Studying cytogenetic aspects and DNA content in populations throughout their distribution is key to understanding the species. DNA content and cytogenetic characteristics were analyzed in four populations of G. quehlianum (615, 744, 948 and 1257 masl). The genome size in the four populations varied between 3.55 and 4.30 pg. The populations were diploid (2n = 22). All populations showed the karyotype formula of 10 metacentrics (m) + 1 submetacentric (sm). The species presented symmetrical karyotypes and constitutive heterochromatin CMA+/DAPI- associated with nucleolar organizing regions, always found in the first pair of m chromosomes. The 18-5.8-26S rDNA locus is found in the terminal regions of the first pair of chromosomes m, and the 5S locus is adjacent to the 18-5.8-26S locus. A tendency for DNA content to decrease with increasing altitude was observed.

RESUMEN A lo largo de los gradientes altitudinales se producen cambios importantes en los tipos de vegetación. El género Gymnocalycium es endémico del sur de América del Sur y sus especies se distribuyen en gradientes altitudinales. En particular, Gymnocalycium quehlianum es un cactus globular endémico de las Sierras de Córdoba. Estudiar aspectos citogenéticos y de contenido de ADN en las poblaciones a lo largo de su distribución es clave para comprender a la especie. En cuatro poblaciones de G. quehlianum (615, 744, 948 y 1257 msnm) se analizaron el contenido de ADN y las características citogenéticas. El tamaño del genoma en las cuatro poblaciones varió entre 3,55 y 4,30 pg. Las poblaciones resultaron diploides (2n=22). Todas las poblaciones presentaron la fórmula del cariotipo de 10 metacéntricos (m) + 1 submetacéntrico (sm). La especie presentó cariotipos simétricos y heterocromatina constitutiva CMA+/DAPI- asociados con regiones organizadoras nucleolares, que siempre se encontraban en el primer par de cromosomas m. El locus de ADNr 18-5.8-26S se encuentra en las regiones terminales del primer par de cromosomas m y el locus de 5S está adyacente al locus 18-5.8-26S. Se observó una tendencia del contenido de ADN a disminuir con el aumento de la altitud.

Phenology of the endangered palm Ceroxylon quindiuense (Arecaceae) along an altitudinal gradient in Colombia / Fenología de la palma en peligro Ceroxylon quindiuense (Arecaceae) a lo largo de un gradiente altitudinal en Colombia

Abstract Introduction: Understanding the phenology of plant populations is vital for their conservation and management. We studied the vegetative and reproductive phenology of the endangered palm Ceroxylon quindiuense along an altitudinal gradient in the Central Cordillera of Colombia. Objective: We describe the leaf production rate, and flowering and fruiting cycles, and calculate food offer for the fauna, as a tool for the proper management of the palm. Methods: At each sampling site (2 400, 2 600, 2 800, 3 000 m.a.s.l.), we marked 40 adult individuals (20 pistillate, 20 staminate), which we followed bimonthly for 24 months. We studied leaf production by counting fallen leaves. We followed flower and fruit production through observations with binoculars and photographs. Results: Each adult individual produced, on average, one leaf every 69 days. Although isolated individuals flowered throughout the year, most palms flowered synchronously at each elevation in October 2016-August 2017 and in August 2018-February 2019 and had ripe fruits 7-13 months later. Flowering started at 2 600 m, followed by 2 800 and 3 000 m. Palms at 2 400 m, the lower limit of the palm stands in the area, showed a singular behavior, with scarce flower and fruit production, some individuals that changed sex, and a higher proportion of pistillate palms. Each palm produced 1-11 (x̄ = 5.3, SD = 2.2) inflorescences and 1-10 (x̄ = 5.3, SD = 2.2) infructescences. The average number of fruits per infructescence was 4 465 (SD = 1 488). With an estimated population of adult palms between 256 000 and 600 000 and an overall ratio of pistillate: staminate individuals 1:1 or 1:2, total fruit production in the area during each fruiting period is estimated as 2.0-7.1 billion fruits. Conclusions: The huge number of flowers and fruits and their gradual availability along the altitudinal gradient have a major impact on the spatial and temporal distribution of food offer for fauna associated with the palm.

Resumen Introducción: Comprender la fenología de las poblaciones de plantas es vital para su conservación y manejo. Estudiamos la fenología vegetativa y reproductiva de la palma amenazada Ceroxylon quindiuense a lo largo de un gradiente altitudinal en la Cordillera Central de Colombia. Objetivo: Describimos la tasa de producción de hojas, los ciclos de floración y fructificación, y calculamos la oferta alimentaria para la fauna, como una herramienta para el adecuado manejo de la palma. Métodos: En cada sitio de muestreo (2 400, 2 600, 2 800, 3 000 m.s.n.m.), marcamos 40 individuos adultos (20 pistilados, 20 estaminados), que seguimos bimestralmente durante 24 meses. Estudiamos la producción de hojas contando las caídas al suelo. Seguimos la producción de flores y frutos a través de observaciones con binoculares y fotografías. Resultados: Cada individuo adulto produjo, en promedio, una hoja cada 69 días. Aunque los individuos aislados florecieron durante todo el año, la mayoría de las palmas florecieron sincrónicamente en cada elevación entre octubre 2016 y agosto 2017 y de agosto 2018 a febrero 2019 y tuvieron frutos maduros entre 7-13 meses después. La floración comenzó a los 2 600 m, seguida de los 2 800 y los 3 000 m. Las palmas a 2 400 m, límite inferior de los palmares de la zona, mostraron un comportamiento singular, con escasa producción de flores y frutos, varios individuos que cambiaron de sexo y una mayor proporción de palmas pistiladas. Cada palma produjo 1-11 (x̄ = 5.3, SD = 2.2) inflorescencias y 1-10 (x̄ = 5.3, SD = 2.2) infrutescencias. El número promedio de frutos por infrutescencia fue de 4 465. Con una población estimada de palmas adultas entre 256 000 y 600 000 y una proporción total de individuos pistilados: estaminados 1:1 o 1:2, la producción total de frutos en el área durante cada período de fructificación se estima en 2.0-7.1 mil millones de frutos. Conclusiones: La gran cantidad de flores y frutos y su progresiva disponibilidad a lo largo del gradiente tienen un impacto importante en la distribución espacial y temporal de la oferta de alimento para la fauna asociada a la palma.

Variación en la fenología de floración de una bromelia epífita a lo largo de un gradiente de elevación / Variation in the flowering phenology of an epiphytic bromeliad along an elevational gradient

ABSTRACT Elevational patterns in flowering phenology have been reported for trees, shrubs and herbs. However, for vascular epiphytes that rely on atmospheric sources for humidity and nutrients, and depend on phorophyte microhabitat, elevational patterns of variation are unknown. In this study, we described the flowering phenology of Tillandsia carlos-hankii, an epiphytic bromeliad, along an elevational gradient in Capulálpam de Méndez, Oaxaca. We analyzed the onset, seasonality and duration of flowering along and within different elevation zones, and we evaluated the effect of phorophyte features (tree height, DBH and canopy diameter) on flowering start date and duration. From June 2016 to May 2017, we periodically recorded phenological data from six populations along three elevation zones ("low": 2151 to 2283 m. a. s. l., "medium": 2284 to 2416 m. a. s. l. and "high": 2417 to 2548 m. a. s. l.), monitoring two population per zone. Start of flowering occurred between December and January, beginning six to 16 days earlier at low elevations than in the other zones, although this difference was not statistically significant. We observed marked flowering seasonality at all the elevation zones, with differences between zones (W≥18.49, p≤0.0001) and between the populations at medium and high elevations (W≥8.57, p≤0.05). Flowering duration spanned from December to May. Phorophyte features were not related to the onset or duration of flowering (t≤-1.47, p≥0.14, in all cases). Our results suggest that vascular epiphytes follow the same elevational patterns in phenology as other life forms, and that populations in the same elevation range can vary. The causes of such intra-elevational variation merit further investigation.

RESUMEN Se han reportado los patrones altitudinales en la fenología de floración para árboles, arbustos y hierbas. Sin embargo, para epífitas vasculares, que dependen de fuentes atmosféricas para la humedad y los nutrientes, y del microhábitat del forofito, los patrones de variación en gradientes de elevación se desconocen. Se describe la fenología de floración de Tillandsia carlos-hankii, una bromelia epífita, en un gradiente de elevación en Capulálpam de Méndez, Oaxaca. Se analiza el inicio, estacionalidad y duración de su floración entre y dentro de diferentes elevaciones y se evalúa también el efecto del forofito (altura, DAP y diámetro de copa) sobre el inicio y la duración de la floración. De junio de 2016 a mayo de 2017, se monitorearon individuos localizados en seis poblaciones en tres elevaciones (bajo: 2151-2283 m. s. n. m., medio: 2284-2416 m. s. n. m., alto: 2417-2548 m. s. n. m.), dos poblaciones por zona. El inicio de la floración ocurrió entre diciembre y enero, empezando de seis a 16 días antes en la elevación baja que en las otras, aunque estas diferencias no fueron significativas. Hubo una marcada estacionalidad en todas las zonas de elevación, con diferencias entre elevaciones (W≥18,49, p≤0,0001) y entre poblaciones de media y alta elevación (W≥8,57, p≤0,05). La floración duró de diciembre a mayo. Las características del forofito no estuvieron relacionadas con el inicio ni la duración de la floración (t≤-1,47, p≥0,14, en todos los casos). Los resultados sugieren que las epífitas vasculares siguen el mismo patrón fenológico altitudinal de otras formas de vida, y que las poblaciones en un misma elevación altitudinal pueden variar. Las causas de tal variación intra-altitudinal merecen mayor investigación.

A new inventory for fishes of headwater streams from the rio das Cinzas and rio Itararé basins, rio Paranapanema system, Paraná, Brazil / Um novo inventário para peixes de riachos de cabeceira das bacias dos rio das Cinzas e rio Itararé, sistema do rio Paranapanema, Paraná, Brasil

Abstract: The rio das Cinzas and rio Itararé basins are important tributaries of the rio Paranapanema, a major left-bank tributary of the upper rio Paraná basin. The upper reaches of both drainages intersect the northern portion of the APA Escarpa Devoniana (Devonian Escarpment Environment Protection Area, EPA), an area considered crucial for the preservation of biodiversity. This study aimed to provide an ichthyofaunistic inventory for headwater streams of the rio das Cinzas and rio Itararé basins, both within and off of the borders of the EPA, increasing the knowledge about the species already known from streams in the rio Paranapanema system. We found 32 fish species, representing five orders and 12 families. Siluriformes was the richest order followed by Characiformes. Ten species presented high abundance of sampled individuals, contributing with 85.0% of all specimens. Most species were classified as occasional (captured in less than 25% of the samples) and only two species were classified as constant (captured in more than 50% of samples), which may reflect the altitudinal gradient. We did not record any introduced species in the sampled streams, reinforcing the need of, at least, maintaining the original area of the EPA. We expanded the geographic distribution of Astyanax bifasciatus to the upper rio Paraná system, confirming the cases of faunal exchange among several drainage systems in the limits of the Ponta Grossa Arch. Finally, we identified three putatively undescribed species that show a large biodiversity knowledge shortfall for the region studied.

Resumo: As bacias do rio das Cinzas e do rio Itararé são afluentes importantes do rio Paranapanema, um dos principais afluentes da margem esquerda do alto rio Paraná. Os trechos superiores de ambas as drenagens interceptam a porção norte da Área de Proteção Ambiental (APA) da Escarpa Devoniana, uma área considerada crucial para a preservação da biodiversidade. Este trabalho teve como objetivo fornecer um inventário ictiofaunístico para riachos de cabeceira das bacias do rio das Cinzas e do rio Itararé, dentro e fora das fronteiras da APA, aumentando o conhecimento sobre as espécies já conhecidas dos riachos do rio Paranapanema. Encontramos 32 espécies de peixes, representando cinco ordens e 12 famílias. Siluriformes foi a ordem mais rica seguida por Characiformes. Dez espécies apresentaram alta abundância de indivíduos amostrados, contribuindo com 85,0% de todos os espécimes. A maioria das espécies foi classificada como ocasional (capturada em menos de 25% das amostras) e apenas duas espécies foram classificadas como constantes (capturadas em mais de 50% das amostras), o que pode refletir o gradiente altitudinal. Não registramos nenhuma espécie introduzida nos riachos amostrados, reforçando a necessidade de, pelo menos, manter a área original do APA. Expandimos a distribuição geográfica de Astyanax bifasciatus para o sistema do alto rio Paraná, confirmando os casos de intercâmbio faunístico entre vários sistemas de drenagem nos limites do Arco de Ponta Grossa. Finalmente, identificamos três espécies supostamente não descritas que mostram um grande déficit de conhecimento da biodiversidade para a região estudada.

Energy storage, body size and immune response of herbivore beetles at two different elevations in Costa Rica

The physiological condition and immune responses of organisms living at different elevations are expected to display local adaptations to the different climatic and biotic conditions. Small ectotherms with specialized diets are highly susceptible to environmental change, as their life cycle is largely affected by temperature and by the presence of specific resources. This study focuses on two species of rolled-leaf beetles (Chrysomelidae), both present at two different elevations in Costa Rica: Cephaloleia belti Baly, a diet-generalist, and Chelobasis bicolor Gray, a diet-specialist. Body size, energetic condition (lipid storage), muscle mass and immune condition (melanization response) were compared in beetle populations from a tropical rainforest (50 m elevation) and a tropical montane forest (2 000 m elevation). These measurements reflect current and past nutritional condition and hence are good estimators of individual fitness. We analyzed a total of 172 individuals from both species, sexes and elevations. We predicted that beetles at higher elevation would display larger body size, higher energetic condition and lower immune response associated with metabolic requirements and parasitic pressure in colder temperatures. In general, beetles at high altitude were larger, had more lipids and muscle and showed stronger melanization (i.e., immune response) than beetles at low altitudes. Such differences among populations at different elevations may reflect local adaptation to altitude or phenotypic plasticity. However, the effect of elevation was not equivalent amongst species or sex. Measuring physiological traits in organisms with broad elevational distributions could be useful in understanding possible species responses to climate change.

La condición fisiológica y la respuesta inmune de poblaciones que habitan a distintas altitudes pueden mostrar adaptación local a las condiciones abióticas y bióticas locales. Entre los organismos más susceptibles al cambio ambiental están los ectotermos pequeños con dietas especializadas, debido a que su ciclo de vida es, en gran medida, afectado tanto por la temperatura como por la presencia de recursos específicos. Este estudio se enfoca en dos especies de escarabajos (Chrysomelidae) presentes a lo largo de un gradiente altitudinal en Costa Rica: Cephaloleia belti Baly, una especie de dieta generalista, y Chelobasis bicolor Gray, de dieta especialista. Se comparó el tamaño corporal, la condición energética (almacenamiento de lípidos), la masa muscular y la condición inmunológica (respuesta de melanización) entre poblaciones de escarabajos de un bosque tropical (a 50 m de altitud) y un bosque tropical montano (a 2 000 m de altitud). Las variables seleccionadas reflejan las condiciones nutricionales actuales y pasadas y son buenos estimadores de la adecuación individual. Se analizaron un total de 172 escarabajos de ambas especies, sexos y elevaciones. Predecimos que los escarabajos a mayor elevación tendrán mayor tamaño corporal, mayor condición energética y menor respuesta inmune asociadas con los requerimientos metabólicos y la presión de los parásitos asociados con ambientes fríos. En general, los escarabajos a mayor altitud fueron más grandes, tuvieron más lípidos y masa muscular, y presentaron una mayor respuesta inmune de melanización que los escarabajos a menor altitud. Es posible que las diferencias entre las poblaciones a diferentes altitudes reflejen adaptaciones locales a las condiciones ambientales a distintas altitudes o plasticidad fenotípica. Sin embargo, el efecto de la altitud no fue de la misma magnitud entre las dos especies ni entre los dos sexos. La medición de caracteres fisiológicos en organismos ectotérmicos de amplia distribución altitudinal puede ser útil para entender las respuestas de ciertas especies al cambio climático.

Ichthyofauna of headwater streams from the rio Ribeira de Iguape basin, at the boundaries of the Ponta Grossa Arch, Paraná, Brazil / Ictiofauna de riachos de cabeceira da bacia do rio Ribeira de Iguape, nos limites do Arco de Ponta Grossa, Paraná, Brasil

Abstract: The rio Ribeira de Iguape basin (Paraná State) is highly relevant for the preservation of remnants of the Atlantic Forest. Its high levels of diversity and fish endemism explain the river dynamics promoted by the Ponta Grossa Arch, a geological structure that promotes headwater capture and isolation between the upper rio Paraná drainage, the rio Iguaçu and the rio Ribeira de Iguape. Here, our objective was to provide an unprecedented inventory for headwater streams of the rio Ribeira de Iguape basin at the boundaries of the Ponta Grossa Arch. We found 29 species of fish representing four orders and nine families. Siluriformes was the richest order followed by Characiformes. Nine species presented high abundance of sampled individuals, contributing with 87.8% of the collections. Four species appeared in less than 25% of the sampled sites (occasional), and six species appeared in more than 50% (constant). We identified three non-described species and one non-native (Coptodon rendalli). Two species had their geographical distribution extended and the presence of Astyanax bifasciatus, endemic to the Iguaçu river basin, ratifies recent events of headwater capture between coastal drainages and those that flow into the continent. Studies of biogeographic divisors are necessary to explain the origin and dispersion processes of species in order to direct studies on diversity and preventive management actions. Coptodon rendalli (Tilapia) is an alarming record on the introduction of species in the region.

Resumo: A bacia do rio Ribeira de Iguape (Estado do Paraná) é altamente relevante para a preservação de remanescentes da Mata Atlântica. Os seus altos níveis de diversidade e de endemismo de peixes explicam a dinâmica fluvial promovida pelo Arco de Ponta Grossa, estrutura geológica que promove eventos de captura de cabeceira e de isolamento entre as drenagens do alto rio Paraná, do rio Iguaçu e do rio Ribeira de Iguape. Aqui, nosso objetivo foi fornecer um inventário inédito para riachos de cabeceira da bacia do rio Ribeira de Iguape nos limites do Arco de Ponta Grossa. Encontramos 29 espécies de peixes representando quatro ordens e nove famílias. Siluriformes foi a ordem mais rica seguida por Characiformes. Nove espécies apresentaram alta abundância de indivíduos amostrados, contribuindo com 87,8% das coletas. Quatro espécies apareceram em menos de 25% dos locais amostrados (ocasionais), e seis espécies apareceram em mais de 50 % (constantes). Identificamos três espécies não descritas e uma (Coptodon rendalli) não nativa. Duas espécies tiveram sua distribuição geográfica ampliada e, a presença de Astyanax bifasciatus, endêmica para a bacia do rio Iguaçu, ratifica eventos recentes de captura de cabeceira entre drenagens costeiras e aquelas que fluem para dentro do continente. Estudos de divisores biogeográficos são necessários para explicar os processos de origem e dispersão de espécies a fim de direcionar estudos sobre diversidade e ações de manejo preventivas. Coptodon rendalli (Tilápia) é um registro alarmante sobre a introdução de espécies na região.

Composición y distribución de hepáticas (Marchantiophyta) en un intervalo altitudinal en la Cordillera Oriental de Colombia / Composition and distribution of liverworts (Marchantiophyta) in a continuous altitudinal range on the Cordillera Oriental of Colombia

Resumen La composición de especies de hepáticas sobre los Andes del Norte varía con la altitud en relación con diferentes factores bióticos (vegetación) y abióticos (temperatura, humedad y luminosidad). Para probar esta afirmación se determinó la diversidad y distribución de las Marchantiophytas en un rango altitudinal entre los 2 400 y 3 400 m sobre la Cordillera Oriental colombiana, estableciendo cómo éstas varían entre altitudes y zonas de vida con respecto a los factores abióticos. Se realizaron muestreos cada 200 m y se registraron datos ambientales durante un año. Se encontraron 162 especies, la composición de hepáticas varió a lo largo del gradiente altitudinal con un gran número de especies únicas en cada altitud. Se encontró la máxima diversidad en los 3 000 m, con una dominancia del hábito folioso y de especies epifitas, mientras que la mayor riqueza de familias y géneros se presentó entre los 3 200 y 3 400 m. Anoplolejeunea conferta presentó la mayor cobertura en la zona así como el mayor valor del índice de valor de importancia (IVI) y distribución altitudinal más amplia, ubicándose desde los 2 400 hasta 3 000 m en cuatro diferentes sustratos. Las hepáticas se distribuyeron altitudinalmente de manera diferencial, con una diversidad beta alta (0.864) debido al recambio altitudinal de especies, con más del 30 % de disimilaría en la composición de especies cada 200 m altitudinales, dependiendo principalmente de cambios en la luminosidad. Consecuentemente, la temperatura, humedad y luminosidad y su relación con la vegetación son determinantes en la diversidad y distribución de las hepáticas en la Cordillera Oriental de los Andes colombianos.

Abstract The species composition of liverworts varies with altitude in the Northern part of the Andes due to the relationship of biotic (vegetation) and abiotic factors (temperature, humidity, and sunlight brightness). In order to test this affirmation we determined the diversity, species composition, abundance, and distribution of species of Marchantiophyta in an altitudinal range from 2 400 to 3 400 m on the Colombian Cordillera Oriental, and established how these vary with altitude and life-zones, regarding abiotic factors. Samples, taken every 200 m in the altitudinal range, and environmental data were registered during a year. We found 162 species, the composition of liverworts varied throughout the altitudinal gradient with a high number of unique species in each altitude. The maximum diversity was found at 3 000 m, along with a dominance of leafy habit and epiphytic species, while the higher richness of families and genera was found between 3 200 and 3 400 m. Anoplolejeunea conferta had the largest value of coverage in the zone, the highest value of importance value index (IVI), and the widest altitudinal distribution, from 2 400 to 3 000 m in four different substrates. The liverworts were distributed differently with altitude, we found a high beta diversity (0.864) due to the replacement of species, with more that 30 % of dissimilarity in species composition every 200 altitudinal meters, mainly depending on sunlight brightness variation. Accordingly, we found that abiotic factors like temperature, humidity, and sunlight brightness and its relationship vegetation are determinant in the diversity and altitudinal distribution of liverworts in the study area. Rev. Biol. Trop. 66(2): 559-570. Epub 2018 June 01.

Diversidad y composición de murciélagos en los bosques montanos del Santuario Nacional Pampa Hermosa, Junín, Perú / Bats diversity and composition in montane forest of Pampa Hermosa National Sanctuary, Junin, Peru

El Santuario Nacional Pampa Hermosa (SNPH) es un área protegida importante debido a que protege los relictos de los bosques montanos de las Yungas centrales del Perú, donde los estudios de la diversidad de murciélagos son escasos. Nuestro objetivo fue documentar la diversidad y composición de los murciélagos del SNPH y compararlo con otros bosques de las Yungas peruanas en el rango de 1200 - 2000 m. Se evaluaron cuatro localidades: Podocarpus (1900 m), Los Cedros (1600 m), Santa Isabel (1450 m) y Nueva Italia (1370 m). Se registraron 36 especies de murciélagos en las familias Phyllostomidae (30 spp.), Vespertilionidae (5 spp.) y Molossidae (1 sp.) con un esfuerzo de 560 redes-noche. Los estimadores Chao 1 y Chao 2 indicaron que se cubrió el 77% y 42% de las especies en la zona de estudio, respectivamente. Las curvas de rango-abundancia muestran a Carollia brevicauda como la más abundante en todas las localidades; se resalta la abundancia de Vampyressa melissa en las localidades de Los Cedros y Podocarpus. Se muestra una relación inversa significativa entre la riqueza de especies y la elevación (r = -0.90, P= 0.014). En rangos de 1200-1600 m, la riqueza del SNPH (35 spp.) fue mayor que en las otras Yungas presentando una mayor similitud con el Manu (Ij = 0.59); por otro lado, en rangos de 1600 - 2000 la riqueza del SNPH (14 spp.) fue la segunda más alta después del Manu (21 spp.), presentando una mayor similitud con San Ramón (Ij = 0.30). Los valores de complementariedad fueron altos entre el SNPH y los bosques de Yungas, entre 55-76% (1200-1600 m) y entre 70-83% en (1600-2000 m). Estos resultados indican que la diversidad β de los murciélagos en las Yungas peruanas es alta; sin embargo, debemos tomar en cuenta los esfuerzos dispares entre las localidades comparadas y que se requiere más trabajo de campo en zonas de vida y elevaciones aun no exploradas del SNPH para resultados más precisos.

The Pampa Hermosa national sanctuary (SNPH) is an important area because it preserves relict montane forests of the Peruvian central Yungas where studies of bat's diversity are scarce. Our objective was to document the species diversity and composition of bats communities in Pampa Hermosa and make comparisons with other Peruvian Yungas forests ranging between 1200-2000 m. We sampled four localities: Podocarpus (1900 m), Los Cedros (1600 m), Santa Isabel (1450 m) and Nueva Italia (1370 m) by using 560 mist-nights. Our results show 36 species distributed in families Phyllostomidae (30 spp.), Vespertilionidae (5 spp.) and Molossidae (1 sp.). According to the estimators Chao 1 and Chao 2, we found 77% and 42% of the species in the study area, respectively. The rank-abundance curves point to Carollia brevicauda as the most abundant in all localities; abundance of Vampyressa melissa is highlighted in Los Cedros and Podocarpus. There is a significant inverse relationship between species richness and elevation (r = -0.90, P = 0.014). Altitudes of 1200-1600 m show a species richness (35 spp.) higher than other Yungas forests, and a greater similarity to those in Manu (Ij = 0.59); on the other hand, richness at altitudes of 1600-2000 (14 spp.) was the second highest after Manu (21 spp.) and more similar to San Ramon (Ij = 0.30). Values of complementarity were higher between Pampa Hermosa and other forests in the Peruvian Yungas, ranging from 55-76% (1200 - 1600 m) to 70-83% (1600 - 2000 m). These results indicate there is a high β diversity in the bat communities from the Peruvian Yungas; however, we have to take into account the disparate sampling efforts among the evaluated localities and that additional research in areas of the SNPH not yet explored must give a stronger support to our results.

Fish distribution in watersheds of the eastern part of the Serra da Mantiqueira (state of São Paulo) / Distribuição de peixes em microbacias da serra da Mantiqueira oriental (Estado de São Paulo)

The present work aims to analyse jointly four contiguous watersheds in the eastern part of the Serra da Mantiqueira with respect to the distribution of fish fauna and physical structure. The watersheds of Piracuama river, Ribeirão Grande, Buenos and Guaratinguetá are located in Pindamonhangaba, Campos do Jordão and Guaratinguetá municipalities, in the state of São Paulo. Data were collected between the years 2001 and 2010, with collections distributed throughout the seasons, including sites located on the slope and piedmont. The limnological parameters analysed were different between watersheds and habitat structure was different only for the slope segments between Ribeirão Grande and Buenos watersheds, and between Ribeirão Grande and Piracuama watersheds. Thirty-five species of fish were caught, with the highest species richness found in the Ribeirão Grande watershed (30 species), followed by the Piracuama (23 species) and Buenos and Guaratinguetá (21 species each). The most abundant species in both the segments (slope and piedmont) was Trichomycterus itatiayae. The highest degree of species dominance occurred in the Guaratinguetá watershed and in the segment slope, being T. itatiayae the dominant species. Species diversity was lower at the slope than the piedmont, indicating variability in species abundance. Again T. itatiayae was the most abundant species in both segments, showing to be a well adapted species to these streams systems by presenting, as well as other species, morphological adaptations to the stream environment.

O presente trabalho tem por objetivo analisar conjuntamente quatro microbacias contíguas na serra da Mantiqueira oriental com respeito à distribuição da ictiofauna e estrutura física. As microbacias do rio Piracuama, do Ribeirão Grande, do ribeirão dos Buenos e do rio Guaratinguetá situam-se nos municípios de Pindamonhangaba, Campos do Jordão e Guaratinguetá, no estado de São Paulo. Os dados foram coletados entre os anos de 2001 e 2010, sendo as coletas distribuídas ao longo das estações e contemplando pontos localizados na encosta e no pediplano. Os parâmetros limnológicos analisados foram diferentes entre as microbacias e a estrutura de habitat foi diferente apenas para os segmentos de encosta entre as microbacias do Ribeirão Grande e Buenos, e entre Ribeirão Grande e Piracuama. Trinta e cinco espécies de peixes foram capturadas, sendo a maior riqueza de espécies encontrada na microbacia do Ribeirão Grande (30 espécies), seguida pela do rio Piracuama (23 espécies) e dos Buenos e Guaratinguetá (21 espécies cada). A espécie mais abundante tanto na encosta como pediplano foi Trichomycterus itatiayae. O maior grau de dominância de espécies ocorreu na microbacia do Guaratinguetá e no segmento de encosta, sendo T. itatiayae a espécie dominante. A diversidade de espécies para encosta foi inferior à do pediplano, indicando variabilidade na abundância das espécies. Novamente T. itatiayae foi a espécie mais abundante nos dois segmentos, espécie bem adaptada a esses sistemas de riachos por apresentar, assim como outras espécies, adaptações morfológicas ao ambiente de riachos torrentosos.

Morfometría geométrica del corazón de hyla plicata a través de un gradiente altitudinal en el eje neovolcánico mexicano / Geometric morphometric of the heart in hyla plicata through an altitudinal gradient in the mexican neovolcanic axe

Se ha descrito que el medio aéreo representa menos problemas a los organismos en relación con la hipoxia a excepción de circunstancias especiales, como la exposición a grandes alturas o las madrigueras. El ambiente de gran altitud es desafiante en diversos sentidos, dado que existen factores bióticos y abióticos que pueden interactuar para determinar la distribución y sobrevivencia de los organismos. Para conocer estos aspectos, la biología se apoya en la ecomorfología, área que ayuda a definir las diferencias morfológicas con respecto al cambio del hábitat y en la morfometría geométrica que permite analizar estadísticamente esos cambios. En el presente estudio, se evaluaron diferentes poblaciones de la rana Hyla plicata que es una de las especies que se distribuyen a mayor altitud en México, (1500 m hasta los 3700 m). Por lo que el objetivo de este estudio, fue analizar la morfología del corazón en Hyla plicata a través de un gradiente altitudinal. Para ello se colectaron organismos en cuatro localidades, una de ellas fue en La Cima (Distrito Federal a 3016 m), y tres ubicadas en el Estado de México: Buenavista (3200 m), El Cerrillo ( 2632 m) y San Juan Atezcapan (1860 m). Los organismos colectados se disectaron para extraer el corazón con la finalidad de digitalizarlos mediante fotografías, y analizarlos con puntos geométricos y de esta forma evaluar la forma del órgano. Los resultados indican que las localidades de mayor altitud presentan aurículas y ventrículos más ensanchados, lo que señala que esta estructura evolucionó y se adaptó para efectuar un bombeo más eficaz de la sangre y posteriormente dirigirla hacia los diferentes tejidos del cuerpo. Esta adaptación en la morfología del corazón, permitió que Hyla plicata se adaptara a los ambientes de alta montaña como se ha visto en otros vertebrados que habitan zonas de mayor altitud.

It has been reported that the air environment is less problematic for organisms in relation to hypoxia except for special circumstances, such as exposure to high altitudes or burrows. The high altitude environment is challenging in different ways, since there are biotic and abiotic factors may interact to determine the distribution and survival of organisms. For these aspects, biology is based on the ecomorphology, area that helps to define the morphological differences with respect to habitat change and geometric morphometrics to analyze statistically those changes. In the present study, we evaluated different populations of the frog Hyla plicata is a species that are distributed at higher elevations in Mexico (1500 m to 3700 m). For the purpose of this study was to analyze the morphology in Hyla plicata heart through an altitudinal gradient. The organisms were collected at four sites, one was located in La Cima (Distrito Federal to 3016 m), and three in the Estado of Mexico: Buenavista (3200 m), El Cerrillo (2632 m) and San Juan Atezcapan (1860 m). The organisms collected were dissected to extract the heart for the purpose of scan them through photographs, and analyzed with geometric points and thus evaluate the shape of the organ. The results indicate that higher altitude locations have enlarged atria and ventricles, indicating that this structure evolved and adapted to effect a more efficient pumping of blood and then direct it to different body tissues. This adaptation in the morphology of the heart, allowed to adapt to Hyla plicata in high altitude environments as seen in other vertebrates that inhabit higher elevations.

Changes in structure and composition of evergreen forests on an altitudinal gradient in the Venezuelan Guayana Shield

There have been several ecological studies in forests of the Guayana Shield, but so far none had examined the changes in structure and composition of evergreen forests with altitude. This study describes and analyzes the structure, species composition and soil characteristics of forest stands at different altitudinal zones in Southeastern Venezuelan Guayana, in order to explain the patterns and the main factors that determine the structure and composition of evergreen forests along the altitudinal gradient. Inventories of 3 948 big (>10cm DBH) and 1 328 small (5-10cm DBH) woody stems were carried out in eleven plots, ranging from 0.1 to 1.0ha, along a 188km long transect with elevations between 290 and 1 395masl. It has been found that 1) hemiepihytes become more dominant and lianas reduce their dominance with increasing altitude and 2) the forest structure in the study area is size-dependent. Five families and 12 genera represented only 9% of the total number of families and genera, respectively, recorded troughout the gradient, but the two groups of taxa comprised more than 50% of the Importance Value (the sum of the relative density and the relative dominance) of all measured stems. Moreover, the results suggest that low species richness seems to be associated with the dominance of one or few species. Stand-level wood density (WD) of trees decreased significantly with increasing elevation. WD is an indicator of trees’life history strategy. Its decline suggests a change in the functional composition of the forest with increasing altitude. The Canonical Correspondence Analysis (CCA) indicated a distinction of the studied forests on the basis of their altitudinal levels and geographic location, and revealed different ecological responses by the forests, to environmental variables along the altitudinal gradient. The variation in species composition, in terms of basal area among stands, was controlled primarily by elevation and secondarily ...

A pesar de los diversos estudios ecológicos realizados en los bosques del Escudo de Guayana, ninguno de ellos había analizado hasta ahora los cambios en la composición y estructura de bosques siempreverdes que ocurren al incrementar la altitud. Con el fin de identificar patrones y factores determinantes de la estructura y la composición de bosques en un gradiente altitudinal (290-1 395msnm) en el sudeste de Venezuela se realizaron inventarios de 3 948 fustes grandes (>10cm DAP) y 1 328 pequeños (5-10cm DAP) en once parcelas a lo largo de un transecto de 188km. Con el incremento de la altitud, el área basal aumenta en las hemiepífitas y disminuye en las lianas. Las familias y los géneros más importantes representaron una reducida proporción del total de taxones, pero abarcaron más del 50% del Valor de Importancia. Bajos valores de riqueza se asocian con la dominancia de pocas especies. La densidad de madera decrece significativamente a mayor altitud, y sugiere un cambio en la composición funcional. Existen diferentes respuestas ecológicas de los rodales ante cambios físico-ambientales. La variación de la composición de especies en el gradiente fue controlada por altitud, lluvia y condiciones edáficas; pero se desconoce el efecto de otros factores no considerados como régimen de perturbaciones, interacciones biológicas, productividad e historia de dispersión. La variabilidad observada en la estructura y la composición de bosques en el gradiente parece ser un resultado del efecto combinado de diferentes climas y procesos locales aleatorios que interactúan en un complejo paisaje.

Composição florística e distribuição altitudinal de epífitas vasculares da Floresta Ombrófila Densa na Serra da Prata, Morretes, Paraná, Brasil / Floristic composition and altitudinal distribution of vascular epiphytes in the Ombrophilous Dense Forest of the Prata Mountain Range, Morretes, Paraná State, Brazil

O levantamento de epífitas vasculares foi realizado na porção norte da Serra da Prata (48º 41' 59,39" O e 25º 36' 46,39" S), município de Morretes, abrangendo 6,3 ha de encosta situada entre 400 e 1.100 m s.n.m., coberta por Floresta Ombrófila Densa Submontana e Montana. Os objetivos do trabalho foram: 1) caracterizar a flora epifítica vascular; 2) discutir sua distribuição altitudinal e nas categorias ecológicas; 3) avaliar a similaridade florística com outras áreas do sul e sudeste do Brasil. O levantamento foi efetivado entre 2005 e 2010. Cento e vinte forófitos, distribuídos por quatro altitudes (400, 600, 800 e 1.000 m), foram escalados e detalhadamente vasculhados. Foram registradas 278 espécies, 109 gêneros e 30 famílias de epífitas vasculares. Pteridófitas englobaram 74 espécies, 30 gêneros e 10 famílias. Angiospermas totalizaram 204 espécies, 79 gêneros e 20 famílias. A riqueza de epífitas vasculares foi a maior já registrada em estudos de Floresta Ombrófila Densa no sul do Brasil. Sete espécies tiveram seu primeiro registro para o Paraná e seis enquadraram-se como ameaçadas em nível estadual. Orchidaceae foi a mais rica, com 103 (37,2%) espécies e 43 (39,1%) gêneros, seguida de Bromeliaceae (38), Polypodiaceae (28), Hymenophyllaceae (15), Araceae (14) e Piperaceae (14). As holoepífitas características constituíram o grupo dominante, perfazendo 83% do total. Apenas 54 (19,5%) espécies foram registradas em todas as faixas altitudinais, sendo que 131 (47,3%) foram registradas somente abaixo dos 700 m e 54 (19,5%) encontradas somente acima dos 800 m. Detectou-se reduzida similaridade florística entre as extremidades da encosta estudada, o que destaca a importância da altitude na distribuição das espécies. A flora epifítica da Serra da Prata apresentou reduzida similaridade com outras comunidades de Floresta Ombrófila Densa do PR e SP.

The floristic survey of vascular epiphytes was done in the northern part of the Prata Mountain Range (48º 41' 59.39" W and 25º 36' 46.39" S), Morretes municipality, comprising 6.3 ha of a slope between 400 and 1,100 m a.s.l., covered by submontane and montane Atlantic Rainforest. The aims of this study were: 1) characterize the vascular epiphytic flora; 2) discuss the species distribution along the slope and in ecological categories; 3) evaluate the floristic similarity among the study area and other forests of South and Southeastern Brazil. The present survey was carried out between 2005 and 2010. One hundred twenty phorophytes were climbed and closely examined. Two hundred seventy-eight species, 109 genus and 30 families of vascular epiphytes were recorded. Pteridophytes comprised 74 species, 30 genus and 10 families. Angiosperms comprised 204 species, 79 genus and 20 families. The vascular epiphytic richness was the highest registered in studies of Atlantic Rainforest in South Brazil. Seven species were the first records for the Paraná State and six are threatened considering the Paraná state official list of endangered species. Orchidaceae was de richest family, with 103 (37.2%) species and 43 (39.1%) genus, followed by Bromeliaceae (38), Polypodiaceae (28), Hymenophyllaceae (15), Araceae (14) and Piperaceae (14). The holoepiphytes were the dominant group, comprising 83% of the total. Only 54 (19.5%) species were recorded in all altitudinal belts. Other 131 (47.3%) species were recorded only under the 700 m a.s.l. and 54 (19.5%) were found just above the 800 m a.s.l. The floristic similarity between the two extremities of the studied slope was low, showing the importance of the altitude for the species distribution. The epiphytic flora of the Prata Mountain Range presented low similarity with others Atlantic Rainforest communities of Paraná and São Paulo states.

Diferenças florísticas e estruturais entre duas cotas altiduninais da Floresta Ombrófila Densa Submontana Atlântica, do Parque Estadual da Serra do Mar, município de Ubatuba/SP, Brasil / Floristic and structural differences, between two altitudinal quotas, of the Submontane Atlantic Rainforest within the Serra do Mar State Park, municipality of Ubatuba/SP, Brazil

Este estudo apresenta a análise comparativa entre duas áreas da Floresta Atlântica Ombrófila Densa Submontana, em Ubatuba (SP), Brasil e testa a hipótese de que diferenças em altitude podem representar alterações na composição florística e estrutura fitossociológica. As duas parcelas de um hectare (100 x 100 m) foram instaladas a 190 (PLOT G) e 350 m (PLOT I) acima do nível do mar, sendo amostrados e identificados todos os indivíduos, exceto lianas, com DAP (Diâmetro à Altura do Peito) > 4.8 cm. No total, foram encontradas 252 espécies, pertencentes a 134 gêneros e 53 famílias, a diversidade H' de 4,425 nats/indivíduos e 103 espécies (41 por cento do total) em comum entre as duas áreas. Mas, entre as 10 principais espécies em dominância absoluta apenas duas se repetem entre as áreas: Cryptocarya mandioccana e Sloanea guianensis. No PLOT G existem 1.496 indivíduos distribuídos em 152 espécies, 101 gêneros e 41 famílias, com H' = 3,961 nats/indivíduo e 48 espécies exclusivas à área (32 por cento). No PLOT I existem 1.993 indivíduos distribuídos em 203 espécies, 111 gêneros, 50 famílias, com H' = 4,339 nats/indivíduo e 100 espécies exclusivas à área (49 por cento). Entre as duas parcelas, aos 190 e 350 m, houve diferença significantiva (gl = 198) na densidade (p < 0,01, t = 7,10), riqueza (p < 0,01, t = 7,76) e volume (p = 0,02, t = 2,44). Os resultados indicam que a diversidade específica, estrutura fitossociológica e composição florística diferem entre as duas cotas altitudinais, sendo observados mais indivíduos, maior riqueza e volume na parcela instalada próxima ao meio da encosta (350 m de altitude) do que naquela instalada mais próxima à base da encosta (190 m de altitude).

This study presents a comparative analyzes of two areas of Atlantic Rain Forest, in the municipality of Ubatuba (SP), Brazil, and tests the hypothesis that floristic composition and phytosociological structure change along an altitudinal gradient. Two 1-ha plots were installed, respectively, at 190 (PLOT G) and 350 m (PLOT I) above see level, and within these plots all individuals with DBH > 4.8 cm were sampled, measured and identified. In total we found 252 species, belonging to 134 genera and 53 families, diversity H' of 4.425 nats/individual, and 103 species (41 percent of total) common to both plots. But, among the 10 top species in Absolute Dominance only two: Cryptocarya mandioccana and Sloanea guianensis were found in both plots. In PLOT G we found 1496 individuals distributed in 152 species, 101 genera and 41 families, with H' = 3.961 nats/individual and 48 exclusive species (32 percent). In PLOT I we found 1993 individuals distributed in 203 species, 111 genera, 50 families, with H' = 4.339 nats/individual and 100 exclusive species (49 percent). Supporting our hypothesis, the comparative analyzes showed that there are significant differences in density (p < 0.01, t = 7.10), richness (p < 0.01, t = 7.76) and volume (p = 0.02, t = 2.44), between the two sampled areas. The pattern here observed shows that the plot installed closer to the middle of the Serra do Mar slope (350 m) presented a higher number of individuals, higher richness and higher scores of volume, when compared to that closer to the base of the slope (190 m).

Distribución y diversidad de colémbolos (Hexapoda: Collembola) en el gradiente altitudinal de un bosque templado en México

Distribution and diversity of springtails (Hexapoda: Collembola) on the altitudinal gradient of a temperate forest in Mexico. Mountain ecosystems have shown slow mineralization activity due to weather conditions, and to some groups with arthropods with special roles. The Collembola is an important group for litter fragmentation, showing different distribution patterns. The objective of the present study was to determine the diversity of Collembola along a volcano altitudinal gradient. For this, four sampling expeditions evaluated four altitudinal levels (I=2 753, II=3 015, III=3 250 and IV=3 687 masl) in Iztaccihuatl Volcano, from November 2003, and March, June and August 2004. Shannon diversity (H’), Pielou evenness (J’) and Simpson dominance (1/λ) indices were calculated. The similarity between the associations of springtails between the sampling sites was evaluated by a cluster analysis using the Pearson correlation coefficient, as distance and the unpaired arithmetic averages (UPGMA) as amalgamation method. A total of 24 075 springtails, distributed in 12 families, 46 genera and 86 species was collected. The higher species abundance was found at the altitudinal area II. The lowest diversity value was recorded in IV, while the higher diversity values were found in III. Significant differences between Shannon indices were found between zones II-III (t0.01, 187=4.11, p<0.05) and between III-IV (t0.01, 187=3.8, p<0.05) according to modified t-test. When considering sampling dates, no significant differences were found. The dendrogram showed that in composition the level I is more homogeneous throughout the year. In conclusion, a statistically significant seasonal variation in springtail abundances was not found, but it was observed that, the lower altitude (I) resulted more homogeneous along the studied period, followed by level II and III. There is a particular assemblage of springtails community in each altitudinal area studied; in general, the sites with low slope resulted more diverse in Collembola communities. These results show that there are important factors such as altitude, vegetation type and microhabitat heterogeneity that may affect the distribution of springtails communities along an altitudinal gradient. Rev. Biol. Trop. 59 (1): 315-327. Epub 2011 March 01.

Los colémbolos son fragmentadores importantes de la hojarasca, presentan diferentes patrones de distribución a lo largo de un gradiente altitudinal. El objetivo del presente trabajo es determinar la diversidad y distribución de Collembola en el volcán Iztaccíhuatl. Para ello, se realizaron cuatro muestreos, a lo largo de un año en cuatro pisos altitudinales (I=2 753, II=3 015, III=3 250 y IV=3 687m.s.n.m.) y se calcularon los índices de diversidad de Shannon, equitatividad de Pielou y dominancia de Simpson, para compararlos mediante una prueba de t modificada. Los resultados muestran al piso III como el más diverso, y la mayor equitatividad se encuentra en el II. Además, se hallaron diferencias significativas entre los pisos II-III (t0.01, 187=4.11, p<0.05) y entre III-IV (t0.01, 187=3.8, p<0.05). Para las fechas de recolección no obtuvimos diferencias significativas (t0.01, 187=2.71, p<0.05). Al final encontramos que la temporalidad no incrementa la diversidad (estadísticamente), por consiguiente, condiciones como la altitud, vegetación y heterogeneidad geográfica crean microambientes, para protegerse de inclemencias ambientales. El piso I es el más homogéneo, seguida por el II y el III, además hallamos que los sitios más diversos son aquellos de pendientes menos pronunciadas.

ESTRUCTURA DE UNA COMUNIDAD DE LÍQUENES Y MORFOLOGIA DEL GÉNERO Sticta(STICTACEAE) EN UN GRADIENTE ALTITUDINAL / Lichen Community Structure And Morphological Changes In The Genus Sticta (STICTACEAE) Associated To An Altitude Gradient

La distribución y el crecimiento de los líquenes están condicionados por diferentes factores ambientales, entre estos la variación en gradientes altitudinales. En la cordillera Oriental de los Andes de Colombia, no se han realizado estudios sobre zonación altitudinal de líquenes. En este trabajo se estudiaron las variaciones en la estructura de la comunidad de líquenes epifitos en un gradiente altitudinal (2.000- 2.600 m) en el PNN Tatamá. Se encontró que con el aumento en altura hay una disminución en riqueza y diversidad, siendo esto una desviación del patrón encontrado generalmente en otros trabajos sobre líquenes y gradientes altitudinales. La comunidad a bajas alturas se compone principalmente de líquenes fruticosos (cobertura de 30% a 2.070 m y 0% a 2.560 m) y a mayores alturas de líquenes foliosos (cobertura de 15% a 2.070 m y 43% a 2.560 m). La altura, además de influenciar la estructura de la comunidad de los líquenes, puede afectar el desarrollo y la morfología de estos. En el género folioso Sticta se presentaron variaciones intraespecificas en la densidad de cifelas (órganos de intercambio gaseoso) asociadas a la altura, encontrándose un efecto significativo de la altura sobre la densidad de cifelas en las especies S. andensis y S. gyalocarpa (ANOVA, valor p= 0.008 y 0.05 respectivamente). Esto muestra un mecanismo de adaptación a los cambios ambientales que se dan con la altura.

Lichen’s growth and distribution are conditioned by various environemental factors, altitude being an important one. In the Cordillera Oriental of Colombian Andes, there haven’t been studies on lichen’s altitudinal zonation. We studied the variation on lichen community structure along an altitudinal gradient (2000- 2600 m) in PNN Tatamá, we found diversity diminishes as altitude increases, this being a variation from what’s generally found in lichen community behavior. At low altitudes, the community was conformed by fruticose lichens (30% cover at 2070 m and 0% at 2560 m), and by foliose lichens at high altitudes (15% cover at 2070 m and 43% at 2560 m). Altitude, besides influencing lichen’s community structure, may affect their development and morphology. In the foliose genus Sticta we found intraspecific variation on cyphellae (gaseous exchange organs) density associated with altitude, a significant effect of altitude on cyphellae density was found for the species S. andensis and S. gyalocarpa (ANOVA p value= 0.008 and 0.05 respectively). This shows an adaptation mechanism of these organisms to the environmental changes given with altitude.

Escarabajos coprófagos (Coleoptera: Scarabaeinae) de la vertiente voroccidental, Sierra Nevada de Santa Marta, Colombia / Dung beetles (Coleoptera: Scarabaeinae) of the northwestern slope of the Sierra Nevada of Santa Marta, Colombia

The community structure of dung beetles in the middle and lower river basin of the Gaira river, Sierra Nevada de Santa Marta, Colombia, is described. Four sites were selected along an altitudinal gradient of 50-940 m for sampling from June to October, 2004. Dung beetles were captured using modified pitfall traps and manual recollections. We captured 7,872 individuals belonging to 29 species, distributed in 15 genera and five tribes of Scarabaeinae. Canthon and Onthophagus were the most diverse genera, each represented by six species. The sampled sites shared the following species: Onthophagus acuminatus Harold, O. clypeatus Blanchard, O. marginicollis Harold. Bocatoma was the most diverse site with 23 species; whereas Port Mosquito presented the highest abundance, with 3,262 individuals. Seven species represented 89 percent of all captures: Canthidium sp., Dichotomius sp., Uroxys sp. 1, Uroxys sp. 2, O. marginicollis, O. clypeatus and O. acuminatus. Of the 29 captured species, 17 belonged to the functional group of diggers and 10 were ball-rollers. We did not observe significant among-site differences in community structure. Abiotic factors such as altitude, temperature and humidity cannot explain observed variation in community structure across sites, indicating other variables such as vegetation cover, density of the vegetation and soil type may play a role in the community structure of these insects.

Se describe la estructura de la comunidad de escarabajos coprófagos en la cuenca media y baja del río Gaira, Sierra Nevada de Santa Marta, Colombia. Se seleccionaron cuatro sitios de muestreo a lo largo de un gradiente altitudinal de 50-940 m, realizándose muestreos desde junio hasta octubre, 2004. La captura de los escarabajos se realizó con trampas pitfall modificadas y colecta manual. Se capturaron 7,872 individuos pertenecientes a 29 especies, repartidos en 15 géneros y 5 tribus de Scarabaeinae. Canthon y Onthophagus fueron los géneros más diversos con seis especies cada uno. Las cuatro estaciones comparten tres especies: Onthophagus acuminatus Harold, O. clypeatus Blanchard, O. marginicollis Harold. Bocatoma tuvo el mayor número de especies, 23; mientras que Puerto Mosquito con 3.262 individuos presentó la mayor abundancia. Las especies Canthidium sp., Dichotomius sp, Uroxys sp.1, Uroxys sp.2, O. marginicollis, O. clypeatus y O. acuminatus representaron el 89 por ciento de la abundancia en el área de estudio. Entre las 29 especies capturadas; 17 pertenecen a los cavadores, 10 a los rodadores y dos residentes. No se registraron diferencias significativas entre las cuatro estaciones con respecto estructura de la comunidad. Tampoco se observó correlación entre los factores abióticos y la estructura de la comunidad. La altitud, temperatura y humedad no explican las diferencias en la distribución de la comunidad, indicando que otras variables, como la cobertura vegetal, la densidad de la vegetación y el tipo de suelo pueden jugar un papel en la estructura de la comunidad de estos insectos.

Altitudinal distribution and body resource allocation in a High Mountain social wasp (Hymenoptera: Vespidae)

Jame's rule proposes a direct relationship between body size and altitude. There are several studies about this rule; however, few studies analyze proportional changes in body parts along gradients. The morphological variation of Agelaia pallipes (Olivier) in five sites along an altitudinal gradient (2600-3380 m) in the Santuario de Iguaque, Colombia, were studied in order to test whether or not the species follows Jame's rule, and whether body parts follow a homogeneous variation. Body variation analysis was conducted through multivariate analysis of variance (MANOVA) and the relationship between altitude and each morphometric measurement was studied through regression analyses. The MANOVA indicated significant differences among sites. An increase in altitude leads to a reduction in body size, especially in hind femur length and head width. However, measurements linked to flight such as mesosoma height, mesoscutum width, and fore wing size showed a reverse tendency. Possibly all described changes are consequence of both reduction on food availability and lower atmospheric pressure. The low temperature of high areas may strongly limit foraging and thus food availability. Lower atmospheric pressure reduces flight potential and may result in an increase in size of both wings and flight muscles. This paper underscores the need to study in detail the changes in body proportions in species with wide distribution ranges in latitude and altitude.

A regra de Jame propõe uma relação direta entre o tamanho do corpo e a altitude. Muitos estudos são relacionados a essa regra; no entanto, poucos analisam as mudanças proporcionais em partes do corpo ao longo de gradientes. Foi estudada a variação morfológica em Agelaia pallipes (Olivier) em cinco faixas altitudinais (2600-3380 m), no Santuario de Iguaque (Colombia), com o objetivo de testar se a espécie segue a regra de Jame e se o tamanho de determinadas estruturas varia homogeneamente ao longo do gradiente. O efeito da altitude em estruturas foi testado com análise de variância multivariada (MANOVA), e a relação entre cada variável e altitude avaliada com análises de regressão. A MANOVA mostrou diferenças no tamanho das estruturas entre os locais. O aumento na altura conduz à redução no tamanho de corpo, especialmente no comprimento do fêmur traseiro e na largura da cabeça. No entanto, medidas de estruturas relacionadas ao vôo, tais como o comprimento do mesosoma, largura do mesoscutum, e ainda, tamanho da asa anterior, apresentam tendência inversa. É possível que todas as mudanças sejam conseqüência da redução de alimento e da diminuição da pressão atmosférica. A temperatura baixa das altitudes maiores pode limitar o forrageamento e, portanto, os recursos. A baixa pressão atmosférica torna o vôo mais difícil e pode resultar no aumento do tamanho das asas e dos músculos do vôo. Este trabalho enfatiza a necessidade de estudos relacionados a mudanças nas proporções corporais em espécie com amplas distribuições, latitudinal e altitudinal.

Bosques andinos del sur de Ecuador, clasificación, regeneración y uso

Existen muy pocos inventarios y descripciones sintaxonómicas de la vegetación de bosques montanos tropicales. Este trabajo presenta datos sobre los bosques del sur de Ecuador localizados en la Reserva Biológica San Francisco, límite norte del Parque Nacional Podocarpus. Se propone la siguiente clasificación junto con notas sobre los factores edáficos que contribuyen a su establecimiento. El «Bosque Montano Bajo» (1800-2150 m), formando el orden Alzateetalia verticillatae, muestra 2-3 estratos arbóreos muy diversos, con árboles de 20-35 m de altura, y es una clímax mosaico típico. Creciendo sobre Terric Haplosaprists y Aquic Dystrupepts, originado del material de derrumbes viejos, este tipo de bosque se extiende hasta los 2300 m sobre el nivel del mar en quebradas protegidas de viento. A altitudes de 2100-2650 m (menos de 2750 m) la estructura del bosque y la composición florística cambia totalmente. Esta vegetación, el «Bosque Montano Alto» forma el orden de Purdiaeaetalia nutantis y crece sobre Histic Petraquepts. Representando una vegetación monotípica con un solo estrato arbóreo de 5-10 m (15 m) de altura, completamente dominado por Purdiaea nutans (Cyrillaceae). El bosque ubicado a mayor altitud en el área, densamente enlazado con el páramo es el «Bosque Nublado Subalpino». Descritos como Clusio ellipticae-Weinmannietum cochensis aparecen más como una vegetación arbustiva casi impenetrable, y crecen sobre Humaquic Epiaquents. El límite del bosque es causado principalmente por los vientos fuertes de la región. Derrumbes e incendios naturales representan el «motor» de regeneración de los bosques. Se encontró carbón en la base de los niveles A de muchos perfiles de suelo. El análisis 14C precisó una edad de 710-980 ±50 años antes del presente. Esto indica que fuegos en la vegetación han contribuido a la dinámica de esta vegetación en el pasado y no es un fenómeno reciente. El diámetro basal de los árboles y el volumen total de madera por hectárea disminuyen rápidamente con la altitud a partir de los 2100 m y no pueden ser eficazmente utilizados para una explotación de madera sostenible.

Few floristic inventories and even less syntaxonomical vegetation descriptions of tropical mountain forests exist. The author presents a syntaxonomical treatment of the vegetation of Reserva Biológica of San Francisco at the northern limit of Podocarpus National Park, Ecuador, together with notes on the corresponding soil types. The Lower Montane Forest (1800-2150 m), grouped in the new order Alzateetalia verticillatae, has a very diverse tree layer 20-35 m tall, and are a typical mosaic-climax. It grows on Terric Haplosaprists and Aquic Dystrupepts, developed from old landslide material and extends up to elevations of 2300 m at the bottom of wind-protected riverine valleys. At altitudes from 2100-2650 m (2750 m), the forest structure and floristic composition change completely. The vegetation types belonging to this Upper Montane Forest form the newly described Purdiaeaetalia nutantis, growing on Histic Petraquepts. They represent a monotypic vegetation, with only one tree stratum, and stems between 5-10 m, rarely up to 15 m tall. The canopy is completely dominated by the twisted stems of Purdiaea nutans (Cyrillaceae). The Subalpine-elfin forest which closely resembles that of the the Bolivian Jalca forms the uppermost forest belt of the study area. Described as Clusio ellipticae-Weinmannietum cochensis, this forest more like an impenetrable bushland grows on Humaqueptic Epiaquents and is closely dovetailed with the adjacent páramo region. The timberline in the area is mainly induced by strong winds. Charcoal was found at the base of the A horizons of many soil profiles up to the top region and 14C dated to 710-980 +/-50 years BP. This indicates that vegetation fires occurred in the past, and are not only a recent phenomenon.