scholarly journals The City in the Tropics: Lizard Community Structure and Spatial Resource Use Along an Habitat Gradient of the Dahomey Gap (West Africa)

2021 ◽  
Author(s):  
Luca Luiselli ◽  
Daniele Dendi ◽  
Fabio Petrozzi ◽  
Gabriel Hoinsoudé Segniagbeto
Keyword(s):  
Community Structure ◽  
West Africa ◽  
Niche Partitioning ◽  
Habitat Types ◽  
Lizard Species ◽  
Natural Habitats ◽  
Interspecific Differences ◽  
Forest Sites ◽  
Habitat Gradient ◽  
Species Specific

Abstract Studies on habitat gradients are particularly interesting for the community ecology theory, but almost no investigation has been carried out on community structure of any vertebrate groups along gradients of habitat that were modified by humans in historical or prehistorical times, such as for instance the Dahomey Gap in West Africa. Here, we analyze the community structure of lizards in suburban Lomé (Togo) and in comparison with nearby savannah and forest sites, with a suite of statistical methods. Overall, we recorded 25 lizard species, with a heavy reduction in species richness from forest (18 taxa) to savannah (13) and suburbs (9). 24% of the species occurred in all habitat types, 40% exclusively in forest, and only two were exclusive of suburban habitats. Suburban habitat types were relatively homogeneous in terms of number of observed species (maximum number of taxa per habitat = 6). There were significant interspecific differences in both substratum type preferences and vertical spatial niche by species, but with no evidence of a nonrandom niche partitioning pattern, and hence with a competitively assembled community structure. There was a nonrandom “clustered” distribution of the various species along the available resource categories, thus indicating that species-specific preferences instead of community-driven mechanisms are more likely to explain the observed patterns. We concluded that lizard communities in tropical cities are (i) less species-rich than in the surrounding more natural habitats, (ii) usually clustered into specific habitat/substratum types (often artificial ones), and (iii) not assembled through competitive interactions.

scholarly journals Species coexistence and overlapping distributions in a metacommunity are compatible with niche differences and competition at a local scale

2020 ◽  
Author(s):  
Maxime Dubart ◽  
Patrice David ◽  
Frida Ben-Ami ◽  
Christoph R. Haag ◽  
V. Ilmari Pajunen ◽  
...  
Keyword(s):  
Species Coexistence ◽  
Scale Up ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Apparent Paradox ◽  
Extinction Rates ◽  
Interspecific Differences ◽  
Baltic Coast ◽  
Species Specific

AbstractNiche partitioning is the most studied factor structuring communities of competing species. In fragmented landscapes, however, a paradox can exist: different taxa may competitively dominate different types of habitat patches, resulting in a form of spatial niche partitioning, yet differences in long-term distributions among species can appear surprisingly small. This paradox is illustrated by an emblematic metacommunity - that of Daphnia spp. in rockpools on the Finnish Baltic coast, where three species compete with each other, have distinct ecological preferences, yet largely overlap in long-term distributions. Here we examine how metacommunity models that explicitly estimate species-specific demographic parameters can solve the apparent paradox. Our research confirms previous studies that local extinction rates are influenced by environmental variables in a strong and species-specific way and are considerably increased by interspecific competition. Yet, our simulations show that this situation exists alongside interspecific differences in realized niches that are, overall, small, and identified three main explanations for this compatibility. Our results illustrate how state-space modelling can clarify complex metacommunity dynamics and explain why local competition and niche differentiation do not always scale up to the landscape level.

Diversity and community structure of mosquitoes (Diptera: Culicidae) in suburban, field, and forest habitats in Montréal, Québec, Canada

2021 ◽  
pp. 1-19
Author(s):  
Christopher A. Cloutier ◽  
James W. Fyles ◽  
Christopher M. Buddle
Keyword(s):  
Community Structure ◽  
Light Emitting Diode ◽  
Community Analysis ◽  
Habitat Types ◽  
Important Species ◽  
Light Emitting ◽  
Mosquito Abundance ◽  
Coquillettidia Perturbans ◽  
Forest Sites ◽  
Abundance And Diversity

Abstract Understanding the medical and economic impacts of mosquitoes (Diptera: Culicidae) begins with knowing their natural history and distribution, including their association with habitat types, particularly those in which human activity is high. The effects of habitat on shaping the community structure of mosquitoes were studied across periurban habitats on the island of Montréal, Québec, Canada in 2014 and 2015. Mosquitoes were collected from 20 fixed sampling locations in suburban backyards, fields, and forests, using CO2-baited light-emitting diode encephalitis vector survey traps. A total of 184 607 mosquitoes were collected, representing eight genera and 35 species. Suburban, field, and forest sites had different communities of mosquitoes, but differences were not apparent among sites within similar habitat types in nonmetric multidimensional scaling ordinations and permutational multivariate analysis of variance. In both years, the greatest abundance of mosquitoes was collected from field habitat, and the highest species richness, from forests. Suburban sites consistently generated the lowest abundance and diversity. Nearly 75% of the total individuals collected were from three species: Aedes vexans (Meigen), 39%; Coquillettidia perturbans (Walker), 18%; and Aedes canadensis (Theobald), 16%. This research shows that diverse communities of mosquitoes can be found in forests, fields, and backyards, yet the communities between forests differ from more open habitats. Our community analysis reveals that medically important species (e.g., Culex sp.) are more commonly encountered in suburban backyards, yet overall mosquito nuisance potential is greater in forest and field habitats. This information highlights important patterns of mosquito abundance and species occurrence, vital for the development of management programmes.

scholarly journals Distribution of crabs along a habitat gradient on the Yellow Sea coast after Spartina alterniflora invasion

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6775 ◽  
Author(s):  
Pan Chen ◽  
Yan Zhang ◽  
Xiaojing Zhu ◽  
Changhu Lu
Keyword(s):  
Community Structure ◽  
Spartina Alterniflora ◽  
Yellow Sea ◽  
The Yellow Sea ◽  
Total Biomass ◽  
Crab Species ◽  
Habitat Types ◽  
Habitat Gradient ◽  
Marsh Type ◽  
Sea Coast

The effects of Spartina alterniflora invasion on macrobenthos have long been of concern; however, there is currently no unified conclusion regarding these effects. Most studies on crabs focus on one species or limited habitat types, and assessments of the community-level effects of S. alterniflora invasion considering multiple species and habitat types have rarely been conducted. In this study, we sampled crabs along a habitat gradient from the shoreline to inland areas on the Yellow Sea coast, including the mudflat, S. alterniflora marsh, Suaeda salsa marsh and Phragmites australis marsh. A total of 10 crab species were found among all habitats, with five species in the mudflat, six species in S. alterniflora marsh, seven species in S. salsa marsh and four species in P. australis marsh. The Shannon index values for the crab communities were similar between S. alterniflora marsh and S. salsa marsh, and these values were significantly higher than those for the mudflat and P. australis marsh. However, the total biomass of crabs was highest in the mudflat, and Metaplax longipes, Philyra pisum and Macrophthalmus dilatatus exclusively preferred the mudflat. The analysis of principal components and similarities showed that the crab community structure in S. alterniflora marsh was most similar to that in S. salsa marsh, while the crab community structure in the mudflat was most different from that in the other habitat types. Our results demonstrate that the distribution of crabs varies across a habitat gradient after S. alterniflora invasion and that the crab community in S. alterniflora marsh is slightly different from that associated with the local vegetation but shows a large difference from that in the mudflat. This study indicates that some crab species may have adapted to habitat containing alien S. alterniflora, while other crab species reject this new marsh type. The effects of the distribution of crabs after S. alterniflora invasion on the regional ecosystem need further study in the future.

scholarly journals Responses of Terrestrial Herpetofauna to Persistent, Novel Ecosystems Resulting from Mountaintop Removal Mining

2017 ◽  
Vol 8 (2) ◽  
pp. 387-400 ◽  
Author(s):  
Jennifer M. Williams ◽  
Donald J. Brown ◽  
Petra B. Wood
Keyword(s):  
Habitat Type ◽  
Habitat Associations ◽  
Habitat Characteristics ◽  
Novel Ecosystems ◽  
Habitat Types ◽  
Mountaintop Removal ◽  
Mountaintop Removal Mining ◽  
Forest Sites ◽  
Large Trees ◽  
Species Specific

Abstract Mountaintop removal mining is a large-scale surface mining technique that removes entire floral and faunal communities, along with soil horizons located above coal seams. In West Virginia, the majority of this mining occurs on forested mountaintops. However, after mining ceases the land is typically reclaimed to grasslands and shrublands, resulting in novel ecosystems. In this study, we examined responses of herpetofauna to these novel ecosystems 10–28 y postreclamation. We quantified differences in species-specific habitat associations, (sub)order-level abundances, and habitat characteristics in four habitat types: reclaimed grassland, reclaimed shrubland, forest fragments in mined areas, and nonmined intact forest. Habitat type accounted for 33.2% of the variation in species-specific captures. With few exceptions, forest specialists were associated with intact forest and fragmented forest sites, while habitat generalists were either associated with grassland and shrubland sites or were distributed among all habitat types. At the (sub)order level, salamander (Order Urodela) captures were highest at fragmented and intact forest sites, frog and toad (Order Anura) captures were lowest at intact forest sites, and snake (Suborder Serpentes) captures were highest at shrubland sites. Habitat type was a strong predictor for estimated total abundance of urodeles, but not for anurans or snakes. Tree stem densities in grasslands differed from the other three habitat types, and large trees (>38 cm diameter at breast height) were only present at forest sites. Overstory vegetation cover was greater in forested than in reclaimed habitat types. Ground cover in reclaimed grasslands was distinct from forest treatments with generally less woody debris and litter cover and more vegetative cover. It is important to consider the distributions of habitat specialists of conservation concern when delineating potential mountaintop mine sites, as these sites will likely contain unsuitable habitat for forest specialists for decades or centuries when reclaimed to grassland or shrubland.

scholarly journals Responses of Bat Communities (Mammalia: Chiroptera) to Forest Loss and Habitat Conversion in Southern Cameroon

2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou
Keyword(s):  
Secondary Forest ◽  
Biosphere Reserve ◽  
Abundant Species ◽  
Primary Forest ◽  
Habitat Types ◽  
Habitat Transformation ◽  
Significant Difference ◽  
Southern Cameroon ◽  
Habitat Conversion ◽  
Species Specific

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.

scholarly journals Bark traits, decomposition and flammability of Australian forest trees

2017 ◽  
Vol 65 (4) ◽  
pp. 327 ◽  
Author(s):  
Saskia Grootemaat ◽  
Ian J. Wright ◽  
Peter M. van Bodegom ◽  
Johannes H. C. Cornelissen ◽  
Veronica Shaw
Keyword(s):  
Forest Tree ◽  
Remarkable Feature ◽  
Interspecific Differences ◽  
Eucalypt Plantations ◽  
Physical Traits ◽  
Key Driver ◽  
Multiple Species ◽  
Species Specific ◽  
First Time ◽  
Different Tissues

Bark shedding is a remarkable feature of Australian trees, yet relatively little is known about interspecific differences in bark decomposability and flammability, or what chemical or physical traits drive variation in these properties. We measured the decomposition rate and flammability (ignitibility, sustainability and combustibility) of bark from 10 common forest tree species, and quantified correlations with potentially important traits. We compared our findings to those for leaf litter, asking whether the same traits drive flammability and decomposition in different tissues, and whether process rates are correlated across tissue types. Considerable variation in bark decomposability and flammability was found both within and across species. Bark decomposed more slowly than leaves, but in both tissues lignin concentration was a key driver. Bark took longer to ignite than leaves, and had longer mass-specific flame durations. Variation in flammability parameters was driven by different traits in the different tissues. Decomposability and flammability were each unrelated, when comparing between the different tissue types. For example, species with fast-decomposing leaves did not necessarily have fast-decomposing bark. For the first time, we show how patterns of variation in decomposability and flammability of bark diverge across multiple species. By taking species-specific bark traits into consideration there is potential to make better estimates of wildfire risks and carbon loss dynamics. This can lead to better informed management decisions for Australian forests, and eucalypt plantations, worldwide.

Bird community structure in natural and urbanized habitats along an altitudinal gradient in Pauri district (Garhwal Himalaya) of Uttarakhand state, India

Biologia ◽  
2012 ◽  
Vol 67 (4) ◽  
Author(s):  
Archana Naithani ◽  
Dinesh Bhatt
Keyword(s):  
Community Structure ◽  
Altitudinal Gradient ◽  
Diversity Index ◽  
Bird Species ◽  
Bird Community ◽  
High Elevation ◽  
Base Line ◽  
Natural Habitats ◽  
Forest Habitat ◽  
Rarefaction Analysis

AbstractIn the Indian subcontinent there is hardly any study that compares the bird community structure of urban/suburban areas with those of forest habitat. The present survey identified diverse assemblages of birds in the Pauri district at different elevations. A total of 125 bird species belonging to 40 families including two least count species (Lophura leucomelanos and Pucrasia marcolopha) were recorded during this survey in the forest and urbanized habitats of Pauri District (Garhwal Hiamalaya) of Uttarakhand state, India. The high elevation (Pauri 1600–2100 m a.s.l.), mid elevation (Srikot-Khanda 900–1300 m a.s.l.) and low elevation (Srinagar 500–900 m a.s.l.) contributed 88.8%, 63.2% and 58.4% of the total species respectively. Rarefaction analysis and Shannon diversity index showed that the high elevation forest habitat had highest bird species richness (BSR) and bird species diversity (BSD) followed by the mid and then the low elevation forests. BSR and BSD fluctuated across seasons at all elevations but not across habitat types. Present study provides a base line data about avian community composition in urbanized and natural habitats along altitudinal gradient in the study area. This information may be useful to the conservation biologists for the better management and conservation of the avifauna in the Western Himalaya, a part of one of the hot biodiversity spots of the world.

Disease and community structure: white-nose syndrome alters spatial and temporal niche partitioning in sympatric bat species

2014 ◽  
Vol 20 (9) ◽  
pp. 1002-1015 ◽  
Author(s):  
David S. Jachowski ◽  
Chris A. Dobony ◽  
Laci S. Coleman ◽  
William M. Ford ◽  
Eric R. Britzke ◽  
...  
Keyword(s):  
Community Structure ◽  
Niche Partitioning ◽  
Temporal Niche ◽  
White Nose Syndrome

scholarly journals Environmental correlates and energetics of winter flight by bats in southern Alberta, Canada

2016 ◽  
Vol 94 (12) ◽  
pp. 829-836 ◽  
Author(s):  
B.J. Klüg-Baerwald ◽  
L.E. Gower ◽  
C.L. Lausen ◽  
R.M. Brigham
Keyword(s):  
Heat Loss ◽  
Barometric Pressure ◽  
Myotis Lucifugus ◽  
Energetic Cost ◽  
Cold Temperatures ◽  
Bat Activity ◽  
Environmental Correlates ◽  
Interspecific Differences ◽  
Winter Activity ◽  
Species Specific

Winter activity of bats is common, yet poorly understood. Other studies suggest a relationship between winter activity and ambient temperature, particularly temperature at sunset. We recorded echolocation calls to determine correlates of hourly bat activity in Dinosaur Provincial Park, Alberta, Canada. We documented bat activity in temperatures as low as −10.4 °C. We observed big brown bats (Eptesicus fuscus (Palisot de Beauvois, 1796)) flying at colder temperatures than species of Myotis bats (genus Myotis Kaup, 1829). We show that temperature and wind are important predictors of winter activity by E. fuscus and Myotis, and that Myotis may also use changes in barometric pressure to cue activity. In the absence of foraging opportunity, we suggest these environmental factors relate to heat loss and thus the energetic cost of flight. To understand the energetic consequences of bat flight in cold temperatures, we estimated energy expenditure during winter flights of E. fuscus and little brown myotis (Myotis lucifugus (Le Conte, 1831)) using species-specific parameters. We estimated that winter flight uses considerable fat stores and that flight thermogenesis could mitigate energetic costs by 20% or more. We also show that temperature-dependent interspecific differences in winter activity likely stem from differences between species in heat loss and potential for activity–thermoregulatory heat substitution.

scholarly journals Bioacoustic characterization of mating calls of a freshwater fish (Prochilodus magdalenae) for passive acoustic monitoring

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Sebastián Muñoz-Duque ◽  
Silvia López-Casas ◽  
Héctor Rivera-Gutiérrez ◽  
Luz Jiménez-Segura
Keyword(s):  
Pulse Rate ◽  
Peak Frequency ◽  
Acoustic Monitoring ◽  
Passive Acoustic Monitoring ◽  
Natural Habitats ◽  
Train Duration ◽  
Acoustic Characterization ◽  
Species Specific ◽  
Passive Acoustic

Fish produce sounds that are usually species-specific and associated with particular behaviors and contexts. Acoustic characterization enables the use of sounds as natural acoustic labels for species identification. Males of Prochilodus magdalenae produce mating sounds. We characterized  these sounds and tested their use in natural habitats, to use passive acoustic monitoring for spawning ground identification. We identified two types of acoustic signals: simple pulses and pulse trains. Simple pulses were 13.7 ms long, with peak frequency of 365 Hz, whereas pulse train were 2.3 s long, had peak frequency of 399 Hz, 48.6 pulses and its pulses lasted 12.2 ms, with interpulse interval of 49.0 ms long and 22.3 Hz pulse rate. We did not detect spawning in  absence of male calls nor differences in male sounds at different female densities. We found differences in train duration, pulse rate, and pulse duration in trains, according to the fish's source sites, but these sites were not well discriminated based on bioacoustical variables. In rivers, we located two P. magdalenae spawning grounds and recognized calls from another fish species (Megaleporinus muyscorum). We did not find a significant relationship between fish size and call peak frequency for P. magdalenae.

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