scholarly journals Do persistent rare species experience stronger negative frequency dependence than common species?

2016 ◽  
Author(s):  
Glenda Yenni ◽  
Peter Adler ◽  
Morgan Ernest

Understanding why so many species are rare yet persistent remains a significant challenge for both theoretical and empirical ecologists. Yenni, Adler, and Ernest (2012) proposed that strong negative frequency dependence causes species to be rare while simultaneously buffering them against extinction. This hypothesis predicts that, on average, rare species should experience stronger negative frequency dependence than common species. However, it is unknown if ecological communities generally show this theoretical pattern, or if rarity is primarily determined by other processes that overwhelm the effects of strong negative frequency dependence. We discuss the implications of this mechanism for natural communities, and develop a method to test for a non-random relationship between negative frequency dependence and relative abundance, using species abundance data from 90 communities across a broad range of environments and taxonomic groups. To account for biases introduced by measurement error, we compared the observed correlation between species relative abundance and the strength of frequency dependence against expectations from a randomization procedure. In approximately half of the analyzed communities, rare species showed disproportionately strong negative frequency dependence compared to common species. Specifically, we found a pattern of increasingly strong negative frequency dependence with decreasing relative abundance. Our results suggest that strong negative frequency dependence is a signature of both rarity and persistence for many species in many communities.

2018 ◽  
Author(s):  
Jean-François Arnoldi ◽  
Michel Loreau ◽  
Bart Haegeman

AbstractEmpirical knowledge of ecosystem stability and diversity-stability relationships is mostly based on the analysis of temporal variability of population and ecosystem properties. Variability, however, often depends on external factors that act as disturbances, making it difficult to compare its value across systems and relate it to other stability concepts. Here we show how variability, when viewed as a response to stochastic perturbations, can reveal inherent stability properties of ecological communities, with clear connections with other stability notions. This requires abandoning one-dimensional representations, in which a single variability measurement is taken as a proxy for how stable a system is, and instead consider the whole set of variability values associated to a given community, reflecting the whole set of perturbations that can generate variability. Against the vertiginous dimensionality of the perturbation set, we show that a generic variability-abundance pattern emerges from community assembly, which relates variability to the abundance of perturbed species. As a consequence, the response to stochastic immigration is governed by rare species while common species drive the response to environmental perturbations. In particular, the contrasting contributions of different species abundance classes can lead to opposite diversity-stability patterns, which can be understood from basic statistics of the abundance distribution. Our work shows that a multidimensional perspective on variability allows one to better appreciate the dynamical richness of ecological systems and the underlying meaning of their stability patterns.


1987 ◽  
Vol 82 (1) ◽  
pp. 119-124 ◽  
Author(s):  
M. Dora Feliciangeli

A study on the ecology of phlebotomine sandfly fauna in a restricted focus of cutaneous leishmaniasis in northern Venezuela was undertaken in order to investigate the species responsible for the transmission. The study area and catching methods for phlebotomine sandflies are described. A total of 9,061 females and 1,662 males were collected during a year-term study. 12 species of Lutzomya and 1 species of Brumptomya sp. were identified. Absolute and relative abundance and ocurrence for each species were determined. The rel ative occurrence allowed to distinguish the common species, viz. L. panamensis, L. ovallesi, L. gomezi, L. tinidadensis, L. atroclavata, L. cayennensis, L. shannoni and L. olmeca bicolor from the rare species vis., L. punctigeniculata, L. rangeliana, L. evansi and L. dubitans. General comments on the species composition of the sandfly fauna in this locality are made.


2017 ◽  
Vol 26 (5) ◽  
pp. 513-523 ◽  
Author(s):  
Glenda Yenni ◽  
Peter B. Adler ◽  
S. K. Morgan Ernest

2021 ◽  
Author(s):  
Daniel P. Cariveau ◽  
Michael Roswell ◽  
Tina Harrison ◽  
Mark A. Genung ◽  
Jason Gibbs ◽  
...  

Installing pollinator habitat is a ubiquitous conservation tool, but little is known about which pollinator taxa require support, or which benefit from habitat installations. We studied the response of rare and common bees to pollinator habitat enhancement. We used independent regional datasets to designate bee species as common or rare based on their rank according to one of three metrics: a) site occurrence frequency, b) local relative abundance, and c) geographic range size. We asked whether the abundance or richness of rare and common bees were greater in pollinator habitat, relative to old-field controls. Because we used an arbitrary, quantile-based cutoff to categorize species rarity, we conducted sensitivity analysis and controlled for rarity classification errors with a null model. With this null model, we determined whether rare and/or common species responded to pollinator habitat disproportionately, compared to the expectation for "typical" bee species. We found that the number of individuals and of species designated as rare based on local relative abundance was greater in pollinator habitat enhancements. The number of individuals from bee species designated as rare based on site occurrence was lower in pollinator habitat enhancements, but the number of species was not clearly different between habitat types. We did not find a clear positive nor negative effect of habitat enhancement for species designated rare based on geographic range size. For all three rarity metrics, common species increased in abundance and richness in pollinator habitat relative to controls. Null models indicated that in most cases, neither rare nor common species disproportionately benefited from pollinator habitat. Synthesis and Applications: Our results suggest that pollinator habitat can lead to an increase in the abundance and richness of bees, including species that are rare and that are common. However, rare species appeared to respond differently than typical species, and depending on how species were classified as rare, could display muted or even negative responses to habitat enhancement. Targeting rare species with specific floral resources or unique habitat types may lead to better outcomes for rare and threatened species.


2017 ◽  
Author(s):  
Sara Snell ◽  
Brian S. Evans ◽  
Ethan P. White ◽  
Allen H. Hurlbert

AbstractTransient species occur infrequently in a community over time and do not maintain viable local populations. Because transient species interact differently than non-transients with their biotic and abiotic environment, it is important to characterize the prevalence of these species and how they impact our understanding of ecological systems. We quantified the prevalence and impact of transient species in communities using data on over 17,000 community time series spanning an array of ecosystems, taxonomic groups, and spatial scales. We found that transient species are a general feature of communities regardless of taxa or ecosystem. The proportion of these species decreases with spatial scale leading to a need to control for scale in comparative work. Removing transient species from analyses influences the form of a suite of commonly studied ecological patterns including species-abundance distributions, species-energy relationships, species-area relationships, and temporal turnover. Careful consideration should be given to whether transient species are included in analyses depending on the theoretical and practical relevance of these species for the question being studied.


2010 ◽  
Vol 24 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Igor Aurélio Silva ◽  
Marcus Vinicius Cianciaruso ◽  
Marco Antônio Batalha

We examined the species abundance distribution (SAD) of plant communities in: (1) a wet grassland, waterlogged throughout most of the year; (2) a seasonal savanna, with an annual dry season; and (3) a hyperseasonal savanna, with alternating drought and waterlogging over the year. We searched for differences in the abundance distributions of all species, as well as of the common and rare species. We tested whether the SADs fitted the lognormal, log-series, power fraction, and random assortment models. We found that environmental constraints may reduce the evenness of plant communities and change the SADs in savannas. We observed a lognormal abundance distribution in the wet grassland and a random abundance distribution in the hyperseasonal cerrado. The SAD of the seasonal savanna did not follow any model. The common species in the three communities were better fitted by the lognormal model. The rare species in the wet grassland and the hyperseasonal cerrado were better fitted by the random assortment model. The SAD of the rare species of the seasonal savanna did not follow any model. Seasonality seems to modify the lognormal distribution of the overall plant community, generating abundance distributions indistinguishable from random. However, differential community structuring between common and rare species may not be affected by seasonality. The different signatures of the abundance distributions of common and rare plants indicate that composite models are better predictors for SADs in savannas.


2020 ◽  
Author(s):  
Juan A. Balbuena ◽  
Clara Montlleó ◽  
Cristina Llopis-Belenguer ◽  
Isabel Blasco-Costa ◽  
Volodimir L. Sarabeev ◽  
...  

Abstract1. Most species in ecological communities are rare whereas only a few are common. This distributional paradox has intrigued ecologists for decades but the interpretation of species abundance distributions remains elusive.2. We present Fuzzy Quantification of Common and Rare Species in Ecological Communities (FuzzyQ) as an R package. FuzzyQ shifts the focus from the prevailing species-categorization approach to develop a quantitative framework that seeks to place each species along a rare-commonness gradient. Given a community surveyed over a number of sites, quadrats, or any other convenient sampling unit, FuzzyQ uses a fuzzy clustering algorithm that estimates a probability for each species to be common or rare based on abundance-occupancy information. Such as probability can be interpreted as a commonness index ranging from 0 to 1. FuzzyQ also provides community-level metrics about the coherence of the allocation of species into the common and rare clusters that are informative of the nature of the community under study.3. The functionality of FuzzyQ is shown with two real datasets. We demonstrate how FuzzyQ can effectively be used to monitor and model spatio-temporal changes in species commonness, and assess the impact of species introductions on ecological communities. We also show that the approach works satisfactorily with a wide range of communities varying in species richness, dispersion and abundance currencies.4. FuzzyQ produces ecological indicators easy to measure and interpret that can give both clear, actionable insights into the nature of ecological communities and provides a powerful way to monitor environmental change on ecosystems. Comparison among communities is greatly facilitated by the fact that the method is relatively independent of the number of sites or sampling units considered. Thus, we consider FuzzyQ as a potentially valuable analytical tool in community ecology and conservation biology.


2017 ◽  
Vol 13 (1) ◽  
pp. 17
Author(s):  
Badrudin Badrudin ◽  
Duto Nugroho ◽  
Ali Suman

Variation in species abundance provides one of the striking phenomena observed in ecological communities. This variation has led ecologists to pose central questions pertaining to the nature of communities. Most of the deep sea regions provide the most widely habitat, but until recently information on its community is very little.


Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus


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