scholarly journals Drivers of bird diversity in an understudied African centre of endemism: The Angolan Central Escarpment Forest

2017 ◽  
Vol 27 (2) ◽  
pp. 256-268 ◽  
Author(s):  
AIMY CÁCERES ◽  
MARTIM MELO ◽  
JOS BARLOW ◽  
RICARDO FAUSTINO DE LIMA ◽  
MICHAEL S. L. MILLS
Keyword(s):  
Species Richness ◽  
Model Averaging ◽  
Canopy Cover ◽  
Habitat Characteristics ◽  
Bird Diversity ◽  
Remotely Sensed Data ◽  
Landsat Images ◽  
Natural Habitats ◽  
Explanatory Variables ◽  
Point Counts

SummaryNatural habitats are being rapidly lost due to human activities. It is therefore vital to understand how these activities influence biodiversity so that suitable guidelines can be established for conservation. This is particularly important in understudied, high biodiversity, areas such as the Angolan Escarpment. Here we examine which habitat characteristics drive bird diversity and endemic species presence at Kumbira Forest, a key site in the Central Escarpment Forest. Bird diversity was sampled by 10 min bird point counts, whereas habitat characteristics were measured by a combination of ground-based vegetation surveys and remotely sensed data modelling of Landsat images. GLM, multi-model inference and model averaging were used to determine the most important variables driving species richness and the presence of endemics. The remote sensing variables performed poorly in predicting presence of Red-crested Turaco Tauraco erythrolophus and Gabela Bushshrike Laniarius amboimensis but they contributed significantly to explain species richness and Gabela Akalat Sheppardia gabela presence, both of which were associated with greater canopy cover. Liana density and elevation were also important explanatory variables in certain cases. Conservation actions at Kumbira should focus on increasing canopy cover and maintaining forest integrity (as measured by liana density), as these actions are likely to have the most positive outcomes for the avifauna.

scholarly journals Resource selection by Javan Slow Loris Nycticebus javanicus E. Geoffroy, 1812 (Mammalia: Primates: Lorisidae) in a lowland fragmented forest in Central Java, Indonesia

2019 ◽  
Vol 11 (6) ◽  
pp. 13667-13679 ◽  
Author(s):  
Mahfut Sodik ◽  
Satyawan Pudyatmoko ◽  
Pujo Semedi Hargo Yuwono ◽  
Muhammad Ali Imron
Keyword(s):  
Resource Selection ◽  
Small Sample Size ◽  
Canopy Cover ◽  
Small Sample ◽  
Habitat Characteristics ◽  
Ratio Test ◽  
Natural Habitats ◽  
Slow Loris ◽  
Central Java ◽  
Habitat Variables

Habitat loss and forest fragmentation have negative impacts on Javan Slow Loris Nycticebus javanicus, a Critically Endangered nocturnal primate endemic to Java.  Reports confirmed that less than 9% of forest area remains on Java Island.  One of the remaining natural habitats of the Javan Slow Loris is the fragment of Kemuning Forest in Temanggung Regency, Central Java.  The purpose of this study was to determine resource selection and habitat variables that determine the presence of Javan Slow Loris.  Habitat variables measured were basal area, tree connectivity, crown coverage on tree stage, slope, elevation, and distance to river.  Data analysis performed was logistic regression, likelihood ratio test, and Akaike’s Information Criterion with a backward elimination procedure.  We also used direct observation and interviews with locals to collect data on environment and anthropogenic features of this forest.  The results showed that the Javan Slow Loris uses resources selectively on a microhabitat scale.  The habitat factors that influence the probability of resource selection by the species are canopy cover and slope.  Habitat characteristics preferred by the Javan Slow Loris in Kemuning Forest are secondary lowland tropical rainforest with dense canopy cover located on a steep slope with low level of habitat disturbances.  Although this study uses a small sample size, the expectation is that the results can be used as preliminary information for the habitat and population management of Javan Slow Loris in Kemuning Forest to guide conservation efforts and design management strategies.

scholarly journals Landscape effects on the occurrence of ichthyofauna in first-order streams of southeastern Brazil

2016 ◽  
Vol 28 (0) ◽  
Author(s):  
Gabriela Santos Tibúrcio ◽  
Carolina da Silva Carvalho ◽  
Fabio Cop Ferreira ◽  
Roberto Goitein ◽  
Milton Cezar Ribeiro
Keyword(s):  
Species Richness ◽  
Functional Groups ◽  
Riparian Vegetation ◽  
Riparian Forest ◽  
Vegetation Type ◽  
Canopy Cover ◽  
Southeastern Brazil ◽  
Temperature Conductivity ◽  
Explanatory Variables ◽  
First Order

Abstract Objective In this study we aimed to understand how extrinsic environmental factors measured in the watercourses and the surrounding landscape influence the ichthyofauna of first-order streams. Methods Data were collected within the Corumbataí River Basin, São Paulo, southeastern Brazil, during the dry season of 2012. We sampled the ichthyofauna in 13 stretches of streams distributed across four river sub-basins. The stretches differed in relation to the presence/absence of riparian forest, the predominant type of matrix and the percentage of forest. Response variables were species richness and the occurrence of functional groups and explanatory variables include both local and landscape structures from the surrounding environment. Local variables comprised the following water quality and structural attributes: pH, temperature, conductivity, turbidity, flow rate, depth, width, type of substrate. Landscape variables included presence/absence of riparian vegetation, type of vegetation, type of matrix, percentage of forest and canopy cover. Results A total of 268 individuals were recorded, which were distributed among 12 species. The landscape structure influenced the occurrence of functional groups in first-order streams, especially allochthonous-feeders, nektonic and hypoxia-intolerant species. The presence of riparian forest was the most important predictor. Species richness was negatively related to the presence of riparian vegetation, supporting the hypothesis that degraded landscapes lead to a reduction in diversity. Conclusion The protection of riparian vegetation is critical to the maintenance of ichthyofauna diversity in first-order streams. The presence or absence of riparian vegetation differently affected the occurrence of species depending on their functional characteristics, particularly those related to the tolerance to hypoxia, source of alimentary items and the position in the water column.

The Effect of Anthropization on Sarcophagidae (Diptera: Calyptratae) Community Structure: An Assessment on Different Types of Habitats in the Humid Chaco Ecoregion of Argentina

2020 ◽  
Vol 57 (5) ◽  
pp. 1468-1479 ◽  
Author(s):  
Matias I Dufek ◽  
Dario D Larrea ◽  
Miryam P Damborsky ◽  
Pablo R Mulieri
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Habitat Type ◽  
Canopy Cover ◽  
Natural Habitats ◽  
Cattle Farm ◽  
Species Richness And Diversity ◽  
Environmental Impact Assessments ◽  
Spatial Turnover ◽  
Main Driver

Abstract Sarcophagidae (Diptera) are of great interest from a veterinary, medical, and forensic viewpoint, and are potential bioindicators for environmental impact assessments. In this study, we evaluated changes in abundance, species richness, and diversity of flesh flies in different habitat types in the Humid Chaco ecoregion of South America: 1) anthropized habitats: urban, cattle farm, and alfalfa crop, and 2) natural habitats: savanna and forest. We hypothesized that sarcophagid fly community parameters are affected by the anthropization and that spatial turnover will contribute more to the overall beta diversity than nestedness between habitats. In each habitat, samplings were conducted monthly from March 2015 to February 2016 in 25 sites, 5 per habitat, totaling 300 independent samples at the end of the study. We collected 5,790 Sarcophagidae (55 species). Community parameters of Sarcophagidae were evaluated and compared. The ecological effects of anthropization and habitat type were observed in the present study. As expected, our results showed the highest abundance, species richness, and diversity in the savanna and forest habitats (natural), whereas the lowest values were registered in the urban and alfalfa crop habitats, supporting the hypotheses of anthropization as the main driver of diversity loss. In addition, sarcophagid assemblages differed between all habitats and the overall dissimilarity was structured by spatial turnover. The main conclusion of this research is that flesh fly community structure is greatly affected by anthropization and habitat type, and this would be related to canopy cover and microclimate conditions of each environment.

scholarly journals Effects of Forest Regeneration on Crickets: Evaluating Environmental Drivers in a 300-Year Chronosequence

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Neucir Szinwelski ◽  
Cassiano S. Rosa ◽  
José H. Schoereder ◽  
Carina M. Mews ◽  
Carlos F. Sperber
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Forest Regeneration ◽  
Canopy Cover ◽  
Environmental Drivers ◽  
Patch Area ◽  
Forest Patch ◽  
Regeneration Time ◽  
Explanatory Variables ◽  
Litter Depth

We evaluated the relation of cricket species richness and composition with forest regeneration time, evaluating canopy and litter depth as environmental drivers. Effects of forest patch area, nearest distance to the 300-year patch, cricket abundance, sampling sufficiency, and nestedness were also evaluated. We collected 1174 individuals (five families, 19 species). Species richness increased asymptotically with regeneration time and linearly with canopy cover and litter depth. Canopy cover increased linearly, while litter depth increased asymptotically. Richness was not affected by patch area and nearest distance to the 300-year patch. Richness increased with cricket abundance, and this explanation could not be distinguished from regeneration time, evidencing collinearity of these two explanatory variables. Rarefaction curve slopes increased with regeneration time. Species composition differed among patches, with no nested pattern. We suggest that regeneration and consequent increases in canopy and litter promote recovery of cricket biodiversity, abundance, and changes in species composition. We conclude that the recovery of cricket diversity involves an increase along the spatial scale of complementarity, together with a change in species composition.

scholarly journals Acoustic indices applied to biodiversity monitoring in a Costa Rica dry tropical forest

2018 ◽  
Vol 2 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Mónica I. Retamosa Izaguirre ◽  
Oscar Ramírez-Alán
Keyword(s):  
Tropical Forests ◽  
Diversity Index ◽  
Bird Species ◽  
Canopy Cover ◽  
Lower Percentage ◽  
Bird Diversity ◽  
Biodiversity Monitoring ◽  
Bird Abundance ◽  
Point Counts ◽  
Bird Richness

Standardized methods for biodiversity monitoring are needed to evaluate conservation efforts. Acoustic indices are used in biodiversity assessments, but need to be compared to traditional wildlife methods. This work was conducted in the Santa Rosa National Park between June and November, 2015. We installed recorders and conducted bird point counts in twelve sampling sites. We compared acoustic indices (Acoustic Evenness Index [AEI], Acoustic Diversity Index [ADI], Acoustic Complexity Index [ACI], Bioacoustic Index [BIO], Normalized Difference Soundscape Index [NDSI], Total Entropy [TE], Median Amplitude Envelope [MAE], Number of peaks [NP]) with indices from bird point counts (Bird Abundance, Bird Richness, Bird Diversity and Bird Evenness), and discuss the utility of acoustic indices as indicators for biodiversity monitoring in tropical forests. ADI, ACI, BIO and TE presented a similar temporal pattern peaking between 5 am and 6 am; and an additional peak at 5 pm, except for ACI. These patterns were consistent with the daily biological rhythms. AEI, ACI, BIO and Bird Abundance were related to characteristics of younger forests (lower percentage of canopy cover) but NP, ADI, TE, Bird Diversity and Bird Evenness were related to characteristics of older forests (higher percentage of canopy cover and a lower number of patches). ACI was positively correlated to Bird Abundance and NP was positively correlated to Bird Diversity. ACI reflects biological activity, but not necessarily a more diverse bird community in this study area. This might be an indication of a strong acoustic competition, or several highly dominant bird species in younger forests. Furthermore, acoustic communities in tropical forests commonly include insects (cicadas) and frogs, which might affect resulting acoustic indices. A variety of methods are probably needed to thoroughly assess biodiversity. However, a combination of indices such as ACI and NP might be considered to monitor trends in abundance and diversity of birds in dry forests.

scholarly journals Variegated tropical landscapes conserve diverse dung beetle communities

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3125 ◽  
Author(s):  
Cristiane Costa ◽  
Victor Hugo F. Oliveira ◽  
Rafaella Maciel ◽  
Wallace Beiroz ◽  
Vanesca Korasaki ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Canopy Cover ◽  
Dung Beetle ◽  
Dung Beetles ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Natural Habitats ◽  
Vegetation Heterogeneity ◽  
Tropical Landscapes

BackgroundConserving biodiversity in tropical landscapes is a major challenge to scientists and conservationists. Current rates of deforestation, fragmentation, and land use intensification are producing variegated landscapes with undetermined values for the conservation of biological communities and ecosystem functioning. Here, we investigate the importance of tropical variegated landscapes to biodiversity conservation, using dung beetle as focal taxa.MethodsThe study was carried out in 12 variegated landscapes where dung beetles were sampled using six pitfall traps, 30 m apart from each other, along a transect in each studied landscape use and cover classes—LUCC (forest fragment and corridor, coffee plantation, and pasture). We baited each pitfall trap with 30 g of human feces and left open for a 48 h period. We also measured three environmental variables reflecting structural differences among the studied classes: canopy cover, local vegetation heterogeneity and soil sand content.ResultsWe collected 52 species and 2,695 individuals of dung beetles. We observed significant differences in the mean species richness, abundance and biomass among classes, with forest fragments presenting the highest values, forest corridors and coffee plantations presenting intermediate values, and pastures the lowest values. Regarding community structure, we also found significant differences among classes. Canopy cover was the only variable explaining variation in dung beetle species richness, abundance, biomass, and community structure. The relative importance of spatial turnover was greater than nestedness-resultant component in all studied landscapes.DiscussionThis study evaluated the ecological patterns of dung beetle communities in variegated tropical landscapes highlighting the importance of these landscapes for conservation of tropical biodiversity. However, we encourage variegation for the management of landscapes that have already been fragmented or as a complementary initiative of current conservation practices (e.g., protection of natural habitats and establishment of reserves).

scholarly journals Bird diversity in the coastal talukas of Sindhudurg District, Maharashtra, India

2019 ◽  
Vol 11 (9) ◽  
pp. 14166-14186
Author(s):  
Golusu Babu Rao ◽  
Santhanakrishnan Babu ◽  
Goldin Quadros ◽  
Anoop Vijay Kumar
Keyword(s):  
Species Richness ◽  
Grey Literature ◽  
Bird Diversity ◽  
Coastal Zones ◽  
Wetland Birds ◽  
Natural Habitats ◽  
Secondary Sources ◽  
Threat Categories ◽  
High Species Richness ◽  
Secondary Information

The list of birds of Sindhudurg coastal district was compiled based on primary and secondary information.  All observations were made along the Sindhudurg coast, i.e., from Terekhol to Vijaydurg.  Wetland birds were recorded during sampling while terrestrial birds were recorded opportunistically.  Besides, we also collated bird occurrence records from published literature (including grey literature and online resources) to prepare a comprehensive list of birds for Sindhudurg coast.  During our study, we recorded 283 species, and 24 more species were compiled from secondary sources.  Altogether, 307 species belonging to 78 families and 22 orders were recorded from the Sindhudurg coast.  Order Passeriformes was dominant with 111 species.  Among the 307 species, four species are endemic to the Western Ghats.  Three species of vultures had been reported earlier but two were not encountered in recent years.  Great Knot (EN), Woolly-necked Stork (VU) and 14 other species (NT) fall under various threat categories of IUCN.  Species richness was higher in Vengurla (256) followed by Malvan (247) and Devgad talukas.  Construction of homestays, unregulated tourism in coastal areas, and conversion of natural habitats to meet increasing tourism are the major threats to the coastal avifauna of the district.  A high species richness of birds in Sindhudurg coast is attributed to the availability of a wide array of habitats (coastal to woodlands with different degrees of anthropogenic disturbances).  Considering the high species richness of birds and livelihood dependency of humans on the coastal zones, a few estuaries namely Mochemad, Karli and Mitbav estuaries may be recognized as community/ conservation reserve to manage the ecosystem sustainably for long-term conservation of these estuaries and sub-habitats therein.  Also, those sites can be perceived as Important Bird and Biodiversity Areas of IBCN as they fulfill the IBA criteria. 

scholarly journals Potential for crown diameter as a predictor of canopy cover under National Park conditions

2020 ◽  
Vol 28 (s1) ◽  
pp. 305-317
Author(s):  
S.T. Angombe ◽  
R.N. Shikangalah ◽  
E.G. E.G. Kwembeya ◽  
N. Kanime
Keyword(s):  
National Park ◽  
Canopy Cover ◽  
Tree Height ◽  
Natural Habitats ◽  
Relative Population ◽  
Explanatory Variables ◽  
Colophospermum Mopane ◽  
Crown Diameter ◽  
Significant Relationships ◽  
The Relationship

The global loss of biodiversity has led to relentless calls from conservationists to protect the environment and natural habitats. The objective of this study was to determine the effectiveness of crown diameter for prediction of canopy cover under national park conditions. The study was conducted in Etosha National Park, Namibia in 2015. Three tree species, namely Combretum imberbe, Colophospermum mopane and Terminalia prunioides were considered as representative members of the park species based on their relative population density. The study employed regression analysis to examine the nature of relationships between tree crown diameter (the dependent variable) and tree height, diameter at breast height (DBH) and distance from watering holes as independent variables. The regression coefficients for Combretum imberbe were not significant (P = 0.116; P = 0.431; P = 0.884, respectively), suggesting that crown diameter was not well estimated by these explanatory variables. On the other hand, there were significant relationships between DBH and crown diameter, as well as between crown diameter and tree height. Tree height emerged as the stronger predictor of crown diameter for both Terminalia prunioides and Colophospermum mopane. Therefore, the relationship between tree height and crown diameter as explained by cubic function can further be used to evaluate and estimate canopy cover under national park conditions.

scholarly journals Composition and structure of bird communities in vegetational gradients of Bodoquena Mountains, western Brazil

2016 ◽  
Vol 88 (1) ◽  
pp. 211-225 ◽  
Author(s):  
MAURICIO N. GODOI ◽  
FRANCO L. SOUZA ◽  
RUDI R. LAPS ◽  
DANILO B. RIBEIRO
Keyword(s):  
Vegetation Type ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Bird Diversity ◽  
Bird Conservation ◽  
Natural Habitats ◽  
Bird Abundance ◽  
Point Counts ◽  
Composition And Structure

ABSTRACT The informations of bird species distribution in different habitats and the structure of their communities are crucial for bird conservation. We tested the differences in composition, richness and abundance of birds in different phytophysiognomies at Bodoquena Mountains, western Brazil, and we demonstrated the variations in richness and abundance of birds between different trophic groups. Sampling was conducted between July 2011 and June 2012 in 200 point counts arranged in the study area. A total of 3350 contacts were obtained belonging to 156 bird species. Woodland savannas, seasonal forests and arboreal savannas had higher bird abundance and richness, while riparian forests, clean pastures and dirty pastures had smaller values of these parameters. The bird community was organized according to local vegetational gradient, with communities of forests, open areas and savannas, although many species occurred in more than one vegetation type. The insectivorous, omnivorous, frugivorous and gramnivorous birds composed most of the community. These data showed how important environmental heterogeneity is to bird communities. Furthermore, the presence of extensive patches of natural habitats, the small distance between these patches and the permeability of pastures, with high arboreal and shrubby cover, are indicated as important factors to maintain the bird diversity.

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