scholarly journals Influence of Zostera marina L. and Z. noltei Hornem. (Zosterales: Liliopsida) on the composition, species richness and coenotic diversity of the phytobenthos of the Azov Sea

2021 ◽  
Vol 38 ◽  
pp. 00001
Author(s):  
Dmitry Afanasyev ◽  
Valery Akatov
Keyword(s):  
Species Richness ◽  
Zostera Marina ◽  
Higher Plants ◽  
Small Community ◽  
Species Diversification ◽  
Number Of Species ◽  
Azov Sea ◽  
Silty Soils ◽  
High Degree ◽  
Coenotic Diversity

The influence of marine higher plants Zostera marina and Z. noltei on the composition, species richness and coenotic diversity of the phytobenthos of sandy and silty soils of the Taman Bay in the Azov Sea at the depths from 0.5 to 3 m has been investigated. It is shown that 1) macrophytobenthic communities with a high degree of Z. noltei and Z. marina dominance (DD), both at very small and relatively large sites, are characterized by lower species richness than the communities with low DD; 2) that being said, for the majority of co-occurring species it is possible to grow in coenoses with any DD; 3) accordingly, about the same number of species can grow at the small community sites with low DD and at the larger sites with high DD; 4) DD has little to no influence on the species diversification of coenoses. However, both the growth of Zostera marina and Z. noltei and the decrease in their participation can lead to considerable drop in occurrence of some macroalgae species or to disappearance of those species from a community.

scholarly journals Species richness and diversity in shrub savanna using ordinary kriging

2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Diversity Index ◽  
Spatial Models ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Species Richness And Diversity ◽  
Number Of Species

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.

scholarly journals Scavenging in the Anthropocene: Human impact drives vertebrate scavenger species richness at a global scale

2020 ◽  
Author(s):  
E Sebastián-González ◽  
JM Barbosa ◽  
JM Pérez-García ◽  
Z Morales-Reyes ◽  
F Botella ◽  
...  
Keyword(s):  
Species Richness ◽  
Human Impact ◽  
Large Scale ◽  
Diversity Index ◽  
Global Scale ◽  
Climatic Conditions ◽  
Ecosystem Functions ◽  
Number Of Species ◽  
Terrestrial Vertebrate ◽  
Latitudinal Patterns

© 2019 John Wiley & Sons Ltd Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large-scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion-consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using 2,485 carcasses monitored between 1991 and 2018. First, we evaluated how scavenger richness (number of species) and diversity (Shannon diversity index) varied among seasons (cold vs. warm, wet vs. dry). Then, we studied the potential effects of human impact and a set of macroecological variables related to climatic conditions on the scavenger assemblages. Vertebrate scavenger richness ranged from species-poor to species rich assemblages (4–30 species). Both scavenger richness and diversity also showed some seasonal variation. However, in general, climatic variables did not drive latitudinal patterns, as scavenger richness and diversity were not affected by temperature or rainfall. Rainfall seasonality slightly increased the number of species in the community, but its effect was weak. Instead, the human impact index included in our study was the main predictor of scavenger richness. Scavenger assemblages in highly human-impacted areas sustained the smallest number of scavenger species, suggesting human activity may be overriding other macroecological processes in shaping scavenger communities. Our results highlight the effect of human impact at a global scale. As species-rich assemblages tend to be more functional, we warn about possible reductions in ecosystem functions and the services provided by scavengers in human-dominated landscapes in the Anthropocene.

scholarly journals A checklist of gilled mushrooms (Basidiomycota: Agaricomycetes) with diversity analysis in Hollongapar Gibbon Wildlife Sanctuary, Assam, India

2015 ◽  
Vol 7 (15) ◽  
pp. 8272 ◽  
Author(s):  
Girish Gogoi ◽  
Vipin Parkash
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Abundant Species ◽  
Shannon Diversity Index ◽  
Diversity Analysis ◽  
Wildlife Sanctuary ◽  
Shannon Diversity ◽  
Number Of Species ◽  
Simpson Diversity Index ◽  
Richness Index

<p>Hollongapar Gibbon Wildlife Sanctuary is comprised of five distinct compartments.  A total of 138 species of gilled mushrooms belonging to 48 genera, 23 families, five orders of the class Agaricomycetes, division Basidiomycota, have been collected and analyzed. The order Agaricales was was found with the highest number of species (113), followed by Russulales (14), Polyporales (5), Cantharellales (4) and Boletales (2). The species <em>Coprinellus disseminatus </em>and <em>Megacollybia rodmani</em> have shown the highest (8.26) and the lowest density (0.05), respectively.  A total of 24 species, e.g., <em>Termitomyces albuminosus, Marasmius curreyi, Marasmiellus candidus, Leucocoprinus medioflavus, Mycena leaiana, Hygrocybe miniata, Collybia chrysoropha, Gymnopus confluens</em> were common with frequency percentage of 11.9, whereas <em>Megacollybia rodmani</em> with less frequency percentage (2.4) was found only in few quadrates of the sanctuary.  The highly abundant species were <em>Termitomyces medius</em> (91.7) and <em>Coprinellus disseminatus </em>(86.8), and less abundant species were <em>Psilocybe wayanadensis</em> (1.0) and <em>Lepiota</em> sp. (1.0) in the study site.  The order of the species richness index (<em>R</em>) compartment wise was 2&gt;3&gt;4&gt;5&gt;1. Both the Shannon diversity index and Simpson diversity index of agarics was maximum (1.88, 0.98) in compartment 2, whereas minimum (1.72, 0.95) in compartment 1 and 5, respectively.  Moreover, the compartment 2 was found very much similar with compartment 3 and very less similar with compartment 1.</p><div> </div>

The Biosynthesis of 4-Methylsulfinyl-3-butenylglucosinolate (Glucoraphenin) in Matthiola Species / Evidence for Homomethionine and 2-Amino-6-methylthiocaproic Acid as Intermediates

1975 ◽  
Vol 30 (3-4) ◽  
pp. 233-239 ◽  
Author(s):  
W. Löffelhardt ◽  
H. Kindi
Keyword(s):  
Higher Plants ◽  
Chain Elongation ◽  
Mustard Oil ◽  
High Degree

Abstract [35S] L-Methionine and [methyl-14C] ʟ-methionine were fed to shoots of Matthiola annua and Matthiola sinuata. The label from both precursors was incorporated to a high degree into 4-methylsulfinyl- 3-butenylglucosinolate, the main mustard oil glucoside of M atth iola species. Two homologues of methionine, homomethionine and 2-amino-6-methylthiocaproic acid, were also labelled in these experiments. 2-Amino-6-methylthiocaproic acid, deriving from methionine via homomethionine by two successive C1-chain elongation steps, was higher plants

Habitat-specific distributions of some fishes in a tropical estuary

1996 ◽  
Vol 47 (6) ◽  
pp. 827 ◽  
Author(s):  
MJ Sheaves
Keyword(s):  
Species Richness ◽  
Abundant Species ◽  
Epinephelus Coioides ◽  
Tropical Estuary ◽  
Habitat Types ◽  
Number Of Species ◽  
Fish Traps ◽  
Tropical Australia ◽  
Sampling Trip ◽  
Probability Of Capture

The species richness of fishes and the distributions of six fish species were compared among four habitat types, snaggy banks, clear banks, mud banks and mid channels, in an estuary in tropical Australia. Both day and night samples were collected in fish traps, on four occasions, three months apart. On each sampling trip the highest number of species was trapped from snaggy habitats, intermediate numbers from clear banks or mud banks, and the fewest species from mid channels. Although more species occurred in night than in day samples, the pattern of difference among habitats was consistent. The probability of capture of the six most abundant species, Acanthopagrus australis, Acanthopagrus berda, Arothron manilensis, Arius argyropleuron, Epinephelus coioides and Lutjanus russelli, was compared among habitat types and between day and night samples. Overall, snag habitats tended to be associated with high probabilities of capture of a number of species, particularly A. berda and L. russelli. At night, mid channels were characterized by high numbers of A. argyropleuron. Clear and mud banks, and day samples from mid channels were associated with low numbers of most species.

scholarly journals Biogeographic and species richness patterns of Gastropoda on the southwestern Atlantic

1999 ◽  
Vol 59 (4) ◽  
pp. 567-575 ◽  
Author(s):  
S. R. FLOETER ◽  
A. SOARES-GOMES
Keyword(s):  
Species Richness ◽  
Transition Zone ◽  
Rio Grande ◽  
Distribution Patterns ◽  
Southwestern Atlantic ◽  
Rio Grande Do Sul ◽  
Biogeographic Province ◽  
Number Of Species ◽  
Richness Patterns ◽  
The Tropics

Patterns of richness and biogeography of Gastropoda molluscs were determined based on lists of species from five sites along the southwestern Atlantic. The analysis of the distribution patterns of these sites confirmed the existence of a broader transition zone between southern Espírito Santo State (21°S) and Rio Grande do Sul State (32°S). This zone is very heterogeneous, presenting a low endemism rate and a significant number of species common to the near provinces, and does not show enough consistency to be considered as an independent biogeographic province as proposed by Palacio (1980). Observing the distribution of species along the southwestern Atlantic we find an increase in the proportion of species with greatest latitudinal ranges (occurring from the tropics to Patagonia) from lowest to highest latitudes, following Rappoport's rule.

Geographic ranges of genera and their constituent species: structure, evolutionary dynamics, and extinction resistance

Paleobiology ◽  
2016 ◽  
Vol 42 (2) ◽  
pp. 269-288 ◽  
Author(s):  
Michael Foote ◽  
Kathleen A. Ritterbush ◽  
Arnold I. Miller
Keyword(s):  
Species Richness ◽  
Evolutionary Dynamics ◽  
Species Structure ◽  
Sampled Data ◽  
Widespread Species ◽  
Geographic Ranges ◽  
Number Of Species ◽  
Constituent Species ◽  
The Mean

AbstractWe explore the relationships among the geographic ranges of genera, the ranges and positions of their constituent species, and the number of species they contain, considering variation among coeval genera and changes within genera over time. Measuring range size as the maximal distance, or extent, between occurrences within a taxon, we find that the range of the most widespread species is a good predictor of the range of the genus, and that the number of species is a better predictor still. This analysis is complicated by a forced correlation: the range of a genus must be at least as large as that of each of its constituent species. We therefore focus on a second measure of range, the mean squared distance, or dispersion, of occurrences from the geographic centroid, which, by analogy to the analysis of variance, allows the total dispersion of a genus to be compared to the mean within-species dispersion and the dispersion among species centroids. We find that among-species dispersion is the principal determinant of genus dispersion. Within-species dispersion also plays a major role. The role of species richness is relatively small. Our results are not artifacts of temporal variation in the geographic breadth of sampled data. The relationship between changes in genus dispersion and changes in within- and among-species dispersion shows a symmetry, being similar in cases when the genus range is expanding and when it is contracting. We also show that genera with greater dispersion have greater extinction resistance, but that within- and among-species dispersion are not demonstrable predictors of survival once the dispersion of the genus is accounted for. Thus it is the range of the genus, rather than how it is attained, that is most relevant to its fate. Species richness is also a clear predictor of survival, beyond its effects on geographic range.

Weed infestation during the transition phase from conventional to conservation agriculture

2020 ◽  
Author(s):  
Felice Sartori ◽  
Donato Loddo ◽  
Ilaria Piccoli ◽  
Antonio Berti
Keyword(s):  
Species Richness ◽  
Seed Bank ◽  
Conservation Agriculture ◽  
Soil Disturbance ◽  
Transition Phase ◽  
Effective Control ◽  
Silty Clay ◽  
Weed Species ◽  
Number Of Species ◽  
Weed Species Richness

&lt;p&gt;Despite conservation agriculture and, overall, the reduction of soil disturbance are considered soil improving cropping systems, these practices could conflict with weed control. Indeed, reduced tillage is usually linked to increased weed species richness and abundance and, thus, it could increase the dependence on chemical treatments. Weed management is one of the reasons behind the distrust of European farmers in the conservation agriculture, that is still not widespread, despites European subsidies. In fact, conservation agriculture is implemented only in the 2.8% of European cropland.&lt;/p&gt;&lt;p&gt;The aim of this study is to evaluate the effect of different tillage intensities on spring-summer weeds richness and abundance in a maize monoculture, during the transition phase from conventional to conservation agriculture.&lt;/p&gt;&lt;p&gt;The weed survey was conducted in June 2019 on an experiment comparing three levels of tillage management: conventional agriculture (CT), which represents the most common choice in Veneto region, involving deep ploughing and harrowing in spring; minimum tillage (MT), consisting only in harrowing at 20 cm; and no tillage (NT), namely sod seeding. The experiment started in 2018, at Padova University experimental farm, in a sub-humid area, with a silty clay loam soil. The survey was conducted with a set of random throws of a 30&amp;#215;30 cm square frame in each plot (ca. 3300 m&lt;sup&gt;2&lt;/sup&gt;). &amp;#160;Weed plants found within the frame were classified and counted. Subsequently, data analysis assessed which botanical families were promoted by each treatment.&lt;/p&gt;&lt;p&gt;The NT resulted the treatment with the highest weed density (915 plant/m&lt;sup&gt;2&lt;/sup&gt;): 6% higher than MT (823 plant/m&lt;sup&gt;2&lt;/sup&gt;) and four-fold more than CT (209 plant/m&lt;sup&gt;2&lt;/sup&gt;). The latter showed to be the treatment with higher diversity, according to both Shannon and Simpson indices. The survey evidenced higher weed species richness in MT, where both annual and perennial species were identified, while the lowest number of species were detected in NT. Plantago major and Chenopodium album were the species with the highest density in CT (&gt;32 plant/m&lt;sup&gt;2&lt;/sup&gt;) while they are negligible in NT and MT (7 plant/m&lt;sup&gt;2&lt;/sup&gt;, on average). Digitaria sanguinalis was instead the dominant species in MT and NT (&gt;600 plant/m&lt;sup&gt;2&lt;/sup&gt;) while a lower density was observed in CT (11 plant/m&lt;sup&gt;2&lt;/sup&gt;). Low levels of Asteraceae weeds were measured in all treatments. These results shows that the actual flora rapidly changes depending on tillage intensity, with an increase of both dominance and number of species in MT. Differently, only a limited number of adapted species germinated in NT, despite higher infestations if compared with the other treatments.&lt;/p&gt;&lt;p&gt;It should be expected that other species more adapted to conservation agriculture (namely Asteraceae), still marginally present in the seed bank, will spread in the next years. This stresses the importance of a continuous monitoring and effective control of weeds to avoid uncontrolled evolutions of the weed flora and increase of seed bank in the transition phase from conventional to conservation agriculture.&lt;/p&gt;

Potensi Makroalga di Paparan Terumbu Karang Perairan Teluk Lampung

2017 ◽  
Vol 2 (1) ◽  
pp. 55 ◽  
Author(s):  
Tri Handayani
Keyword(s):  
Species Richness ◽  
Reef Flat ◽  
Life Form ◽  
Coastal Ecosystem ◽  
Economic Values ◽  
Number Of Species ◽  
Average Biomass ◽  
Study Sites ◽  
Surrounding Areas ◽  
Base Substrate

<strong>The Potency of Macroalgae in the Reef Flat of Lampung Bay.</strong> Lampung Bay is a strategic area that develops quite rapidly. This condition will put pressure on the coastal ecosystem as the estuary of all activities from surrounding areas. Macroalgae, which is one component of the coastal ecosystem, is also under pressure. Therefore, we need to know the species richness, potency, and macroalgae life characteristics in Lampung Bay waters. The study was conducted in March 2009, in eight locations, namely Piabung, Klagian, Pancur, Limbungan, Puhawang Barat, Puhawang Timur, Puhawang Kecil, and Kalangan. The macroalgae samples were collected by the quadratic transect method. The parameters observed were species, biomass, substrate, and macroalgae life form. A total of 27 macroalgae species were identified consisting of three divisions and 17 genera. Division Chlorophyta, Ochrophyta, and Rhodophyta each consisted of nine species. Nineteen species were macroalgae that have important economic values. The highest number of macroalgae species was found in Pancur, while the lowest was in Kalangan. The genera that dominated the study sites were Halimeda and Caulerpa. The highest average biomass was found in Pancur with 675.5 g/m2, whereas in Kalangan there was no macroalgae observed. The base substrate was dominated by sand. The condition of the base substrate affects the number of species and the nature of macroalgae life. In general, macroalgae resources in the waters of Lampung Bay are not potential to be developed, but Sargassum in Pancur has the potential to be developed as seeds.

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