bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluctuaciones Temporales en la Composición Floristica del Bosque Tropical Atlántico1
Authors: Rolim Samir Gonçalves , Couto Hilton Thadeu Zarate do , de Jesus Renato Moraes 
Published: March 2006

ABSTRACTTemporal and spatial changes in floristic composition over a 15‐year period in an Atlantic tropical forest in Brazil were analyzed. The data were recorded in five 0.5‐ha (50 × 100 m) plots within a 22,000‐ha forest reserve. In each plot, all stems ± 10 cm diameter at breast height (DBH) were repeatedly inventoried. The overall number of species among all plots was steady over time but changed within a given plot. In all plots, the proportion for the disappearance of species was 7 percent and that for immigration of new species into the plots was 9.5 percent. Approximately 65 percent of the disappearance occurred between 1986 and 1989, and 74 percent of the immigration happened after 1986. The observed changes in composition evidently were due to natural disturbance and climatic events, such as an unusual four‐month drought. Disappearance of species from the plots did not denote regional extinction of those species, because they persisted elsewhere in the forest reserve. The changes in species composition within the plots and persistence outside them, however, indicated that large areas are required for in situ conservation of tropical tree species. These areas must be large enough for population changes to occur without negative effects on genetic and demographic structures of tree species.RESUMESForam analisadas as variações temporais e espaciais na composição florística de uma floresta tropical num período de 15 anos entre os anos de 1980 e 1995. Em 5 parcelas de 0.5 ha (50 × 100 m) amostraram‐se todas as árvores com diàmetro a altura do peito (DAP) ≥ 10 cm. Para a escala e período que este estudo abrangeu pode‐se concluir que há uma estabilidade no número de espécies da comunidade ao longo do tempo e esta estabilidade foi significativamente afetada por um distúrbio natural (um período seco de 4 meses) ocorrido em 1987. Foi constatado que em 15 anos desapareceram 7 por ciento das espécies nas parcelas monitoradas, contra um total de 9.5 por ciento de novas espécies recrutadas. Aproximadamente 65 por ciento do desaparecimento de espécies ocorreu entre 1986 e 1989 e 74 por ciento das novas espécies foram recrutadas apos 1986. O desaparecimento não significa necessariatmente um fenômeno de extinção e foi demonstrado que as espécies continuam ocorrendo na comunidade. O desaparecimento de espécies dentro das parcelas e sua pcrsisténcia fora delas indica que são necessárias grandes áreas para conservação in situ de espécies arbóreas. Estas áreas devem ser capazes de absorver as flutuaç&#x007a;̃oes populacionais sem afetar a estrutura genética e demográfica das espécies.
Detrital Fruit Processing in a Hawaiian Stream Ecosystem1
Authors: Larned Scott T. , Chong Charles T. , Punewai Noelani 
Published: March 2006

ABSTRACTIn temperate forested streams, fruit from riparian trees is generally a minor and seasonal component of the allo‐chthonous detritus. In contrast, riparian fruit input to tropical streams is often high and continuous. Detrital fruit is abundant in some forested Hawaiian streams compared to other forms of riparian detritus, and rates of leaf litter processing by macroscopic invertebrates are very low. These observations suggested that fruit is an important food resource for detritivores. A microcosm system was used to measure the rates at which two common detrital fruits, guava and mango, were processed by two common detritivores, the prawn Macrobrachium lar and the gastropod Tarebia granifera. Comparisons of fruit weight loss rates normalized by detritivore weight indicated that M, lar processed guavas at significantly higher rates than T. granifera, differences in rates of mango processing by M. lar and T. granifera were not significant. Microcosms containing both M. lar and T. granifera were used to test for interactions between the invertebrates that affected rates of mango processing. No interspecific interactions were detected. A field study was conducted in Kaiwiki Stream, Island of Hawaii, to determine rates of detrital fruit input and export. Detrital fruit was supplied to the study area year‐round, with peaks corresponding to summer and autumn fruiting seasons. Guavas and mangos accounted for 85 percent of the fruit biomass entering the stream and 92 percent of the fruit exported from the stream. Mean daily export rates of guava were 7 percent of input, and export rates of mango were 5 percent of input. These measurements suggested that most of the fruit entering the stream is retained and comprises a substantial food resource for detritivores. Comparisons of the biomass‐specific rates at which M. lar and T. granifera processed mangos and guavas with the rates at which mangos and guavas entered Kaiwiki Stream suggested that these invertebrates can process most of the detrital fruit in the stream.
Tropical Rain Forest Recovery from Cyclone Damage and Fire in Samoa1
Authors: Hjerpe Johan , Hedenâs Henrik , Elmqvist Thomas 
Published: March 2006

ABSTRACTIn 1990 and 1991, Samoa was struck by two cyclones, Ofa and Val. In the Tafua Rain Forest Preserve on the island of Savai'i, one part of the forest also burned after the first cyclone. Here we report on patterns of regeneration and changes in tree species composition in the Tafua lowland rain forest after five years of recovery from cyclone and fire disturbance. In the unburned area, tree canopy cover increased from 27 percent after the last cyclone to 58 percent, and in the burned area from below 12 to 49 percent. Nine of the ten most common tree species decreased in relative abundance in the entire forest after the last cyclone. One fast growing pioneer species, Macaranga harveyana now makes up 42 percent of the total number of trees (>5 cm DBH) in the unburned area and 86 percent in the burned area. Large interspecific differences occur in size distribution and there are at least four distinguishable regeneration patterns, which may be related to shade tolerance. Mean number of species per plot was generally higher in the unburned area than in the burned area, while the Shannon evenness index was higher in the unburned than in the burned area only for trees above 1 cm DBH. Species with fruits known to be fed upon by birds and/or bats generally made up a larger proportion of all trees in the burned than in the unburned area. In contrast to other studies of post‐cyclone regeneration, in which recovery is often rapid due to resprouting of trees, recovery in the Tafua forest was a slow process with regeneration more dependent on vertebrate seed dispersal than on resprouting.
Removal of Nonnative Vines and Post‐Hurricane Recruitment in Tropical Hardwood Forests of Florida1
Authors: Horvitz Carol C. , Koop Anthony 
Published: March 2006

ABSTRACTIn hardwood subtropical forests of southern Florida, nonnative vines have been hypothesized to be detrimental, as many species form dense “vine blankets” that shroud the forest. To investigate the effects of nonnative vines in post‐hurricane regeneration, we set up four large (two pairs of 30 X 60 m) study areas in each of three study sites. One of each pair was unmanaged and the other was managed by removal of nonnative plants, predominantly vines. Within these areas, we sampled vegetation in 5 X 5 m plots for stems 2 cm DBH (diameter at breast height) or greater and in 2 X 0.5 m plots for stems of all sizes. For five years, at annual censuses, we tagged and measured stems of vines, trees, shrubs and herbs in these plots. For each 5 X 5 m plot, we estimated percent coverage by individual vine species, using native and nonnative vines as classes. We investigated the hypotheses that: (1) plot coverage, occurrence and recruitment of nonnative vines were greater than that of native vines in unmanaged plots; (2) the management program was effective at reducing cover by nonnative vines; and (3) reduction of cover by nonnative vines improved recruitment of seedlings and saplings of native trees, shrubs, and herbs. In unmanaged plots, nonnative vines recruited more seedlings and had a significantly higher plot‐cover index, but not a higher frequency of occurrence. Management significantly reduced cover by nonnative vines and had a significant overall positive effect on recruitment of seedlings and saplings of native trees, shrubs and herbs. Management also affected the seedling community (which included vines, trees, shrubs, and herbs) in some unanticipated ways, favoring early successional species for a longer period of time. The vine species with the greatest potential to “strangle” gaps were those that rapidly formed dense cover, had shade tolerant seedling recruitment, and were animal‐dispersed. This suite of traits was more common in the nonnative vines than in the native vines. Our results suggest that some vines may alter the spatiotemporal pattern of recruitment sites in a forest ecosystem following a natural disturbance by creating many very shady spots very quickly.
Pollination and Predation Limit Fruit Set in a Shrub, Bourreria succulents (Boraginaceae), after Hurricanes on San Salvador Island, Bahamas1
Authors: Rathcke Beverly J. 
Published: March 2006

ABSTRACTHurricanes have been assumed to reduce the reproduction of plants, either directly by leaf stripping and stress or indirectly by reducing pollinators. I examined the pollination and fruit set of a common shrub, Bourreria succulenta, after hurricanes on San Salvador island, Bahamas. Contrary to the assumption of resource limitation, B. succulenta showed unusually prolific flowering after Hurricane Lili stripped leaves from most of the plants in October 1996. I predicted that the abundant flowering would saturate pollinators and that fruit set would be pollination‐limited. Fruit set was strongly pollination‐limited by 71 percent. Butterflies are probably the major pollinators and were present at the site, but they rarely visited B. succulenta flowers even though flowers were brimming with nectar. Nectarivorous birds (Bananaquits and Bahama Wbodstars) visit B. succulenta flowers, but their populations were decimated by Hurricane Lili and they rarely visited flowers during this time. Fruit set was also severely predation‐limited; a moth caterpillar (Gelechiidae) was extremely abundant and ate buds, flowers, and fruits, causing a further 68 percent reduction in fruit set. Together, pollination limitation and predation limitation reduced fruit set to only 7 percent or less. Predation was also intense in 1999 after Hurricane Floyd and resulted in 11 percent fruit set or less. Whether or not hurricanes were the cause of limited pollinators or abundant predators, the resulting low fruit set could have population effects because hurricanes can provide opportunities for the recruitment of new plants. These results emphasize that understanding plant–animal interactions may be necessary for predicting the effects of hurricanes on plant reproductive success, which may affect subsequent recruitment. Species on small islands like San Salvador (150 km2) with relatively few species may be especially vulnerable to environmental disturbances such as hurricanes.
Mammalian Diet and Broad Hunting Strategy of the Dingo (Canis familiaris dingo) in the Wet Tropical Rain Forests of Northeastern Australia1
Authors: Vernes Karl , Dennis Andrew , Winter John 
Published: March 2006

ABSTRACTThe diet of dingoes (Canis familiaris dingo) in the Australian Wet Tropics was examined by analyzing 383 dingo scats collected throughout the region for the presence of mammal prey remains. The scats yielded 29 native and 4 introduced mammal prey species from 14 families. The most important species in terms of percentage occurrence in the scats were Melomys cervinipes (22.2%), hoodon macrourus (17.0%), Perameles nasuta (12.5%), and Thylogale stigmatica (12.5%). The most important families were Muridae (37.1%), Peramelidae (29.5%), and Macropodidae (25.8%). Examination of small‐scale habitat preferences revealed species that preferentially use the forest edge ranked significantly higher in the diet than those that do not, and species that are terrestrial ranked higher in the diet than those that are arboreal. Relative abundance was also a significant factor in the ranked dietary occurrence of each species, with abundant species ranked significantly higher than those that are less abundant. These results suggest that dingoes in the Australian Wet Tropics are opportunistic predators of a wide variety of mammal species, with abundant terrestrial and forest edge‐dwelling taxa the most susceptible to predation.
Home Range Size of Sympatric Squirrel Species Inhabiting a Lowland Dipterocarp Forest in Malaysia1
Authors: Saiful A. A. , Idris A. H. , Rashid Y. N. , Tamura N. , Hayashi F. 
Published: March 2006

ABSTRACTHome range sizes and spatial overlap of four sympatric squirrel species were investigated in a lowland dipterocarp forest in Malaysia using a radio‐tracking method. The population density of Callosciurus caniceps was highest and C. notatus was next highest, while C. nigrovittatus and Lariscus insignis were scarce. C. caniceps was larger than C. nigrovittatus and C. notatus while L. insignis was extremely small. For females, home range size was smaller in L. insignis than Callosciurus spp., which may support the body weight hypothesis: larger species have larger home ranges. Among the three Callosciurus species, female C. caniceps had the smallest home range. These differences were accounted for by habitat characteristics rather than by density or body weight; C. caniceps was dominant in bushy areas and used crowded small trees while C. notatus and C. nigrovittatus used large trees in the forest. In this study, home range size did not change seasonally; this differs from studies in temperate regions, possibly because food availability is much less variable among seasons in tropical rain forest. Home range overlap among heterospecific individuals was common but different species seemed to partition space by using different vertical levels of the forest. Consequently, the home range size and spatial overlap of sympatric squirrel species may be affected by habitat diversity in tropical rain forest.
Communities of Endophytic Fungi in Leaves of a Tropical Timber Tree (Guarea guidonia: Meliaceae)1
Authors: Gamboa Miguel A. , Bayman Paul 
Published: March 2006

ABSTRACTEndophytes are microorganisms that live inside plant tissues without causing symptoms of disease. They are a largely unexplored component of biodiversity, especially in the tropics. In this study, leaves from two populations of Guarea guidonia trees (Meliaceae) in the Luquillo region, Puerto Rico, were screened for diversity and composition of en‐dophytic fungal communities. A total of 268 leaf fragments from 14 trees were surveyed. Thirty‐eight morphospecies of endophytes were found. Phomopsis, Colletotrichum, Xylaria, and Rhizoctonia‐iike fungi were the most abundant taxa. Over 95 percent of the leaf pieces had endophytes. Communities had a few abundant species and many species with few individuals. The fungal community from the Guarea population in a forest preserve was more diverse than that from a disturbed area. Fungal communities were stratified according to height within a tree, but no differences were found between blade, petiolule, and rachis. The data suggest that the smaller and the more scattered the plant fragments sampled, the higher the probability of approaching real diversity values of endophytic fungal communities.RESUMESLos endófitos son microorganismos que viven dentro de las tejidos vegetales sin manifestarse patológicamente. Ellos constituyen un componente poco explorado de la biodiversidad, especialmente en las zonas tropicales. En este trabajo se estudió la diversidad y composición de las comunidades de hongos endófitos en hojas de dos poblaciones del árbol Guarea guidonia (Meliaceae), en la región de Luquillo, Puerto Rico. Un total de 268 fragmentos provenientes de 14 árboles fueron muestreados, encontrándose 38 morfoespecies de hongos endófitos. Los taxones más abundantes fueron Phomopsis, Colletotrichum, Xylaria, y Rhizoctonia. Más del 95 por ciento de los fragmentos presentó endófitos; las comunidades tenían pocas especies abundantes y muchas especies raras. De las dos poblaciones de G. guidonia estudiadas, la situada en una zona más conservada fue más diversa en cuanto a su comunidad de endófitos. Se observó estratificación de acuerdo con la altura del árbol, pero no se observaron diferencias entre la lámina, el peció1ulo, y el raquis de las hojas. Los datos sugieren que entre más pequeños y esparcidos scan los fragmentos muestreados, mayor será la probabilidad de aproximarse a los valores reales de diversidad de las comunidades de hongos endófitos.
Seed Size, Seed Germination, and Seedling Survival of Brazilian Tropical Tree Species Differing in Successional Status1
Authors: de Souza Rogéria Pereira , Válio I. F. M. 
Published: March 2006

ABSTRACTSeed germination and seedling establishment patterns have been used to classify species as shade tolerant or intolerant. The main objective of this research was to investigate, under controlled conditions, seed germination of species from different successional positions as well as to follow seed germination and seedling survival under natural shade in the field. The species studied were Solarium granuloso‐leprosum, Trema micrantha, Cecropia pachystachya, Croton piptocalyx, Bauhinia forficata subsp. pruinosa. Senna macranthera, Schizolobium parahyba, Piptadenia gonoacantha, Chorisia speciosa, Pseudobombax grandiflorum, Ficus guaranitica, Esenbeckia leiocarpa, Pachystroma longifolium, Myroxylon peruiferum, and Hymenaea courbaril. Field trials were carried out at Santa Genebra Municipal Reserve, Campinas, SP, Brazil, at the forest edge and in the understory. No significant correlations were detected between successional status and seed size or seed water content. Light‐regulated germination was present only in small‐seeded species. In field experiments, most species, including the light‐sensitive ones, were able to germinate under the canopy, where a low red/far‐red ratio predominates. Most species, mainly those of early‐ and intermediate successional positions, presented low seedling survival rates under shade. Myroxylon peruiferum was the most shade tolerant species, while 5. granuloso‐leprosum, C. speciosa, P. gonoacantha, F. guaranitica, T. micrantha, and 5. parahyba were the most shade intolerant. These latter species showed little or no survival under the shade conditions.
The Fate of Attalea phalerata (Palmae) Seeds Dispersed to a Tapir Latrine1
Authors: Quiroga‐Castro Verónica D. , Roldán Alexandra I. 
Published: March 2006

ABSTRACTAt the Beni Biological Station, Bolivia, we compared the fate of seeds of the palm Attalea phalerata dispersed by tapirs to a latrine with that of non‐dispersed seeds. Survival of seeds that had passed through tapir guts did not differ significantly from that of unconsumed seeds, demonstrating that tapirs are legitimate seed dispersers of A. phalerata. Experimental and observational studies showed that tapir dispersal can contribute to escape from seed predation by bruchid beetles such as Pachymerus cardo. Nevertheless, the major contribution of the dispersal process may simply be the mechanical barrier to bruchid attack represented by the fecal material covering seeds. Furthermore, total absence of seedlings and adults from the tapir latrine studied suggests that seasonally flooded tapir latrines are not safe sites for A. phalerata.RESUMESEn la Estación Biologica del Beni, Bolivia, comparamos el destino de las semillas de la palmera Attalea phalerata dispersadas por tapires a su letrina con aquel de las semillas no dispersadas. La sobrevivencia de las semillas que pasaron por el tracto digestive de tapires no difirió significativamente de aquellas no consumidas, mostrando que los tapires son legítimos dispersores de semillas de A. phalerata. Estudios experimentales y observacionales mostraron que la dispersión de semillas por tapir puede ayudar al escape de los depredadores de semillas como el bruquido Pachymerus cardo. Sin embargo, la principal contribución del proceso de dispersión puede ser simplemente la barrera mecánica al ataque por brúquidos representada por la materia fecal que cubre a las semillas. Ademas, la ausencia total de plántulas y adultos en la letrina estudiada sugiere que las letrinas de tapir que se inunden estacionalmente no son sitios seguros para la germinación y sobrevivencia de A. phalerata.
Geographic Variation in Host Location Cues for a Dipteran Parasitoid of Paraponera clavata1
Authors: Morehead Shellee A. 
Published: March 2006

ABSTRACTParasitoid insects face considerable trade‐offs in locating suitable hosts within complex environments. Apocephalus paraponerae (Diptera: Phoridae) locates its host ant Paraponera clavata (Formicidae: Ponerinae) using olfactory cues. Here, comparing two populations of A. paraponerae, I describe differences in host location cues between two sites, Barro Colorado Island (BCI) in Panama and La Selva Biological Research Station in Costa Rica. At La Selva, A. paraponerae uses the ant mandibular gland products 4‐methyl‐3‐heptanone and 4‐ methyl‐3‐heptanol in host location, but does not do so on BCI. I propose that higher colony density of P. clavata causes A. paraponerae to use more species‐specific cues on BCI. I also discuss how geographic variation in host location cues could lead to allopatric speciation.RESUMESLos insectos parasitoides enfrentan muchas dificultades cuando buscan hospederos en ambientes complejos. Apocephalus paraponerae (Diptera: Phoridae) localiza a su hormiga hospedera, Paraponera clavata (Formicinae: Ponerinae), a travéz de pistas olfativas. En este estudio describe las diferencias en los mecanismos de localizatión de hospederos en dos sitios, la Isla Barro Colorado en Panamá y La Estación de Investigacion Biológica La Selva en Costa Rica. En La Selva, A. paraponerae usa productos de la glándula mandibular (4‐metil‐3‐heptanona y 4‐metil‐3‐heptanoI) para localizar a su hospedero, pero no hace lo mismo en IBC. Considero que un mayor densidad poblacional de P. clavata hace que A. paraponerae tenga que usar pistas más específicas en IBC. Además, propongo la existencia de otros factores ecol#oAgicos y de comportamiento que pueden afectar los mecanismos de localizacion y discuto como la variación geográfica de las pistas olfativas afecta la evolución y especiacion de los linajes de parasitoides.