scholarly journals Beta Diversity along an Elevational Gradient at the Pico da Neblina (Brazil): Is Spider (Arachnida-Araneae) Community Composition Congruent with the Guayana Region Elevational Zonation?

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 620
Author(s):  
André A. Nogueira ◽  
Antonio D. Brescovit ◽  
Gilmar Perbiche-Neves ◽  
Eduardo M. Venticinque
Keyword(s):  
Beta Diversity ◽  
Species Abundance ◽  
Elevational Gradient ◽  
Similar Species ◽  
Species Abundance Distribution ◽  
Similarity Indices ◽  
Spider Community ◽  
Indicator Analysis ◽  
Climate Crisis ◽  
Very High

Beta diversity is usually high along elevational gradients. We studied a spider community at the Pico da Neblina (Brazil), an Amazonian mountain which is one of the southern components of the Guayana region. We sampled six elevations and investigated if beta diversity patterns correspond to the elevational division proposed for the region, between lowlands (up to 500 m), uplands (500 m to 1500 m), and highlands (>1500 m). Patterns of dominance increased with elevation along the gradient, especially at the two highest elevations, indicating that changes in composition may be accompanied by changes in species abundance distribution. Beta diversity recorded was very high, but the pattern observed was not in accordance with the elevationaldivision proposed for the region. While the highlands indeed harbored different fauna, the three lowest elevationshad similar species compositions, indicating that the lowlands spider community extends into the uplands zone. Other measures of compositional change, such as similarity indices and species indicator analysis, also support this pattern. Our results, in addition to a revision of the literature, confirm the high diversity and endemism rates of montane spider communities, and we stress the importance of protecting those environments, especially considering the climate crisis.

scholarly journals Gamma diversity and under-sampling together generate patterns in beta-diversity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aniruddha Marathe ◽  
Dharma Rajan Priyadarsanan ◽  
Jagdish Krishnaswamy ◽  
Kartik Shanker
Keyword(s):  
Beta Diversity ◽  
Species Abundance ◽  
Elevational Gradient ◽  
Species Pool ◽  
Gamma Diversity ◽  
Ant Communities ◽  
Species Pools ◽  
Local Abundance ◽  
Regional Species Pool ◽  
Under Sampling

AbstractBeta diversity represents how species in the regional pool segregate among local communities and hence forms a link between local and regional species diversities. Therefore, the magnitude of beta diversity and its variation across geographic gradients can provide insights into mechanisms of community assembly. Along with limits on local or regional level diversities, effects of local abundance that lead to under-sampling of the regional species pool are important determinants of estimated beta diversity. We explore the effects of regional species pools, abundance distributions, and local abundance to show that patterns in beta diversity as well as the mean of species abundance distribution have distinct outcomes, depending on limits on species pools and under-sampling. We highlight the effect of under-sampling in some established relationships between gamma diversity and beta diversity using graphical methods. We then use empirical data on ant communities across an elevational gradient in the Eastern Himalayas to demonstrate a shift from effect of reduction in species pool to under-sampling at mid-elevations. Our results show that multiple processes with contrasting effects simultaneously affect patterns in beta diversity across geographic gradients.

scholarly journals Infestation and Related Ecology of Chigger Mites on the Asian House Rat (Rattus tanezumi) in Yunnan Province, Southwest China

2021 ◽  
Vol 59 (4) ◽  
pp. 377-392
Author(s):  
Fan Ding ◽  
Wen-Li Jiang ◽  
Xian-Guo Guo ◽  
Rong Fan ◽  
Cheng-Fu Zhao ◽  
...  
Keyword(s):  
Species Abundance ◽  
Abundant Species ◽  
Mite Species ◽  
Species Abundance Distribution ◽  
Chigger Mite ◽  
Geographical Regions ◽  
Rattus Tanezumi ◽  
Curve Equation ◽  
Large Host ◽  
Very High

This paper is to illustrate the infestation and related ecological characteristics of chigger mites on the Asian house rat (Rattus tanezumi). A total of 17,221 chigger mites were collected from 2,761 R. tanezumi rats, and then identified as 131 species and 19 genera in 2 families. Leptotrombidium deliense, the most powerful vector of scrub typhus in China, was the first major dominant species on R. tanezumi. All the dominant mite species were of an aggregated distribution among different individuals of R. tanezumi. The species composition and infestations of chiggers on R. tanezumi varied along different geographical regions, habitats and altitudes. The species-abundance distribution of the chigger mite community was successfully fitted and the theoretical curve equation was. Ŝ (R)=37e–(0.28R)2 The total chigger species on R. tanezumi were estimated to be 199 species or 234 species, and this further suggested that R. tanezumi has a great potential to harbor abundant species of chigger mites. The results of the species-plot relationship indicated that the chigger mite community on R. tanezumi in Yunnan was an uneven community with very high heterogeneity. Wide geographical regions with large host samples are recommended in the investigations of chigger mites.

scholarly journals Niches, rather than neutrality, structure a grassland pioneer guild

2005 ◽  
Vol 272 (1570) ◽  
pp. 1357-1364 ◽  
Author(s):  
Lindsay A Turnbull ◽  
Liz Manley ◽  
Mark Rees
Keyword(s):  
Seed Size ◽  
Adult Stage ◽  
Niche Differentiation ◽  
Competitive Dynamics ◽  
Similar Species ◽  
Adult Density ◽  
Pioneer Species ◽  
Trade Offs ◽  
Very High ◽  
Early Establishment

Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails.

Duplex DNA barcoding allows accurate species determination of morphologically similar limpets (Patella spp.) from non-destructive sampling

2016 ◽  
Vol 97 (7) ◽  
pp. 1479-1482 ◽  
Author(s):  
Thomas J. Ashton ◽  
Meriem Kayoueche-Reeve ◽  
Andrew J. Blight ◽  
Jon Moore ◽  
David M. Paterson
Keyword(s):  
Dna Barcoding ◽  
Species Abundance ◽  
Microscopic Analysis ◽  
Cost Effective ◽  
Field Studies ◽  
Similar Species ◽  
Species Determination ◽  
Destructive Sampling ◽  
Species Specific ◽  
Non Destructive

Accurate discrimination of two morphologically similar species of Patella limpets has been facilitated by using qPCR amplification of species-specific mitochondrial genomic regions. Cost-effective and non-destructive sampling is achieved using a mucus swab and simple sample lysis and dilution to create a PCR template. Results show 100% concurrence with dissection and microscopic analysis, and the technique has been employed successfully in field studies. The use of highly sensitive DNA barcoding techniques such as this hold great potential for improving previously challenging field assessments of species abundance.

Using a Macroecological Approach to Study Geographic Range, Abundance and Body Size in the Fossil Record

2010 ◽  
Vol 16 ◽  
pp. 117-141 ◽  
Author(s):  
S. Kathleen Lyons ◽  
Felisa A. Smith
Keyword(s):  
Body Size ◽  
Fossil Record ◽  
Species Abundance ◽  
Geographic Range ◽  
Species Abundance Distribution ◽  
Abundance Distribution ◽  
Geographic Ranges ◽  
Spatial And Temporal Scales ◽  
Geographic Range Size ◽  
Fossil Data

Macroecology is a rapidly growing sub-discipline within ecology that is concerned with characterizing statistical patterns of species' abundance, distribution and diversity at spatial and temporal scales typically ignored by traditional ecology. Both macroecology and paleoecology are concerned with answering similar questions (e.g., understanding the factors that influence geographic ranges, or the way that species assemble into communities). As such, macroecological methods easily lend themselves to many paleoecological questions. Moreover, it is possible to estimate the variables of interest to macroecologists (e.g., body size, geographic range size, abundance, diversity) using fossil data. Here we describe the measurement and estimation of the variables used in macroecological studies and potential biases introduced by using fossil data. Next we describe the methods used to analyze macroecological patterns and briefly discuss the current understanding of these patterns. This chapter is by no means an exhaustive review of macroecology and its methods. Instead, it is an introduction to macroecology that we hope will spur innovation in the application of macroecology to the study of the fossil record.

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