scholarly journals Niche Diversification of Sphagnum in Bolivia

1997 ◽  
Vol 13 (1) ◽  
pp. 65-73
Author(s):  
Cyrus B. McQueen
Keyword(s):  
North America ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Common Species ◽  
Cloud Forests ◽  
Bolivian Andes ◽  
Niche Diversification

Niche breadth values of Sphagnum species in the páramo and cloud forests of Bolivia are similar to those reported for Sphagnum-dominated peatlands in North America, but niche overlap values are higher for Sphagnum species in Bolivia. The pH, conductivity, and concentrations of Ca, Mg, Na, K, and P suggest that Sphagnum habitats in Bolivia are ombrotrophic in nature. Sphagnum is limited to small, scattered carpets in the páramo and cloud forests of the Bolivian Andes between 1800 and 4200 m. Common species found in these habitats include S. alegrense Warnst., S. boliviae Warnst., S. cuspidatum Ehrh., S. magellanicum Brid., S. oxyphyllum Warnst., S. recurvum P. Beauv., S. sanctojosephense Crum & Crosby, and S. sparsum Hampe.

scholarly journals Niche Breadth and Overlap of Sphagnum Species in Costa Rica

1995 ◽  
Vol 11 (1) ◽  
pp. 119-127
Author(s):  
Cyrus B. McQueen
Keyword(s):  
Costa Rica ◽  
North America ◽  
South America ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Common Species ◽  
The Common ◽  
Sphagnum Magellanicum

Niche breadth and overlap values of Sphagnum species in Costa Rica are similar to those reported for Sphagnum-dominated peatlands in North America. Sphagnum magellanicum Brid. and S. sparsum Hampe have the broadest niche breadth of the common species in Costa Rica. Although S. sancto-josephense Crum & Crosby has a relatively narrow niche breadth, it is one of the most common species along with S. magellancium and S. sparsum in the Sphagnum habitats of Costa Rica. Niche overlap is high among species with the exception of S. platyphyllum (Braithw.) Warnst. which is found in habitats that are rich in iron. The pH, conductivity, and concentrations of Ca, Fe, Mg, Mn, Na, K, and P of Sphagnum habitats in Costa Rica are similar to those reported for páramo habitats in South America.

Niche diversification of Sphagnum relative to environmental factors in northern Minnesota peatlands

1984 ◽  
Vol 62 (7) ◽  
pp. 1409-1430 ◽  
Author(s):  
Dale H. Vitt ◽  
Nancy G. Slack
Keyword(s):  
Niche Breadth ◽  
Niche Overlap ◽  
Individual Species ◽  
Ph Gradients ◽  
Surface Water Chemistry ◽  
Ph Values ◽  
Red Lake ◽  
Landscape Units ◽  
Independent Species ◽  
Niche Diversification

The peatlands sampled in this study are located in northern Minnesota and include 32 stands positioned in seven sites in the Red Lake peatland and Lake Itasca areas. Surface water chemistry ranges from pH values of 4.6 to 7.4, with corrected conductivity of 53 to 476 μohms cm−1 and calcium of 6.9 to 44.5 ppm. Six broad physiognomic landscape units are delimited based on quantitative analysis of the vegetation; these range from ombrotrophic ovoid islands to strongly minerotrophic forested fens. These landscape units can best be further divided or themselves characterized by the dominant Sphagnum species. Calculations of niche breadth across eight microhabitat axes and niche overlap for four microhabitat axes (pH, corrected conductivity, height above H2O level, and shade) for 13 species of Sphagnum suggest independent species utilization of the gradients. Among the mire-expanse species, niche breadths become narrower from hollow to hummock along calcium and pH gradients, whereas broadest niche breadths are present for midhummock species along the height gradient. For the taxonomically close species, S. fallax and S. angustifolium, niche overlap is greatest for conductivity and pH, whereas overlap is least along the height gradient. Quantification of niche breadth and niche overlap indicates considerable niche diversification along these microhabitat gradients, with individual species interacting independently to different gradients. These differing niche breadths along several different gradients suggest that these species of Sphagnum are largely equilibrium species, not opportunistic ones. In general, niche overlap is smaller in mire habitats where an abundance of bryophytes coexist with Sphagnum and highest in mire-expanse situations where Sphagnum is dominant.

Ecological structure of a herpetological assemblage in South India

1987 ◽  
Vol 8 (3) ◽  
pp. 189-202 ◽  
Author(s):  
M. Koshy ◽  
Robert F. Inger ◽  
H.B. Shaffer ◽  
R. Bakde
Keyword(s):  
South India ◽  
Niche Breadth ◽  
Niche Overlap ◽  
Common Species ◽  
Evergreen Forest ◽  
Terrestrial Species ◽  
South Indian ◽  
Tropical Evergreen Forest ◽  
The Western Ghats ◽  
Level Of Analysis

AbstractWe collected detailed microhabitat information on 1460 specimens comprising 52 species of amphibians and reptiles from a small area of tropical evergreen forest in South India. Although most individuals were found in non-riparian situations, the number caught in and along streams was higher than expected on the basis of collecting effort. Very few animals were caught under logs and rocks. When niche breadth values are corrected for variation in sample size, we find no correlation between magnitude of niche breadth and general habitat usage, such as terrestriality vs. arboreality. A cluster analysis of 28 common species using niche overlap values reveals one group of 6 terrestrial species with very high niche overlap values and high co-occurrence within collecting sorties; this group probably represents a genuine terrestrial guild. Another set of 4 terrestrial species is peripherally associated with the first 6, whereas the remaining species show generally low overlap values. Altitudinal restriction is an almost ubiquitous feature of the distribution of species in this fauna, with distinct groups of low (below 300 m), intermediate (300-399 m), and high altitude (above 399 m) taxa roughly corresponding to major shifts in forest types. At a broader level of analysis, we find considerable evidence for local endemism within partially isolated hill ranges in the Western Ghats, suggesting that geographic isolation may be an important contributing factor to the diversity of the South Indian herpetofauna.

scholarly journals Ecology of colonizing populations of the figfly Zaprionus indianus (Diptera, Drosophilidae) in Porto Alegre, Southern Brazil

2005 ◽  
Vol 95 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Norma Machado da Silva ◽  
Carina da Conceição Fantinel ◽  
Vera Lucia da Silva Valente ◽  
Vitor Hugo Valiati
Keyword(s):  
Niche Breadth ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Survival Strategies ◽  
Porto Alegre ◽  
Zaprionus Indianus ◽  
Feeding Sites ◽  
Substrate Choice ◽  
Oviposition Substrate ◽  
Feeding Substrate

Ecological parameters such as trophic niche overlap and niche breadth were computed from the frequency of all drosophilid species collected in 2001 and 2002, in the urban area of Porto Alegre city, Brazil. Independently of place, drosophilids community composition and components breeding or feeding sites, the highest frequencies of Zaprionus indianus (Gupta, 1970) were obtained during seasons with higher average temperatures, especially during summer. From a total of the 19,146 individuals of Z. indianus sampled, 80% were found in this season. The data of trophic niche breadth suggest a higher opportunism of adult flies in feeding substrate use, but the females are still selective in oviposition substrate choice. For the values of niche overlap, only for some species, did we find any correlation between these and species richness and/or number of resources, and the most of the correlation values considering breeding and feeding sites were positive. The colonization of Z. indianus in Porto Alegre could be leading to adjustments in the survival strategies of the resident species, but it is possible that many species have conditions for coexisting with the invader.

scholarly journals Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

2011 ◽  
Vol 9 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Rodrigo Moncayo-Estrada ◽  
Owen T Lind ◽  
Carlos Escalera-Gallardo
Keyword(s):  
Niche Breadth ◽  
Temporal Distribution ◽  
Niche Overlap ◽  
Species Interaction ◽  
Trophic Relationships ◽  
Water Volume ◽  
Species Flock ◽  
Small Range ◽  
Mean Values ◽  
Significant Difference

Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala , Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, and C. consocium). Diets were described in critical shallow (August 2000) and volume recovery conditions (August 2005). Diets included mainly cladocerans (Bosmina, Ceriodaphnia, and Daphnia) and copepods (Cyclops). A significant difference in diets was detected when comparing years (MRPP analysis, A = 0.22, p < 0.0001) and sites at different years (MRPP analysis, A = 0.17, p = 0.004). According to niche breadth mean values, species were classified as specialized and intermediate feeders. In shallow conditions, the small range of niche breadth (1.72 to 3.64) and high diet overlap values (D = 0.64, L = 8.62) indicated a high potential for interspecific exploitative interaction. When the lake volume recovered, an increase in the niche breadth range (1.04 to 4.96) and low niche overlap values (D = 0.53, L = 2.32) indicated a reduction of the species interaction. The Mann-Whitney U-test supported this pattern by showing a significant difference between years for niche overlap (p = 0.006). The increased interaction during the low volume suggests alternative segregation in life-history variations and other niche dimensions such as spatial or temporal distribution.

Toruiopsis candida. [Descriptions of Fungi and Bacteria].

1986 ◽  
Author(s):  
C. Davis
Keyword(s):  
North America ◽  
South America ◽  
Geographical Distribution ◽  
Bovine Mastitis ◽  
Common Species ◽  
Yeast Flora ◽  
Torulopsis Glabrata ◽  
Systemic Infections ◽  
Intravenous Inoculation

Abstract A description is provided for Toruiopsis candida. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Torulopsis candida is one of the less common species of the commensal yeast flora in humans and has been associated with both superficial and systemic infections. The organism has occasionally been implicated in cases of fungal septicaemia and has been isolated from urine, vagina and feet. Veterinary associations of T. candida include bovine mastitis, bovine and ovine abortion and isolation from cervical swats in mares. Pathogenicity studies have been carried out by Khon et al. who found Torulopsis glabrata to be non-pathogenic to normal mice following intravenous inoculation with up to 10 cells but 50% mortality in cortisone treated mice inoculated with similar doses (Sabouraudia 18: 319-327, 1980). The diseased mice were found to have macroscopic lesions on liver, lung, kidney and spleen. GEOGRAPHICAL DISTRIBUTION: Africa (Sudan); Asia (Japan, Kuwait); Europe (Austria, Belgium, Czechoslovakia, Finland, France, Greece, Italy, UK); North America (USA); South America (Brazil, Venezuela).

scholarly journals Wetland selection, niche breadth and overlap in 10 duck species wintering in northern Campania (Italy)

2018 ◽  
Vol 87 (2) ◽  
pp. 3-8
Author(s):  
Stefano Giustino ◽  
Marcello Bruschini ◽  
Elio Esse ◽  
Silvana Grimaldi ◽  
Danila Mastronardi ◽  
...  
Keyword(s):  
Niche Breadth ◽  
Selection Index ◽  
Niche Overlap ◽  
Campania Region ◽  
Duck Species ◽  
Wintering Area ◽  
Morisita Index ◽  
Species Preferences

Analysis of the selection index, the niche breadth and the niche overlap of 10 species of wintering ducks in 11 wetland areas of the Campania region between January 2003 and 2015 revealed that the distribution of the species in the examined sites was not casual. In fact, each species actively chose their wintering area. Using selection index, we were able to measure the species’ preferences and non-preferences for the 11 examined sites. By calculating Shannon-Wiener entropy and its normalized value (Evenness), we determined niche breadth; the Morisita index allowed us to check niche overlap.

Assessing the diet and trophic niche breadth of an omnivorous fish (Glanidium ribeiroi) in subtropical lotic environments: intraspecific and ontogenic responses to spatial variations

2019 ◽  
Vol 70 (8) ◽  
pp. 1116 ◽  
Author(s):  
B. C. K. Kliemann ◽  
M. C. Baldasso ◽  
S. F. R. Pini ◽  
M. C. Makrakis ◽  
S. Makrakis ◽  
...  
Keyword(s):  
Forest Cover ◽  
Agricultural Land ◽  
Niche Breadth ◽  
Intraspecific Variability ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Main Channel ◽  
Size Classes ◽  
Intraspecific Variations ◽  
Environmental Variations

The diet of Glanidium ribeiroi was investigated in lotic stretches downstream from a cascade of reservoirs to determine how it responds to intraspecific and environmental variations. Monthly sampling was performed from 2013 to 2016 at sites including the main channel of the Iguaçu River and tributaries in preserved basins and agricultural land. The diet of individuals in the preserved tributaries was primarily associated with allochthonous resources, whereas in the non-preserved tributaries and main channel the diets were primarily associated with autochthonous resources. Trophic niche breadth and intraspecific variability differed significantly among sampling areas and size classes. Trophic niche overlap among size classes and sampling areas was low. Positive and negative relationships between the trophic niche breadth and the standard length of individuals were also found in different sampling areas. Intraspecific and ontogenic variations were strongly and consistently associated with forest cover. Individuals responded differently to local environmental variations due to differences in landscape gradients and life cycle changes. Therefore, the effects of spatial heterogeneity on diet composition and intraspecific variations therein appear to be crucial to the success of the populations evaluated. These results may help with the implementation of conservation measures for this and other endemic species.

scholarly journals Resource use by two electric fishes (Gymnotiformes) of the National Forest Saracá-Taquera, Oriximiná, Pará

2017 ◽  
Vol 15 (2) ◽  
Author(s):  
Bruno E. Soares ◽  
Daniela C. O. Rosa ◽  
Nathália C. S. Silva ◽  
Miriam P. Albrecht ◽  
Érica P. Caramaschi
Keyword(s):  
Resource Use ◽  
Niche Breadth ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Feeding Strategies ◽  
National Forest ◽  
Microhabitat Use ◽  
Use Patterns ◽  
Head Morphology

ABSTRACT Fishes of the order Gymnotiformes have high diversity of oral and head morphology, which suggests trophic specializations within each clade. The aim of this study was to describe resource use patterns by two fish species (Gymnorhamphichthys rondoni and Gymnotus coropinae) in the National Forest Saracá-Taquera, Oriximiná - Pará, analyzing microhabitat use, diet composition, feeding strategies, niche breadth and niche overlap. Stomach contents of 101 individuals (41 G. rondoni and 60 G. coropinae), sampled in 23 headwater streams were analyzed and volume of food items was quantified to characterize their feeding ecology. Gymnorhamphichthys rondoni was captured mainly on sandy bottoms, whereas G. coropinae in crevices. Both species had a zoobenthivorous diet and consumed predominantly Sediment/Detritus and Diptera larvae, but also included allochthonous prey in their diet. These species had high niche overlap, with small variations related to the higher consumption of Ceratopogonidae larvae by G. rondoni and of Chironomidae larvae by G. coropinae. Both species had a generalist feeding strategy, but G. coropinae had a broader niche breadth. Our results demonstrate that G. rondoni and G. coropinae occupy different microhabitats but rely on similar food resources.

Sign in / Sign up

Export Citation Format

Share Document