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Rain Forest (rain + forest)
Kinds of Rain Forest Terms modified by Rain Forest Selected AbstractsSpathaspora arborariae sp. nov., a d -xylose-fermenting yeast species isolated from rotting wood in BrazilFEMS YEAST RESEARCH, Issue 8 2009Raquel M. Cadete Abstract Four strains of a new yeast species were isolated from rotting wood from two sites in an Atlantic Rain Forest and a Cerrado ecosystem in Brazil. The analysis of the sequences of the D1/D2 domains of the large-subunit rRNA gene showed that this species belongs to the Spathaspora clade. The new species ferments d -xylose efficiently and is related to Candida jeffriesii and Spathaspora passalidarum, both of which also ferment d -xylose. Similar to S. passalidarum, the new species produces unconjugated asci with a single greatly elongated ascospore with curved ends. The type strain of Spathaspora arborariae sp. nov. is UFMG-HM19.1AT (=CBS11463T=NRRL Y-48658T). [source] Is There a Political Ecology of the Sierra Leonean Landscape?AMERICAN ANTHROPOLOGIST, Issue 3 2001A. Endre Nyerges Corruption and State Politics in Sierra Leone. William Reno. Cambridge: Cambridge University Press, 1995. 229 pp. Fighting for the Rain Forest: War, Youth and Resources in Sierra Leone. Paul Richards. Portsmouth, NH: Heinemann, 1996. 182 pp. Myth and Reality in the Rain Forest: How Conservation Strategies Are Failing in West Africa. John F. Oates. Berkeley: University of California Press, 1999. 310 pp. [source] Pollination Biology of Distylous Rubiaceae in the Atlantic Rain Forest, SE BrazilPLANT BIOLOGY, Issue 5 2002C. C. de Castro Abstract: Data on pollination biology constitute important clues for the comprehension of pollen flow and genetic differentiation in plant populations. Pollinator type, availability and behaviour may modify morphological and mating patterns in populations of typically distylous species. This study investigates the pollination biology of four distylous species of Rubiaceae in the Atlantic rain forest, SE Brazil. Data on flowering phenology, floral lifespan, stigmatic receptivity, pollen availability, nectar volume and concentration, and pollinator activity were collected. The species studied flower sequentially throughout the wet season, and produce terminal inflorescences which bear small, tubular, diurnal, nectariferous flowers. Despite these similarities, some of the species studied are pollinated by different groups of pollinators, probably due to their distribution, availability of flowers and corolla length. On the other hand, pollinator specificity does not seem to be so important for distylous species. Long mouthparts, like those of most of the recorded pollinators, may reach lower sexual organs and, together with the self- and intramorph-incompatibilities observed, be sufficient to perform legitimate pollination and maintain levels of intermorph mating. [source] Factors Affecting the Distribution and Abundance of Asplenium nidus L. in a Tropical Lowland Rain Forest in Peninsular MalaysiaBIOTROPICA, Issue 4 2010Liwen Zhang ABSTRACT Asplenium nidus is an abundant epiphytic fern of tropical rain forests in the Old World, where it plays an important ecological role in the forest canopy as host to diverse arthropod communities. We investigated the factors that determine the distribution and abundance of A. nidus in the canopy of an aseasonal lowland dipterocarp forest at Pasoh Forest Reserve, Malaysia. We found that A. nidus was more abundant in the understory, and on hosts with smooth bark and relatively flat branch angles. Ferns were found on a wide diversity and size range of host taxa. However, both host taxa and host diameter at breast height had a significant effect on A. nidus occupancy. Asplenium nidus had an aggregated spatial distribution at all scales within the study area. Spatial aggregation at larger scales appears to be driven by habitat preference, as A. nidus abundance was positively associated with swampy areas and negatively associated with hilly areas. At smaller scales, limited dispersal of their wind-dispersed spores most likely explains the aggregated distribution. Larger individuals occurred higher in the canopy and were more common in the hilly area. Thus, the distribution of A. nidus may represent a trade-off between the availability of suitable microsites for establishment in the understory and better growth conditions higher in the canopy. However, A. nidus is known to comprise a complex of cryptic species, and future studies should incorporate molecular techniques to elucidate the potential role of speciation in explaining these patterns. Abstract in Malaysian is available at http://www.blackwell-synergy.com/loi/btp [source] Contrasting Population Dynamics of the Endemic New Caledonian Conifer Araucaria laubenfelsii in Maquis and Rain ForestBIOTROPICA, Issue 4 2010Lesley S. Rigg ABSTRACT This study compares demographic parameters and population dynamics for high disturbance (maquis) and low disturbance (rain forest) environments of the montane conifer, Araucaria laubenfelsii, in New Caledonia. The establishment, growth, survival and reproduction of ca 2500 individuals were followed in permanent plots over 10 yr. Growth and survival rates for A. laubenfelsii show that it is a long-lived, slow growing tree, with evidence of suppression in the sapling size classes in mature rain forest. Growth rates for all size classes are generally faster in maquis than rain forest. Transition matrix analyses estimated positive rates of population increase (, values>1), with populations expanding in maquis, and stable in mature forest. Araucaria laubenfelsii is able to regenerate continuously in maquis and early successional rain forest, but recruitment is limited in older stands. Life table response experiment analyses showed that reproduction, and transitions from sapling to mature tree stage, contributed positively to , in maquis, but negatively in forest. Araucaria laubenfelsii on Mont Do can be considered a long-lived pioneer, with early maquis colonizers helping to drive succession from maquis to forest. While opportunities for recruitment decline with time as rain forest sites develop a closed canopy, occasional gap phase recruitment, combined with disturbance by cyclones, landslides and fire, provide opportunities to ensure species persistence. Understanding contrasting population dynamics of A. laubenfelsii in maquis and rain forest will better facilitate conservation management of this species, particularly given current high rates of land conversion and degradation in New Caledonia. Abstract in French is available at http://www.blackwell-synergy.com/loi/btp [source] Species-Specific Growth Responses to Climate Variations in Understory Trees of a Central African Rain ForestBIOTROPICA, Issue 4 2010Camille Couralet ABSTRACT Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the understory, however, tree growth is supposed to be mainly affected by interference for access to light and other resources. In the semi-deciduous Mayombe forest of the Democratic Republic of Congo, the evergreen species Aidia ochroleuca, Corynanthe paniculata and Xylopia wilwerthii dominate the understory. We studied their wood to determine whether they form annual growth rings in response to changing climate conditions. Distinct growth rings were proved to be annual and triggered by a common external factor for the three species. Species-specific site chronologies were thus constructed from the cross-dated individual growth-ring series. Correlation analysis with climatic variables revealed that annual radial stem growth is positively related to precipitation during the rainy season but at different months. The growth was found to associate with precipitation during the early rainy season for Aidia but at the end of the rainy season for Corynanthe and Xylopia. Our results suggest that a dendrochronological approach allows the understanding of climate,growth relationships in tropical forests, not only for canopy trees but also for evergreen understory species and thus arguably for the whole tree community. Global climate change influences climatic seasonality in tropical forest areas, which is likely to result in differential responses across species with a possible effect on forest composition over time. Abstract in French is available at http://www.blackwell-synergy.com/loi/btp [source] Tree Diversity, Forest Structure and Productivity along Altitudinal and Topographical Gradients in a Species-Rich Ecuadorian Montane Rain ForestBIOTROPICA, Issue 2 2010Jürgen Homeier ABSTRACT We studied the spatial heterogeneity of tree diversity, and of forest structure and productivity in a highly diverse tropical mountain area in southern Ecuador with the aim of understanding the causes of the large variation in these parameters. Two major environmental gradients, elevation and topography, representing a broad range of climatic and edaphic site conditions, were analyzed. We found the highest species richness of trees in valleys <2100 m. Valleys showed highest values of basal area, leaf area index and tree basal area increment as well. Tree diversity also increased from ridges to valleys, while canopy openness decreased. Significant relationships existed between tree diversity and soil parameters (pH, total contents of Mg, K, Ca, N and P), and between diversity and the spatial variability of pH and Ca and Mg contents suggesting a dependence of tree diversity on both absolute levels and on the small-scale heterogeneity of soil nutrient availability. Tree diversity and basal area increment were positively correlated, partly because both are similarly affected by soil conditions. We conclude that the extraordinarily high tree species richness in the area is primarily caused by three factors: (1) the existence of steep altitudinal and topographic gradients in a rather limited area creating a small-scale mosaic of edaphically different habitats; (2) the intermingling of Amazonian lowland plant species, that reach their upper distribution limits, and of montane forest species; and (3) the geographical position of the study area between the humid eastern Andean slope and the dry interandean forests of South Ecuador. [source] Effects of Logging on the Diversity of Lianas in a Lowland Tropical Rain Forest in Hainan Island, South ChinaBIOTROPICA, Issue 5 2009Yi Ding ABSTRACT Lianas are an integral part of tropical forest ecosystems, which usually respond strongly to severe disturbances, such as logging. To compare the effect of different logging systems on the lianas diversity in tropical rain forest, we recorded all lianas and trees ,1 cm dbh in two 40-year-old forest sites after clear cutting (CC) and selective cutting (SC) as well as in an old-growth (OG) lowland tropical rain forest on Hainan Island in south China. Results showed that OG contained fewer liana stems and lower species richness (stems: 261, richness: 42 in 1 ha) than CC (606, 52) and SC (727, 50). However, OG had the highest Fisher's , diversity index (17.3) and species richness per stem (0.184). Species composition and dbh class distribution of lianas varied significantly with different logging systems. The mean liana dbh in OG (22.1 cm) were higher than those in CC (7.0 cm) and SC (10.4 cm). Stem twining was the most frequent climbing mechanism represented in the forest, as shown by the greatest species richness, abundance, basal area, and host tree number with this mechanism. The percent of host tree stems ,4 cm dbh hosting at least one liana individual in SC (39%) was higher than CC (23%) and OG (19.5%). Large host trees (dbh,60 cm) were more likely to be infested by lianas in SC and OG. Our study demonstrated that logging disturbance could significantly change the composition and structure of liana communities in the lowland tropical rain forest of south China. [source] Fine Root Distribution in a Lower Montane Rain Forest of PanamaBIOTROPICA, Issue 3 2009Dirk Hölscher ABSTRACT In a Panamanian lower montane rain forest we: (1) analyzed the vertical and horizontal distribution of fine roots; and (2) assessed the relationship of fine root mass to thickness of the soil organic layer, soil pH, and soil-extractable nitrogen. The soil in the study area has developed on volcanic ash deposits and was classified as Hapludand. In randomly distributed samples, the median fine root mass (biomass and necromass, diam , 2 mm) to a depth of 100 cm mineral soil was 544 g/m2, 41 percent of which was found in the organic layer. Fine root mass was approximately twice as high in the vicinity of stems of the tree species Oreomunnea mexicana (1069 g/m2) and the palm species Colpothrinax aphanopetala (1169 g/m2) and was associated with thick organic layers. The median thickness of the soil organic layer in a larger random sample (N= 64) was 8 cm with a considerable variation (interquartile range: 7 cm). In these samples, the density of fine root biomass was correlated with the concentration of extractable nitrogen (r= 0.33, P= 0.011), and on an areal basis, fine root biomass in the organic layer increased with increasing thickness of the organic layer (r= 0.63, P < 0.001) and decreasing pHKCl (r=,0.33, P < 0.01). Fine root biomass in the upper mineral soil did not show significant correlations with any of the studied parameters. RESUMEN En un bosque panameño bajo montano tropical (1) analizamos la distribución horizontal y vertical de las raíces finas, y (2) evaluamos la relación de la masa de las raíces finas con el espesor de la capa de suelo orgánico, pH del suelo, y nitrógeno extraíble del suelo. El suelo del área de estudio se ha desarrollado en depósitos de ceniza volcánica y fue clasificado como Hapludand. En muestras distribuidas aleatoriamente, la media de la masa de raíces finas (biomasa y masa necrosada, diámetro , 2 mm) a una profundidad de 100 cm del suelo mineral fue 544 g/m2, 41 por ciento de las cuales fueron encontradas en suelo orgánico. La masa de raíces finas fue aproximadamente el doble en la vecindad entre los pies de especies de árboles Oreomunnea mexicana (1069 g/m2) y especies de palmera Colpothrinax aphanopetala (1169 g/m2) y fue asociada con el espesor de capa orgánica. El espesor mediano de la capa de suelo orgánico en una amplia muestra aleatoria (N= 64) fue 8 cm con una considerable variación (intervalo entre cuartilas: 7 cm). En estas muestras, la densidad de raíces finas fue correlacionada con la concentración de nitrógeno extraíble (r= 0.33, P= 0.011), y en base al área, la biomasa de raíces finas en la capa orgánica aumentó con el incremento del espesor de la capa orgánica (r= 0.63, P < 0.001) y decrecimiento del pHKCl (r=,0.33, P < 0.01). La biomasa de raíces finas en el suelo mineral superior no mostró ninguna significante correlación con los parámetros estudiados. [source] Seasonality of a Diverse Beetle Assemblage Inhabiting Lowland Tropical Rain Forest in AustraliaBIOTROPICA, Issue 3 2009Peter S. Grimbacher ABSTRACT One of the least understood aspects of insect diversity in tropical rain forests is the temporal structuring, or seasonality, of communities. We collected 29,986 beetles of 1473 species over a 4-yr period (45 monthly samples), with the aim to document the temporal dynamics of a trophically diverse beetle assemblage from lowland tropical rain forest at Cape Tribulation, Australia. Malaise and flight interception traps were used to sample adult beetles at five locations at both ground and canopy levels. Beetles were caught throughout the year, but individual species were patchy in their temporal distribution, with the 124 more abundant species on average being present only 56 percent of the time. Climatic variables (precipitation, temperature, and solar radiation) were poorly correlated with adult beetle abundance, possibly because: (1) seasonality of total beetle abundance was slight; (2) the peak activity period (September,November) did not correspond to any climatic maxima or minima; or (3) responses were nonlinear owing to the existence of thresholds or developmental time-lags. Our results do not concur with the majority of tropical insect seasonality studies suggesting a wet season peak of insect activity, perhaps because there is no uniform pattern of insect seasonally for the humid tropics. Herbivores showed low seasonality and individual species' peaks were less temporally aggregated compared to nonherbivores. Canopy-caught and larger beetles (> 5 mm) showed greater seasonality and peaked later in the year compared to smaller or ground-caught beetles. Thus seasonality of adult beetles varied according to the traits of feeding ecology, body size, and habitat strata. [source] Regional Fragmentation of Rain Forest in West Africa and Its Effect on Local Dung Beetle Assemblage StructureBIOTROPICA, Issue 2 2009Adrian L. V. Davis ABSTRACT Data from Ghana and Côte d'Ivoire, for local dung beetle assemblages of rain forest, plantations, and savanna, suggest that a subset of the savanna fauna has expanded its range across the Eastern Guinean Forest ecoregion, presumably in response to its conversion from continuous rain forest into an archipelago of forest fragments within a disturbance matrix of less shady plantation and farmland vegetation that more resembles moist savanna. [source] Resource Partitioning in Sympatric Cynopterus bats in Lowland Tropical Rain Forest, ThailandBIOTROPICA, Issue 2 2007Sara Bumrungsri ABSTRACT Diet and habitat use of the closely related and size-overlapping sympatric Cynopterus brachyotis and C. sphinx were established in lowland dry evergreen forest, Thailand, between March 1998 and March 2000. Feces from netted bats were analyzed, and the recapture rate determined. Although both species share a set of food plants, and fruits from early successional forest contribute about half of their diet, C. brachyotis, the smaller of the two species, ate a significantly greater proportion of fruits from early successional forest than C. sphinx. The latter ate a significantly greater proportion of fruit species in larger size classes. More C. brachyotis were captured in early successional forest in almost every month, while C. sphinx is more common in old-growth forest. However, the capture rate of C. sphinx increased in early successional forest in the mid-dry season when its preferred fruits become available. The recapture rate of C. brachyotis in early successional forest was significantly higher than that of C. sphinx, and the reverse situation was observed in old-growth forest. Male C. sphinx had a significantly higher recapture rate in early successional forest than females. Fruit size and habitat use are the major determinants of resource partitioning between these size-overlapping congeners. [source] Nitrogen Fixation in Bryophytes, Lichens, and Decaying Wood along a Soil-age Gradient in Hawaiian Montane Rain ForestBIOTROPICA, Issue 1 2003Virginia Matzek ABSTRACT We determined rates of acetylene reduction and estimated total nitrogen fixation associated with bryophytes, lichens, and decaying wood in Hawaiian montane rain forest sites with underlying substrate ranging in age from 300 to 4.1 million years. Potential N fixation ranged from ca 0.2 kg/ha annually in the 300-year-old site to ca 1 kg/ha annually in the 150,000-year-old site. Rates of acetylene reduction were surprisingly uniform along the soil-age gradient, except for high rates in symbiotic/associative fixers at the 150,000-year-old site and in heterotrophic fixers at the 2100-year-old site. Low fixation at the youngest site, where plant production is known to be N-limited, suggests that demand for N alone does not govern N fixation. Total N fixation was highest in sites with low N:P ratios in leaves and stem wood, perhaps because epiphytic bryophytes and lichens depend on canopy leachate for mineral nutrients and because heterotrophic fixation is partly controlled by nutrient supply in the decomposing substrate; however, differences in substrate cover, rather than in fixation rates, had the largest effect on the total N input from fixation at these sites. [source] The Role of Cloud Combing and Shading by Isolated Trees in the Succession from Maquis to Rain Forest in New Caledonia1BIOTROPICA, Issue 2 2002L. S. Rigg ABSTRACT This study examined the role of shading and cloud combing of moisture by scattered trees of the emergent conifer Araucaria laubenfelsii (Corbass.) in montane shrubland-maquis at Mont Do, New Caledonia, in facilitating the succession from shrubland to rain forest. Water collection experiments showed that these trees combed significant amounts of water from low clouds on days when no rainfall was recorded and deposited this moisture on the ground beneath the tree canopy. Analysis of photosystem II function in A. laubenfelsii and five other plant species using fluorometry revealed much lower photosystem stress in plants beneath scattered A. laubenfelsii than for individuals exposed to full sunlight in the open maquis. Transition matrix analyses of vegetation change based on "the most likely recruit to succeed" indicated that the transition from maquis to forest was markedly faster when emergent trees of A. laubenfelsii acted as nuclei for forest species invasion of die maquis. On the basis of these lines of evidence, it is argued that increased moisture and shading supplied to the area directly below the crown of isolated A. laubenfelsii trees in the maquis facilitates the establishment of both conifer seedlings and other rain forest tree and shrub species. In the absence of fire, rain forest can reestablish through spread in two ways: first, by expansion from remnant patches, and second, from coalescence of small rain forest patches formed around individual trees of A. laubenfelsii. [source] Jaguar (Panthera onca) Food Habits in Atlantic Rain Forest of Southeastern Brazil,BIOTROPICA, Issue 4 2001Ricardo C. Garla ABSTRACT Between January and December 1996, the food habits of a relict population of jaguars were studied in 220 km2 Linhares Forest Preserve, which comprises much of the remaining old-growth Atlantic Forest of Espirito Santo, Brazil. Fecal analysis indicated opportunistic feeding on 24 prey species (N= 101 scats). Mammals represented 87 percent of the total items, followed by reptiles (9.8%) and birds (2.8%). Considering prey weight, 23.4 percent of the items weighed 1,3 kg, 40.5 percent were 3,10 kg, and 27.7 percent weighed more than 10 kg. Analysis of relative prey frequency and biomass indicated that the diet was concentrated in two prey types: long-nosed armadillo and white-lipped peccary. Literature data suggest that forest jaguars rely on the same mammal prey over their entire geographic range. RESUMES Entre janeiro e dezembro de 1996, os hábiros alimentares de uma populaçáo da onga pinrada foram estudados na Reserva Florestal de Linhares (220 km2), que cornpreende 25 porcento da floresra Atlintica primlria remanescente do Esrado do Espirito Santo, Brasil. A andise de fezes indicou o consumo de 24 esptcies de presas (N = 101 arnosrras). Mamiferos representaram 87 porcento do total de itens, seguidos por rtpteis (9.8%) e aves (2.8%). Considerando o peso das presas 23.4 porcento dos itens pesavam entre 1 e 3 kg, 40.5 porcenro de 3 a 10 kg, e 27.7 porcento acima de 10 kg. De acordo com a análise de freqütncia relariva de ocorrsncia e a estimariva de biomassa relativa, a dieta concentra-se em dois itens: o tatu galinha e queixada. A onga pintada parece basear sua dieta nas mesmas esptcies de mamiferos ao longo de sua distribuig8o geogrlfica. [source] Nutrient Content and Substrate Effect on Fine Root Density and Size Distribution in a Nicaraguan Rain Forest,BIOTROPICA, Issue 4 2001Brent C. Blair First page of article [source] Spatial Distribution of Vascular Epiphytes (including Hemiepiphytes) in a Lowland Amazonian Rain Forest (Surumoni Crane Plot) of Southern Venezuela,BIOTROPICA, Issue 3 2000Jürgen Nieder ABSTRACT The mobile crane of the Surumoni project allowed for the first time ever a complete inventory and spatial description of the epiphytic vegetation of a tropical lowland rain forest plot (1.5 ha), at La Esmeralda on the upper Orinoco River, Venezuela. A total of 778 individual vascular epiphytes of 53 species was found, dominated by 19 orchid species and 14 species of Araceae. Fifty percent of all individual plants were obligate ant-garden epiphytes. The distribution of epiphytes was highly clumped and not random. The clumped occurrence of holoepiphytes (complete life cycle on host tree) was the consequence of the rarity of suitable phorophytes (host trees; e.g., size and age) in the plot and the preference of ants for gaps where most of the ant-garden epiphytes were found. In comparison, hemiepiphytes were distributed more evenly because of greater independence from tree suitability. The dispersal modes of epiphytes did not explain their distribution patterns. There was no consistent difference in distribution between anemochorous and zoochorous epiphytes, presumably because availability of suitable substrate is the more important factor for epiphyte establishment and growth. Whereas the vertical distribution of epiphytes could be attributed largely to deterministic factors such as physiological adaptation and requirements, horizontal distribution appeared to be governed by suitable substrate, which in turn seemed to be governed by stochastic gap formation. RESUMEN En el context0 del proyecto Surumoni se hizo un inventario y un analisis espacial de la vegetación epifitica de un plot de 1.5 ha en el alto rio Orinoco cerca de La Esmeralda (Venezuela) en 1997. Consiste de 778 plantas individuales de 53 especies, entre las cuales destacan las orquideas (19 especies) y las aráceas (14 especies). El 50 porciento de todas las epifitas se encuentran en los jardines epifiticas de hormigas. Las plantas epifiticas muestran una distribución aglomerada y no casual. En el caso de las holoepifitas esto es la consecuencia de la raridad de forófitas aduecadas (p.e., altura y edad) en el plot y la preferencia de claros ("gaps") por parte de las hormigas. En comparación, tienen una distribución más homogénea las hemi-epifitas porque se desarrollan más independientemente de la calidad de sus forofitas. Las estrategias de dispersión de las epifitas sólo en parte explica sus patrones de distribución. No hay diferencias consistentes entre especies anemocorias y zoocorias, probablemente porque la disponibilidad de sustrato adecuado es el factor más importante para el establecimiento y desarrollo de epifitas. La distribución vertical de las epifitas se caracteriza por una zonación marcada, visible en las diferencias significantes entre la rnayoria de las taxas epifiticas. Mientras que se puede atribuir la distribución vertical a factores deterministicos como adaptaciones y exigencias fisiológicos de las plantas epifiticas, su distribución horizontal se arregla según la presencia de sustrato adecuado, que por su parte es resultado de factores estoquáticos en la formación de claros. [source] The Flight Heights of Chalcid Wasps (Hymenoptera, Chalcidoidea) in a Lowland Bornean Rain Forest: Fig Wasps are the High Fliers,BIOTROPICA, Issue 3 2000Stephen G. Compton ABSTRACT Tropical rain forests are characterized by their rich plant diversity and highly diverse insect faunas containing mainly rare species. Phytophagous and parasitoid insects utilizing such fragmented resources often must travel considerable distances to find suitable hosts. For small, weak-flying insects, entry into the fast-flowing air above the canopy can provide one way by which long-distance dispersal is achieved. Using sticky traps placed at different heights in a lowland rain forest of Borneo, we compared the diurnal and nocturnal flight heights of chalcids, a group of mainly very small parasitoids and phytophages, to determine if the air above the canopy was used for dispersal. Most families were represented throughout the range of trap heights, including those above the general canopy. A higher proportion of individuals were trapped above the canopy at night than during the day. Fig wasps were exceptional in that they were trapped almost entirely above the canopy. They included species associated with host trees that do not fruit in the canopy, suggesting that these short-lived, slow-flying insects actively fly up above the canopy and then use the wind to passively carry them the long distances needed to reach their highly localized and ephemeral hosts. Once the fig wasps detect the species-specific volatiles released by their host figs, they then may fly down into the canopy, where the lower wind speeds would allow them to fly actively upwind to their hosts. [source] Tropical Rain Forests: an Ecological and Biogeographical ComparisonAUSTRAL ECOLOGY, Issue 6 2005RALF BUCKLEY No abstract is available for this article. [source] Soil Charcoal in Old-Growth Rain Forests from Sea Level to the Continental DivideBIOTROPICA, Issue 6 2007Beyhan Titiz ABSTRACT Soil charcoal is an indicator of Holocene fires as well as a palaeoecological signature of pre-Colombian land use in Neotropical rain forests. To document rain forest fire history, we examined soil charcoal patterns in continuous old-growth forests along an elevational transect from sea level to the continental divide on the Atlantic slope of Costa Rica. At 10 elevations we sampled 1-ha plots, using 16 cores/ha to collect 1.5-m deep soil samples. We found charcoal in soils at every elevation, with total dry mass ranging from 3.18 g/m2 at 2000-m elevation to as much as 102.7 g/m2 at 300 m. Soil charcoal is most abundant at the wettest lowland sites (60,500 m) and less at montane elevations (> 1000 m) where there is less rainfall. Between 30- and 90-cm soil depth, soil charcoal is present consistently and every 1-ha plot has charcoal evidence for multiple fire events. Radiocarbon dates range from 23,240 YBP at 1750-m elevation to 140 YBP at 2600 m. Interestingly, none of the charcoal samples from 2600 m are older than 170 yr, which suggests that forests near the continental divide are relatively young replacement stands that have re-established since the most recent localized volcanic eruption on Volcán Barva. We propose that these old-growth forests have been disturbed infrequently but multiple times as a consequence of anthropogenic and natural fires. RESUMEN El carbón es un indicador de los fuegos Holocenos así como una huella paleoecológica del uso de las tierras precolombinas en bosques neotropicales. Para documentar la historia de fuegos en los bosques, examinamos modelos de carbón en la tierra en bosques primarios continuos a lo largo de un transecto en altitud en zonas de vida forestal desde el nivel del mar hasta la División Continental en la vertiente atlántica de Costa Rica. En diez elevaciones tomamos muestras de parcelas de una hectárea, donde se usaron dieciséis cilíndricas de acero por hectárea para recoger muestras de suelo a 1.5 metros de profundidad. Descubrimos carbón en suelos en cada elevación, con un rango de masa seca total desde los 3.18 g/m2 a 2000 metros de altura hasta un máximo de 102.7 g/m2 a 300 metros de altura. El carbón abunda más en las zonas más lluviosas (60,500 metros) y menos en elevaciones montañosas (>1000 metros) donde hay menos precipitación. Entre los 30 a los 90 centímetros de profundidad en la tierra, el carbón está presente consistentemente y cada parcela de una hectárea tiene evidencia de carbón de incendios múltiples. Fechas de 14C van desde los 23,240 años a.P. a 1750 metros de elevación hasta los 140 años a.P. a 2600 metros. De modo interesante, ninguna de las muestras de carbón a partir de los 2600 metros de altura tiene más de 170 años, lo que sugiere que los bosques cerca de la División Continental son árboles relativamente jóvenes que se han reestablecido después de las erupciones volcánicas confinadas del Volcán Barva. Pensamos que estos bosques primarios han sido disturbados en muchas ocasiones pero en un largo periodo de tiempo como consecuencia de fuegos antropogénicos y naturales. [source] New Perspectives in Comparative Ecology of Neotropical Rain Forests: Reflections on the Past, Present, and FutureBIOTROPICA, Issue 1 2004Jennifer S. Powers ABSTRACT In an effort to understand variations in ecological patterns among lowland tropical rain forests, Alwyn Gentry and colleagues synthesized data sets from four of the premier Neotropical field stations,La Selva (Costa Rica), Barro Colorado Island (Panama), Cocha Cashu (Peru), and the Biological Dynamics of Forest Fragmentation Project (Brazil). To promote the kind of geographically comparative tropical ecology advocated in the 1990 Gentry book, the Organization for Tropical Studies and the Smithsonian Tropical Research Institute organized a course in 2001 that visited each of these field stations. Papers from some of the studies resulting from this course are highlighted in this special section. These studies are notable for the consistent methods applied across forests, and they underscore the acute need and bright future for comparative tropical ecology. Key site characteristics for each of the field stations are summarized here. RESUMEN En un esfuerzo de entender las variaciones en patrones ecológicos entre selvas tropicales de bajura, Alwyn Gentry y colegas sintetizaron bases de datos en las cuatro principales estaciones biológicos del Neotrópico: La Selva (Costa Rica), Barro Colorado Island (Panamá), Cocha Cashu (Perú), y el Proyecto de Dinámica Biológica de Fragmentación de Bosque (Brasil). Con el fin de promover el estudio ecologico tropical comparativa a nivel geográfico recomendada por Gentry en 1990 la Organización para Estudios Tropicales y el Smithsonian Tropical Research Institution organizaron un curso en el año 2001, el cual visitó cada una de éstas estaciones. Los artículos científicos de algunos de los estudios producto de este curso se presentan en esta sección especial. Estos estudios son notables debido a la consistencia en los metodología aplicada a través de los cuatro sitios. Asimismo, estos estudios denotan la necesidad y el potencial de Uevar a cabo mas investigación a nivel de ecología tropical comparativa. Caracteristicas importantes para cada una de las estaciones de campo son resumidos en esta sección. [source] Mammalian Diet and Broad Hunting Strategy of the Dingo (Canis familiaris dingo) in the Wet Tropical Rain Forests of Northeastern Australia,BIOTROPICA, Issue 2 2001Karl Vernes ABSTRACT The 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. [source] Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestryJOURNAL OF ANIMAL ECOLOGY, Issue 2 2006ALEXANDRA-MARIA KLEIN Summary 1Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0,1415 m), light intensity (37·5,899·6 W/m,2) and number of vascular plant species (7,40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3A total of 13 617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey. [source] Rain forest invasion of eucalypt-dominated woodland savanna, Iron Range, north-eastern Australia: II.JOURNAL OF BIOGEOGRAPHY, Issue 8 2004Rates of landscape change Abstract Aim, To explore rates of rain forest expansion and associated ecological correlates in Eucalyptus -dominated woodland savanna vegetation in north-eastern Australia, over the period 1943,91. Location, Iron Range National Park and environs, north-east Queensland, Australia. This remote region supports probably the largest extent of lowland (< 300 m) rain forest extant in Australia. Rainfall (c. 1700 mm p.a.) occurs mostly between November and June, with some rain typically occurring even in the driest months July,October. Methods, Interpretation of change in lowland rain forest vegetation cover was undertaken for a 140 km2 area comprising complex vegetation, geology and physiography using available air photos (1943, 1970 and 1991). A GIS database was assembled comprising rain forest extent for the three time periods, geology, elevation, slope, aspect, proximity to streams and roads. Using standard GIS procedures, a sample of 6996 10 × 10 m cells (0.5% of study area) was selected randomly and attributed for vegetation structure (rain forest and non-rain forest), and landscape features. Associations of rain forest expansion with landscape features were examined with logistic regression using the subset of cells that had changed from other vegetation types to rain forest, and remained rain forest over the assessment period, and comparing them with cells that showed no change from their original, non-rain forest condition. Results, Rain forest in the air photo study area increased from 45 km2 in 1943 to 78.1 km2 by 1970, and to 82.6 km2 by 1991. Rainfall (and atmospheric CO2 concentration) was markedly lower in the first assessment period (1943,70). Modelled rates of rain forest invasion differed predominantly with respect to substrate type, occurring faster on substrates possessing better moisture retention properties, and across all elevation classes. Greatest expansion, at least in the first assessment period, occurred on the most inherently infertile substrates. Expansion was little constrained by slope, aspect and proximity to streams and roads. On schist substrates, probability of invasion remained high (> 60%) over distances up to 1500 m from mature rain forest margins; on less favourable substrates (diorite, granites), probability of expansion was negligible at sites more than 400 m from mature margins. Main conclusions, (i) Rain forest expansion was associated primarily with release from burning pressure from c. the 1920s, following major disruption of customary Aboriginal lifestyles including hunting and burning practices. (ii) Decadal-scale expansion of rain forest at Iron Range supports extensive observations from the palaeoecological literature concerning rapid rain forest invasion under conducive environmental conditions. (iii) The generality of these substrate-mediated observations requires further testing, especially given that landscape-scale rain forest invasion of sclerophyll-dominated communities is reported from other regions of north-eastern Australia. [source] Litter Decomposition Within the Canopy and Forest Floor of Three Tree Species in a Tropical Lowland Rain forest, Costa RicaBIOTROPICA, Issue 3 2010Catherine L. Cardelús ABSTRACT The rain forest canopy hosts a large percentage of the world's plant biodiversity, which is maintained, in large part, by internal nutrient cycling. This is the first study to examine the effects of site (canopy, forest floor) and tree species (Dipteryx panamensis, Lecythis ampla, Hyeronima alchorneoides) on decay rates of a common substrate and in situ leaf litter in a tropical forest in Costa Rica. Decay rates were slower for both substrates within the canopy than on the forest floor. The slower rate of mass loss of the common substrate in the canopy was due to differences in microclimate between sites. Canopy litter decay rates were negatively correlated with litter lignin:P ratios, while forest floor decay rates were negatively correlated with lignin concentrations, indicating that the control of litter decay rates in the canopy is P availability while that of the forest floor is carbon quality. The slower cycling rates within the canopy are consistent with lower foliar nutrient concentrations of epiphytes compared with forest floor-rooted plants. Litter decay rates, but not common substrate decay rates, varied among tree species. The lack of variation in common substrate decay among tree species eliminated microclimatic variation as a possible cause for differences in litter decay and points to variation in litter quality, nutrient availability and decomposer community of tree species as the causal factors. The host tree contribution to canopy nutrient cycling via litter quality and inputs may influence the quality and quantity of canopy soil resources. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] Predicting global abundance of a threatened species from its occurrence: implications for conservation planningDIVERSITY AND DISTRIBUTIONS, Issue 1 2009Marcos S. L. Figueiredo Abstract Aim, Global abundance is an important characteristic of a species that is correlated with geographical distribution and body size. Despite its importance these estimates are not available since reliable field estimates are either expensive or difficult to obtain. Based on the relationship between a species' local abundance and distribution, some authors propose that abundance can be obtained through spatial distribution data from maps plotted at different scales. This has never been tested over the entire geographical range of a species. Thus, the aim of this study was to estimate global abundance of the Neotropical primate Brachyteles hypoxanthus (northern muriqui) and compare the results with available field estimates. Location, From southern Bahia to Minas Gerais and Espírito Santo states, in the Brazilian Atlantic rain forest. Methods, We compiled 25 recent occurrence localities of B. hypoxanthus and plotted them in grid cells of five different sizes (1, 25, 50, 75 and 100 km per side) to evaluate the performance and accuracy of abundance estimates over a wide range of scales. The abundance estimates were obtained by the negative binomial distribution (NBD) method and corrected by average group size to take into account primate social habits. To assess the accuracy of the method, the predicted abundances were then compared to recent independent field estimates. Results, The NBD estimates were quite accurate in predicting B. hypoxanthus global abundance, once the gregarious habits of this species are taken into account. The predicted abundance estimates were not statistically different from those obtained from field estimates. Main conclusions, The NBD method seems to be a quick and reliable approach to estimate species abundance once several limiting factors are taken into account, and can greatly impact conservation planning, but further applications in macroecological and ecological theory testing needs improvement of the method. [source] Nutrient storage and turnover in organic layers under tropical montane rain forest in EcuadorEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2002W. Wilcke Summary In tropical montane forests nutrients released from the organic layers of the soil can supply a large part of the vegetation's requirements. We have examined concentrations, storage, and turnover times of nutrients in the organic layer and the fluxes of nutrients by the fall of small litter (leaves, seeds, flowers, small twigs, and plant debris that passed an opening of 0.3 m × 0.3 m) in such a forest in Ecuador. The times taken for litter to turn over were estimated by relating nutrient storage in the organic layer to rate of litterfall and by incubating samples in the laboratory. The organic layer had a thickness of 2,43 cm, a mass of 30,713 t ha,1, and a nutrient storage of 0.87,21 t N, 0.03,0.70 t P, 0.12,2.5 t K, 0.09,3.2 t Ca, and 0.07,1.0 t Mg ha,1. The pH (in H2O) ranged between 3.1 and 7.4 and was correlated with the concentrations of Ca and Mg (r=,0.83 and 0.84, respectively). The quantity of small litter (8.5,9.7 t year,1) and mean concentrations of nutrients in litter (19,22 g N, 0.9,1.6 g P, 6.1,9.1 g K, 12,18 g Ca, and 3.5,5.8 g Mg kg,1) were larger than in many other tropical montane forests. The mean turnover times of elements in the organic layer increased in the order, Mg (7.0 years) < Ca (7.9) < K (8.5) < P (11) < N (14) < S (15) when calculated as the quotient of storage in the organic layer to flux by litterfall; they were <,12 years for N, P, and S in the incubation experiment. Under optimum conditions in the laboratory, the mineralization of S was just as large as the S deposition by litterfall. In weakly acid soils Mn and Zn and in strongly acid soils Ca added in a nutrient solution were immobilized during incubation. Thus, lack of S, Mn, Zn, and Ca might limit plant growth on some soils. [source] The effect of tree height and light availability on photosynthetic leaf traits of four neotropical species differing in shade toleranceFUNCTIONAL ECOLOGY, Issue 1 2000T. Rijkers Abstract 1.,Light-saturated rate of photosynthesis (Amax), nitrogen (N), chlorophyll (Chl) content and leaf mass per unit area (LMA) were measured in leaves of trees of different heights along a natural light gradient in a French Guiana rain forest. The following four species, arranged in order from most shade-tolerant to pioneer, were studied: Duguetia surinamensis, Vouacapoua americana, Dicorynia guianensis and Goupia glabra. Light availability of trees was estimated using hemispherical photography. 2.,The pioneer species Goupia had the lowest LMA and leaf N on both an area and mass basis, whereas Duguetia had the highest values. In general, leaf variables of Vouacapoua and Dicorynia tended to be intermediates. Because Amax/area was similar among species, Goupia showed both a much higher light-saturated photosynthetic nitrogen-use efficiency (PNUEmax) and Amax/mass. Leaves of Vouacapoua demonstrated the greatest plasticity in Amax/area, particularly in small saplings. 3.,A distinction could be made between the effect of tree height and light availability on the structural, i.e. LMA, and photosynthetic leaf characteristics of all four species. The direction and magnitude of the variation in variables were similar among species. 4.,LMA was the key variable that mainly determined variation in the other leaf variables along tree height and light availability gradients, with the exception of changes in chlorophyll concentration. Amax/area, N/area, LMA and stomatal conductance to water vapour (gs) increased, whereas Chl/mass decreased, with both increasing tree height and canopy openness. Amax/mass, PNUEmax and Amax/Chl increased with increasing openness only. N/mass and Chl/area were independent of tree height and openness, except for small saplings of Goupia which had a much lower Chl/area. [source] ORNITHOPHILIA: THOUGHTS ON GEOGRAPHY IN BIRDINGGEOGRAPHICAL REVIEW, Issue 2 2010MARK BONTA abstract. The deeper motives of bird-watchers have rarely been subjected to geographical inquiry. Birders are sometimes dismissed as hobbyists bent on compensating for feelings of inadequacy and lack of control in their personal lives. In this article, utilizing textual references as well as experiences from my own participant-observer status as geographer-cum-birder and bird-tour leader, I construct a geographically oriented approach to understanding the fascinations of bird-watching. I detail ethnographically the annual Christmas Bird Count and a bird walk in the Honduran rain forest. Then, drawing from the nest-as-home metaphors of Gaston Bachelard and the "becoming-bird" relationships suggested by Gilles Deleuze and Félix Guattari, I position birding as extraordinarily intimate exploration of place, reinforced by anticipation, repetition, experience of beauty, and the culminating encounter of human self, bird or bird spectacle, and landscape. [source] Two-step vegetation response to enhanced precipitation in Northeast Brazil during Heinrich event 1GLOBAL CHANGE BIOLOGY, Issue 6 2010LYDIE M. DUPONT Abstract High resolution palynological and geochemical data of sediment core GeoB 3910-2 (located offshore Northeast Brazil) spanning the period between 19 600 and 14 500 calibrated year bp (19.6,14.5 ka) show a land-cover change in the catchment area of local rivers in two steps related to changes in precipitation associated with Heinrich Event 1 (H1 stadial). At the end of the last glacial maximum, the landscape in semi-arid Northeast Brazil was dominated by a very dry type of caatinga vegetation, mainly composed of grasslands with some herbs and shrubs. After 18 ka, considerably more humid conditions are suggested by changes in the vegetation and by Corg and C/N data indicative of fluvial erosion. The caatinga became wetter and along lakes and rivers, sedges and gallery forest expanded. The most humid period was recorded between 16.5 and 15 ka, when humid gallery (and floodplain) forest and even small patches of mountainous Atlantic rain forest occurred together with dry forest, the latter being considered as a rather lush type of caatinga vegetation. During this humid phase erosion decreased as less lithogenic material and more organic terrestrial material were deposited on the continental slope of northern Brazil. After 15 ka arid conditions returned. During the humid second phase of the H1 stadial, a rich variety of landscapes existed in Northeast Brazil and during the drier periods small pockets of forest could probably survive in favorable spots, which would have increased the resilience of the forest to climate change. [source] | ||||||||||||||||||||||||||||||||||