scholarly journals Influence of habitat structure on Pristimantis species (Anura: Craugastoridae) in a bamboo-dominated forest fragment in southwestern Amazonia

2015 ◽  
Vol 14 (1) ◽  
pp. 19
Author(s):  
Jhon Jairo López-Rojas ◽  
Moisés Barbosa Souza ◽  
Elder Ferreira Morato
Keyword(s):  
Species Composition ◽  
Habitat Structure ◽  
Neutral Theory ◽  
Canopy Cover ◽  
Spatial Distance ◽  
Niche Theory ◽  
Forest Fragment ◽  
Biodiversity Research ◽  
Remnant Forest ◽  
Southwestern Amazonia

Structural and determinate factors for the composition of assemblages of species are diverse. Two theories attempt to explain the pattern of species composition in assemblies using different approaches—i.e., Niche Theory and Neutral Theory. Anurans have complex responses to habitat structure. Species of Pristimantis are good indicators for conservation because they are organisms with direct development. The effect of habitat structure on species of Pristimantis in a bamboo-dominated remnant forest located in southwestern Amazonia is analyzed herein. Active visual and auditory searches in 10 plots of the Biodiversity Research Program (PPBio) were conducted between November 2012 and May 2013. Four hundred and sixty individuals of five species were recorded: Pristimantis altamazonicus, P. diadematus, P. fenestratus, P. reichlei, and P. skydmainus. Neither spatial distance nor the structure of the habitat of the plots affected the composition of Pristimantis. The first axis of PCA explained 45.6% variation of the characterization habitat structure, correlated significantly with the number of Pristimantis, species increasing with trees between 10 ≤ dbh < 30 cm and decreased with density of bamboo. The increase in litter depth and canopy cover influenced in the occurrence of P. reichlei, the occurrence of P. skydmainus decreased with increased density of bamboo and trees dbh ≥ 30 cm and the occurrence of P. diadematus decreased relative to increased canopy cover. Pristimantis diadematus and P. skydmainus were the most restricted species in terms of habitat and were especially susceptible to bamboo density.

scholarly journals Cross-scale habitat structure driven by coral species composition on tropical reefs

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Laura E. Richardson ◽  
Nicholas A. J. Graham ◽  
Andrew S. Hoey
Keyword(s):  
Species Composition ◽  
Habitat Structure ◽  
Coral Species ◽  
Tropical Reefs

scholarly journals ASSESSING THE CANOPY INTEGRITY USING CANOPY DIGITAL IMAGES IN SEMIDECIDUOUS FOREST FRAGMENT IN SÃO CARLOS - SP- BRAZIL1

2017 ◽  
Vol 41 (5) ◽  
Author(s):  
Thiago Yamada ◽  
Emerson Carlos Pedrino ◽  
João Juares Soares ◽  
Maria do Carmo Nicoletti
Keyword(s):  
Digital Image Analysis ◽  
Digital Images ◽  
Research Work ◽  
Canopy Structure ◽  
Canopy Cover ◽  
Relevant Information ◽  
Canopy Closure ◽  
Forest Fragment ◽  
Semideciduous Forest

ABSTRACT It is well-known that conducting experimental research aiming the characterization of canopy structure of forests can be a difficult and costly task and, generally, requires an expert to extract, in loco, relevant information. Aiming at easing studies related to canopy structures, several techniques have been proposed in the literature and, among them, various are based on canopy digital image analysis. The research work described in this paper empirically compares two techniques that measure the integrity of the canopy structure of a forest fragment; one of them is based on central parts of canopy cover images and, the other, on canopy closure images. For the experiments, 22 central parts of canopy cover images and 22 canopy closure images were used. The images were captured along two transects: T1 (located in the conserved area) and T2 (located in the naturally disturbance area). The canopy digital images were computationally processed and analyzed using the MATLAB platform for the canopy cover images and the Gap Light Analyzer (GLA), for the canopy closure images. The results obtained using these two techniques showed that canopy cover images and, among the employed algorithms, the Jseg, characterize the canopy integrity best. It is worth mentioning that part of the analysis can be automatically conducted, as a quick and precise process, with low material costs involved.

scholarly journals Squamata reptiles of a fragment of tropical dry forest in northwestern Venezuela (Lake Maracaibo region)

Check List ◽  
2012 ◽  
Vol 8 (6) ◽  
pp. 1220 ◽  
Author(s):  
Junior T. Larreal ◽  
Gilson A. Rivas ◽  
Carlos Portillo-Quintero ◽  
Tito R. Barros
Keyword(s):  
Species Composition ◽  
San Francisco ◽  
Tropical Dry Forest ◽  
Single Species ◽  
Dry Forest ◽  
Forest Fragment ◽  
Dry Forests ◽  
Maracaibo Basin ◽  
Lake Maracaibo

We present a commented taxonomic list of the reptiles found during herpetological surveys carried out in an isolated fragment of tropical dry forest located in the municipality of San Francisco, Zulia state, northwestern Venezuela between January-December 2011. We report a total of 24 species belonging to the order Squamata, distributed in 12 families and 21 genera. Colubridae is the most diverse family with six species, followed by Dipsadidae (four species), Boidae, Gymnophthalmidae, Phyllodactylidae and Teiidae with two species each, and finally Dactyloidae, Iguanidae, Elapidae, Gekkonidae, Sphaerodactylidae and Viperidae with a single species each. The species composition at this site matches what would be expected in a tropical dry forest in the region. Our study suggests that this isolated tropical dry forest fragment is the last refuge of the herpetofauna that once occupied much of the dry forests of the northern Maracaibo basin and should therefore be considered for conservation purposes.

scholarly journals Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

1988 ◽  
Vol 18 (3-4) ◽  
pp. 309-315 ◽  
Author(s):  
Heraldo Luís de Vasconcelos
Keyword(s):  
Species Composition ◽  
Rain Forest ◽  
Abundant Species ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Terra Firme ◽  
Atta Sexdens ◽  
Conservation Areas ◽  
Continuous Forest ◽  
Leaf Cutting

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

scholarly journals Breeding records of Leptotila rufaxilla (Aves: Columbidae) in southwestern Brazilian Amazon with notes on nesting in some regions of occurrence

2021 ◽  
Vol 28 (3) ◽  
pp. e18793
Author(s):  
Jônatas Lima ◽  
Railene Almeida ◽  
Edson Guilherme
Keyword(s):  
Growth Rate ◽  
Brazilian Amazon ◽  
Nesting Success ◽  
Daily Survival Rate ◽  
Forest Fragment ◽  
Lowland Forest ◽  
Constant Growth Rate ◽  
Nestling Period ◽  
Constant Growth ◽  
Southwestern Amazonia

We present new aspects of breeding biology of Gray-fronted Dove Leptotila rufaxilla, from five nests found between 2012 and 2014 in a lowland forest fragment in southwestern Brazil. The nests simple/platform shape were built at a mean height of 1.90 m above ground. The clutch size was two eggs white and elliptic, incubated for 15 days (based on three nests). We recorded predation in two nests still in incubation phase. Minimum hatch weight of nestlings was 10 g and young fledged with a mean mass of 56 g. The constant growth rate (K) of nestlings was 0.40 with a growth asymptote of 60.7 g. Daily survival rate, Mayfield and apparent nesting success in the incubation period was 90, 20 and 56%, respectively, while in the nestling period were all 100%. Our data and the contribution of citizen science showed that L. rufaxilla breeds over the year, mainly in the rainy season, both in southwestern Amazonia and in other regions of occurrence.

scholarly journals New records and geographic distribution of Grey Woolly Monkeys, Lagothrix cana (É. Geoffroy, 1812) (Primates, Atelidae), in southern Brazilian Amazonia

Check List ◽  
2016 ◽  
Vol 12 (6) ◽  
pp. 2007
Author(s):  
André V. Nunes ◽  
Vinicius S. Orsini
Keyword(s):  
Endangered Species ◽  
Geographic Distribution ◽  
New Record ◽  
New Records ◽  
Forest Fragment ◽  
Woolly Monkey ◽  
Mato Grosso ◽  
Woolly Monkeys ◽  
Arc Of Deforestation ◽  
Southwestern Amazonia

We report a range extension of the Grey Woolly Monkey, Lagothrix cana, from southwestern Amazonia, Mato Grosso, Brazil. Lagothrix cana was seen in a forest fragment near the “arc of deforestation”. This new record shows the need for conservation of forests in the region to protect this endangered species.

Conservation value of koa (Acacia koa) reforestation areas on Hawaii Island

2018 ◽  
Vol 24 (1) ◽  
pp. 35
Author(s):  
Laurie Strommer ◽  
Sheila Conant
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Native Species ◽  
Canopy Cover ◽  
Basal Area ◽  
Forest Tree ◽  
Native Forest ◽  
Acacia Koa ◽  
Total Species Richness ◽  
Hawaii Island

Efforts to restore forests for ecological and economic benefit in Hawaii are converging on koa (Acacia koa), an endemic dominant or codominant canopy tree common across broad elevation and moisture gradients. We quantified plant species composition and forest structure in koa reforestation areas (KRAs) and in nearby intact native forest on Hawaii Island. Total species richness and percentage native species richness were lower in the plantation forests than in the intact forests, although species richness in the KRAs at one site was not significantly different from that in intact forest. Tree, sapling, and seedling densities differed between KRAs and forest sites at one site. At another, the native forest and one KRA had similar tree and seedling densities and similar canopy height and percentage canopy cover. Total stand basal area was greatest in the intact forest at both sites, although the basal area for the KRAs at one site exceeded those for intact forest at the other. Koa plantings can be structurally similar to intact forests though species composition differs. Our results suggest that koa forestry can facilitate native understorey development in some cases.

scholarly journals Rapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savanna

2019 ◽  
Vol 16 (7) ◽  
pp. 1493-1503 ◽  
Author(s):  
Shaun R. Levick ◽  
Anna E. Richards ◽  
Garry D. Cook ◽  
Jon Schatz ◽  
Marcus Guderle ◽  
...  
Keyword(s):  
Carbon Storage ◽  
Vegetation Structure ◽  
Habitat Structure ◽  
Canopy Structure ◽  
Three Dimensional ◽  
Canopy Cover ◽  
Fire Regimes ◽  
Dry Season ◽  
Airborne Lidar ◽  
Climate Conditions

Abstract. Fire regimes across the globe have been altered through changes in land use, land management, and climate conditions. Understanding how these modified fire regimes impact vegetation structure and dynamics is essential for informed biodiversity conservation and carbon management in savanna ecosystems. We used a fire experiment at the Territory Wildlife Park (TWP), northern Australia, to investigate the consequences of altered fire regimes for vertical habitat structure and above-ground carbon storage. We mapped vegetation three-dimensional (3-D) structure in high spatial resolution with airborne lidar across 18 replicated 1 ha plots of varying fire frequency and season treatments. We used lidar-derived canopy height and cover metrics to extrapolate field-based measures of woody biomass to the full extent of the experimental site (R2=0.82, RMSE = 7.35 t C ha−1) and analysed differences in above-ground carbon storage and canopy structure among treatments. Woody canopy cover and biomass were highest in the absence of fire (76 % and 39.8 t C ha−1) and lowest in plots burnt late in the dry season on a biennial basis (42 % and 18.2 t C ha−1). Woody canopy vertical profiles differed among all six fire treatments, with the greatest divergence in height classes <5 m. The magnitude of fire effects on vegetation structure varied along the environmental gradient underpinning the experiment, with less reduction in biomass in plots with deeper soils. Our results highlight the large extent to which fire management can shape woody structural patterns in savanna landscapes, even over time frames as short as a decade. The structural profile changes shown here, and the quantification of carbon reduction under late dry season burning, have important implications for habitat conservation, carbon sequestration, and emission reduction initiatives in the region.

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