Spatio-temporal variation of seed rain between urban and rural fragments of humid tropical forests / Variación espacio-temporal de la lluvia de semillas entre fragmentos urbanos y rurales de bosques tropicales húmedos

Introduction: The type of land use surrounding the remnants of tropical forest may generate changes in the characteristics of plant populations and communities. Consequently, there may be a significant reduction in processes of pollination and diasporas dispersion. Therefore, causing changes in some parameters of seed rain. Objective: To characterize and compare seed density, species richness, floristic composition, habit, dispersal syndrome, and successional category of seed rain between urban and rural fragments of Atlantic Forest, in the 2015 and 2016 weather seasons. Methods: The study areas were defined after mapping and quantification of urban and rural occupations around the remnants, based on satellite images. In each fragment, were installed 36 collectors of 0.25 m2. The material was collected monthly during two consecutive years. Results: Seed rain richness was higher in the urban fragment during the rainy season in the two years, whereas it was similar between the fragments in the dry season. The seed density in the rural fragment was higher than in the urban during the rainy season; did not vary in urban between years or between seasons; and it was higher in the rural fragment in the rainy season of one year. There was a difference in the floristic composition of the seed rain between the fragments along time. The variations in the functional attributes of habit, dispersal syndrome, and successional category, were explained by the variables fragment, season, and year. Conclusions: Differences in the characteristics of the seed rain between the fragments might reflect the spatial and temporal heterogeneity, due to the diverse uses of the soil and external pressures (anthropogenic actions) present in the surroundings of the forest fragments and temporal variation in precipitation.

Introducción: El tipo de uso del suelo que rodea los remanentes de bosque tropical puede generar cambios en las características de las poblaciones y comunidades vegetales. En consecuencia, puede haber una reducción significativa en los procesos de polinización y dispersión de las diásporas. Por lo tanto, provocando cambios en algunos parámetros de la lluvia de semillas. Objetivo: Caracterizar y comparar la densidad de semillas, la riqueza de especies, la composición florística, el hábito, el síndrome de dispersión y la categoría sucesional de la lluvia de semillas entre fragmentos urbanos y rurales de Mata Atlántica, en las estaciones climáticas del 2015 y 2016. Métodos: Las áreas de estudio se definieron luego del mapeo y cuantificación de las ocupaciones urbanas y rurales alrededor de los remanentes, con base en imágenes satelitales. En cada fragmento se instalaron 36 colectores de 0.25 m2. El material fue recolectado mensualmente durante dos años consecutivos. Resultados: La riqueza de lluvia de semillas fue mayor en el fragmento urbano durante la estación lluviosa en los dos años, mientras que fue similar entre los fragmentos en la estación seca. La densidad de semillas en el fragmento rural fue mayor que en el urbano durante la estación lluviosa; no varió en urbano entre años o entre estaciones; y fue mayor en el fragmento rural en la estación lluviosa del primer año. Hubo una diferencia en la composición florística de la lluvia de semillas entre los fragmentos a lo largo del tiempo. Las variaciones en los atributos funcionales de hábito, síndrome de dispersión y categoría sucesional, fueron explicadas por las variables fragmento, estación y año. Conclusiones: Las diferencias en las características de la lluvia de semillas entre los fragmentos podrían reflejar la heterogeneidad espacial y temporal, debido a los diversos usos del suelo y presiones externas (acciones antropogénicas) presentes en el entorno de los fragmentos de bosque y variación temporal de la precipitación.

Formación del banco de semillas durante la revegetación temprana de áreas afectadas por la minería en un bosque pluvial tropical del Chocó, Colombia / Soil seed bank formation during early revegetation of areas affected by mining in a tropical rain forest of Chocó, Colombia

ResumenLa minería es una de las principales actividades económicas en muchas regiones tropicales y también es la causa de la devastación de amplias superficies de bosques tropicales naturales. El conocimiento del potencial regenerativo de las áreas alteradas por minería es vital para la restauración ecológica de estas áreas críticas. El objetivo del presente trabajo fue evaluar el efecto de la edad de abandono de las minas y su distancia al bosque adyacente sobre la formación del banco de semillas del suelo en minas abandonadas en el San Juan, Chocó, Colombia. Para ello, se determinó la abundancia y composición de especies del banco de semillas, así como la dinámica de la lluvia de semillas, en minas de distinta edad (6 y 15 años), tras el cese de la actividad minera, y distancia a la matriz del bosque adyacente (50 y 100 m). La lluvia de semillas estuvo compuesta por cinco especies de plantas, todas de dispersión anemócora, y fue mayor en la mina de 6 años que en la de 15. No hubo diferencias significativas en la cantidad de semillas recolectadas a 50 m y 100 m de distancia del bosque adyacente. El banco de semillas estuvo representado por ocho especies: dos de dispersión anemócora (comunes a la lluvia de semillas) y el resto de dispersión zoócora. La abundancia de semillas en el suelo no varió con la edad de la mina, pero fue mayor a distancias próximas al bosque que alejadas de este. Durante la regeneración temprana, la formación del banco de semillas en el seno de las minas parece estar relacionada con la cercanía a otras áreas alteradas más que con su proximidad al bosque adyacente o la edad de las minas. Al respecto, el establecimiento de perchas artificiales o conservación de árboles remanentes en el seno de las minas podrían promover la entrada de semillas dispersadas por aves. No obstante, dado que el banco de semillas del suelo puede verse afectado por la alta precipitación de la zona, se recomienda promover estudios que valoren medidas encaminadas a favorecer la formación del banco de semillas del suelo de las minas en ambientes de alta pluviosidad como en la región del Chocó.

Abstract:Mining is one of the main economic activities in many tropical regions and is the cause of devastation of large areas of natural tropical forests. The knowledge of the regenerative potential of mining disturbed areas provides valuable information for their ecological restoration. The aim of this study was to evaluate the effect of age of abandonment of mines and their distance from the adjacent forest, on the formation of soil seed bank in abandoned mines in the San Juan, Chocó, Colombia. To do this, we determined the abundance and species composition of the soil seed bank, and the dynamics of seed rain in mines of different cessation period of mining activity (6 and 15 years), and at different distances from the adjacent forest matrix (50 and 100 m). Seed rain was composed by five species of plants with anemocorous dispersion, and was more abundant in the mine of 6 years than in the mine of 15 years. There were no significant differences in the number of seeds collected at 50 m and 100 m from the adjacent forest. The soil seed bank was represented by eight species: two with anemocorous dispersion (common among the seed rain species) and the rest with zoochorous dispersion. The abundance of seeds in the soil did not vary with the age of the mine, but was higher at close distances to the forest edge than far away. During the early revegetation, the formation of the soil seed bank in the mines seems to be related to their proximity to other disturbed areas, rather than their proximity to the adjacent forest or the cessation activity period of mines. Therefore, the establishment of artificial perches or the maintenance of isolated trees in the abandoned mines could favour the arrival of bird-dispersed seeds at mines. However, since the soil seed bank can be significantly affected by the high rainfall in the study area, more studies are needed to evaluate management actions to encourage soil seed bank formation in mines of high-rainfall environments in the Chocó region. Rev. Biol. Trop. 65 (1): 393-404. Epub 2017 March 01.

Frugivory and seed dispersal of Solanum granuloso-leprosum Dunal (Solanaceae) by birds in deciduous seasonal forest / Frugivoria e dispersão de sementes em Solanum granuloso-leprosum Dunal (Solanaceae) por aves em Floresta Estacional Decidual

Abstract The goal of this study was to identify which bird species consume Solanum granuloso-leprosum fruits and disperse its seeds. 60 hours of focal observations were carried out between April and May 2006 on the edge of a deciduous forest fragment in the Uruguay River region, Rio Grande do Sul state, Brazil. Ten species were observed in total removing 443 fruits. Saltator similis removed 61.8% of the fruits, followed by Tangara sayaca (17.1%), Pipraeidea bonariensis (11.7%), and T. preciosa (6.8%), while the remaining six species accounted for only 2.5% of the fruits removed. Most fruit removal occurred early in the day or mid-afternoon. The most common feeding behaviors were picking (60.7%), followed by stalling (23%) and hovering (16%). Birds flew more than 10 m from the fruit plant in 62% of the removal events. All bird species observed here may be considered potential dispersers of S. granuloso-leprosum, as they moved the seeds away from the mother plant where strong competition and predation are likely to occur. Results also suggest that S. granuloso-leprosum may be useful in ecological restoration programs.

Resumo O objetivo deste estudo foi identificar quais as espécies de aves consomem frutos de Solanum granuloso-leposum e dispersam suas sementes. Para tanto, 60 horas de observações focais foram realizadas entre abril e maio de 2006 na borda de um fragmento de floresta decídua na região do rio Uruguai, Rio Grande do Sul, Brasil. Dez espécies foram observadas removendo 443 frutos. Saltator similis removeu 61,8% dos frutos, seguido de Tangara sayaca (17,1%), Pipraeidea bonariensis (11,7%), e T. preciosa (6,8%), enquanto as restantes seis espécies representaram apenas 2,5% dos frutos removidos. A maioria das remoções dos frutos ocorreram no início do dia ou meio da tarde. Os comportamentos alimentares mais comuns foram picking (60,7%), seguido por stalling (23%) e hovering (16%). As aves voaram mais de 10 m da planta de onde removeram frutos em 62% dos eventos de remoção. Todas as espécies de aves observadas aqui podem ser consideradas potenciais dispersores de S. granuloso-leprosum, moveram sementes para longe da planta-mãe, onde a concorrência e a predação são mais susceptíveis de ocorrer. Os resultados também sugerem que S. granuloso-leprosum pode ser útil em programas de restauração ecológica.

Papel de los mamíferos en los procesos de dispersión y depredación de semillas de Mauritia flexuosa (Arecaceae) en la Amazonía colombiana / Role of mammals on seed dispersal and predation processes of Mauritia flexuosa (Arecaceae) in the Colombian Amazon

ResumenLos mamíferos y las palmas son importantes elementos de la fauna y flora en el neotrópico. Por lo tanto, las interacciones entre ellos son una de las relaciones ecológicas más significativas en estos ecosistemas. Con el fin de identificar la importancia de los mamíferos que consumen los frutos de la palma Mauritia flexuosa y determinar su participación en la dispersión y depredación de sus semillas, se instalaron trampas cámara en frente de cúmulos de semillas caídas y de racimos con frutos. Con los videos obtenidos se preparó un catálogo de especies. Además, se clasificaron y cuantificaron los comportamientos de forrajeo exhibidos. También se utilizaron dos tratamientos de exclusión con tres repeticiones. En el tratamiento abierto se permitió el libre acceso de mamíferos pequeños, medianos y grandes, mientras que en el tratamiento semi-abierto se cercó la parcela con malla metálica dejando cuatro aberturas en la base para permitir el acceso y evaluar la remoción de semillas por mamíferos pequeños y medianos. Se registraron 19 especies de mamíferos, de las cuales nueve se alimentaron de los frutos de la palma y cinco de éstas fueron dispersoras de semillas. Se reporta por primera vez el consumo de los frutos de M. flexuosa por pare de Atelocynus microtis. La especie con mayor importancia relativa fue Dasyprocta fuliginosa, que mostro el mayor porcentaje de dispersión de semillas (63.5%) en comparación con las otras especies. Tayassu pecari fue identificado como consumidor in situ, porque consume hasta el 45.3 % de las semillas, sin dispersarlas. El número de semillas consumidas in situ en el tratamiento abierto mostró diferencias significativas con respecto al tratamiento semi-abierto, lo que sugiere una mayor participación de los mamíferos grandes en este proceso. En conclusión, los frutos de M. flexuosa son una fuente alimenticia importante para la comunidad de mamíferos. Además, el consumo de las semillas bajo la copa de la palma madre, el cual favorece la mortalidad de las mismas por efectos densodependientes, es proporcionalmente mayor que la dispersión. Generalmente la presión ejercida por las especies frugívoras sobre las semillas puede moldear las estrategias reproductivas de las especies de plantas. Sin embargo se deben realizar investigaciones sobre dispersión efectiva, distancias de dispersión y efectos demográficos, para determinar la función específica de los mamíferos medianos y grandes en la ecología de esta palma.

AbstractMammals and palms are important elements of fauna and flora in the Neotropics, and their interactions, such as fruit consumption and seed dispersal, are one of the most important ecological relationships in these ecosystems. The main objective of this study was to identify the relative importance of mammals in the dispersal and predation of Mauritia flexuosa palm fruits. We installed camera-traps in front of palm fallen seeds and clusters with fruits. A catalog of species was prepared with the recorded videos and the foraging behaviors exhibited were classified and identified. In addition, two exclusion treatments with three repetitions each were used. In the semi-open treatment, a plot was fenced with metal mesh leaving four openings in order to allow access only to small and medium sized mammals, while in the open treatment, the small, medium and large sized mammals had free access. In both cases, seed removal was evaluated. We recorded a total of 19 species of mammals, nine of which fed on palm fruits and the other five were seed dispersers. We reported for the first time the consumption of Mauritia flexuosa fruits by Atelocynus microtis. The species with the highest relative importance was Dasyprocta fuliginosa, which showed the highest percentage of seed dispersal (63.5%) compared to the other species. Tayassu peccary was identified as an in situ consumer, eating 45.3% of seeds without dispersing them. The number of seeds consumed in situ in the open treatment showed significant differences regarding the semi-open treatment, suggesting greater involvement of large mammals in this process. In conclusion, the fruits of M. flexuosa are an important food source for the local mammal community. Additionally, the consumption of seeds under the canopy of the mother palm is proportionally greater than their dispersion. Generally, the pressure of frugivorous species over seeds may determine the reproductive strategies of plants. However, research on effective dispersion, dispersal distances and demographic impact should be conducted to determine the specific role of medium and large sized mammals in the ecology of this palm. Rev. Biol. Trop. 64 (1): 5-15. Epub 2016 March 01.

Floristic similarity and dispersal syndromes in a rocky outcrop in semi-arid Northeastern Brazil / Similitud florística y síndromes de dispersión en un afloramiento rocoso de la región semiárida del noreste de Brasil

Floristic studies provide valuable information on species richness in a region, and are particularly important if these areas belong to less studied environments, such as rocky outcrops, that may increase our knowledge. An important aspect for species colonization includes the mechanisms of diaspores dispersal in each community; these are essential to understand its structure, dynamics, and the regeneration process, and constitute an important tool for conservation. We developed a floristic survey on a granite-gneiss outcrop with the objective to increase the knowledge on plant diversity, through a floristic similarity analysis and detection of dispersal syndromes of sampled species, in a semi-arid region of Brazil. The fieldwork included collection and observation of the botanical material in locoduring a period of 12 months. A total of 161 species belonging to 127 genera and 50 families of angiosperms were recorded. Fabaceae, Asteraceae and Convolvulaceae were the most representative families in number of species. Allophylus quercifolius(Mart.) Radlk. (Capparaceae) and Lafoensia pacariA. St.-Hil. (Lythraceae) represented new records for the State of Paraiba. The autochoric syndrome was the most representative, with 51.5 % of the recorded species; the anemochory was the second most representative syndrome with 26.7 % of the species; and finally the zoochory, representing 22.3 % of the species. The floristic similarity dendrogram showed the formation of three well-defined groups, whose area with the highest value (J = 33.2) is located in a Caatinga region called Cariri Paraibano, while the lowest value observed (J = 5.2), occurred in a settled area in two geomorphological units, a crystalline complex and a plateau region. These results may be due to the varying topographic conditions and edaphic heterogeneity arising from the specific geological formation of the region. These results yet demonstrate that, in rocky outcrops, abiotic syndromes represent an effective dispersion of its diaspores, favoring plant specie's colonization dynamics.

Los estudios florísticos proveen información valiosa sobre la riqueza de especies de una región, y son particularmente importantes si estas áreas pertenecen a ambientes menos estudiados como los afloramientos rocosos. Un aspecto importante para la colonización de especies incluye los mecanismos de dispersión de diáspo-ras en cada comunidad; estos son esenciales para entender la estructura, dinámica y el proceso de regeneración, constituyendo una herramienta importante para la conservación. En este estudio se realizó un levantamiento florístico de un afloramiento de granito-gneis con el objetivo de ampliar el conocimiento sobre la diversidad vegetal a través del análisis de similitud florística con la de otros afloramientos rocosos del nordeste brasileño y la detección de los síndromes de dispersión de las especies muestreadas en un área de la región semiárida de Brasil. Los trabajos de campo incluyeron recolección y observación de los materiales vegetales 'i" loco'durante el periodo de 12 meses. Un total de 161 especies pertenecientes a 127 géneros y 50 familias de angiospermas fueron registradas. Fabaceae, Asteraceae y Convolvulaceae fueron las familias más representativas en número de especies. Allophylus quercifolius(Mart.) Radlk. (Sapindaceae) y Lafoensia pacariA.St.-Hil. (Lythraceae) representan nuevas citas para el estado de Paraíba. El síndrome autocórico fue lo más representativo, con 51 % de las especies registradas; la anemocoria el segundo, con 27.7 % de las especies y finalmente la zoocoria, representando el 22.3 %. El dendrograma de similitud florística ha demostrado la formación de tres grupos bien definidos, cuya área con mayor índice (J = 33.2) está ubicada en una región de Caatinga llamada Cariri Paraibano mientras el menor índice "in loco"(J = 5.2) ocurrió en un área ubicada en dos unidades geomorfológicas: un complejo cristalino y una región de Planalto. Estos resultados se deben a las variables condiciones topográficas y a la heterogeneidad edáfica proveniente de la formación geológica especifica de la región. Estos resultados demuestran todavía que en afloramientos rocosos, síndromes abióticos representan una dispersión eficaz de sus diásporas, favoreciendo la dinámica de colonización de las especies vegetales.

Edge effect on post-dispersal artificial seed predation in the southeastern Amazonia, Brazil / Efeito de borda na predação de sementes artificiais pós-dispersão no sudeste da Amazônia, Brasil

This paper evaluates the post-dispersal artificial seed predation rates in two areas of the southeastern Amazon forest-savanna boundary, central Brazil. We conducted the survey in a disturbance regime controlled research site to verify if exists an edge effect in these rates and if the disturbance (in this case annual fire and no fire) affects seed predation. We placed 800 peanuts seeds in each area at regular distance intervals from the fragment`s edge. Data were analyzed by a likelihood ratio model selection in generalized linear models (GLM). The complete model (with effects from edge distance and site and its interaction) was significative (F3=4.43; p=0.005). Seeds had a larger predation rates in fragment’s interior in both areas, but in the controlled area (no disturbance) this effect was less linear. This suggests an edge effect for post-dispersal seed predation, and that disturbances might alter these effects. Even if we exclude the site effect (grouping both areas together) there is still a strong edge effect on seed predation rates (F3=32.679; p>0.001). We did not verify predator’s species in this study; however, the presence of several species of ants was extremely common in the seeds. The detection of an edge effect in only a short survey time suggests that there is heterogeneity in predation rates and that this variation might affect plant recruitment in fragmented areas of the Amazon forest. Henceforth, this seed predation should be taken in consideration in reforestation projects, where the main source of plants species is from seed distribution.

Este artigo avaliou a predação de sementes pós-dispersão em duas áreas da borda entre a Amazônia e o Cerrado, no Brasil central. O experimento foi realizado em uma área de estudos controlados, no qual foi verificada a existência de um efeito de borda na predação de sementes e se a existência de distúrbio (área sujeita a fogo anual e área controle) afeta estes valores. Foram colocadas 800 sementes de amendoim em cada uma das duas áreas em distância regulares da borda do fragmento. Os dados obtidos foram analisados através de seleção de modelos por verossimilhança em modelos lineares generalizados (GLM). O modelo completo (com efeitos da distância da borda e da área amostrada com suas interações) foi significativo (F3=4,43; p=0,005). As sementes apresentaram uma maior taxa de predação no interior do fragmento em relação a sua borda em ambas as áreas, mas na área controle (sem distúrbio), o efeito foi menos linear. Isto sugere que existe um efeito de borda para a predação de sementes, e que distúrbios podem alterar estes efeitos. Mesmo se o efeito das áreas for removido (considerando ambas as áreas em conjunto), o efeito de borda sobre a predação de sementes persiste (F3=32,679; p>0,001). Não foram verificadas diretamente as espécies de predadores neste estudo, no entanto a presença de algumas espécies de formigas nas sementes foi extremamente comum. A detecção deste efeito de borda em um espaço de tempo curto sugere que existe uma heterogeneidade nas taxas de predação e que esta variação pode afetar o recrutamento vegetal em áreas fragmentadas da floresta amazônica. Portanto, este efeito sobre a predação de sementes deve ser levado em consideração em projetos de reflorestamento, nos quais a principal fonte de espécies vegetais seja através da distribuição de sementes.

Frugivory and potential of birds as dispersers of Siparuna guianensis / Frugivoria e potencial de aves como dispersores de Siparuna guianensis

Siparuna guianensis is a neotropical tree species, found both on edge and interior of forest fragments, mainly on understory and regeneration areas. The fruit are zoochorous with a sweet aril. This work aims to determine the bird species that eat the fruits of S. guianensis in a semi deciduous forest fragment in Brazilian Cerrado and measure which species have the highest potential as seed dispersers. Seven individuals of S. guianensis were sampled, totaling 69 hours. A hundred and fifty four visits were registered by seven species of birds. Antilophia galeata had the biggest potential as seed dispersal agent. Antilophia galeata, Lanio penicillatus and Dacnis cayana can be important seed dispersers, since they have a high consumption and visitation rate. The consumption of S. guianensis by species of different feeding guilds can be an important strategy for dispersal of plant species in regeneration habitats, raising the chances of an effective dispersal.

Siparuna guianensis é uma espécie arbórea neotropical do Cerrado, encontrada tanto na borda quanto no interior de fragmentos florestais, principalmente no sub-bosque de matas em regeneração. Os frutos são zoocóricos com arilos adocicados. Os objetivos desse estudo foram: determinar quais espécies de aves consomem os frutos de S. guianensis em um fragmento de floresta semidecídua do Cerrado brasileiro, e inferir quais espécies apresentaram maior potencial de dispersão. Sete indivíduos de S. guianensis foram amostrados, totalizando 69 horas-planta. Foram registradas 153 visitas, realizadas por sete espécies de aves. Antilophia galeata apresentou o maior potencial de dispersão. Entre as espécies exclusivamente florestais, A. galeata, Dacnis cayana e Lanio penicillatus podem ser importantes dispersores, devido à taxa de consumo elevada, maior número de visitação e maior potencial para dispersar as sementes em sítios viáveis de germinação. O consumo dos frutos de S. guianensis por espécies de diferentes guildas alimentares pode ser uma importante estratégia para esta espécie em ambientes em regeneração, por maximizar a possibilidade de dispersão.

Frugivory and seed dispersal by birds in Cereus jamacaru DC. ssp. jamacaru (Cactaceae) in the Caatinga of Northeastern Brazil / Frugivoria e dispersão de sementes por aves em Cereus jamacaru DC. ssp. jamacaru (Cactaceae) na Caatinga, uma floresta seca no Nordeste do Brasil

Studies of the dispersal modes of plants aid our understanding of the dynamics of resource and its availability for dispersal agents. The present work sought to characterize the fruiting patterns of the native Caatinga (dryland) cactus Cereus jamacaru, identify its principal dispersers, and evaluate the effects of seed passage through digestive tract of dispersers on its germination. Cereus jamacaru present an annual fruiting pattern and fruiting peaks occurred during June/2009 and February/2010. A total of 135 visits by nine species of resident Caatinga bird species were recorded. The most frequent visiting bird species were Paroaria dominicana and Euphonia chlorotica. Length of bird visits varied from 15 seconds to 4 minutes and seeds removed by birds travelled 10.6 ± 11.2 m until dispersers make the first landing perch, in some cases more than 40 meters away. Germination tests show birds had a high quantity of viable seeds of C. jamacaru in its feces. Seeds that passed through the digestive tract of birds showed a similar germinability of the seeds of the control group. However, the seeds dispersed by birds showed lowest mean germination time related to the control group seeds. This study highlights the potential role of birds as seed dispersers of C. jamacaru, swallowing the whole seeds and defecating intact seeds, accelerating the germination process and transporting seeds away from the mother plant.

Estudos do modo de dispersão das espécies vegetais permitem o entendimento da dinâmica dos recursos e sua disponibilidade para os dispersores. O objetivo deste trabalho foi caracterizar o padrão de frutificação de Cereus jamacaru, uma espécie nativa da Caatinga, identificar os seus principais dispersores e avaliar o efeito da passagem das sementes pelo trato digestivo destes animais sobre sua germinação. Cereus jamacaru apresentou um padrão de frutificação anual, com pico de frutificação nos meses de Junho/2009 e Fevereiro/2010. No total foram registradas 135 visitas de nove espécies de aves frugívoras da Caatinga, sendo os dispersores mais frequentes Paroaria dominicana e Euphonia chlorotica. O tempo de duração das visitas foi curto, variando de 15 segundos a 4 minutos, e a distância média dos voos pós-alimentação foi 10,6 ± 11,2 m da planta-mãe, podendo também alcançar distâncias superiores a 40 metros. Os resultados dos testes de germinação mostraram que as aves apresentam uma alta quantidade de sementes viáveis de C. jamacaru em suas fezes. As sementes que passaram pelo trato digestivo das aves mostraram germinabilidade semelhante aquelas do grupo controle. No entanto, as sementes dispersadas pelas aves apresentaram um menor tempo médio necessário para germinação. Esse estudo destaca o papel das aves como potenciais dispersores de C. jamacaru, eliminando sementes intactas, acelerando o processo de germinação e carregando as sementes para longe da planta mãe.

Floristic analysis and dispersal syndromes of woody species of the Serra de Maracaju, Mato Grosso do Sul, Brazil / Análise florística e síndromes de dispersão de espécies lenhosas da Serra de Maracaju, Mato Grosso do Sul, Brasil

This paper presents a floristic survey of the wood component of cerrado s.s. (eastern face) and gallery forest (western face) areas carried out in the southern part of the Serra de Maracaju. The dispersal syndromes and floristic relations of this portion of the Serra were compared to those of other formations from different regions of Brazil. Between October 2007 and September 2008, monthly collections identified 144 species. As for dispersal syndromes, zoochory prevails, followed by autochory and anemochory. The gallery forest is a heterogeneous formation that shelters floristic elements shared with the Atlantic rain forest, the Amazonian forest, semi-deciduous seasonal forests and dry forests of the Pantanal. Low similarity between the two areas analyzed makes this region unique and suggests that the Serra de Maracaju is greatly influenced by the semi-deciduous seasonal forests of the southeastern region.

Ao sul da Serra de Maracaju, foi efetuada a florística do componente lenhoso de áreas de cerrado s.s. (Face Leste) e Mata de Galeria (Face Oeste), com investigações das síndromes de dispersão e das relações florísticas desta porção da Serra com outras formações em diferentes regiões do Brasil. Os dados obtidos resultaram em 144 espécies, em coletas mensais, no período de outubro de 2007 a setembro de 2008. Para as síndromes de dispersão, verificou-se predominância da zoocoria, seguida por autocoria e anemocoria. A Mata de Galeria da Serra de Maracaju é uma formação heterogênea, que detém elementos florísticos compartilhados com a Floresta Pluvial Atlântica, a Floresta Amazônica, a Floresta Estacional Semidecidual e as Florestas Secas do Pantanal. A baixa similaridade entre as áreas analisadas confere um caráter único à região e sugere que a Serra de Maracaju recebe maior influência das Florestas Estacionais Semideciduais da Região Sudeste.

Frugivoría y dispersión de semillas de la palma Oenocarpus bataua (Arecaceae) en un bosque de los Andes colombianos / Frugivory and seed dispersal Oenocarpus bataua palm (Arecaceae) in a forest from the Colombian Andes

Seed dispersal is a key process that determines the spatial structure and dynamics of populations of plants, establishes the potential area of recruitment and in this way, the basis for subsequent processes such as predation, germination, competition and growth. The purpose of this research was to identify the guild of frugivores of the Oenocapus bataua palm in fragments of Andean forest, determine the effective dispersers and relate the spatial distribution of palm populations with the dispersion of seeds. To this end, between August 2005-June 2006, observations of the removal of fruits from eight clusters were done, and counting of consumption of fruits beneath 78 palms with mature fruits was undertaken; focal observations of 13 individuals during 90 hours; registration of frugivory with photographic traps during 165 days/nights for a total of 195 photographs and 144 consumption events; experiments with dispersion using 751 perforated fruits/seeds attached to strings and finally, plots to determine spatial distribution all were carried out. In the study area at least five species of mammals ate, dispersed, buried (Sciurus granatensis, Microsciurus mimulus, Dasyprocta punctata y Proechimys sp.), cover (Marmosa robinsoni) and carried the fruits of O. bataua off to caves (Marmosa robinsoni y Proechimys sp.) without damaging the seed. A 21.7% of the fruits were dispersed, 13.2 gnawed or peeled, 5.6% covered, buried and carried to caves. The average distance of removal of seeds and fruits was 3.1m although in a lesser proportion, dispersion events of >50m were recorded. The abundant production of fruits, their size and weight, their intense removal by frugivores, the short dispersion distances, the absence of large size frugivores (reduced by hunting and fragmentation), that might perform long-distance dispersion, and the increase of rodents, especially squirrels, that strongly pressure the fruit resource, generate a spatially restricted ...

En zonas bajas tropicales, en bosques continuos y relativamente poco intervenidos, los frutos de la palma Oenocarpus bataua Mart., son consumidos por diversas especies de vertebrados, sin embargo, no hay estudios de dispersión de más largo plazo con esta especie. Entre agosto 2005-septiembre 2006 se realizaron observaciones de remoción de frutos, conteo de frutos comidos, observaciones focales, registros de frugivoría mediante trampas fotográficas, experimentos de dispersión y parcelas para determinar distribución espacial de Oenocarpus bataua. Cinco especies de mamíferos comen, dispersan, entierran (Sciurus granatensis, Microsciurus mimulus, Dasyprocta punctata y Proechimys sp.), tapan (Marmosa robinsoni) y llevan a las cuevas (Marmosa robinsoni y Proechimys sp.), los frutos de O. bataua, sin dañar la semilla. El 21.7% de los frutos fueron dispersados, 13.2% roídos o pelados, 5.6% tapados, enterrados y llevados a cuevas. La distancia media de remoción de semillas y frutos fue 3.1m, aunque en menor proporción se registraron eventos de dispersión > a 50m. La abundante producción, el tamaño, el peso, la intensa remoción de los frutos por frugívoros, las cortas distancias de dispersión, la ausencia de frugívoros de gran porte disminuidos por cacería y fragmentación, encargados de la dispersión de larga distancia y el aumento de roedores, especialmente ardillas que presionan fuertemente el recurso frutos, generan una lluvia de semillas espacialmente restringida, posiblemente responsable de los patrones de distribución agregados en semillas, plántulas y posteriormente en juveniles y sub-adultos.

Color and odor of artificial fruit used to signal potential dispersers in the Atlantic forest in Brazil

Fruit color and odor are the main features regulating the rate of fruit predation and dispersal. The aim of this study was to analyze the effect of odor and color on fruit predators and dispersers. The present study was conducted in a 30ha area of secondary forest in Southeastern Atlantic Brazil. This area was divided into two transects, in which four points were marked with a 30m distance from each other. Each sampling point contained a total of 30 artificial fruit which belong to six different treatment groups, with five artificial fruit per group. Each group was randomly placed on the ground and that artificial fruit was checked every seven days. For each group of five fruit, 5mL of essence (vanilla or pineapple) were placed, and no essence was used in the control group. Artificial fruit was made with green and red nontoxic modeling clay, as well as artificial essences (vanilla and pineapple). A total of 960 fruits were used. Predated fruit equaled 26.9% (258 units), from which the red/pineapple had the highest predation rate (81.9%), followed by red/vanilla (46.3%), while green/control fruits were not predated. Throughout the experiment, bitten fruit and pecked fruit equaled 58.3% and 41.7%, respectively. No significant differences were recorded (x²=7.57, df=5, p=0.182) between bitten and pecked fruit. Fruit color and odor are important in attracting predators and dispersers, which explains the high rate of predation of red/vanilla and red/pineapple, and the absence of predated fruits in the green/control group. Regarding the potential disperser, there was no statistically significant difference between pecked fruit and bitten fruit. As a result, it should be taken into consideration that zoochory (mammalochory and ornithochory) is the most important dispersal; therefore, it should be concluded that birds are more attracted by color and mammals by odor. Rev. Biol. Trop. 60 (2): 925-931. Epub 2012 June 01.

El olor y el color de los frutos son las características principales que regulan el nivel de consumo y la dispersión de las semillas. Este estudio tuvo como objetivo analizar el efecto que tiene el olor y el color de los frutos sobre los depredadores y dispersores de semillas. El área de estudio abarca 30ha de bosque secundario localizado en el Atlántico sureste de Brasil. Este espacio se dividió en dos sectores, en los cuales se marcaron cuatro puntos con una distancia de 30m entre sí. En cada punto de muestreo se utilizaron 30 frutos que se distribuyeron en seis tratamientos, con cinco frutos artificiales para cada tratamiento. Además, cabe resaltar que cada tratamiento se colocó en el suelo de forma aleatoria y que los frutos artificiales se verificaron cada siete días. Para cada grupo de cinco frutos se utilizaron 5mL de esencia (vainilla y ananá) y para el grupo de control no se utilizó ningún aditivo de olor. Los frutos se confeccionaron con plastilina atóxica de color verde y roja, además de esencias artificiales (ananá y vainilla), asimismo se obtuvieron 960 frutos. El nivel de frutos consumidos fue del 26.9% (258 unidades), de los cuales los rojos/ananá fueron los más consumidos (81.9%), seguidos del rojo/vainilla (46.3%), mientras que los verde/control no fueron comidos. Durante el experimento la tasa de frutos mordidos fue del 58.3% y de picoteados un 41.7%. No se registró una diferencia significativa (x²=7.57, gl=5, p=0.182) entre frutos mordidos y picoteados. El color y el olor de los frutos son aspectos importantes para atraer depredadores y dispersores, lo que explica los niveles de consumo de los frutos rojos/vainilla y rojo/ananá y la ausencia de frutos comidos en el tratamiento del verde/control. En cuanto al potencial dispersor, no hubo una diferencia estadística significativa entre frutos mordidos y picoteados, por lo que se debe tomar en cuenta que la dispersión principal es la zoocoria (ornitocoria y mamalocoria). Por lo tanto, se puede concluir que las aves son atraídas por el color y los mamíferos por el olor.

A new hypothesis for the importance of seed dispersal in time

Most studies on seed dispersal in time have focused on seed dormancy and the physiological triggers for germination. However, seed dispersed by animals with low metabolic and moving rates, and long gutpassage times such as terrestrial turtles, could be considered another type of dispersal in time. This study tests the hypothesis that seeds dispersed in time may lower predation rates. We predicted that seeds deposited below parent trees after fruiting fall has finished is advantageous to minimize seed predators and should show higher survival rates. Four Amazonian plant species, Dicranostyles ampla, Oenocarpus bataua, Guatteria atabapensis and Ocotea floribunda, were tested for seed survival probabilities in two periods: during fruiting and 10-21 days after fruiting. Experiments were carried out in two biological stations located in the Colombian Amazon (Caparú and Zafire Biological Stations). Seed predation was high and mainly caused by non-vertebrates. Out of the four plant species tested, only Guatteria atabapensis supported the time escape hypothesis. For this species, seed predation by vertebrates after the fruiting period increased (from 4.1% to 9.2%) while seed predation by nonvertebrates decreased (from 54.0% to 40.2%). In contrast, seed predation by vertebrates and by non-vertebrates after the fruiting period in D. ampla increased (from 7.9% to 22.8% and from 40.4% to 50.6%, respectively), suggesting predator satiation. Results suggest that for some species dispersal in time could be advantageous to avoid some type of seed predators. Escape in time could be an additional dimension in which seeds may reach adequate sites for recruitment. Thus, future studies should be address to better understand the survival advantages given by an endozoochory time-dispersal process. Rev. Biol. Trop. 59 (4): 1795-1803. Epub 2011 December 01.

La mayoría de estudios sobre dispersión de semillas en el tiempo tratan sobre la dormancia de las semillas y los procesos fisiológicos que disparan su germinación. Sin embargo, la dispersión de semillas por animales de bajas tasas metabólicas y largos tiempos de retención, como por ejemplo los reptiles, podría ser considerada otro tipo de dispersión en el tiempo. Este estudio prueba la hipótesis que las semillas dispersadas por tortugas pueden evadir a los depredadores en el tiempo. Semillas depositadas bajo árboles parentales luego de que la cosecha haya terminado es ventajoso para escapar de depredadores denso-dependientes y por lo tanto deberían mostrar mayores tasas de supervivencia. La hipótesis se probó en cuatro especies de plantas amazónicas, Dicranostyles ampla, Oenocarpus bataua, Guatteria atabapensis y Ocotea floribuna, durante dos periodos: durante la cosecha y varios días después de la cosecha de frutos. Los experimentos se llevaron en dos estaciones biológicas de la Amazonia colombiana (Caparú y Zafire). Los principales depredadores de semillas fueron los no vertebrados y por lo tanto fueron el factor que más influyó en la supervivencia de las semillas en ambas áreas de estudio. De las cuatro especies probadas, sólo Guatteria atabapensis validó la hipótesis de la ventaja de la dispersión en el tiempo. Para esta especie, la depredación de semillas por vertebrados después del periodo de cosecha incrementó (de 4.1% a 9.2%) mientras que la depredación de semillas por no vertebrados disminuyó (de 54.0% a 40.2%). Por el contrario, la depredación de semillas por vertebrados y por no vertebrados después del período de la cosecha para D. ampla incrementó (de 7.9% a 22.8% y de 40.4% a 50.6% respectivamente), sugiriendo saciación de depredadores. Los resultados sugieren que para algunas especies, el escape en el tiempo podría ser ventajoso para evadir algunos tipos de depredadores. El escape en el tiempo podría ser una dimensión adicional en donde las semillas podrían alcanzar lugares adecuados para su reclutamiento. Futuros estudios deberían realizarse con el fin de entender mejor las ventajas de supervivencia dadas por la dispersión en el tiempo luego de un proceso de endozoocoria.

Phenology, seed dispersal and difficulties in natural recruitment of the canopy tree Pachira quinata (Malvaceae)

Life history and recruitment information of tropical trees in natural populations is scarce even for important commercial species. This study focused on a widely exploited Neotropical canopy species, Pachiraquinata (Malvaceae), at the southernmost, wettest limit of its natural distribution, in the Colombian Amazonia. We studied phenological patterns, seed production and natural densities; assessed the importance of seed dispersal and density-dependent effects on recruitment, using field experiments. At this seasonal forest P. quinata was overrepresented by large adult trees and had very low recruitment caused by the combination of low fruit production, high seed predation and very high seedling mortality under continuous canopies mostly due to damping off pathogens. There was no evidence of negative distance or density effects on recruitment, but a clear requirement of canopy gaps for seedling survival and growth, where pathogen incidence was drastically reduced. In spite of the strong dependence on light for survival of seedlings, seeds germinated readily in the dark. At the study site, the population of P. quinata appeared to be declining, likely because recruitment depended on the rare combination of large gap formation with the presence of reproductive trees nearby. The recruitment biology of this species makes it very vulnerable to any type of logging in natural populations. Rev. Biol. Trop. 59 (2): 921-933. Epub 2011 June 01.

Información acerca de la historia de vida y reclutamiento de poblaciones naturales de árboles tropicales es escasa, incluso para especies de alto interés comercial. Este estudio se centró en una especie de dosel altamente explotada, Pachira quinata (Malvaceae), en la zona más húmeda de su distribución geográfica, en la Amazoní a colombiana. Estudiamos sus patrones fenológicos, producción de semillas y densidades naturales, además de la importancia de la dispersión de semillas y efectos denso-dependientes en el reclutamiento natural, todo lo anterior se logró con el uso de experimentos y observaciones en el campo. En este bosque estacional, la población de P. quinata estaba dominada por grandes árboles adultos y el reclutamiento era extremadamente bajo, como consecuencia de la baja producción de frutos, alta depredación de semillas y muy alta mortalidad de plántulas bajo el bosque por infección de patógenos. No encontramos evidencia de efectos de distancia al árbol parental o densidad de semillas en el reclutamiento, pero si hallamos un evidente requerimiento de claros de luz para la supervivencia y el crecimiento de plántulas, donde la mortalidad por patógenos se reduce drásticamente. Sin embargo, a pesar de la dependencia de la luz para la supervivencia, las semillas germinan en la oscuridad. En la zona de estudio, la población de P. quinata parece estar en claro declive, probablemente porque el reclutamiento depende de la coincidencia de la formación de grandes claros con la presencia cercana de árboles reproductivos. Los requerimientos de reclutamiento de esta especie la hacen muy vulnerable a cualquier actividad extractiva de árboles adultos en poblaciones naturales.