scholarly journals Climatic variables and altitude as predictors of anuran species richness and number of reproductive modes in Brazil

2010 ◽  
Vol 26 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Tiago da Silveira Vasconcelos ◽  
Tiago Gomes dos Santos ◽  
Célio Fernando Baptista Haddad ◽  
Denise de Cerqueira Rossa-Feres
Keyword(s):  
Species Richness ◽  
Positive Association ◽  
Annual Rainfall ◽  
Published Data ◽  
Anuran Species ◽  
Hand Temperature ◽  
Reproductive Modes ◽  
Total Annual Rainfall ◽  
Partial Redundancy Analysis ◽  
Partial Redundancy

Abstract:Because anuran species are highly dependent on environmental variables, we hypothesized that anuran species richness and the number of reproductive modes from different Brazilian localities vary according to climatic and altitudinal variables. Published data were compiled from 36 Brazilian localities and climatic and altitudinal data were extracted from an available database. A partial redundancy analysis (pRDA) showed that 23.5% of the data set's variation was explained by climatic and altitudinal data, while the remaining 76.5% remained unexplained. This analysis suggests that other factors not analysed herein may also be important for predicting anuran species richness and the number of reproductive modes in Brazil. Altitude and total annual rainfall were positively correlated with anuran species richness and the number of reproductive modes, and total annual rainfall was strongly associated with these two biotic variables in the triplot of pRDA. The positive association of total annual rainfall and the negative association of the concentration of annual rainfall were already expected based on physiological and reproductive requirements of anurans. On the other hand, temperature was not associated with richness or the number of reproductive modes.

scholarly journals Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Felipe Augusto Trindade Gondim-Silva ◽  
Alessandra Rodrigues Santos Andrade ◽  
Rafael Oliveira Abreu ◽  
Jamile Santos Nascimento ◽  
Geovane Paixão Corrêa ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Rainy Season ◽  
Dominant Species ◽  
The State ◽  
Northeastern Brazil ◽  
Freshwater Wetland ◽  
Northern Coast ◽  
Anuran Species

Abstract The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the 'main rainy season' and two in a 'lesser rainy season', using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H' indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H'= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H' = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).

scholarly journals Untangling the positive association of phylogenetic, functional, and taxonomic diversity with alien bird species richness

Ecosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
A. Andrikou‐Charitidou ◽  
G. Boutsis ◽  
E. Karadimou ◽  
A. S. Kallimanis
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Positive Association ◽  
Taxonomic Diversity ◽  
Bird Species Richness

scholarly journals Structure in parasite component communities in wild rodents: predictability, stability, associations and interactions .... or pure randomness?

Parasitology ◽  
2008 ◽  
Vol 135 (7) ◽  
pp. 751-766 ◽  
Author(s):  
J. M. BEHNKE
Keyword(s):  
Species Richness ◽  
Published Data ◽  
Data Sets ◽  
Wild Rodents ◽  
Heligmosomoides Polygyrus ◽  
Wood Mice ◽  
Core Species ◽  
Helminth Communities ◽  
Immune Mediated ◽  
Concurrent Infections

SUMMARYExperimental data establish that interactions exist between species of intestinal helminths during concurrent infections in rodents, the strongest effects being mediated through the host's immune responses. Detecting immune-mediated relationships in wild rodent populations has been fraught with problems and published data do not support a major role for interactions in structuring helminth communities. Helminths in wild rodents show predictable patterns of seasonal, host age-dependent and spatial variation in species richness and in abundance of core species. When these are controlled for, patterns of co-infection compatible with synergistic interactions can be demonstrated. At least one of these, the positive relationship betweenHeligmosomoides polygyrusand species richness of other helminths has been demonstrated in three totally independent data-sets. Collectively, they explain only a small percentage of the variance/deviance in abundance data and at this level are unlikely to play a major role in structuring helminth communities, although they may be important in the more heavily infected wood mice. Current worm burdens underestimate the possibility that earlier interactions through the immune system have taken place, and therefore interactions may have a greater role to play than is immediately evident from current worm burdens. Longitudinal studies are proposed to resolve this issue.

scholarly journals Temporal patterns of diversification in Brassicaceae demonstrate decoupling of rate shifts and mesopolyploidization events

2019 ◽  
Vol 125 (1) ◽  
pp. 29-47 ◽  
Author(s):  
Xiao-Chen Huang ◽  
Dmitry A German ◽  
Marcus A Koch
Keyword(s):  
Species Richness ◽  
Driving Forces ◽  
Size Variation ◽  
Internal Transcribed Spacers ◽  
Nuclear Ribosomal Dna ◽  
Published Data ◽  
Glacial Cycles ◽  
Genome Size Variation ◽  
Crown Group ◽  
Plastid Genomes

Abstract Background and Aims Whole-genome duplication (WGD) events are considered important driving forces of diversification. At least 11 out of 52 Brassicaceae tribes had independent mesopolyploid WGDs followed by diploidization processes. However, the association between mesopolyploidy and subsequent diversification is equivocal. Herein we show the results from a family-wide diversification analysis on Brassicaceae, and elaborate on the hypothesis that polyploidization per se is a fundamental driver in Brassicaceae evolution. Methods We established a time-calibrated chronogram based on whole plastid genomes comprising representative Brassicaceae taxa and published data spanning the entire Rosidae clade. This allowed us to set multiple calibration points and anchored various Brassicaceae taxa for subsequent downstream analyses. All major splits among Brassicaceae lineages were used in BEAST analyses of 48 individually analysed tribes comprising 2101 taxa in total using the internal transcribed spacers of nuclear ribosomal DNA. Diversification patterns were investigated on these tribe-wide chronograms using BAMM and were compared with family-wide data on genome size variation and species richness. Key Results Brassicaceae diverged 29.9 million years ago (Mya) during the Oligocene, and the majority of tribes started diversification in the Miocene with an average crown group age of about 12.5 Mya. This matches the cooling phase right after the Mid Miocene climatic optimum. Significant rate shifts were detected in 12 out of 52 tribes during the Mio- and Pliocene, decoupled from preceding mesopolyploid WGDs. Among the various factors analysed, the combined effect of tribal crown group age and net diversification rate (speciation minus extinction) is likely to explain sufficiently species richness across Brassicaceae tribes. Conclusions The onset of the evolutionary splits among tribes took place under cooler and drier conditions. Pleistocene glacial cycles may have contributed to the maintenance of high diversification rates. Rate shifts are not consistently associated with mesopolyploid WGD. We propose, therefore, that WGDs in general serve as a constant ‘pump’ for continuous and high species diversification.

scholarly journals Diversity and associations between coastal habitats and anurans in southernmost Brazil

2013 ◽  
Vol 85 (2) ◽  
pp. 575-584 ◽  
Author(s):  
MAURO C.L.M. OLIVEIRA ◽  
MAURICIO B. DOS SANTOS ◽  
DANIEL LOEBMANN ◽  
ALEXANDRE HARTMAN ◽  
ALEXANDRO M. TOZETTI
Keyword(s):  
Species Richness ◽  
Water Availability ◽  
Plant Cover ◽  
Abundant Species ◽  
Thermal Variation ◽  
Environmental Filter ◽  
Anuran Species ◽  
Drift Fence ◽  
Pampa Biome ◽  
The Relationship

This study aimed to verify the relationship between habitat and the composition of anuran species in dune and restinga habitats in southernmost Brazil. The habitats were sampled between April 2009 and March 2010 using pitfalls with drift fence. We have captured 13,508 individuals of 12 anuran species. Species richness was lower in the dunes and dominance was higher in the resting. Apparently the less complex plant cover, water availability, and wide daily thermal variation in dunes act as an environmental filter for frogs. This hypothesis is reinforced by the fact that the most abundant species (Physalaemus biligonigerus and Odonthoprynus maisuma) bury themselves in the sand, minimizing these environmental stresses. Despite being in the Pampa biome, the studied community was more similar to those of coastal restinga environment of southeast Brazil than with other of the Pampa biome. The number of recorded species is similar to those observed in other open habitats in Brazil, showing the importance of adjacent ones to the shoreline for the maintenance of the diversity of anurans in southernmost Brazil.

scholarly journals Effect of land use on mayfly assemblages structure in Neotropical headwater streams

2014 ◽  
Vol 86 (4) ◽  
pp. 1735-1747 ◽  
Author(s):  
ANA EMILIA SIEGLOCH ◽  
MARCIA SURIANO ◽  
MARCIA SPIES ◽  
ALAÍDE FONSECA-GESSNER
Keyword(s):  
Land Use ◽  
Tropical Rainforest ◽  
Headwater Streams ◽  
Environmental Indicators ◽  
Semideciduous Forest ◽  
Analysis Of Similarity ◽  
Negative Effect ◽  
Water Ph ◽  
Partial Redundancy Analysis ◽  
Partial Redundancy

The aim of this study was to test the effect of agricultural and forestry land use on the structure of mayfly assemblages in low-order streams. Twenty-nine headwater streams were investigated in the state of São Paulo. We analyzed 15 streams in pristine areas (mixed tropical rainforest, semideciduous forest and dense tropical rainforest), and 14 streams covered with sugarcane, eucalyptus and pasture. Mayfly richness obtained by rarefaction curves was higher in pristine areas (21 genera), especially in mixed and semideciduous forest when compared to land use (9 genera), where values were particularly low in sugarcane plantation (3 genera). The non-metric multidimensional scaling (NMDS) ordination showed clear difference in mayfly assemblages between land uses and pristine areas, supported by analysis of similarity (R=0.67, p=0.001). In partial redundancy analysis (pRDA), the environmental descriptors that best explained differences in assemblage structure were Riparian, Channel and Environmental Inventory (RCE) index score, percentage of fine sediment stream substrate, water pH and land elevation. Our results show that agricultural and forestry land use has a strong negative effect on the structure of mayfly assemblages. These results also support the use of mayflies as environmental indicators, as some genera were sensitive to changes in land use, while others responded to naturally occurring changes in the study area.

The elevation gradient of lichen species richness in Nepal

2009 ◽  
Vol 42 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Chitra Bahadur BANIYA ◽  
Torstein SOLHØY ◽  
Yngvar GAUSLAA ◽  
Michael W. PALMER
Keyword(s):  
Species Richness ◽  
Endemic Species ◽  
Elevation Gradient ◽  
Distribution Patterns ◽  
Lichen Species ◽  
Ecological Niches ◽  
Published Data ◽  
Elevation Gradients ◽  
Wide Range ◽  
Taxonomic Groups

AbstractThis study of elevation gradients of lichen species richness in Nepal aimed to compare distribution patterns of different life-forms, substratum affinities, photobiont types, and Nepalese endemism. Distribution patterns of lichens were compared with elevational patterns shown by a wide range of taxonomic groups of plants along the Nepalese Himalayan elevational gradient between 200–7400m. We used published data on the elevation records of 525 Nepalese lichen species to interpolate presence between the maximum and minimum recorded elevations, thereby giving estimates of lichen species richness at each 100-m elevational band. The observed patterns were compared with previously published patterns for other taxonomic groups. The total number of lichens as well as the number of endemic species (55 spp.) showed humped relationships with elevation. Their highest richness was observed between 3100–3400 and 4000–4100m, respectively. Almost 33% of the total lichens and 53% of the endemic species occurred above the treeline (>4300m). Non-endemic richness had the same response as the total richness. All growth forms showed a unimodal relationship of richness with elevation, with crustose lichens having a peak at higher elevations (4100–4200m) than fruticose and foliose lichens. Algal and cyanobacterial lichen richness, as well as corticolous lichen richness, all exhibited unimodal patterns, whereas saxicolous and terricolous lichen richness exhibited slightly bimodal relationships with elevation. The highest lichen richness at mid altitudes concurred with the highest diversity of ecological niches in terms of spatial heterogeneity in rainfall, temperature, cloud formation, as well as high phorophyte abundance and diversity implying large variation in bark roughness, moisture retention capacity, and pH. The slightly bimodal distributions of saxicolous and terricolous lichens were depressed at the elevational maximum of corticolous lichens.

Effects of oil palm plantations on anuran diversity in the eastern Amazon

2015 ◽  
Vol 65 (3-4) ◽  
pp. 321-335 ◽  
Author(s):  
Fabricio S. Correa ◽  
Leandro Juen ◽  
Lenise C. Rodrigues ◽  
Heriberto F. Silva-Filho ◽  
Maria C. Santos-Costa
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Oil Palm ◽  
Soil Conditions ◽  
Total Abundance ◽  
Anuran Species ◽  
Forested Areas ◽  
Acoustic Surveys ◽  
Negative Impacts ◽  
The Tropics

The extent of land use for oil palm plantations has grown considerably in the tropics due to climate, appropriate soil conditions for cultivation and its profitability. However, oil palm plantations may endanger biodiversity through reduction and fragmentation of forest areas. Herein we analyzed the effects on anuran species richness, composition and total abundance in oil palm plantations and surrounding forests in eastern Amazon. We installed seven plots in oil palm plantations and seven plots in surrounding forests, which we surveyed for the presence of anurans through active visual and acoustic surveys during periods of high and low rainfall levels. Anuran assemblages found in forests and oil palm plantations differed in species richness and composition, with a loss of 54% of species in oil palm plantations. No difference was observed in total abundance of anurans between both environments. While conversion of forests to oil palm plantations may result in less negative impacts on anuran diversity than other types of monocultures, such loss is nevertheless high, making the maintenance of relatively greater forested areas around oil palm plantations necessary in order to conserve anuran diversity.

scholarly journals Ground data confirm warming and drying are at a critical level for forest survival in western equatorial Africa

2019 ◽  
Author(s):  
Emma R Bush ◽  
Kathryn Jeffery ◽  
Nils Bunnefeld ◽  
Caroline Tutin ◽  
Ruth Musgrave ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Meteorological Data ◽  
Climatic Variability ◽  
Central Africa ◽  
Dry Season ◽  
Annual Rainfall ◽  
Evergreen Forests ◽  
Total Annual Rainfall ◽  
Equatorial Africa

Background.The humid tropical forests of Central Africa influence weather worldwide and play a major role in the global carbon cycle. However they are also an ecological anomaly, with evergreen forests dominating the western equatorial region despite less than 2000mm total annual rainfall. Meteorological data for Central Africa are notoriously sparse and incomplete and there are substantial issues with satellite-derived data because of inability to ground-truth estimates and persistent cloudiness. Long-term climate observations are urgently needed to verify regional climate and vegetation models, shed light on the mechanisms that drive climatic variability and assess the viability of evergreen forests in equatorial Africa under future climate scenarios. Methods. We have the rare opportunity to analyse a 34-year dataset of rainfall and temperature (and shorter periods of absolute humidity, wind speed, solar radiation and aerosol optical depth) from Lopé National Park, a long-term ecological research site in western equatorial Africa. We used linear mixed models and spectral analyses to assess seasonal and inter-annual variation, long-term trends and oceanic influences on local weather patterns. Results. Lopé’s weather is characterised by a light-deficient, cool, long dry season. Long-term climatic means have changed significantly over the last three decades, with warming occurring at a rate of 0.23°C per decade (minimum daily temperature) and drying at a rate of 50mm per decade (total annual rainfall). Inter-annual variability is highly influenced by sea surface temperatures of the major oceans. In El Niño years Lopé experiences both higher temperatures and less rainfall with increased contrast between wet and dry seasons. Lopé rainfall observations lend support for the role of the Atlantic cold tongue in “dry” models of climate change in the region. Conclusions. Dry season cloud in western equatorial Africa plays a key role in reducing evaporative demand during seasonal drought and maintaining evergreen tropical forests despite relatively low annual rainfall. In the context of a rapidly warming and drying climate, urgent research is needed into the sensitivity of clouds to ocean temperatures and the viability of humid forests in this dry region should the clouds disappear.

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