Niche differentiation mechanisms among canopy frugivores and zoochoric trees in the northeastern extreme of the Amazon

Frugivores and zoocoric trees represent an important proportion of tropical rainforest biodiversity. As niche differences favor species coexistence, we aimed to evaluate morphological and temporal niche segregation mechanisms among zoochoric trees and canopy frugivores in a tropical rainforest in the northeastern extreme of the Brazilian Amazon. We tested the effects of fruit morphology, tree size, frugivore body size and time of day on fruit consumption. We recorded the frugivore species that fed on 72 trees (44 species, 22 genera) and whether these frugivores swallowed the seeds. We monitored trees only once from 07:00 to 17:00 h between January and September 2017. We observed fruit consumption in 20 of the 72 trees. Seventy-three frugivore individuals from 22 species visited the trees. Heavier fruits were consumed by larger frugivores, while seed size was inversely correlated with frugivore size. Narrower fruits and fruits with smaller seeds had greater probability of having their seeds ingested, and larger frugivores were more prone to ingest seeds. Trees bearing fruits with smaller seeds were visited by a greater number of frugivores. Taxonomic groups differed in the time of arrival at fruiting trees. None of the evaluated variables (fruit weight and size, and seed size) affected the richness of frugivores that visited the trees. We concluded that, in the studied forest, fruit morphology (weight, size and seed size) is a niche segregation mechanism among zoochoric trees, while body size and time of day are niche segregation mechanisms among frugivores. (AU)

Aves como indicadoras ecológicas de etapas sucesionales en un bosque secundario, Antioquia, Colombia

Las áreas que se recuperan perturbaciones tales como actividades agrícolas y ganaderas, generan un aumento de bosques secundarios que causan cambios en la cantidad y calidad del hábitat disponible para las aves. El Índice de Integridad Biótica (IIB) compara la estructura, composición y función del ensamblaje de las aves en una regeneración secundaria del bosque, desde edades tempranas hasta maduras, para evaluar su condición ecológica. Se estudió la integridad ecológica utilizando el IIB en cuatro etapas de sucesión de bosque secundario. El IBI se calculóutilizando ensamblajes de aves encontrados en estas cuatro etapas de la sucesión de bosques, y su desempeño se comparócon la riqueza general y elíndice de diversidad de Shannon. Se realizaron cinco muestreos de campo entre junio 2016 y febrero 2017, en los que se registraron las aves utilizando recuentos de puntos de radio fijo. En total, se registraron 9 516 individuos de 187 especies de aves pertenecientes a 42 familias y 15 órdenes. Para cada especie se estableció hábitat de presencia, gremio de forrajeo y grupos de indicadores potenciales. La riqueza de especies y el Índice de Abundancia Puntual (PAI) de todas las categorías, se utilizaron como métricas candidatas y luego de evaluar un total de 34 métricas, se seleccionaron 13 para los análisis. Las métricas que se correlacionaron positivamente con el gradiente, de mayor a menor perturbación, fueron: riqueza de insectívoros de interior de bosque, abundancia de especies exclusivamente de interior de bosque, abundancia de especies de interior y borde, abundancia de especies endémicas y abundancia de especies amenazadas. Las métricas que se correlacionaron negativamente con el gradiente, de mayor a menor perturbación, fueron abundancia de especies de áreas abiertas, abundancia de especies de áreas abiertas y de borde, abundancia de frugívoros, abundancia de granívoros, abundancia de omnívoros, abundancia de insectívoros, abundancia de carroñeros y abundancia de especies migratorias. El IBI mostró una correlación lineal significativa positiva con el gradiente de regeneración secundaria del bosque, desde edades tempranas hasta maduras, mientras que la riqueza total de especies y el índice de diversidad de Shannon mostraron una correlación lineal negativa. El IBI, en este caso particular, demostró ser mejor que las medidas clásicas de la riqueza de especies y el índice de diversidad de Shannon para evaluar e interpretar la condición ecológica y ambiental de las etapas de la sucesión del bosque secundario evaluado.

Recovering areas from disturbance, after agriculture and livestock activities, increases secondary forests extension, which might change the quantity and quality of available habitat for birds. The Index of Biotic Integrity (IBI) compare the structure, composition and function of bird assemblages in secondary regeneration forest, from early succession to mature forest, to evaluate the ecological condition. Thus, the ecological condition along four stages of secondary forest in Antioquia, Colombia were studied using the IBI. This index was compared with richness and Shannon's diversity Index of the same bird assemblages. Five field surveys were conducted between June 2016 and February 2017, using fixed-radius point counts. In total 9 516 individuals, from 187 bird species, belonging to 42 families and 15 orders were recorded. Habitat of occurrence, foraging guild and potential indicators groups were established for every species. Species richness and Punctual Abundance Index (PAI) of all categories were defined as candidate metrics, and after evaluating a total of 34 metrics, 13 were selected for further analysis. Metrics that were positively correlated with successional forest gradient, from highest to lowest disturbance, were: species richness of forest interior insectivorous, abundance of exclusively forest species, abundance of forest interior and edge species, abundance of endemic species and abundance of threatened species. Metrics that were negatively correlated with successional forest gradient, from highest to lowest disturbance, were: abundance of species from open areas, abundance of open areas and edge species, abundance of frugivorous, abundance of granivorous, abundance of omnivorous, abundance of insectivorous, abundance of scavengers and abundance of migratory species. IBI showed a positive significant linear correlation with the gradient of secondary forest regeneration, from early to mature forest, while Shannon´s diversity Index and species richness showed a negative significant linear correlation. So that, in this particular case, IBI proved to be better indicator that the classical measures for assessing and interpreting ecological and environmental condition along the secondary forest succession evaluated.

Interaction between Some Soil Physicochemical Properties and Weather Variables on Sub-humid Tropical Rainforest Soils of Cross River State, Southeastern Nigeria

The study deals with the interaction between some soil physicochemical properties and weather variables on sub-humid tropical rainforest soils of Cross River State, Southeastern Nigeria. The study aims to determine the interactions between soil properties and weather variables of three land uses occurring on the tropical sandy soils. Soil samples were obtained from 10,000 m2 of UNICAL Teaching and Research farm (Arable farm), Oil palm plantation and Forestry Teaching and Research farm (Forest and wetland land use) respectively. A total of twenty-seven (27) soil samples were collected with nine (9) samples from each land use at 20 cm depth and at an interval of 50 m with the aid a soil auger and core sampler. The weather variable data from 2012 to 2015 was obtained from NIMET. The result revealed that the sandy soils of Calabar are characterised with coarse, predominantly sandy loam and loamy sand texture with particle size ranging 610-850 g/kg for sand 80 to 240 g/kg for clay and 30-150 g/kg for silt; generally acidic with low to medium organic matter content, low ECEC, low nitrogen, medium available P (15.04 mg/kg, 8.65 mg/kg and 2.78 mg/kg for arable farm, oil palm plantation and forestry land uses respectively). The study showed the correlation coefficient analysis between the high and low impact of weather variables on some soil properties and also recommended a proper management practice such as mulching to avoid direct impact of sunlight on the soil thereby ensuring maximum utilisation of tropical sandy soils of Calabar.

Effects of reduced-impact logging on medium and large-bodied forest vertebrates in eastern Amazonia / Efeitos da exploração de impacto reduzido em vertebrados de médio e grande porte na Amazônia oriental

Standard line-transect census techniques were deployed to generate a checklist and quantify the abundance of medium and large-bodied vertebrate species in forest areas of eastern Amazonia with and without a history of reduced-impact logging (RIL). Three areas were allocated a total of 1,196.9 km of line-transect census effort. Sampling was conducted from April to June 2012 and from April to August 2013, and detected 29 forest vertebrate species considered in this study belonging to 15 orders, 20 families and 28 genera. Additionally, eight species were recorded outside census walks through direct and indirect observations. Of this total, six species are considered vulnerable according to IUCN (Ateles paniscus, Myrmecophaga tridactyla, Priodontes maximus, Tapirus terrestris, Tayassu peccary, Chelonoidis denticulata). Observed species richness ranged from 21 to 24 species in logged and unlogged areas, and encounter rates along transects were highly variable between treatments. However, the relative abundance of species per transect did not differ between transects in logged and unlogged forests. Of the species detected during censuses, only three showed different relative abundance between the two treatments (Saguinus midas, Tinamus spp. and Dasyprocta leporina). Our results show that the effect of RIL forest management was a relatively unimportant determinant of population abundance for most medium and large vertebrates over the time period of the survey.

Técnicas padronizadas de censo por transecções lineares foram empregadas para gerar uma lista e quantificar a abundância de espécies de vertebrados de médio e grande porte em áreas de floresta na Amazônia oriental, com e sem uma história de exploração de impacto reduzido (EIR). Três áreas foram amostradas com um esforço total de 1.196,9 km de censo ao longo de transectos lineares. A amostragem foi realizada de abril-junho de 2012 e de abril-agosto de 2013, e detectou 29 espécies florestais de vertebrados consideradas neste estudo pertencentes a 15 ordens, 20 famílias e 28 gêneros. Adicionalmente, oito espécies foram registradas fora dos censos ao longo dos transectos por meio de observações diretas e indiretas. Desse total, seis espécies são consideradas vulneráveis de acordo com a IUCN (Ateles paniscus, Myrmecophaga tridactyla, Priodontes maximus, Tapirus terrestris, Tayassu pecari, Chelonoidis denticulata). A riqueza das espécies observada variou de 21 a 24 espécies em áreas com e sem corte seletivo, e as taxas de encontro ao longo dos transectos foram bastante variáveis entre os tratamentos. No entanto, a abundância relativa das espécies por transecto não diferiu entre florestas não exploradas e exploradas. Das espécies detectadas durante o censo, apenas três apresentaram diferentes abundâncias relativas entre os dois tratamentos (Saguinus midas, Tinamus spp. e Dasyprocta leporina). Nossos resultados mostram que o efeito do manejo florestal EIR não foi relativamente determinante para abundância populacional da maioria dos vertebrados de médio e grande porte.

New mammalian records in the Parque Nacional Cerros de Amotape, northwestern Peru

The Pacific Tropical Rainforest and Equatorial Dry Forest are found only in southern Ecuador and northern Peru, and are among the most poorly known ecosystems of South America. Even though these forests are protected in Parque Nacional Cerros de Amotape (PNCA), they are threatened by fragmentation because of farming and agriculture. The aim of this study was to determine the medium and large mammalian species richness, using transect census, camera trapping, and specimen bone collection. Nine transects were established and 21 camera trap stations were placed along 16 km² in three localities of PNCA, from August 2012 to April 2013. Total sampling effort was 215 km of transects and 4077 camera-days. We documented 22 species; including 17 with camera trapping, 11 with transect census, and 10 with specimen collection. Camera traps were the most effective method, and four species (Dasyprocta punctata, Cuniculus paca, Leopardus wiedii and Puma concolor) were documented only with this method. This comprised the first Peruvian record for Dasyprocta punctata, and the first record for the western slope of the Peruvian Andes for Cuniculus paca. Also, both specimen collections and sightings confirm the presence of Potos flavus, first record in the western slope of the Peruvian Andes. Panthera onca, Tremarctos ornatus and Saimiri sciureus are considered locally extinct, while several species are in need of further research. We highlight the importance of the high diversity of this rainforests and encourage local authorities to give the area the highest priority in conservation.

El Bosque Tropical de Pacífico y el Bosque Seco Ecuatorial, solo se encuentran desde el Sur de Ecuador hasta el Norte de Perú y están dentro de los ecosistemas más pobremente estudiados de Sudamérica. A pesar que estos bosques se encuentran protegidos dentro del Parque Nacional Cerros de Amotape (PNCA), están amenazados por fragmentación de hábitat debido a la agricultura y la ganadería. El objetivo de esta investigación fue determinar la riqueza de mamíferos medianos y grandes utilizando censos por transecto, cámaras trampa y colecta de especímenes. Se establecieron nueve transectos y se colocaron 21 estaciones con cámaras trampa en tres localidades del PNCA (16 km²) de agosto del 2012 a abril del 2013. El esfuerzo de muestreo acumulado fue 215 km de censos por transecto y 4077 cámara-días. Registramos 22 especies de mamíferos, 17 registradas con cámaras trampa, 11 con censos por transecto y diez con colecta de especímenes. El uso de cámaras trampa fue el método más efectivo y cuatro especies (Dasyprocta punctata, Cuniculus paca, Leopardus wiedii y Puma concolor) fueron registradas únicamente con este método. El registro de Dasyprocta punctata, es el primero para Perú y Cuniculus paca, el primer registro para la vertiente occidental de los Andes peruanos. Además, con avistamientos y colecta de especímenes se confirmó la presencia de Potos flavus para el PNCA siendo también el primer registro para la vertiente occidental de los Andes peruanos. A Panthera onca, Tremarctos ornatus y Saimiri sciureus se les considera localmente extintos, mientras que varias especies más necesitan mayor investigación para confirmar su presencia. Se resalta la importancia y alta diversidad de estos bosques y se recomienda a las autoridades locales darle prioridad en conservación.

Effects of insect and decapod exclusion and leaf litter species identity on breakdown rates in a tropical headwater stream

High species richness of tropical riparian trees influences the diversity of organic detritus entering streams, creating temporal variability in litter quantity and quality. We examined the influence of species of riparian plants and macroinvertebrate exclusion on leaf-litter breakdown in a headwater stream in the Luquillo Mountains of Puerto Rico. Leaf litter of Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae), and Prestoea acuminata (Palmae) were incubated in litter bags in a pool of Quebrada Prieta. Fine mesh bags were used to exclude macroinvertebrates during leaf breakdown, and coarse mesh bags allowed access to decapod crustaceans (juvenile shrimps and crabs) and aquatic insects (mainly mayflies, chironomids, and caddisflies). D. excelsa and G. guidonia (in coarse- and fine-mesh bags) had significantly higher breakdown rates than C. scheberiana, M. bidentata, and P. acuminata. Breakdown rates were significantly faster in coarse-mesh bag treatments for all leaf types, thus indicating a positive contribution of macroinvertebrates in leaf litter breakdown in this headwater stream. After 42 days of incubation, densities of total invertebrates, mayflies and caddisflies, were higher in bags with D. excelsa and G. guidonia, and lower in P. acuminata, C. scheberiana y M. bidentata. Decay rates were positively correlated to insect densities. Our study highlights the importance of leaf identity and macroinvertebrate exclusion on the process of leaf litter breakdown in tropical headwater streams. Rev. Biol. Trop. 62 (Suppl. 2): 143-154. Epub 2014 April 01.

La gran variedad de especies vegetales junto a los ríos tropicales afecta la diversidad de detritos orgánicos que llegan a los arroyos, creando variaciones temporales en cantidad y calidad de hojarasca. Examinamos la influencia de las especies vegetales y de la exclusión de macroinvertebrados sobre la descomposición de hojarasca en la parte alta de un arroyo en las montañas Luquillo de Puerto Rico. Incubamos hojarasca de Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae) y Prestoea acuminata (Palmae) en bolsas descomposición que colocamos en una poza de Quebrada Prieta. Usamos bolsas de malla fina para excluir los macroinvertebrados y de malla gruesa para permitir la entrada a crustáceos decápodos (camarones y cangrejos jóvenes) e insectos acuáticos (principalmente efemerópteros, quironómidos y tricópteros). D. excelsa y G. guidonia (en ambos tipos de malla) tuvieron tasas de descomposición más altas que C. scheberiana, M. bidentata y P. acuminata. La descomposición fue más rápida para todas las especies de hoja con la malla gruesa, resaltando el papel de los descomponedores en este hábitat. Tras 42 días de esta incubación, las densidades totales de invertebrados, efemerópteros y tricópteros fueron mayores en las bolsas con hojas de D. excelsa y G. guidonia, e inferiores en P. acuminata, C. scheberiana y M. bidentata. A mayor densidad de insectos hubo mayor tasa de descomposición. Nuestros resultados indican la importancia de la especie de las hojas y de la presencia de macroinvertebrados en el proceso de descomposición de hojarasca en partes altas de arroyos tropicales.

Avispas de la vegetación arbórea en el Parque Nacional Natural Gorgona, Pacífico de Colombia / Wasps of the arboreal vegetation in the Gorgona National Natural Park, Pacific of Colombia

Wasps from the arboreal vegetation in Gorgona National Natural Park, Colombian Pacific. Studies of Colombian Hymenoptera are incipient, fragmented and there is no comprehensive study about its size and composition. We know that the guild of hymenopteran parasitoids is the richest in species and that they are common and abundant in all terrestrial ecosystems, acting as regulators of populations of other insects. Studies in Gorgona National Natural Park have mostly focused on the natural history and identification of Formicidae and Apidae. This work was directed toward the identification of other hymenopteran species associated with its tropical rain forest. In November 2007, 16 trees were sampled by fogging with a biodegradable pyrethroid insecticide applied from 1m above the ground to the canopy. We found 641 individuals (45% identified to subfamily and 28% to genera) from seven superfamilies, 20 families and 118 morphospecies. Chalcidoidea was the most representative superfamily, Eulophidae the most diverse family and Braconidae the numerically dominant family. The sampling efficiency was 71% and 166 species are estimated to exist in the island. Approximately 71% of the estimated species were captured during this study. We report 12 genera new for the island. Rev. Biol. Trop. 62 (Suppl. 1): 307-315. Epub 2014 February 01.

A pesar de la reconocida riqueza de Colombia, los estudios de la fauna de himenópteros son muy incipientes, fragmentarios y no hay revisiones de base que muestren el tamaño y composición de la fauna del país. Los himenópteros parasitoides son muy comunes y abundantes en todos los ecosistemas terrestres, actuando como reguladores de poblaciones de otros insectos. Este trabajo fue dirigido hacia la identificación de especies asociadas al dosel del bosque húmedo tropical del Parque Nacional Natural Gorgona, ecosistema insular ubicado en la parte sur del Pacífico colombiano, con el propósito de ampliar el conocimiento sobre este orden. En noviembre de 2007, se muestrearon 16 árboles mediante la técnica de nebulización, utilizando un insecticida piretroide biodegradable aplicado desde 1m sobre el nivel del suelo hasta el dosel. Se examinaron 641 individuos (identificados 45% a subfamilias y 28% a género) pertenecientes a siete superfamilias, 20 familias y 118 morfoespecies, siendo Chalcidoidea la superfamilia más representativa, Eulophidae la familia más diversa y Braconidae la familia dominante con el mayor número de ejemplares colectados. Se reportan 12 géneros nuevos para la isla, ampliando su rango de distribución y posicionando este estudio como el primero enfocado en este gremio de Hymenoptera en el parque.

True branched nostocalean cyanobacteria from tropical aerophytic habitats and molecular assessment of two species from field samples

Aerophytic cyanobacteria are commonly found growing on rocks, tree trunks and soil, but the diversity of these organisms is still poorly known. This complex group is very problematic considering the taxonomic arrangement and species circumscription, especially when taking into account tropical populations. In this work, 20 samples of aerophytic cyanobacteria from 15 distinct sampling sites were collected along a tropical rainforest area at the São Paulo State (Brazil). Samples were dried at room temperature after the collection, and once in the laboratory, they were rehydrated and analyzed. The taxonomic study resulted in the record and description of nine species of true-branched cyanobacteria pertaining to the genera Spelaeopogon (one specie), Hapalosiphon (two species) and Stigonema (six species). The similarity of the flora found when compared to surveys conducted in other geographical regions was relatively low. These differences could be addressed to ecological conditions of the habitats, to the extension of the area surveyed or even to taxonomic misinterpretations. The molecular assessment of 16S rDNA on the basis of field material was successful for two morphospecies, Hapalosiphon sp. and Stigonema ocellatum; however, their relationships with other populations and species revealed to be uncertain. The results of the floristic survey and of the molecular approach evidenced the fragile delimitation of some genera and species in the true branched group of cyanobacteria.

Las bacterias aerofíticas crecen comúnmente en las rocas, troncos de árboles y el suelo, pero la diversidad de estos organismos todavía es poco conocida. Este complejo grupo es muy problématico considerando la disposición taxónomica y la circunscripción de las especies, especialmente cuando se toman en cuenta las poblaciones tropicales. En esta investigación, 20 muestras de cianobacterias aerofíticas de 15 distintos sitios de muestro fueron recolectadas a lo largo de un área de selva tropical en el estado de São Paulo (Brasil). Las muestras fueron secadas a temperatura ambiente después de su recolecta, y una vez en el laboratorio, se hidrataron y analizaron. El estudio taxónomico resultó en un registro y descripción de nueve especies de cianobacterias con ramificaciones verdaderas pertenecientes al género Spelaeopogon (una especie), Hapalosiphon (dos especies) y Stigonema (seis especies). La similutud de la flora encontrada en comparación con las encuestas realizadas en otras regiones geográficas fue relativamente baja. Estas diferencias podrían deberse a las condiciones ecológicas de los hábitats, a la extensión de la zona de estudio o incluso a malas interpretaciones taxonómicas. La evaluación molecular del 16S rDNA del material de campo fue un éxito para dos morfoespecies, Hapalosiphon sp. y Stigonema ocellatum, sin embargo, sus relaciones con otras poblaciones y especies revelan que son inciertas. Los resultados del estudio florístico y de la aproximación molecular evidencian la débil delimitación de algunos géneros y especies en el grupo de cianobacterias con ramificaciones verdaderas.

Occurrence and distribution of the exotic lizard Hemidactylus mabouia Moreau de Jonnès, 1818 in Ilha Grande, RJ, Brazil / Ocorrência e distribuição do lagarto exótico Hemidactylus mabouia Moreau de Jonnès, 1818 na Ilha Grande, RJ, Brasil

The gekkonid lizard Hemidactylus mabouia is an exotic species in Brazil and is found in different ecosystems. This species was recorded at Ilha Grande, RJ, one of the largest insular remains of the Atlantic Rainforest in Brazil. In this study, the occurrence of H. mabouia was determined throughout the island, including the rain forest, restinga and anthropic environments. We used the active search method in points along 19 trails that surround Ilha Grande. At each regular interval of 100 m, we searched for the presence of H. mabouia. The species was recorded in a total of 100 points among the 719 sampled and, in all cases, the occurrence of the lizard corresponded to points located in anthropic or perianthropic areas. As most of Ilha Grande is covered by dense tropical rain forest, we believe this has restricted the invasion of H. mabouia in natural environments within the island.

O lagarto geconídeo Hemidactylus mabouia é uma espécie exótica no Brasil, podendo ser encontrada em diferentes ecossistemas. Esta espécie foi registrada na Ilha Grande, um dos maiores remanescentes insulares de Mata Atlântica no Brasil. Neste estudo a ocorrência de H. mabouia foi estimada para a ilha, incluindo ambientes de floresta, de restinga e antrópicos. Usamos o método de procura ativa ao longo de 19 trilhas que circundam a Ilha Grande. Em cada intervalo regular de 100 m, procuramos pela presença de H. mabouia. A espécie foi registrada em 100 pontos de 719 amostrados e, em todos os casos, a ocorrência do lagarto correspondeu a localizações em áreas antrópicas ou periantrópicas. Como a Ilha Grande é em grande parte coberta por floresta ombrófila densa, acreditamos que isso tenha restringido a invasão da lagartixa H. mabouia em ambientes naturais.

Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia

Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.

Estômatos são válvulas operadas a turgor que controlam a perda de água e a captura de CO2 durante a fotossíntese. Assim, as relações hídricas e o acumulo de biomassa vegetal são fortemente influenciadas pelo funcionamento estomático. Os objetivos deste trabalho foram: documentar como os estômatos estão distribuídos na superfície foliar e determinar se existe variação das características estomáticas entre espécies da Amazônia, estudar a relação entre densidade estomática (S D) e altura arbórea. Trinta e cinco árvores (>17 m de altura) de diferentes espécies foram selecionadas. Tipo de complexo estomático, S D, tamanho (S S) e distribuição na superfície foliar foram determinados utilizando impressões de ambas as superfícies foliares com esmalte incolor. Independente da espécie, os estômatos foram encontrados apenas na superfície abaxial (hipoestomatia) com ampla variação na S D e no S S entre espécies. A densidade estomática variou de 110 mm-2 em Neea altissima a 846 mm-2 em Qualea acuminata. Entretanto, a maioria das espécies apresentou S D entre 271 e 543 mm-2, com uma relação negativa entre S D e S S. Observou-se uma relação positiva entre S D e altura arbórea (r² = 0.14, p 0.01), não havendo relação entre S D e espessura foliar. Os tipos estomáticos mais comuns foram: anomocíticos (37%), seguidos de paracíticos (26%) e anisocíticos (11%). Concluiu-se que em espécies da Amazônia, a distribuição de estômatos na superfície foliar está mais relacionada a fatores genéticos de cada espécie do que a variações ambientais. Entretanto, S D é fortemente influenciada por fatores ambientais concernentes à altura da árvore.

Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia / Densidade, tamanho e distribuição estomática em 35 espécies de árvores na Amazônia Central

Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.

Estômatos são válvulas operadas a turgor que controlam a perda de água e a captura de CO2 durante a fotossíntese. Assim, as relações hídricas e o acumulo de biomassa vegetal são fortemente influenciadas pelo funcionamento estomático. Os objetivos deste trabalho foram: documentar como os estômatos estão distribuídos na superfície foliar e determinar se existe variação das características estomáticas entre espécies da Amazônia, estudar a relação entre densidade estomática (S D) e altura arbórea. Trinta e cinco árvores (>17 m de altura) de diferentes espécies foram selecionadas. Tipo de complexo estomático, S D, tamanho (S S) e distribuição na superfície foliar foram determinados utilizando impressões de ambas as superfícies foliares com esmalte incolor. Independente da espécie, os estômatos foram encontrados apenas na superfície abaxial (hipoestomatia) com ampla variação na S D e no S S entre espécies. A densidade estomática variou de 110 mm-2 em Neea altissima a 846 mm-2 em Qualea acuminata. Entretanto, a maioria das espécies apresentou S D entre 271 e 543 mm-2, com uma relação negativa entre S D e S S. Observou-se uma relação positiva entre S D e altura arbórea (r² = 0.14, p < 0.01), não havendo relação entre S D e espessura foliar. Os tipos estomáticos mais comuns foram: anomocíticos (37%), seguidos de paracíticos (26%) e anisocíticos (11%). Concluiu-se que em espécies da Amazônia, a distribuição de estômatos na superfície foliar está mais relacionada a fatores genéticos de cada espécie do que a variações ambientais. Entretanto, S D é fortemente influenciada por fatores ambientais concernentes à altura da árvore.

Ecology of Haemagogus sp. and Sabethes sp. (Diptera: Culicidae) in relation to the microclimates of the Caxiuanã National Forest, Pará, Brazil

This study was conducted in a meteorological tower located in the Caxiuanã Forest (municipality of Melgaço, Pará, Brazil) with the aim of assessing the vertical stratification of species of Haemagogus and Sabethes, potential vectors of the yellow fever virus. To investigate the role of microclimates in mosquito stratification, bimonthly collections were conducted at ground level (0 m), 8 m, 16 m and 30 m (canopy level), with the aid of entomological nets and suction tubes, from July 2005-April 2006. A total of 25,498 mosquitoes were collected; specimens of Sabethes sp. and Haemagogus janthinomyswere found mostly at heights of 16 m and 30 m while Hg. leucocelaenus was most frequently observed at ground level. The largest number of vector species was collected during the rainiest months, but this difference between seasons was not statistically significant. However, the number of Hg. janthinomys was positively correlated with variations in temperature and relative humidity.

Flora arbustivo-arbórea do Parque Estadual do Jaraguá, São Paulo - SP / Floristic composition of tree and shrub species of the Jaraguá State Park, São Paulo - SP, Brazil

O objetivo deste trabalho foi caracterizar a flora arbustivo-arbórea do Parque Estadual do Jaraguá (PEJ), a fim de contribuir para o conhecimento de sua diversidade. Foram feitas coletas mensais de material reprodutivo dos indivíduos arbustivos e arbóreos ao longo de três trilhas, durante um período de 12 meses. O levantamento resultou em uma lista florística contendo 262 espécies nativas, de 153 gêneros e 55 famílias. As famílias mais representativas foram Fabaceae, com 30 espécies, Myrtaceae (26), Asteraceae (24), Melastomataceae (20), Lauraceae (16) e Rubiaceae (15). Assim como relatado para outros remanescentes da região metropolitana de São Paulo e entorno, a vegetação do PEJ está situada em uma zona de transição, onde predomina a floresta ombrófila densa, com a presença de algumas espécies de floresta estacional semidecidual. Destaca-se ainda a existência de uma outra fitofisionomia em uma região de afloramentos de rocha e solo raso, onde ocorrem espécies de cerrado, e que merece estudos específicos. Nessa área, a vegetação é predominantemente herbácea, com árvores e arbustos esparsos, em geral de pequeno porte e com tronco suberoso. Especificamente nessa formação, foram registradas 55 espécies pertencentes a 41 gêneros e 18 famílias, das quais 22 não ocorreram nos outros locais amostrados. A família com maior riqueza foi Asteraceae (15 espécies), seguida por Myrtaceae (7), Fabaceae (5) e Melastomataceae (4). Em todo o levantamento, foram contabilizadas 20 espécies exóticas. Apesar de grande parte da vegetação do Parque ser secundária e estar exposta a fortes pressões antrópicas, foram encontradas 14 espécies presentes em alguma das categorias existentes nas listas oficiais de espécies ameaçadas, reforçando a importância do PEJ para a conservação da biodiversidade.

The objective of this study was to characterize the floristic composition of trees and shrubs of the Jaraguá State Park (PEJ), contributing to the knowledge of its biodiversity. Reproductive botanic material was collected along three trails during a 12-month period. The field survey resulted in a flora of 262 native species, 153 genera and 55 families. Fabaceae was the richest family (30 species), followed by Myrtaceae (26), Asteraceae (24), Melastomataceae (20), Lauraceae (16) and Rubiaceae (15). As mentioned for other forest remnants in São Paulo metropolitan region and surroundings, the PEJ vegetation is in a transition zone, where the main formation is the ombrophilous dense forest, but where species of seasonal semi-deciduous forest also occur. Besides that, there is a completely different phytophysiognomy occurring in a region with rocky outcrops and low depth soils, in which cerrado species were found, and that deserves more specific studies. In this site, the vegetation of grasses is the most abundant, and there are also shrubs and trees sparsely distributed, many of them with low height and suberous trunk. Most specifically in this area there were 55 species of 41 genera and 18 families, from which 22 did not occur in the other sites visited. Asteraceae was the family with the higher number of species (15), followed by Myrtaceae (7), Fabaceae (5) and Melastomataceae (4). Twenty exotic species were found along the trails. Despite the fact that PEJ has a big area of secondary vegetation and that it is exposed to strong anthropogenic pressures, there were 14 species belonging to some threat category defined at the official red lists, reinforcing the importance of the Park for biodiversity conservation.

Precipitação efetiva e interceptação em Caxiuanã, na Amazônia Oriental / Net precipitation and interception in Caxiuanã, in the Eastern Amazonia

O presente trabalho foi realizado na Estação Cientifica Ferreira Penna, dentro da Floresta Nacional de Caxiuanã, Melgaço, Pará, Brasil (01º 42" 30"S; 51º 31" 45"W; 60 m altitude). A região é uma floresta de terra firme, com vegetação densa e dossel com altura média de 35 m e árvores emergentes acima de 50 m, densidade de 450 a 550 árvores por hectare. O objetivo foi o de quantificar a precipitação total incidente acima do dossel, precipitação efetiva e precipitação interna, o escoamento da água pelos troncos e interceptação da precipitação pela vegetação no período de março a dezembro de 2004, quando foram realizadas 40 coletas semanais. Na medida da precipitação interna foram utilizados 25 pluviômetros, distribuídos aleatoriamente em um hectare, subdividido em cem parcelas de 10 x 10 m, os escoamentos pelos troncos foram medidos em sete árvores com diâmetros à altura do peito (DAP) representativos para as árvores da área. O estudo revelou uma precipitação efetiva de 905,4 mm e precipitação interna de 885,4 mm, um escoamento pelos troncos de 20 mm e uma interceptação de 248 mm, correspondendo, a 78,5 por cento, 76,8 por cento, 1,7 por cento e 21,5 por cento da precipitação acima do dossel, que foi de 1.153,4 mm, no período de estudo, respectivamente.

The present work was carried out at the Ferreira Penna Scientific Station, in the Caxiuanã National Forest, Melgaço, Pará, Brazil (01º 42" 30"S; 51º 31" 45"W; 60 m a.s.l.). The studied region is an upland forest with closed vegetation and a mean canopy height of 35 m although some trees can be 50 m high. The species density is between 450 and 550 plants per hectare. The aim was to quantify the net precipitation, throughfall, stemflow and rain interception by vegetation, from March to December of 2004. For the throughfall measurements 25 rain gauges were randomly distributed in an one hectare area subdivided in one hundred parcels of 10 x 10 m, while the stemflow was measured on seven trees with a stem diameter at breast height representative of the area. The results showed values of net precipitation of 905.4 mm, throughfall of 885.4 mm, stemflow 20 mm and rain interception of 248 mm,corresponding respectively to 78.5 percent, 76.8 percent, 1.7 percent e 21.5 percent of the total precipitation above the canopy which was 1,153.4 mm for the study period.

Levantamento florístico de Floresta Atlântica no sul do Estado de São Paulo, Parque Estadual Intervales, Base Saibadela / x

Foi realizado um levantamento florístico no Parque Estadual Intervales, Base Saibadela (24°14'08"S, 48°04'42"W), que faz parte da maior área contínua de Floresta Atlântica brasileira remanescente, situada no sul do Estado de São Paulo. Durante os anos de 1993-1997 e 1999-2002 foram feitas coletas mensais de material botânico, principalmente ao longo de trilhas e parcelas no interior da floresta. Foi registrado um total de 436 espécies vegetais, 74 monocotiledôneas (incluindo os grupos parafiléticos), sendo descobertas cinco espécies novas. A riqueza florística na Base Saibadela foi compatível com a riqueza florística encontrada em outras localidades de Floresta Atlântica. O hábito arbóreo representou 57,1 por cento das espécies, seguido de epífitas (12,6 por cento), lianas (10,3 por cento), herbáceas (9,4 por cento) e arbustos (9,2 por cento). As famílias Myrtaceae (55), Rubiaceae (32), Fabaceae (25), Melastomataceae (23), Araceae (20), Lauraceae, Orchidaceae e Solanaceae (14 espécies cada) apresentaram a maior riqueza florística. O gênero Eugenia apresentou 25 espécies, destacando-se dos demais gêneros encontrados. A dispersão por animais foi expressivamente maior do que os demais modos, representando 80,7 por cento das 419 espécies cuja síndrome foi determinada, confirmando o padrão encontrado para outras florestas tropicais úmidas e ressaltando a importância da fauna na Floresta Atlântica.

A floristic survey was carried out in the Parque Estadual Intervales (PEI), Base Saibadela (24°14'08"S, 48°04'42"W), São Paulo State, southeastern Brazil. The PEI reserve, along with other conservation unities, compose the largest preserved area of Atlantic rain forest remained today. Monthly collections of botanical material were conducted from 1993 to 1997 and 1999 to 2002, mainly along trails and plots inside the forest. A total of 436 plant species, 74 monocots and 362 eudicotiledons (here including the parafiletic groups) were sampled, including five new species. The richness of the flora at Base Saibadela was similar to that observed for other Atlantic forest sites. The trees represented 57.1 percent of the species, followed by epiphytes (12.6 percent), lianas (10.3 percent), herbs (9.4 percent) and shrubs (9.2 percent). The families Myrtaceae (55), Rubiaceae (32), Fabaceae (25), Melastomataceae (23), Araceae (20), Lauraceae Orchidaceae and Solanaceae (14 species each one) showed the highest number of species. The genus Eugenia with 25 species was richest genera surveyed. Seed dispersal by animals was expressively higher than other modes, which comprises 80.7 percent of the 419 species where seed dispersal mode was determined, confirming the pattern found for other tropical wet forests, and highlighting the importance of plant-animal interactions to the Atlantic forest.

Análise ecológica de um hectare em floresta Ombrófila densa de terra-firme, estrada da Várzea, Amazonas, Brasil1

A fitossociological survey was carried out in a terra firme dense tropical rainforest on a stretch of Estrada da Várzea (Foodplain road) linking Manaus to the counties of Silves and Itapiranga in Amazonas state. The work was aimed at analysing floristic composition fitossociological parameters necessary for determining species ecological importance value index (IVI), as well as, the vegetation structure. Sample distribution was carried out through sattelite image analysis. Sampling was done in a 10 x 1.000m transect, divided into 20 subplots, each measuring 10 x 50m. All arboreal individuals with a circumference at breast height (CBH) 30cm, such as, palm trees, vines and terrestrial herbs were included from which samples were taken for later identification; according to the Cronquist system. As a result, 527 individuals distributed into 47 families, 118 genera and 196 species, were recorded. Families presenting the highest diversity were Lecythidaceae (20), Lauraceae (19), Sapotaceae (17), Chrysobalanaceae, Burscraceae (12) and Annonaceae (9), representing 47% of the family diversity, showing local diversity to be concentrated within few families. Species with highest importance value index (IVI), Goupia glabra Aubl. (9.34), Ocotea rubra(Meiss.) Allen (8.71), because of their large diameter represented in the relative dominance. Nevertheless, when comparing local density with the one obtained from other works using the same sampling criteria it was concluded that the locality is less abundant in number of individuals per ha., but the diversity of families and species docs not differ from results reached for terra-firme forests within other areas in Amazonia.

Foi amostrada fítossociologicamente 1 ha. de floresta tropical densa de terra-firme, em um trecho da Estrada da Várzea, que liga Manaus aos municípios de Silves c Itapiranga, no estado do Amazonas. O trabalho teve por objetivo analisar a composição florística e os parâmetros fitossociológicos, necessários para a determinação do índice de valor de importância ecológica das espécies (IVI), bem como a estrutura da vegetação. A distribuição da amostra foi efetuada mediante a análise da imagem de satélite. A amostragem foi na forma de transecto de 10 x 1 .000m dividida em 20 subparcelas de 10 x 50m, totalizando 10.000rn2. Foram abordados todos os indivíduos arbóreos, palmeiras, cipós e ervas terrestres com CAP 30cm, dos quais obteve-se amostras botânicas para posterior identificação, a qual obedeceu ao sistema de classificação de Cronquist. Como resultado foram registrados 527 indivíduos, que estão distribuídos em 47 famílias, 118 gêneros e 196 espécies. As famílias que apresentaram maior diversidade foram Lecythidaceae (20), Lauraceae (19), Sapotaceae (17), Chrysobalanaceae, Burscraceae (12) c Annonaceae (9) representando 47% da diversidade familiar, demonstrando que a diversidade local está concentrada em poucas famílias. As espécies com maior valor de importância (IVI) foram Goupia glabra Aubl. (9,34), Ocotea rubra(Meiss.) Allen (8,71), influenciados pela exuberância dos seus diâmetros, representados na dominância relativa. Contudo, quando da comparação de densidade local com as obtidas em outros trabalhos, sob os mesmos critérios amostrais, concluiu-se que o local é menos abundante quanto ao número de indivíduos por hectare. Todavia, a diversidade por família c espécies não difere dos resultados alcançados em outras áreas da Amazônia, para florestas de terra-firme.