Habitat associations of woodcreeper (Aves: Dendrocolaptidae) assemblage in selectively logged areas of Southern Amazonia

2015 ◽  
Vol 32 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Domingos J. Rodrigues ◽  
Fernando P. Florêncio ◽  
Jocieli Oliveira ◽  
Dalci M. M. Oliveira ◽  
Gregory W. Lollback ◽  
...  
Keyword(s):  
Forest Structure ◽  
Negative Relationship ◽  
Bird Species ◽  
Forest Degradation ◽  
Habitat Associations ◽  
Selective Logging ◽  
Habitat Specialization ◽  
Canopy Openness ◽  
Southern Amazonia

Abstract:The Brazilian Amazon rain forest has lost c. 17% of its originally forested portion, due to deforestation and selective logging. Forest degradation caused by logging contributes to loss of animal species that require specialized habitats to survive, such as woodcreepers that inhabit understorey areas. Habitat associations of woodcreeper species can be important for identifying species that have restricted distribution and/or habitat specialization. Our study investigates the effects of spatial variation in forest structure and some landscape features (canopy openness, altitude, distance to stream and exploited basal area) on the abundance and composition of woodcreeper assemblage in selectively logged tropical forests in Southern Amazonia. We used mist-nets and points count to quantify the composition and abundance of woodcreepers in 32 plots in three sites. Plots were spatially arranged in PPBio LTER sites (long-term ecological research plots, systematically spaced at 1-km intervals) in Southern Amazonia. A total of 240 individuals (captured, observed and/or heard) belonging to 11 woodcreeper species were detected. Mantel tests showed that there is no spatial autocorrelation among woodcreeper assemblage and distance between plots. Altitude and canopy openness were significantly associated with the composition of the woodcreeper assemblage. Altitude was negatively associated with species richness, and the abundance of the two dominant species (Glyphorynchus spirurus and Xiphorhynchus elegans). The negative relationship with canopy openness suggests that woodcreeper assemblages that inhabit understorey are likely to be indirectly affected by selective logging which reduces canopy cover. The selective logging indirectly changes bird species assemblages, and depending on the intensity, may result in the local extinction of some insectivorous species. Short- and long-term studies addressing different intensities of selective logging are needed to determine the impacts on the bird species and forest structure.

scholarly journals Shifting cultivation along the Trans-African Highway and its impact on the understorey bird community in the Ituri Forest, Zaire

1997 ◽  
Vol 7 (4) ◽  
pp. 317-329 ◽  
Author(s):  
Andrew J. Plumptre
Keyword(s):  
Species Composition ◽  
Forest Structure ◽  
Shifting Cultivation ◽  
Secondary Forest ◽  
Bird Species ◽  
Bird Community ◽  
Selective Logging ◽  
Primary Forest ◽  
Forest Sites ◽  
Ituri Forest

summarySince the 1940s, horticulturalists (the Lese) have been settled along the sides of the roads that traverse a large part of the forest in eastern Zaire. These people have maintained their lifestyle of shifting cultivation and trade with the Mbuti pygmies. This has resulted in corridors of heavily disturbed and regenerating forest. The results of a study of the understorey bird community at three sites in the Okapi Reserve in the Ituri forest in Zaire are reported here. Two primary forest sites (one monodominant Gilbertiodendron forest) in the Reserve were compared with an area of forest disturbed by shifting cultivation. The two primary forest sites were more similar in species composition than they were to secondary forest created by shifting cultivation. Shifting cultivation had a more severe impact on the bird community than selective logging does in forests in Uganda and Malaysia. There was a shift following disturbance from a bird community dominated by insectivores to one with more frugivore-insectivores and nectarivores. Ground thrushes Zoothera spp. and flycatchers were abundant in the monodominant Gilbertiodendron forest and appear to suffer from the change in forest structure following disturbance. The Okapi Reserve currently conserves some important bird species and at least 333 birds have been reported to occur there.

scholarly journals Trade-driven trapping dampens the biodiversity benefits of forest restoration in Southeast Asia

2021 ◽  
Author(s):  
H S Sathya Chandra Sagar ◽  
James J Gilroy ◽  
Tom Swinfield ◽  
Ding Li Yong ◽  
Elva Gemita ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Tropical Forest ◽  
Forest Restoration ◽  
Bird Species ◽  
Forest Degradation ◽  
Forest Recovery ◽  
Avian Community ◽  
Pet Trade ◽  
Tropical Forest Restoration

Tropical forest restoration stands to deliver important conservation gains in lowland Southeast Asia, which has suffered some of the world's highest rates of forest degradation and loss. This promise, however, may be undermined by defaunation driven by ubiquitous wildlife trapping in the region, particularly for forest birds that are part of the multi-million-dollar pet trade. To date, quantification of the impacts of trade-driven trapping on rates of biodiversity recovery from forest restoration has been limited. Here, we use a unique long-term survey dataset to ask how trade-driven trapping may interfere with the expected recovery of avian community under forest restoration, at a flagship ecosystem restoration site in the lowland rainforests of Sumatra, Indonesia. We show that tropical forest restoration is associated with the increases in the abundance of 88% of bird species over time. However, impacts of trapping within more accessible areas of the forest meant that this recovery was dampened for 74% of bird species, relative to levels expected as a result of the magnitude of forest recovery observed. Most species (80%) showed increasingly positive relationships between abundance and site remoteness over the period, a pattern that was found for both species targeted for the pet trade (85% of species) and those trapped opportunistically or as 'bycatch' (78% of species). We emphasize the urgency of tackling the emerging threat of pet trade to Southeast Asia's avian diversity, not least to ensure the effectiveness of efforts towards forest restoration.

scholarly journals Quantifying long-term changes in carbon stocks and forest structure from Amazon forest degradation

2018 ◽  
Vol 13 (6) ◽  
pp. 065013 ◽  
Author(s):  
Danielle I Rappaport ◽  
Douglas C Morton ◽  
Marcos Longo ◽  
Michael Keller ◽  
Ralph Dubayah ◽  
...  
Keyword(s):  
Forest Structure ◽  
Forest Degradation ◽  
Carbon Stocks ◽  
Amazon Forest ◽  
Long Term Changes

scholarly journals Abundance of two Dendrocincla woodcreepers (aves: Dendrocolaptidae) in relation to forest structure in Central Amazonia

2006 ◽  
Vol 36 (2) ◽  
pp. 209-219 ◽  
Author(s):  
Renato Cintra ◽  
Adrianny Erika Maruoka ◽  
Luciano Nicolas Naka
Keyword(s):  
Forest Structure ◽  
Bird Species ◽  
Alpha Diversity ◽  
Local Variation ◽  
Canopy Openness ◽  
Linear Regression Models ◽  
Dead Trees ◽  
Species Overlap ◽  
Central Amazonia ◽  
Standing Dead

Few studies have been conducted to verify how the structure of the forest affects the occurence and abundance of neotropical birds. Our research was undertaken between January 2002 and July 2004 at the Reserva Ducke, near Manaus (02º55',03º01'S; 59º53',59º59'W) in central Amazonia, to verify how the forest structure affects the occurrence and abundance of two bird species: the Plain-brown Woodcreeper Dendrocincla fuliginosa and the White-chinned Woodcreeper Dendrocincla merula. Bird species occurrence was recorded using lines of 20 mist-nets (one sample unit), along 51 1-km transects distributed along 9 pararel 8 km trails covering an area of 6400 ha. Along these transects, we placed 50 x 50m plots where we recorded forest structure components (tree abundance, canopy openness, leaf litter, standing dead trees, logs, proximity to streams, and altitude). We then related these variables to bird occurence and abundance using multiple logistic and multiple linear regression models, respectively. We found that D. fuliginosa frequently used plateau areas; being more abundant in areas with more trees. On the other hand, D. merula occurred more frequently and was more abundant in areas with low tree abundance. Our results suggest that although both species overlap in the reserve (both were recorded in at least 68% of the sampled sites), they differ in the way they use the forest microhabitats. Therefore, local variation in the forest structure may contribute to the coexistence of congeneric species and may help to maintain local alpha diversity.

scholarly journals Assessing impacts of selective logging on water, energy, and carbon budgets and ecosystem dynamics in Amazon forests using the Functionally Assembled Terrestrial Ecosystem Simulator

2019 ◽  
Author(s):  
Maoyi Huang ◽  
Yi Xu ◽  
Marcos Longo ◽  
Michael Keller ◽  
Ryan Knox ◽  
...  
Keyword(s):  
Forest Structure ◽  
Management Practices ◽  
Terrestrial Ecosystem ◽  
Carbon Fluxes ◽  
Forest Degradation ◽  
Carbon Stocks ◽  
Selective Logging ◽  
Ecosystem Dynamics ◽  
Stem Density ◽  
Modeling Tools

Abstract. Tropical forest degradation from logging, fire, and fragmentation not only alters carbon stocks and carbon fluxes, but also impacts physical land-surface properties such as albedo and roughness length. Such impacts are poorly quantified to date due to difficulties in accessing and maintaining observational infrastructures, and the lack of proper modeling tools for capturing the interactions among biophysical properties, ecosystem demography, canopy structure, and biogeochemical cycling in tropical forests. As a first step to address these limitations, we implemented a selective logging module into the Functionally Assembled Terrestrial Ecosystem Simulator (FATES) by mimicking the ecological, biophysical, and biogeochemical processes following a logging event. The model can specify the timing and aerial extent of logging events, splitting the logged forest patch into disturbed and intact patches, determine the survivorship of cohorts in the disturbed patch, and modifying the biomass and necromass (total mass of coarse woody debris and litter) pools following logging. We parameterized the logging module to reproduce a selective logging experiment at the Tapajós National Forest in Brazil and benchmarked model outputs against available field measurements. Our results suggest that the model permits the coexistence of early and late successional functional types and realistically characterizes the seasonality of water and carbon fluxes and stocks, the forest structure and composition, and the ecosystem succession following disturbance. However, the current version of FATES overestimates water stress in the dry season therefore fails to capture seasonal variation in latent and sensible heat fluxes. Moreover, we observed a bias towards low stem density and leaf area when compared to observations, suggesting that improvements are needed in both carbon allocation and establishment of trees. The effects of logging were assessed by different logging scenarios to represent reduced impact and conventional logging practices, both with high and low logging intensities. The model simulations suggest that in comparison to old-growth forests the logged forests rapidly recover water and energy fluxes in one to three years. In contrast, the recovery times for carbon stocks, forest structure and composition are more than 30 years depending on logging practices and intensity. This study lays the foundation to simulate land use change and forest degradation in FATES, which will be an effective tool to directly represent forest management practices and regeneration in the context of Earth System Models.

scholarly journals The Sabah Biodiversity Experiment: a long-term test of the role of tree diversity in restoring tropical forest structure and functioning

2011 ◽  
Vol 366 (1582) ◽  
pp. 3303-3315 ◽  
Author(s):  
Andy Hector ◽  
Christopher Philipson ◽  
Philippe Saner ◽  
Juliette Chamagne ◽  
Dzaeman Dzulkifli ◽  
...  
Keyword(s):  
Species Diversity ◽  
Forest Structure ◽  
Ecosystem Functioning ◽  
Initial Conditions ◽  
Selective Logging ◽  
Long Term Results ◽  
Primary Forest ◽  
Large Trees ◽  
The Relationship

Relatively, little is known about the relationship between biodiversity and ecosystem functioning in forests, especially in the tropics. We describe the Sabah Biodiversity Experiment: a large-scale, long-term field study on the island of Borneo. The project aims at understanding the relationship between tree species diversity and the functioning of lowland dipterocarp rainforest during restoration following selective logging. The experiment is planned to run for several decades (from seed to adult tree), so here we focus on introducing the project and its experimental design and on assessing initial conditions and the potential for restoration of the structure and functioning of the study system, the Malua Forest Reserve. We estimate residual impacts 22 years after selective logging by comparison with an appropriate neighbouring area of primary forest in Danum Valley of similar conditions. There was no difference in the alpha or beta species diversity of transect plots in the two forest types, probably owing to the selective nature of the logging and potential effects of competitive release. However, despite equal total stem density, forest structure differed as expected with a deficit of large trees and a surfeit of saplings in selectively logged areas. These impacts on structure have the potential to influence ecosystem functioning. In particular, above-ground biomass and carbon pools in selectively logged areas were only 60 per cent of those in the primary forest even after 22 years of recovery. Our results establish the initial conditions for the Sabah Biodiversity Experiment and confirm the potential to accelerate restoration by using enrichment planting of dipterocarps to overcome recruitment limitation. What role dipterocarp diversity plays in restoration only will become clear with long-term results.

Forest structure and territory size relationship in the neotropical understorey insectivoreHenicorhina leucosticta

2010 ◽  
Vol 27 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Luis Esteban Vargas ◽  
Natalie Viviana Sánchez ◽  
Gerardo Avalos
Keyword(s):  
Leaf Litter ◽  
Forest Structure ◽  
Territory Size ◽  
Canopy Openness ◽  
Area Index ◽  
Understorey Vegetation ◽  
Litter Accumulation ◽  
Old Growth Forest ◽  
Nest Materials

Abstract:The neotropical terrestrial insectivoreHenicorhina leucosticta(Troglodytidae) maintains long-term territories through vocalizations and forages among leaf litter trapped in the understorey vegetation and ground litter. The relationship between forest structure andH. leucostictaterritory size was studied in La Selva Biological Station, Costa Rica, during the non-breeding season in 2009. Forest structure was measured by assessing canopy openness and leaf area index (LAI) using hemispherical photography, while territory size was estimated with the playback technique using local conspecific vocalizations. Mean territory area was 3.8 ± 2.8 ha (mean ± SD, n = 10). Territory radius length was similar in old-growth forest and abandoned agro-forest plantations. We found thatH. leucostictaterritory size decreased as median LAI increased. We propose that LAI is related to territory size through the amount of leaf fall and subsequent leaf litter accumulation over the understorey plants, which constitutes an important reservoir of arthropod prey and nest materials forH. leucosticta. The long-term supply of food resources is likely to affect territory size in this species, as well as other insectivorous birds with similar foraging behaviour. These results are congruent with the structural cues hypothesis.

scholarly journals Assessing impacts of selective logging on water, energy, and carbon budgets and ecosystem dynamics in Amazon forests using the Functionally Assembled Terrestrial Ecosystem Simulator

2020 ◽  
Vol 17 (20) ◽  
pp. 4999-5023
Author(s):  
Maoyi Huang ◽  
Yi Xu ◽  
Marcos Longo ◽  
Michael Keller ◽  
Ryan G. Knox ◽  
...  
Keyword(s):  
Forest Structure ◽  
Management Practices ◽  
Terrestrial Ecosystem ◽  
Carbon Fluxes ◽  
Forest Degradation ◽  
Carbon Stocks ◽  
Selective Logging ◽  
Ecosystem Dynamics ◽  
Stem Density ◽  
Modeling Tools

Abstract. Tropical forest degradation from logging, fire, and fragmentation not only alters carbon stocks and carbon fluxes, but also impacts physical land surface properties such as albedo and roughness length. Such impacts are poorly quantified to date due to difficulties in accessing and maintaining observational infrastructures, as well as the lack of proper modeling tools for capturing the interactions among biophysical properties, ecosystem demography, canopy structure, and biogeochemical cycling in tropical forests. As a first step to address these limitations, we implemented a selective logging module into the Functionally Assembled Terrestrial Ecosystem Simulator (FATES) by mimicking the ecological, biophysical, and biogeochemical processes following a logging event. The model can specify the timing and aerial extent of logging events, splitting the logged forest patch into disturbed and intact patches; determine the survivorship of cohorts in the disturbed patch; and modifying the biomass and necromass (total mass of coarse woody debris and litter) pools following logging. We parameterized the logging module to reproduce a selective logging experiment at the Tapajós National Forest in Brazil and benchmarked model outputs against available field measurements. Our results suggest that the model permits the coexistence of early and late successional functional types and realistically characterizes the seasonality of water and carbon fluxes and stocks, the forest structure and composition, and the ecosystem succession following disturbance. However, the current version of FATES overestimates water stress in the dry season and therefore fails to capture seasonal variation in latent and sensible heat fluxes. Moreover, we observed a bias towards low stem density and leaf area when compared to observations, suggesting that improvements are needed in both carbon allocation and establishment of trees. The effects of logging were assessed by different logging scenarios to represent reduced impact and conventional logging practices, both with high and low logging intensities. The model simulations suggest that in comparison to old-growth forests the logged forests rapidly recover water and energy fluxes in 1 to 3 years. In contrast, the recovery times for carbon stocks, forest structure, and composition are more than 30 years depending on logging practices and intensity. This study lays the foundation to simulate land use change and forest degradation in FATES, which will be an effective tool to directly represent forest management practices and regeneration in the context of Earth system models.

scholarly journals Forest degradation, not loss, drives widespread avian population declines

2021 ◽  
Author(s):  
Matthew Betts ◽  
Zhiqiang Yang ◽  
Adam Hadley ◽  
Josee Rousseau ◽  
Joseph Northrup ◽  
...  
Keyword(s):  
Habitat Loss ◽  
Forest Cover ◽  
Bird Species ◽  
Forest Degradation ◽  
Breeding Habitat ◽  
Population Declines ◽  
Distribution Models ◽  
Eastern Canada ◽  
Bird Abundance

Abstract In many regions of the world, forest management has reduced old forest and simplified forest structure and composition via reliance on monoculture tree plantations. We hypothesized that such forest degradation has resulted in long-term habitat loss for forest-associated bird species of eastern Canada (130,017 km2) which, in turn, has affected bird population declines. Back-cast species distribution models revealed that despite little change in overall forest cover, breeding habitat loss occurred for 66% of the 54 most common species from 1985-2020. This habitat loss was strongly associated with population declines for 72% of species, as quantified in an independent, long-term dataset. Since 1985, net forest bird abundance has declined in this region by an estimated 33-104 million birds due to habitat loss alone. The effects of forest degradation may therefore be a primary cause of biodiversity decline in managed forest landscapes.  

Risk Attitude and Corporate Investment under Output Market Uncertainty: Evidence from The Mekong River Delta, Vietnam

2016 ◽  
pp. 59-70
Author(s):  
Ninh Le Khuong ◽  
Nghiem Le Tan ◽  
Tho Huynh Huu
Keyword(s):  
Negative Relationship ◽  
Risk Attitude ◽  
Business Strategies ◽  
Risk Averse ◽  
Market Uncertainty ◽  
Firm Investment ◽  
Output Market ◽  
The Impact ◽  
The Relationship

This paper aims to detect the impact of firm managers’ risk attitude on the relationship between the degree of output market uncertainty and firm investment. The findings show that there is a negative relationship between these two aspects for risk-averse managers while there is a positive relationship for risk-loving ones, since they have different utility functions. Based on the findings, this paper proposes recommendations for firm managers to take into account when making investment decisions and long-term business strategies as well.

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