scholarly journals Identifying environmental drivers of benthic diatom diversity: the case of Mediterranean mountain ponds

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8825 ◽  
Author(s):  
Saúl Blanco ◽  
Adriana Olenici ◽  
Fernando Ortega ◽  
Francisco Jiménez-Gómez ◽  
Francisco Guerrero
Keyword(s):  
Diversity Index ◽  
Abiotic Factors ◽  
Floristic Composition ◽  
Dispersal Limitation ◽  
High Elevation ◽  
Benthic Diatom ◽  
Temporary Ponds ◽  
Environmental Drivers ◽  
Significant Distance

This study aims at elucidating the environmental factors controlling benthic diatom diversity and uniqueness in Mediterranean mountain ponds. Samples of periphytic diatoms were collected in 45 ponds in Andalusia, south of Spain, and analysed by standard methods. Data analysis reveals that diatom diversity is mainly controlled by elevation and hydroperiod. Contrary to the usual findings in the literature, the highest scores on Shannon’s diversity index were found in high-elevation temporary ponds, but this effect is hidden by lake clustering in the analysed dataset. Significant distance-decay similarity (DDS) trends were detected in the analysis of floristic composition among the samples, stressing the importance of spatial factors that may override the effect of other abiotic factors. These findings highlight the role of isolation and dispersal limitation in the configuration of the biogeographical patterns of benthic diatoms.

scholarly journals Online appendix 2:Plant communities of the uMlalazi Nature Reserve and their contribution to conservation in KwaZulu-Natal

Koedoe ◽  
2018 ◽  
Vol 60 (1) ◽  
Author(s):  
Nqobile S. Zungu ◽  
Theo H.C. Mostert ◽  
Rachel E. Mostert
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Nature Reserve ◽  
Abiotic Factors ◽  
Floristic Composition ◽  
Environmental Drivers ◽  
Relative Contribution ◽  
Online Appendix ◽  
Species Analysis ◽  
Kwazulu Natal

Vegetation research is an important tool for the simplified and effective identification, management and conservation of the very complex ecosystems underlying them. Plant community descriptions offer scientists a summary and surrogate of all the biotic and abiotic factors shaping and driving ecosystems. The aim of this study was to identify, describe and map the plant communities within the uMlalazi Nature Reserve. A total of 149 vegetation plots were sampled using the Braun-Blanquet technique. Thirteen plant communities were identified using a combination of numeric classification (modified Two-way-Indicator Species Analysis) and ordination (non-metric multidimensional scaling). These communities were described in terms of their structure, floristic composition and distribution. An indirect gradient analysis of the ordination results was conducted to investigate the relationship between plant communities and their potentially important underlying environmental drivers. Based on the results, the floristic conservation importance of each plant community was discussed to provide some means to evaluate the relative contribution of the reserve to regional ecosystem conservation targets.Conservation implications: The uMlalazi Nature Reserve represents numerous ecosystems that are disappearing from a rapidly transforming landscape outside of formally protected areas in Zululand. The descriptions of the plant communities of these relatively pristine ecosystems provide conservation authorities with inventories and benchmarks with which the ecological health of similar ecosystems in the region can be measured.

scholarly journals Plant communities of the uMlalazi Nature Reserve and their contribution to conservation in KwaZulu-Natal

Koedoe ◽  
2018 ◽  
Vol 60 (1) ◽  
Author(s):  
Nqobile S. Zungu ◽  
Theo H.C. Mostert ◽  
Rachel E. Mostert
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Nature Reserve ◽  
Abiotic Factors ◽  
Floristic Composition ◽  
Environmental Drivers ◽  
Relative Contribution ◽  
Species Analysis ◽  
Kwazulu Natal ◽  
The Relationship

Vegetation research is an important tool for the simplified and effective identification, management and conservation of the very complex ecosystems underlying them. Plant community descriptions offer scientists a summary and surrogate of all the biotic and abiotic factors shaping and driving ecosystems. The aim of this study was to identify, describe and map the plant communities within the uMlalazi Nature Reserve. A total of 149 vegetation plots were sampled using the Braun-Blanquet technique. Thirteen plant communities were identified using a combination of numeric classification (modified Two-way-Indicator Species Analysis) and ordination (non-metric multidimensional scaling). These communities were described in terms of their structure, floristic composition and distribution. An indirect gradient analysis of the ordination results was conducted to investigate the relationship between plant communities and their potentially important underlying environmental drivers. Based on the results, the floristic conservation importance of each plant community was discussed to provide some means to evaluate the relative contribution of the reserve to regional ecosystem conservation targets.Conservation implications: The uMlalazi Nature Reserve represents numerous ecosystems that are disappearing from a rapidly transforming landscape outside of formally protected areas in Zululand. The descriptions of the plant communities of these relatively pristine ecosystems provide conservation authorities with inventories and benchmarks with which the ecological health of similar ecosystems in the region can be measured.

scholarly journals The contribution of environmental and dispersal filters on phylogenetic and taxonomic beta diversity patterns in Amazonian tree communities

Oecologia ◽  
2021 ◽  
Author(s):  
Juan Ernesto Guevara Andino ◽  
Nigel C. A. Pitman ◽  
Hans ter Steege ◽  
Manuel Peralvo ◽  
Carlos Cerón ◽  
...  
Keyword(s):  
Beta Diversity ◽  
Spatial Scales ◽  
Dispersal Limitation ◽  
Comprehensive Analysis ◽  
Environmental Drivers ◽  
Relative Importance ◽  
Spatial Variables ◽  
Ecuadorian Amazon ◽  
Tree Communities

AbstractEnvironmental and dispersal filters are key determinants of species distributions of Amazonian tree communities. However, a comprehensive analysis of the role of environmental and dispersal filters is needed to understand the ecological and evolutionary processes that drive phylogenetic and taxonomic turnover of Amazonian tree communities. We compare measures of taxonomic and phylogenetic beta diversity in 41 one-hectare plots to test the relative importance of climate, soils, geology, geomorphology, pure spatial variables and the spatial variation of environmental drivers of phylogenetic and taxonomic turnover in Ecuadorian Amazon tree communities. We found low phylogenetic and high taxonomic turnover with respect to environmental and dispersal filters. In addition, our results suggest that climate is a significantly better predictor of phylogenetic turnover and taxonomic turnover than geomorphology and soils at all spatial scales. The influence of climate as a predictor of phylogenetic turnover was stronger at broader spatial scales (50 km2) whereas geomorphology and soils appear to be better predictors of taxonomic turnover at mid (5 km2) and fine spatial scales (0.5 km2) but a weak predictor of phylogenetic turnover at broad spatial scales. We also found that the combined effect of geomorphology and soils was significantly higher for taxonomic turnover at all spatial scales but not for phylogenetic turnover at large spatial scales. Geographic distances as proxy of dispersal limitation was a better predictor of phylogenetic turnover at distances of 50 < 500 km. Our findings suggest that climatic variation at regional scales can better predict phylogenetic and taxonomic turnover than geomorphology and soils.

scholarly journals ENVIRONMENTAL DRIVERS OF FISH ASSEMBLAGES FROM THE SHALLOW INFRALITTORAL AREAS OF THE PARANAGUÁ BAY, SOUTHERN BRAZIL

2020 ◽  
Vol 24 (04) ◽  
pp. 917-927
Author(s):  
Paula Nakayama ◽  
◽  
Alberto Carvalho Peret ◽  
Johnatas Adelir-Alves ◽  
Olímpio Rafael Cardoso ◽  
...  
Keyword(s):  
Fish Assemblages ◽  
Diversity Index ◽  
Abiotic Factors ◽  
Sampling Site ◽  
Fish Fauna ◽  
Environmental Drivers ◽  
Estuarine Fish ◽  
Otter Trawl ◽  
Paranaguá Bay ◽  
Wiener Diversity Index

The composition of estuarine fish fauna is dynamic and complex. Despite the variation in fish fauna in estuaries, it is possible to observe some species associated with microhabitats. The assemblage composition of these communities is apparently derived from habitat selection. The aim of this study was to assess the structure of the demersal fish fauna of the Paranaguá Bay and its relationship with biotic and abiotic factors. To this end, monthly collections were conducted using an otter trawl, from October 1999 to September 2000, at five sites in the shallow infralittoral. Biotic (organic matter, and invertebrates) and abiotic factors (salinity, temperature, pH, dissolved oxygen, seston, and nutrients) were recorded during sampling. A total of 6,623 individuals were captured, belonging to 2 species of Chondrichthyes and 53 species of Actinopterygii (26 families). Sciaenidae was the most representative in terms of richness, with 11 species, and Ariidae was the most representative in terms of abundance. The catfish Cathorops spixii was the most abundant species, representing 21 % of the entire catch. There were significant differences in the composition and abundance of the fish fauna among the studied areas, as evidenced by the Shannon-Wiener diversity index. Such differences seem to be related to the complexity of habitats, which occur due to different types of bottom cover found at each sampling site. The abiotic variables indicated little influence on the structure of the fish assembly. These results contribute to a better understanding of the fish fauna from the shallow infralittoral areas of the Paranaguá Bay, and provide data to decision makers for better implementation of management and conservation measures.

scholarly journals Testing the role of the Red Queen and Court Jester as drivers of the macroevolution of Apollo butterflies

2017 ◽  
Author(s):  
Fabien L. Condamine ◽  
Jonathan Rolland ◽  
Sebastian Höhna ◽  
Felix A. H. Sperling ◽  
Isabel Sanmartín
Keyword(s):  
Large Scale ◽  
Abiotic Factors ◽  
Rapid Development ◽  
Environmental Drivers ◽  
Morphological Evidence ◽  
Red Queen ◽  
Extrinsic Factors ◽  
Positive Dependence ◽  
The Red Queen

AbstractIn macroevolution, the Red Queen (RQ) model posits that biodiversity dynamics depend mainly on species-intrinsic biotic factors such as interactions among species or life-history traits, while the Court Jester (CJ) model states that extrinsic environmental abiotic factors have a stronger role. Until recently, a lack of relevant methodological approaches has prevented the unraveling of contributions from these two types of factors to the evolutionary history of a lineage. Here we take advantage of the rapid development of new macroevolution models that tie diversification rates to changes in paleoenvironmental (extrinsic) and/or biotic (intrinsic) factors. We inferred a robust and fully-sampled species-level phylogeny, as well as divergence times and ancestral geographic ranges, and related these to the radiation of Apollo butterflies (Parnassiinae) using both extant (molecular) and extinct (fossil/morphological) evidence. We tested whether their diversification dynamics are better explained by a RQ or CJ hypothesis, by assessing whether speciation and extinction were mediated by diversity-dependence (niche filling) and clade-dependent host-plant association (RQ) or by large-scale continuous changes in extrinsic factors such as climate or geology (CJ). For the RQ hypothesis, we found significant differences in speciation rates associated with different host-plants but detected no sign of diversity-dependence. For CJ, the role of Himalayan-Tibetan building was substantial for biogeography but not a driver of high speciation, while positive dependence between warm climate and speciation/extinction was supported by continuously varying maximum-likelihood models. We find that rather than a single factor, the joint effect of multiple factors (biogeography, species traits, environmental drivers, and mass extinction) is responsible for current diversity patterns, and that the same factor might act differently across clades, emphasizing the notion of opportunity. This study confirms the importance of the confluence of several factors rather than single explanations in modeling diversification within lineages.

Diversity and spatial patterns of plant communities in volcanic temporary ponds of Sicily (Italy)

Biologia ◽  
2016 ◽  
Vol 71 (7) ◽  
Author(s):  
Saverio Sciandrello ◽  
Maria Privitera ◽  
Marta Puglisi ◽  
Pietro Minissale
Keyword(s):  
Plant Communities ◽  
Spatial Patterns ◽  
Diversity Index ◽  
Floristic Composition ◽  
Hierarchical Cluster ◽  
Community Diversity ◽  
Mount Etna ◽  
Temporary Ponds ◽  
Ecological Gradient ◽  
Floristic Richness

AbstractThe results of a study on plant community diversity, floristic richness, and spatial patterns in volcanic temporary ponds of Sicily are presented. A total of 166 plots were analyzed, 103 for Etna and 63 for Hyblaean sites. For each plot, the floristic composition and species cover were determined using standard relevé methods. Moreover, for these ponds, pH, conductivity, temperature, rainfall, altitude, and a floristic richness and diversity index were assessed. The plant communities were analyzed using a hierarchical cluster analysis, while the ordination method Non-metric Multidimensional Scaling was used to establish spatial patterns in the scattergram and to generate hypotheses on the vegetation/environment relationships. A total of nine plant communities for Hyblaean and seven for Mount Etna with a specific floristic composition were recognized. The spatial patterns of plant communities mainly followed an ecological gradient related to hydroperiod of the ponds, as well as local topography and human activities. The results show a considerable difference in floristic richness between the two study areas, as well as a different distribution of the life forms. Furthermore, for each study area the floristic richness and diversity index increased from the deep zone towards the shallow zone.

scholarly journals Online appendix 1:Plant communities of the uMlalazi Nature Reserve and their contribution to conservation in KwaZulu-Natal

Koedoe ◽  
2018 ◽  
Vol 60 (1) ◽  
Author(s):  
Nqobile S. Zungu ◽  
Theo H.C. Mostert ◽  
Rachel E. Mostert
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Nature Reserve ◽  
Abiotic Factors ◽  
Floristic Composition ◽  
Environmental Drivers ◽  
Relative Contribution ◽  
Online Appendix ◽  
Species Analysis ◽  
Kwazulu Natal

Vegetation research is an important tool for the simplified and effective identification, management and conservation of the very complex ecosystems underlying them. Plant community descriptions offer scientists a summary and surrogate of all the biotic and abiotic factors shaping and driving ecosystems. The aim of this study was to identify, describe and map the plant communities within the uMlalazi Nature Reserve. A total of 149 vegetation plots were sampled using the Braun-Blanquet technique. Thirteen plant communities were identified using a combination of numeric classification (modified Two-way-Indicator Species Analysis) and ordination (non-metric multidimensional scaling). These communities were described in terms of their structure, floristic composition and distribution. An indirect gradient analysis of the ordination results was conducted to investigate the relationship between plant communities and their potentially important underlying environmental drivers. Based on the results, the floristic conservation importance of each plant community was discussed to provide some means to evaluate the relative contribution of the reserve to regional ecosystem conservation targets.Conservation implications: The uMlalazi Nature Reserve represents numerous ecosystems that are disappearing from a rapidly transforming landscape outside of formally protected areas in Zululand. The descriptions of the plant communities of these relatively pristine ecosystems provide conservation authorities with inventories and benchmarks with which the ecological health of similar ecosystems in the region can be measured.

Assemblage Patterns of Hymenoptera at Different Elevations of Gunung Datuk, Rembau

2017 ◽  
Vol 14 (2) ◽  
pp. 1 ◽  
Author(s):  
Noor Nasuha Abd Aziz ◽  
Siti Khairiyah Mohd Hatta ◽  
Idris Abd Ghani ◽  
Saiyid Jalaluddin Saiyid Shaifuddin
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
High Elevation ◽  
Significant Difference ◽  
Index Site ◽  
Evenness Index ◽  
Abundance And Diversity ◽  
Richness Index ◽  
Paired T Test ◽  
Malaise Traps

A study on abundance and diversity of Hymenoptera was conducted in Gunung Datuk, Rembau. Samplings were conducted from November 2014 to February 2015 using six Malaise traps. Three traps were placed at Site 1 at 700m height for high elevation and the remaining traps were placed at Site 2 at 200m height for low elevation. A total number of 221 Hymenopteran were collected which consist of nine families namely Ichneumonidae, Formicidae, Braconidae, Bethylidae, Evaniidae, Tiphiidae, Vespidae, Pompilidae and Apidae. In this study, 93 individuals were obtained from Site 1, comprising nine families and 43 morphospecies while 127 individuals were obtained from Site 2 with nine families and 45 morphospecies. Formicidae was the most dominant family collected from both sites with a total of 104 individuals while the least family recorded was Apidae with only one individual. Shannon’s Weiner Diversity Index (H’) showed Site 1 had the higher diversity value with H’ = 3.17 compared to Site 2 with value H’ = 3.12. For Evenness Index, Site 1 had higher value compared to Site 2 with E’ = 0.84 and E’ = 0.82 respectively. Moreover, for Margalef Richness Index, Site 1 recorded R’ = 9.24 while site two recorded R’ = 9.08 which concluded that Site 1 had higher species richness compared to Site 2. Paired t-test showed that both sites had no significant difference with p>0.05. Overall study showed that the diversity and abundance of Hymenoptera in Gunung Datuk were low since the value of H’ is less than 3.50.

scholarly journals Influence of Land Use on Avian Diversity in North African Urban Environments

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 434
Author(s):  
Hani Amir Aouissi ◽  
Alexandru-Ionuţ Petrişor ◽  
Mostefa Ababsa ◽  
Maria Boştenaru-Dan ◽  
Mahmoud Tourki ◽  
...  
Keyword(s):  
Green Infrastructure ◽  
Diversity Index ◽  
Research Question ◽  
Urban Environments ◽  
Ecological Group ◽  
Avian Diversity ◽  
North African ◽  
Index Method ◽  
Urban Green Spaces

Land cover and use changes are important to study for their impact on ecosystem services and ultimately on sustainability. In urban environments, a particularly important research question addresses the relationship between urbanization-related changes and biodiversity, subject to controversies in the literature. Birds are an important ecological group, and useful for answering this question. The present study builds upon the hypothesis according to which avian diversity decreases with urbanization. In order to answer it, a sample of 4245 observations from 650 sites in Annaba, Algeria, obtained through the point abundance index method, were investigated by computing Shannon-Wiener’s diversity index and the species richness, mapping them, and analyzing the results statistically. The findings confirm the study hypothesis and are relevant for planning, as they stress the role of urban green spaces as biodiversity hotspots, and plead for the need of connecting them. From a planning perspective, the results emphasize the need for interconnecting the green infrastructure through avian corridors. Moreover, the results fill in an important lack of data on the biodiversity of the region, and are relevant for other similar Mediterranean areas. Future studies could use the findings to compare with data from other countries and continents.

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