scholarly journals Structure and temporal dynamics of a seaweed assemblage dominated by the invasive lineage 2 of Asparagopsis taxiformis (Bonnemaisoniaceae, Rhodophyta) in the Alboran Sea

2018 ◽  
Vol 19 (1) ◽  
pp. 147 ◽  
Author(s):  
MARIANELA ZANOLLA ◽  
RAQUEL CARMONA ◽  
JULIO DE LA ROSA ◽  
MARÍA ALTAMIRANO

Asparagopsis taxiformis is a rhodophycean species composed of six genetic lineages, one of which is considered a relevant invasive component of the Mediterranean flora. In the present study we describe seasonal changes of the structure and biomass of the native community associated to Asparagopsis taxiformis in Granada (Southern Spain). Native community was represented by 18 Rhodophyta, 3 Chlorophyta and 4 Ochrophyta species. Biomass was dominated by A. taxiformis and Halopteris filicina. While in January A. taxiformis accounted for only 16% of the community biomass, an explosive dominance was observed only two months later, representing more than 90% of the algal biomass. Furthermore, low and generally stable values of species richness, Shannon’s diversity index and evenness were recorded during the study period. Given that A. taxiformis gametophytes are present year round, they are likely to pose a constant stress to native community development. This survey provides baseline information of macroalgal community structure useful for further studies to assess the true impact of the invasive lineage of A. taxiformis.

Author(s):  
RP Jose ◽  
WA Aureo ◽  
CI Narido ◽  
TD Reyes Jr ◽  
MB Sarnowski

A comprehensive inventory of faunal biodiversity was conducted within three Key Biodiversity Areas of Central Visayas. Mt. Bandilaan Natural Park (MBNP), Balinsasayao Twin Lakes Natural Park (BTLNP), and Rajah Sikatuna Protected Landscape (RSPL). Three primary wildlife groups were surveyed: bats, birds and amphibians. Species diversity and population trends were then analyzed to assess areas of biodiversity importance. RSPL generally had the highest species richness and diversity index while MBNP consistently had the lowest. When pooled. The surveyed areas resulted in a high diversity index and rate of endemicity showing the importance of multiple areas of protection. These findings can be utilized to prioritize habitat protection as well as to serve as a baseline information for future biodiversity inventories. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(2): 27-34


2007 ◽  
Vol 64 (4) ◽  
pp. 393-399 ◽  
Author(s):  
Milene Moreira ◽  
Dilmar Baretta ◽  
Siu Mui Tsai ◽  
Sandra Maria Gomes-da-Costa ◽  
Elke Jurandy Bran Nogueira Cardoso

Araucaria angustifolia (Bert.) O. Ktze. is an endangered Brazilian coniferous tree that has been almost exterminated in the native areas because of uncontrolled wood exploitation. This tree has been shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) and, therefore, AMF may be essential for forest sustainability and biological diversity. Root colonization, density and diversity of AMF spores were assessed in two Araucaria forest stands at the State Park of Alto Ribeira (PETAR), at two sampling dates: May and October. A comparison was made between a mature native stand composed of Araucaria trees mixed into a variety of tropical trees and shrubs, without any sign of anthropogenic interference (FN) and an Araucaria stand planted in 1987 (R), which has been used as a pasture. Assessments included percent root colonization, AMF spore numbers and species richness, Simpson's dominance index (Is), and Shannon's diversity index (H). Mycorrhizal root colonization did not differ between ecosystems in May. In October, however, the native stand (FN) presented a higher colonization than the planted forest (R), and the root colonization was more intense than in May. When considering both sampling periods and forests, 27 species of AM fungi, with higher numbers of spores in FN than in R were found. Canonical discriminant analysis (CDA) indicated Shannon's diversity index as the ecological attribute that contributed the most to distinguish between forest ecosystems, with higher value of H in FN in relation to R. CDA showed to be a useful tool for the study of ecological attributes.


1994 ◽  
Vol 24 (6) ◽  
pp. 1260-1265 ◽  
Author(s):  
David N. Holland ◽  
Robert J. Lilieholm ◽  
David W. Roberts ◽  
J. Keith Gilless

Three indices of forest stand structural and compositional diversity were incorporated into a linear programming timber harvest scheduling model to examine the trade-offs between managing stands for timber production and biodiversity objectives. The indices, based on Shannon's diversity index, characterized stand species diversity, basal area diversity, and vertical crown diversity. While harvest-level objectives were often compatible with the maintenance of vegetative diversity, the maximization of present net value was accompanied by substantial reductions in all three measures of diversity.


2012 ◽  
Vol 60 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Bao-Ming Ge ◽  
Yi-Xin Bao ◽  
Hong-Yi Cheng ◽  
Dai-Zhen Zhang ◽  
Zhi-Yuan Hu

Many coastal habitats in eastern China are being substantially altered by the invasion of Spartina alterniflora. The species richness, density, Margalef's diversity index (R) and Shannon's diversity index (H') of macrobenthic communities on a tidal flat in Wenzhou Bay, China, were analyzed with the factors of invasion stage and season, in 2007. A significant effect of invasion stage, season, and the interaction between them on communities was detected. The macrobenthic community was more complex in the patch of initial S. alterniflora invasion than in the patches of some other invasion stages. Macrobenthic communities were classified by cluster and ordination in accordance with the habitat character of the S. alterniflora invasion stage. Our research demonstrated that the S. alterniflora invasion stage affected the macrobenthic communities significantly. The results indicated that biodiversity increased in the initial stage of invasion (invasion age 1-2 years) and then decreased in the stage of invasion underway (invasion age 3-4 years) and in the stage of invasion completed (invasion age 5-6 years); this phenomenon was related to the change in the S. alterniflora canopy which accompanied the invasion stages.


2021 ◽  
Vol 98 (3) ◽  
pp. 308-318
Author(s):  
A. A. Baturin ◽  
G. A. Tkachenko ◽  
M. L. Ledeneva ◽  
L. V. Lemasova ◽  
O. S. Bondareva ◽  
...  

Aim. A study of the prevalence of West Nile virus (WNV) genetic lineages and genovariants in the south of European Russia between 2010 and 2019.Materials and methods. The study was carried out on 311 WNV containing biological samples from patients, vectors and reservoirs of infection. WNV typing was carried out using reverse transcription and real-time polymerase chain reaction with designed three pairs of primers and three probes and by the sequencing of the 277 bp WNV genome region corresponding to the 5'-untranslated region and locus of the polyprotein gene encoding the capsid protein C. Sequencing results were analyzed using the Nucleotide BLAST software (NCBI).Results. As a result of typing, out of 311 WNV RNA isolates taken for the study, 15 (4.82%) were assigned to lineage 1 (from Astrakhan and Volgograd regions, Krasnodar and Stavropol Territories, Republic of Tatarstan), 285 (91.64%) to lineage 2 (from Astrakhan, Volgograd, Voronezh, Kursk, Lipetsk, Penza, Rostov and Saratov regions, Krasnodar and Stavropol Territories, Republics of Kalmykia and Crimea), and 11 (3.54%) to lineage 4 (from the Volgograd region, Republics of Kalmykia and Crimea). The predominance of viral lineage 2 was demonstrated. The identified isolates of the viral lineage 1 belonged to the «Astrakhan» variant, isolates of lineage 2 belonged to «Russian» and «European» variants. Previously uncommon WNV variants of lineages 1 and 4 were also found.Conclusion. Lineage 2 of WNV prevailed in the south of European Russia in the last decade. The «Russian» variant is most common and its area is expanding. The circulation of various WNV genetic lineages in Russia indicates the need for further study of their spread and improving diagnostic methods and test systems for identifying and differentiating pathogen strains.


2020 ◽  
Vol 38 ◽  
Author(s):  
P.H.S. SOUSA ◽  
M.R.A. MENDES ◽  
A.D.B. VAL ◽  
M.C.S.A. TEIXEIRA

ABSTRACT: This study aimed to identify and quantify the weed species in an area of organic acerola cultivation in the Distrito de Irrigação dos Tabuleiros Litorâneos do Piauí (DITALPI) in Parnaíba, Piauí, Brazil. Phytosociological sampling was completed in the rainy season, before the farmers adopted management techniques for the plants. Thirty plots of 0.25 m2 were sampled. The plots were located between crop rows, which consisted of herbaceous-subshrub plants. The absolute and relative covers and the absolute and relative frequencies of each species were calculated based on the occurrence and cover of each species. In total, 25 species comprising 13 families were registered, among which the Poaceae family that presented the largest number of species. Commelina benghalensis occurred the most frequently overall. Shannon’s diversity index (H’) and evenness were calculated as 2.30 nats ind-1 and 0.69, respectively. Five species accounted for 79.33% of absolute cover at DITALPI. The species were distributed heterogeneously within the field, and Commelina benghalensis, Urochloa plantaginea, Panicum maximum, Amaranthus spinosus, Cynodonsp., and Cyperus aggregatus were the species most likely to infest the acerola crop. As DITALPI is an area of organic cultivation, understanding these species is essential to help farmers select the best form of control.


2004 ◽  
Vol 64 (3a) ◽  
pp. 531-541 ◽  
Author(s):  
C. Volkmer-Ribeiro ◽  
D. L. Guadagnin ◽  
R. De Rosa-Barbosa ◽  
M. M. Silva ◽  
S. Drügg-Hahn ◽  
...  

A new device to sample freshwater benthic macroinvertebrates was used in a low and sandy stretch of a Brazilian sub-tropical river (the River Caí, Triunfo, RS) and in one of its small tributaries, Bom Jardim brook (Arroio Bom Jardim). In this study, the effectiveness of this device, a PET sampler, was tested at different sites in the river and the brook throughout the four seasons between 2001-2002. Comparisons were made by PCA and ANOVA, both employing a bootstrap procedure based on similarity matrices. The PET sampler proved to be a reliable tool for detection of seasonal and spatial differences in richness, total abundance of organisms, and Shannon's diversity index in both river and brook and is therefore recommended for use in the monitoring of macroinvertebrate communities in this system.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Harriet R Thatcher ◽  
Colleen T Downs ◽  
Nicola F Koyama

Abstract The urban landscape is a complex mosaic of costs and benefits for urban wildlife. Although many species may adapt and thrive in the urban mosaic, the complexity of this landscape can be stressful and have health implications for urban wildlife, raising concerns for zoonosis and biodiversity. In this study, we assessed how human–primate interactions influenced parasite risk and anxiety-related behaviour of urban vervet monkeys in KwaZulu-Natal, South Africa. Over 1 year, we collected and analysed faecal samples, assessing eggs per gram, species richness, and Shannon’s diversity index. In addition, using behavioural sampling, we recorded self-directed scratching behaviour, as an indicator of anxiety, and human–primate interactions, both positive (human-food consumption) and negative (human–monkey aggression). To assess parasite risk in the urban mosaic, we ran three models with our parasite measures as dependent variables. Results showed that negative human interactions significantly increased with eggs per gram, species richness, and Shannon’s diversity index and positive human interactions increased with both eggs per gram and species richness. Furthermore, eggs per gram significantly increased with higher scratching rate. We also tested the relationship between scratching and human interactions, finding that scratching significantly increased under higher rates of negative human incidents. Overall, results suggest that there are costs to urban living that increase anxiety-related behaviour and parasite risk despite increased food availability. Our findings are important for developing effective management strategies that focus on cohabitation rather than conflict, for the benefit of human and wildlife health.


2021 ◽  
Vol 30 (4) ◽  
pp. 381-392
Author(s):  
K Hall ◽  
J Bryant ◽  
M Staley ◽  
JC Whitham ◽  
LJ Miller

Behavioural diversity may serve as a positive indicator of animal welfare that can be applied in long-term monitoring schemes in managed settings (eg zoos, laboratories, farms). Behavioural diversity is often higher when animals live in stimulating environments and experience positive events. Unfortunately, welfare researchers have not adopted consistent, standardised approaches to measuring behavioural diversity. The goal of this exploratory study was to utilise data from 41 adult chimpanzees (Pan troglodytes) housed across 16 zoological institutions to examine various models of Shannon's Diversity Index. Specifically, we investigated the impact of: combining versus splitting behaviours, including only positive behaviours, including human interaction, and considering recipient behaviours. We evaluate how the inclusion or exclusion of different behaviours impacts the relationship of behavioural diversity with: (i) concentrations of faecal glucocorticoid metabolites (GCM), a common indicator of adrenal activity; (ii) concentrations of immunoglobulin-A (IgA), an indicator of immune function and potential indicator of positive welfare; and (iii) stereotypic behaviour, a validated indicator of poor welfare. Most indices had significant negative relationships with faecal GCM. Animals that express a variety of behaviours from their species-typical repertoire have lower average faecal GCM concentrations and are likely experiencing better welfare. We did not find significant relationships between the behavioural diversity indices and IgA concentrations. Two indices were inversely associated with stereotypic behaviour. Our findings provide additional support for using Shannon's Diversity Index to calculate behavioural diversity as a robust, valid measure of positive welfare. However, future publications must justify the process for including or excluding behaviours from calculations.


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