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Firme Forest (firme + forest)
Kinds of Firme Forest Selected AbstractsDistance Decay of Tree Species Similarity in Protected Areas on Terra Firme Forests in Colombian AmazoniaBIOTROPICA, Issue 5 2009Álvaro Duque ABSTRACT In this study, we investigated the pattern of floristic similarity as a function of geographical distances and environmental variability in well-drained uplands (terra firme) in Colombian Amazonia. The study site comprised three National Natural Parks, Tinigua, Chiribiquete, and Amacayacu, located in different geological units that represent a soil fertility gradient linked to parental materials. Differences in species richness between sites were compared using rarefaction analysis. A clear floristic transition appeared in the east,west direction following a soil fertility gradient along the first PCoA axis. In multiple regression analyses based on distance matrices, both geographical distances and geology explained 64 percent of the total floristic variation. Geographical distances alone accounted for 12 percent of variation in floristic similarities among plots, while geology alone accounted for 1 percent, and the joint effect of both explained 51 percent of the floristic variation. The species richness trend supports the existence of a latitudinal corridor southward of the geographical Equator in the Amazon basin, where tree diversity reaches the maximum expected values. A coupled effect of stochastic dispersal limitation and habitat specialization would certainly appear to be an appropriate explanation for tree species turnover in terra firme forests in Colombian Amazonia, strongly emphasizing that competition and neutrality must be supplementary rather than mutually exclusive processes. This result pinpoints the effect of dispersal on floral mixing as an ongoing active process for structuring tree communities in NW Amazonia, and the size of the reserves as a relevant issue to protect rare species from extinction by chance. [source] Avian distribution in treefall gaps and understorey of terra firme forest in the lowland AmazonIBIS, Issue 1 2005JOSEPH M. WUNDERLE JR We compared the bird distributions in the understorey of treefall gaps and sites with intact canopy in Amazonian terra firme forest in Brazil. We compiled 2216 mist-net captures (116 species) in 32 gap and 32 forest sites over 22.3 months. Gap habitats differed from forest habitats in having higher capture rates, total captures, species richness and diversity. Seventeen species showed a significantly different distribution of captures between the two habitats (13 higher in gap and four higher in forest). Gap habitats had higher capture rates for nectarivores, frugivores and insectivores. Among insectivores, capture rates for solitary insectivores and army ant followers did not differ between the two habitats. In contrast, capture rates were higher in gaps for members of mixed-species insectivore flocks and mixed-species insectivore,frugivore flocks. Insectivores, especially members of mixed-species flocks, were the predominant species in gap habitats, where frugivores and nectarivores were relatively uncommon. Although few canopy species were captured in gap or forest habitats, visitors from forest mid-storey constituted 42% of the gap specialist species (0% forest) and 46% of rare gap species (38% forest). Insectivore, and total, captures increased over time, but did so more rapidly in gap than in forest habitats, possibly as a response to gap succession. However, an influx of birds displaced by nearby timber harvest also may have caused these increases. Avian gap-use in Amazonian terra firme forests differs from gap-use elsewhere, partly because of differences in forest characteristics such as stature and soil fertility, indicating that the avian response to gaps is context dependent. [source] Nutrient transport within and between habitats through seed dispersal processes by woolly monkeys in north-western AmazoniaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2010Pablo R. Stevenson Abstract The contribution of vertebrate animals to nutrient cycling has proven to be important in various ecosystems. However, the role of large bodied primates in nutrient transport in neotropical forests is not well documented. Here, we assess the role of a population of woolly monkeys (Lagothrix lagothricha lugens) as vectors of nutrient movement through seed dispersal. We estimated total seed biomass transported by the population within and between two habitats (terra firme and flooded forests) at Tinigua Park, Colombia, and quantified potassium (K), phosphorus (P) and nitrogen (N) content in seeds of 20 plant species from both forests. Overall, the population transported an estimated minimum of 11.5 (±1.2 SD),g of potassium, 13.2 (±0.7),g of phosphorus and 34.3 (±0.1),g nitrogen, within 22.4 (±2.0),kg of seeds ha,1,y,1. Approximately 84% of all nutrients were deposited in the terra firme forest mostly through recycling processes, and also through translocation from the flooded forest. This type of translocation represents an important and high-quality route of transport since abiotic mechanisms do not usually move nutrients upwards, and since chemical tests show that seeds from flooded forests have comparatively higher nutrient contents. The overall contribution to nutrient movement by the population of woolly monkeys is significant because of the large amount of biomass transported, and the high phosphorus content of seeds. As a result, the phosphorus input generated by these monkeys is of the same order of magnitude as other abiotic mechanisms of nutrient transport such as atmospheric deposition and some weathering processes. Our results suggest that via seed dispersal processes, woolly monkey populations can contribute to nutrient movement in tropical forests, and may act as important nutrient input vectors in terra firme forests. Am. J. Primatol. 72:992,1003, 2010. © 2010 Wiley-Liss, Inc. [source] Effects of surface fires on understorey insectivorous birds and terrestrial arthropods in central Brazilian AmazoniaANIMAL CONSERVATION, Issue 4 2003Torbjørn Haugaasen Understorey insectivorous birds are highly vulnerable to different forms of habitat disturbance in tropical forests. Here we examine the effects of an unprecedented surface fire on understorey insectivores and forest litter arthropods in a terra firme forest of central Brazilian Amazonia, and compare species and guild abundance both close to and far from the clearly distinguishable fireline separating burnt and unburnt forest. All six of the most abundant insectivorous foraging guilds examined were detrimentally affected by fire, with dead-leaf gleaners and professional ant-followers being the most heavily affected. While army ants were apparently absent from the burnt forest, results from pit-fall traps showed that wildfires had only a limited effect on the abundance of most leaf-litter invertebrates. The fireline appeared to be an abrupt barrier to many understorey insectivorous birds, and there was little evidence to suggest that primary forest species were recolonizing burnt forest up to 1 year after the fires. Factors affecting the capture frequency of insectivorous birds are discussed. [source] Do trails affect relative abundance estimates of rainforest frogs and lizards?AUSTRAL ECOLOGY, Issue 6 2009RUDOLF Von MAY Abstract The selection of a sampling protocol is critical to study amphibian and reptile communities and in many instances researchers have combined the use of visual encounter surveys (VES) conducted on trails and off trails. The effect of human-made trails on relative abundance estimates of amphibians and reptiles has been assessed in a few temperate locations, but data are lacking for tropical sites. Our study was designed to address this issue by comparing abundance estimates of frogs and lizards on and off trails in a lowland rainforest in south-eastern Perú. We used nocturnal VES to sample frogs and lizards along transects established on trails and off trails in two different forest types. We found that the observed relative abundance estimates of frogs and lizards were affected by the location of transects (on trail vs. off trail) and the type of forest (floodplain forest vs. terra firme forest). We also found an interaction between the two main effects, indicating that the effect of transect location with respect to trails varies as a function of habitat. Observed frog abundances were higher on trails than off trails, indicating that studies that include VES on trails will bias relative abundance estimates in contrast to studies that include only VES off trails. We suggest that transects should be established only off trails, especially for monitoring studies because trail use by humans can have a strong influence on observed animal abundance. [source] Impact of Flooding on the Species Richness, Density and Composition of Amazonian Litter-Nesting AntsBIOTROPICA, Issue 5 2009Amy L. Mertl ABSTRACT Litter-nesting ants are diverse and abundant in tropical forests, but the factors structuring their communities are poorly known. Here we present results of the first study to examine the impact of natural variation in flooding on a highly diverse (21 genera, 77 species) litter-nesting ant community in a primary Amazonian forest. Fifty-six 3 × 3 m plots experiencing strong variation in flooding and twenty-eight 3 × 3 m terra firme plots were exhaustively searched for litter-nesting ants to determine patterns of density, species richness and species composition. In each plot, flooding, litter depth, twig availability, canopy cover, plant density, percent soil nitrogen, carbon, and phosphorus were measured. Degree of flooding, measured as flood frequency and flood interval, had the strongest impact on ant density in flooded forest. Flooding caused a linear decrease in ant abundance, potentially due to a reduction of suitable nesting sites. However, its influence on species richness varied: low-disturbance habitat had species richness equal to terra firme forest after adjusting for differences in density. The composition of ant genera and species varied among flood categories; some groups known to contain specialist predators were particularly intolerant to flooding. Hypoponera STD10 appeared to be well-adapted to highly flooded habitat. Although flooding did not appear to increase species richness or abundance at the habitat scale, low-flooding habitat contained a mixture of species found in the significantly distinct ant communities of terra firme and highly flooded habitat. [source] Avian distribution in treefall gaps and understorey of terra firme forest in the lowland AmazonIBIS, Issue 1 2005JOSEPH M. WUNDERLE JR We compared the bird distributions in the understorey of treefall gaps and sites with intact canopy in Amazonian terra firme forest in Brazil. We compiled 2216 mist-net captures (116 species) in 32 gap and 32 forest sites over 22.3 months. Gap habitats differed from forest habitats in having higher capture rates, total captures, species richness and diversity. Seventeen species showed a significantly different distribution of captures between the two habitats (13 higher in gap and four higher in forest). Gap habitats had higher capture rates for nectarivores, frugivores and insectivores. Among insectivores, capture rates for solitary insectivores and army ant followers did not differ between the two habitats. In contrast, capture rates were higher in gaps for members of mixed-species insectivore flocks and mixed-species insectivore,frugivore flocks. Insectivores, especially members of mixed-species flocks, were the predominant species in gap habitats, where frugivores and nectarivores were relatively uncommon. Although few canopy species were captured in gap or forest habitats, visitors from forest mid-storey constituted 42% of the gap specialist species (0% forest) and 46% of rare gap species (38% forest). Insectivore, and total, captures increased over time, but did so more rapidly in gap than in forest habitats, possibly as a response to gap succession. However, an influx of birds displaced by nearby timber harvest also may have caused these increases. Avian gap-use in Amazonian terra firme forests differs from gap-use elsewhere, partly because of differences in forest characteristics such as stature and soil fertility, indicating that the avian response to gaps is context dependent. [source] Nutrient transport within and between habitats through seed dispersal processes by woolly monkeys in north-western AmazoniaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2010Pablo R. Stevenson Abstract The contribution of vertebrate animals to nutrient cycling has proven to be important in various ecosystems. However, the role of large bodied primates in nutrient transport in neotropical forests is not well documented. Here, we assess the role of a population of woolly monkeys (Lagothrix lagothricha lugens) as vectors of nutrient movement through seed dispersal. We estimated total seed biomass transported by the population within and between two habitats (terra firme and flooded forests) at Tinigua Park, Colombia, and quantified potassium (K), phosphorus (P) and nitrogen (N) content in seeds of 20 plant species from both forests. Overall, the population transported an estimated minimum of 11.5 (±1.2 SD),g of potassium, 13.2 (±0.7),g of phosphorus and 34.3 (±0.1),g nitrogen, within 22.4 (±2.0),kg of seeds ha,1,y,1. Approximately 84% of all nutrients were deposited in the terra firme forest mostly through recycling processes, and also through translocation from the flooded forest. This type of translocation represents an important and high-quality route of transport since abiotic mechanisms do not usually move nutrients upwards, and since chemical tests show that seeds from flooded forests have comparatively higher nutrient contents. The overall contribution to nutrient movement by the population of woolly monkeys is significant because of the large amount of biomass transported, and the high phosphorus content of seeds. As a result, the phosphorus input generated by these monkeys is of the same order of magnitude as other abiotic mechanisms of nutrient transport such as atmospheric deposition and some weathering processes. Our results suggest that via seed dispersal processes, woolly monkey populations can contribute to nutrient movement in tropical forests, and may act as important nutrient input vectors in terra firme forests. Am. J. Primatol. 72:992,1003, 2010. © 2010 Wiley-Liss, Inc. [source] Old growth and secondary forest site occupancy by nocturnal birds in a neotropical landscapeANIMAL CONSERVATION, Issue 1 2010M. Sberze Abstract High rates of old growth (OG) forest destruction and difficult farming conditions result in increasing cover of secondary forests (SF) in the Amazon. In this setting, it is opportune to ask which animals use newly available SF and which stay restricted to OG. This study presents a comparison of SF and OG site occupancy by nocturnal birds in terra firme forests of the Amazon Guianan shield, north of Manaus, Brazil. We tested species-specific occupancy predictions for two owls (Lophostrix cristata/Glaucidium hardyi), two potoos (Nyctibius leucopterus/Nyctibius griseus) and two nightjars (Caprimulgus nigrescens/Nyctidromus albicollis). For each pair, we predicted that one species would have higher occupancy in OG while the other would either be indifferent to forest type or favor SF sites. Data were collected in 30 OG and 24 SF sites with monthly samples from December 2007 to December 2008. Our analytic approach accounts for the possibility of detection failure and for spatial autocorrelation in occupancy, thus leading to strong inferences about changes in occupancy between forest types and between species. Nocturnal bird richness and community composition were indistinguishable between OG and SF sites. Owls were relatively indifferent to forest type. Potoos followed the a priori predictions, and one of the nightjars (C. nigrescens) favored SF instead of OG as predicted. Only one species, Nyctib. leucopterus, clearly favored OG. The landscape context of our SF study sites, surrounded by a vast expanse of continuous OG forest, partially explains the resemblance between SF and OG fauna but leaves unexplained the higher occupancy for SF than OG sites for several study species. The causal explanation of high SF occupancy remains an open question, but the result itself motivates further comparisons for other groups, as well as recognition of the conservation potential of SF. [source] Distance Decay of Tree Species Similarity in Protected Areas on Terra Firme Forests in Colombian AmazoniaBIOTROPICA, Issue 5 2009Álvaro Duque ABSTRACT In this study, we investigated the pattern of floristic similarity as a function of geographical distances and environmental variability in well-drained uplands (terra firme) in Colombian Amazonia. The study site comprised three National Natural Parks, Tinigua, Chiribiquete, and Amacayacu, located in different geological units that represent a soil fertility gradient linked to parental materials. Differences in species richness between sites were compared using rarefaction analysis. A clear floristic transition appeared in the east,west direction following a soil fertility gradient along the first PCoA axis. In multiple regression analyses based on distance matrices, both geographical distances and geology explained 64 percent of the total floristic variation. Geographical distances alone accounted for 12 percent of variation in floristic similarities among plots, while geology alone accounted for 1 percent, and the joint effect of both explained 51 percent of the floristic variation. The species richness trend supports the existence of a latitudinal corridor southward of the geographical Equator in the Amazon basin, where tree diversity reaches the maximum expected values. A coupled effect of stochastic dispersal limitation and habitat specialization would certainly appear to be an appropriate explanation for tree species turnover in terra firme forests in Colombian Amazonia, strongly emphasizing that competition and neutrality must be supplementary rather than mutually exclusive processes. This result pinpoints the effect of dispersal on floral mixing as an ongoing active process for structuring tree communities in NW Amazonia, and the size of the reserves as a relevant issue to protect rare species from extinction by chance. [source] Tree Community Change across 700 km of Lowland Amazonian Forest from the Andean Foothills to BrazilBIOTROPICA, Issue 5 2008Nigel C. A. Pitman ABSTRACT We describe patterns of tree community change along a 700-km transect through terra firme forests of western Amazonia, running from the base of the Andes in Ecuador to the Peru,Brazil border. Our primary question is whether floristic variation at large scales arises from many gradual changes or a few abrupt ones. Data from 54 1-ha tree plots along the transect support the latter model, showing two sharp discontinuities in community structure at the genus level. One is located near the Ecuador,Peru border, where the suite of species that dominates large areas of Ecuadorean forest declines abruptly in importance to the east. This discontinuity is underlain by a subterranean paleoarch and congruent with a change in soil texture. A second discontinuity is associated with the shift from clay to white sand soils near Iquitos. We hypothesize that the first discontinuity is part of an edaphic boundary that runs along the Andean piedmont and causes a transition from tree communities preferring richer, younger soils near the base of the Andes to those preferring poorer, older soils farther east. Because the floristic changes observed at this discontinuity are conserved for large distances to the east and west of it, the discontinuity is potentially key for understanding floristic variation in western Amazonia. The significant floristic turnover at the Ecuador,Peru border suggests that the only large protected area in the region,Ecuador's Yasuní National Park,is not adequate protection for the very diverse tree communities that cover vast areas of northern Peru. RESUMEN Describimos cambios en la comunidad de árboles a lo largo de un transecto de 700 km que atraviesa los bosques de tierra firme de la Amazonía occidental, desde la base de los Andes en Ecuador hasta la frontera Perú-Brasil. Nuestra pregunta principal es si la variación florística a grandes escalas es generada a base de muchos cambios graduales o en unos pocos cambios abruptos. Datos de 54 parcelas de árboles de 1 ha a lo largo del transecto apoyan el segundo modelo, mostrando dos discontinuidades bien definidas en la estructura de la comunidad a nivel de género. Una discontinuidad está localizada cerca de la frontera Ecuador-Perú, donde el grupo de especies que domina grandes áreas de la Amazonía ecuatoriana declina abruptamente en importancia hacia el este. Esta discontinuidad está asociada con un paleoarco subterráneo y es congruente con cambios en la textura del suelo. Una segunda discontinuidad está asociada con un cambio de suelos arcillosos a suelos de arena blanca cerca de Iquitos. Sugerimos que la primera discontinuidad es parte de un limite edáfico que corre a lo largo del piedemonte andino y causa una transición de comunidades de árboles que prefieren suelos más fértiles y jóvenes cerca de los Andes, a aquellos que prefieren suelos más pobres y antiguos hacia el este. Ya que los cambios florísticos observados en esta discontinuidad se conservan por grandes distancias hacia el este y oeste, la discontinuidad es potencialmente clave para entender la variación florística en la Amazonía occidental. El importante recambio florístico en la frontera Ecuador-Perú sugiere que la única gran área protegida en la región,el Parque Nacional Yasuní en Ecuador,no presta protección adecuada a las muy diversas comunidades de árboles en el norte del Perú. [source] | ||||||||||