Biological reserves, rare species and the trade-off between species abundance and species diversity

2006 ◽  
Vol 56 (4) ◽  
pp. 570-583 ◽  
Author(s):  
Bertrand Hamaide ◽  
Charles S. ReVelle ◽  
Scott A. Malcolm
Keyword(s):  
Species Diversity ◽  
Rare Species ◽  
Species Abundance ◽  
Trade Off

scholarly journals Ocean currents promote rare species diversity in protists

2020 ◽  
Vol 6 (29) ◽  
pp. eaaz9037
Author(s):  
Paula Villa Martín ◽  
Aleš Buček ◽  
Thomas Bourguignon ◽  
Simone Pigolotti
Keyword(s):  
Species Diversity ◽  
Power Law ◽  
Rare Species ◽  
Species Abundance ◽  
Ecological Factors ◽  
Abundant Species ◽  
Chaotic Advection ◽  
Power Law Decay ◽  
Aquatic Microbes ◽  
Oceanic Currents

Oceans host communities of plankton composed of relatively few abundant species and many rare species. The number of rare protist species in these communities, as estimated in metagenomic studies, decays as a steep power law of their abundance. The ecological factors at the origin of this pattern remain elusive. We propose that chaotic advection by oceanic currents affects biodiversity patterns of rare species. To test this hypothesis, we introduce a spatially explicit coalescence model that reconstructs the species diversity of a sample of water. Our model predicts, in the presence of chaotic advection, a steeper power law decay of the species abundance distribution and a steeper increase of the number of observed species with sample size. A comparison of metagenomic studies of planktonic protist communities in oceans and in lakes quantitatively confirms our prediction. Our results support that oceanic currents positively affect the diversity of rare aquatic microbes.

Plant diversity increases with the strength of negative density dependence at the global scale

Science ◽  
2017 ◽  
Vol 356 (6345) ◽  
pp. 1389-1392 ◽  
Author(s):  
Joseph A. LaManna ◽  
Scott A. Mangan ◽  
Alfonso Alonso ◽  
Norman A. Bourg ◽  
Warren Y. Brockelman ◽  
...  
Keyword(s):  
Species Diversity ◽  
Density Dependence ◽  
Rare Species ◽  
Species Abundance ◽  
Biotic Interactions ◽  
Global Scale ◽  
Latitudinal Shift ◽  
Negative Density Dependence ◽  
The Tropics ◽  
The Relationship

Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.

scholarly journals Ocean currents promote rare species diversity in protists

2020 ◽  
Author(s):  
Paula Villa Martín ◽  
Ales Bucek ◽  
Tom Bourguignon ◽  
Simone Pigolotti
Keyword(s):  
Species Diversity ◽  
Power Law ◽  
Rare Species ◽  
Species Abundance ◽  
Ecological Factors ◽  
Abundant Species ◽  
Coalescence Model ◽  
Power Law Decay ◽  
Aquatic Microbes ◽  
Oceanic Currents

Oceans host communities of plankton composed of relatively few abundant species and many rare species. The number of rare protists species in these communities, as estimated in metagenomic studies, decays as a steep power law of their abundance. The ecological factors at the origin of this pattern remain elusive. We propose that oceanic currents affect biodiversity patterns of rare species. To test this hypothesis, we introduce a spatially-explicit coalescence model able to reconstruct the species diversity in a sample of water. Our model predicts, in the presence of oceanic currents, a steeper power law decay of the species abundance distribution and a steeper increase of the number of observed species with sample size. A comparison of two metagenomic studies of planktonic protist communities in oceans and in lakes quantitatively confirms our prediction. Our results support that oceanic currents positively impact the diversity of rare aquatic microbes.

First data on plasmodial slime moulds (Myxomycetes = Myxogastrea) of Rdeysky Nature Reserve (Novgorod Region, Russia)

2021 ◽  
Vol 55 (2) ◽  
pp. 361-377
Author(s):  
N. I. Borzov ◽  
F. M. Bortnikov ◽  
A. V. Matveev ◽  
V. I. Gmoshinskiy
Keyword(s):  
Species Diversity ◽  
Rare Species ◽  
Nature Reserve ◽  
Common Species ◽  
Slime Moulds ◽  
State Nature Reserve ◽  
Plasmodial Slime Moulds ◽  
State Nature

The results of the first study of the species diversity of myxomycetes of the Rdeysky State Nature Reserve are presented. The 201 field specimens of sporophores belonging to 56 morphospecies from 27 genera, ten families, and six orders were collected from September 30 to October 5, 2020. Fifty-two species of these were new for the Novgorod Region. The most common species at the reserve were Arcyria affinis, Hemitrichia calyculata, Lycogala epidendrum, Metatrichia vesparia, Physarum album, Trichia decipiens, and T. varia. Additionally, detailed morphological descriptions of two rare species Amaurochaete trechispora and Trichia crateriformis are given.

scholarly journals Distance Effects on Diversity and Abundance of the Flower Visitors of Ocimum kilimandscharicum in the Kakamega Forest Ecosystem

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hellen K. Mandela ◽  
Mugatsia H. Tsingalia ◽  
Mary Gikungu ◽  
Wilbur M. Lwande
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Land Use Changes ◽  
Species Abundance ◽  
Diversity Indices ◽  
Forest Edge ◽  
Flower Visitors ◽  
Kakamega Forest ◽  
Species Invasions ◽  
Wiener Diversity Index

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ of Ocimum kilimandscharicum in Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates that Ocimum kilimandscharicum flower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.

scholarly journals The commonness of rarity: Global and future distribution of rarity across land plants

2019 ◽  
Author(s):  
Brian Joseph Enquist ◽  
Xiao Feng ◽  
Bradley Boyle ◽  
Brian Maitner ◽  
Erica A. Newman ◽  
...  
Keyword(s):  
Plant Species ◽  
Rare Species ◽  
Large Fraction ◽  
Neutral Theory ◽  
Species Abundance ◽  
Land Plant ◽  
Observation Data ◽  
Heavy Tailed Distributions ◽  
Species Abundance Distributions ◽  
Heavy Tailed

A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant species observation data in order to quantify the fraction of Earth’s extant land plant biodiversity that is common versus rare. Tests of different hypotheses for the origin of species commonness and rarity indicates that sampling biases and prominent models such as niche theory and neutral theory cannot account for the observed prevalence of rare species. Instead, the distribution of commonness is best approximated by heavy-tailed distributions like the Pareto or Poisson-lognormal distributions. As a result, a large fraction, ~36.5% of an estimated ~435k total plant species, are exceedingly rare. We also show that rare species tend to cluster in a small number of ‘hotspots’ mainly characterized by being in tropical and subtropical mountains and areas that have experienced greater climate stability. Our results indicate that (i) non-neutral processes, likely associated with reduced risk of extinction, have maintained a large fraction of Earth’s plant species but that (ii) climate change and human impact appear to now and will disproportionately impact rare species. Together, these results point to a large fraction of Earth’s plant species are faced with increased chances of extinction. Our results indicate that global species abundance distributions have important implications for conservation planning in this era of rapid global change.

scholarly journals The macrozoobenthos under clam farm (the Black Sea, Sevastopol region)

2018 ◽  
Vol 3 (1) ◽  
pp. 9-22 ◽  
Author(s):  
N. A. Boltacheva ◽  
M. V. Makarov ◽  
L. V. Bondarenko ◽  
M. A. Kovaleva
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Black Sea ◽  
Rare Species ◽  
Trophic Structure ◽  
Bivalve Mollusk ◽  
The Black Sea ◽  
Density And Biomass

During 2015–2106 the macrozoobenthos under the clam farm located in the area of Sevastopol was investigated. The aim of the study is to consider species composition, density and biomass of macrozoobenthos in the area of the clam farm. The samples were taken using standard benthic techniques. Relatively low species diversity was observed, with 56 species of macrozoobenthos identified. The density was 500–975 ind. per m², the biomass varied from 0.8 to 381.1 g·m-2. The community of the bivalve mollusk Lucinella divaricata (Linnaeus, 1758) was found. Trophic structure of the community with high quantity of detritus feeders dominated by small polychaetes was determined. The dominating, typical and rare species were identified. Comparison with the data obtained in 1957 in Evpatoriya – Sevastopol area at the same depths and sediments was made.

scholarly journals Self–organized instability in complex ecosystems

2002 ◽  
Vol 357 (1421) ◽  
pp. 667-681 ◽  
Author(s):  
Ricard V. Solé ◽  
David Alonso ◽  
Alan McKane
Keyword(s):  
Rare Species ◽  
Scaling Law ◽  
Species Abundance ◽  
Field Studies ◽  
Species Number ◽  
Neotropical Forests ◽  
Species Abundances ◽  
Long Tails ◽  
Critical Boundary ◽  
Species Area

Why are some ecosystems so rich, yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. However, the origin of such diversity and the consequences of food web complexity in both species abundances and temporal fluctuations are not well understood. Several regularities are observed in complex, multispecies ecosystems that suggest that these ecologies might be organized close to points of instability. We explore, in greater depth, a recent stochastic model of population dynamics that is shown to reproduce: (i) the scaling law linking species number and connectivity; (ii) the observed distributions of species abundance reported from field studies (showing long tails and thus a predominance of rare species); (iii) the complex fluctuations displayed by natural communities (including chaotic dynamics); and (iv) the species–area relations displayed by rainforest plots. It is conjectured that the conflict between the natural tendency towards higher diversity due to immigration, and the ecosystem level constraints derived from an increasing number of links, leaves the system poised at a critical boundary separating stable from unstable communities, where large fluctuations are expected to occur. We suggest that the patterns displayed by species–rich communities, including rarity, would result from such a spontaneous tendency towards instability.

scholarly journals The commonness of rarity: Global and future distribution of rarity across land plants

2019 ◽  
Vol 5 (11) ◽  
pp. eaaz0414 ◽  
Author(s):  
Brian J. Enquist ◽  
Xiao Feng ◽  
Brad Boyle ◽  
Brian Maitner ◽  
Erica A. Newman ◽  
...  
Keyword(s):  
Plant Species ◽  
Conservation Planning ◽  
Rare Species ◽  
Extinction Risk ◽  
Large Fraction ◽  
Neutral Theory ◽  
Species Abundance ◽  
Risk Assessments ◽  
Human Land Use ◽  
Species Abundance Distributions

A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant diversity to quantify the fraction of Earth’s plant biodiversity that are rare. A large fraction, ~36.5% of Earth’s ~435,000 plant species, are exceedingly rare. Sampling biases and prominent models, such as neutral theory and the k-niche model, cannot account for the observed prevalence of rarity. Our results indicate that (i) climatically more stable regions have harbored rare species and hence a large fraction of Earth’s plant species via reduced extinction risk but that (ii) climate change and human land use are now disproportionately impacting rare species. Estimates of global species abundance distributions have important implications for risk assessments and conservation planning in this era of rapid global change.

Sign in / Sign up

Export Citation Format

Share Document