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.

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.

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

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 Estrutura e composição do estrato herbáceo em um remanescente de Floresta Semidecidual Submontana no Nordeste do Brasil

2013 ◽  
Vol 13 ◽  
Author(s):  
Jéssica Lira Viana ◽  
Maria Regina De Vasconcellos Barbosa
Keyword(s):  
Species Diversity ◽  
Geographic Distribution ◽  
Rare Species ◽  
Abundant Species ◽  
Shannon Index ◽  
Fragmented Landscape ◽  
General Survey ◽  
Natural Heritage ◽  
The Family ◽  
Phytosociological Study

The vegetation of a Submontane Semidecidual Seasonal Forest in the Private Natural Heritage Reserve Pedra D’Anta Farm, in Pernambuco State, Brazil, was sampled with the following objectives: 1- to inventory the terrestrial herbs; 2- to characterize the structure of the herbaceous synusiae; 3- to characterize the geographic distribution of terrestrial herbs; and 4- to characterize the heliophyte and sciophyte herbs. Arbitrary walks were performed for a general survey of species, and 20 transects were used to sample the structure in 50 plots of 1 m² each. Frequencies and densities were calculated, with diversity measured by the indicator of specific richness (S) and the Shannon index (H'). A total of 107 species in 75 genera and 39 families were collected, with 25 of these species included in the phytosociological study. Poaceae was the family with the highest number of species in both floristic and phytosociological studies. The species Parodiolyra micrantha and Oplismenus hirtellus were the most frequent and abundant. Species diversity (H') was 2.85 nats. The herbaceous layer was found to be rich, having a composition consisting mostly of widely dispersed species, with a prevalence of herbal hemicryptophytes. Although the study area presents a fragmented landscape and occurrence of many ruderal species, it represents a refuge for rare species like Psilochilus modestus and Streptochaeta spicata.

Small rodent communities (Muridae) in Gabonese savannas: species diversity and biogeographical affinities

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jean-François Mboumba ◽  
Maxime R. Hervé ◽  
Véronique Guyot ◽  
Frederic Ysnel
Keyword(s):  
Ecological Factors ◽  
Abundant Species ◽  
Small Rodent ◽  
Small Rodents ◽  
South West ◽  
New Information ◽  
Different Types ◽  
Mus Minutoides ◽  
Insight Into ◽  
Coastal Basin

Abstract The study contributes to the knowledge of species composition and biogeographical affinities of savannas rodent in Gabon. Unlike small rodents in Gabonese forests, there is little data on the diversity of small rodents in Gabonese savannas. The diversity and distribution of rodent murid communities was studied in four different types of savanna in Gabon: Coastal Basin (South-West), Lopé/Okanda (in the Center), Batéké Plateaux (Southeastern) and Ngougnié/ N’yanga (in the South). A total of 428 individuals representing six species were captured over 11,920 trap nights. Trap success was highly variable (2.2–6.9 %). The most abundant species were Mus minutoides (69%) followed by Lemniscomys striatus (21.5%). Indices of species richness varied from 2 to 5 and diversity (Shannon and Weaver) was low in the four savannas with the highest value at Ngougnié/N’yanga (H′ = 1.2). Species distributions show that Gabonese savanna small rodents conform to four distribution types, with one species known from Zambesian savannas exhibiting austral affinities (Pelomys campanae: occurs in three southern savannas). This new information provides important insight into the biogeography of small rodents at a local and regional level. Moreover, the correspondence analysis highlighted an influence of local ecological factors on population abundance.

Carabidae (Coleoptera) in Nova Scotia, Canada wild blueberry fields: prospects for biological control

2012 ◽  
Vol 144 (6) ◽  
pp. 779-791 ◽  
Author(s):  
G.C. Cutler ◽  
J.M. Renkema ◽  
C.G. Majka ◽  
J.M. Sproule
Keyword(s):  
Biological Control ◽  
Nova Scotia ◽  
Species Diversity ◽  
Insect Pests ◽  
Abundant Species ◽  
Conservation Biological Control ◽  
Carabid Beetles ◽  
Eastern Canada ◽  
Wild Blueberries ◽  
Wild Blueberry

AbstractThe Carabidae (Coleoptera) are a diverse family of beetles with almost 300 species identified in Nova Scotia, Canada. Carabid beetle communities have been studied in several agricultural systems, but not wild blueberries, an important crop in eastern Canada. In the interest of potentially developing conservation biological control programs in wild blueberry, we collected Carabidae in crop (fruit-bearing) and sprout (vegetative) blueberry fields in Nova Scotia in order to assess species diversity and abundance over space and time. Over 3200 specimens were collected, representing 51 species. A large portion of collected specimens (39%) were nonnative, and the most abundant species were generally predacious and synanthropic. Species diversity tended to be higher near forest edges than further into fields, but not for all abundant species. Several of the most prominent predators showed significant differences in preference of crop versus sprout fields, distribution throughout fields, and seasonable abundance. These findings have implications for conservation biological control efforts with carabid beetles against several insect pests in wild blueberry.

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.

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