scholarly journals Patterns of change in α and β taxonomic and phylogenetic diversity in the secondary succession of semi-natural grasslands in the Northern Apennines

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8683
Author(s):  
Lorenzo Lazzaro ◽  
Lorenzo Lastrucci ◽  
Daniele Viciani ◽  
Renato Benesperi ◽  
Vincenzo Gonnelli ◽  
...  
Keyword(s):  
Species Richness ◽  
Phylogenetic Tree ◽  
Secondary Succession ◽  
Phylogenetic Diversity ◽  
Species Selection ◽  
Dry Grasslands ◽  
Hay Meadows ◽  
Β Diversity ◽  
Natural Grasslands ◽  
Succession Stage

We studied the secondary succession in semi-natural grasslands (dry grasslands and hay meadows) located in the eastern side of the Tuscan Apennines (Tuscany, Central Italy). We compared these habitats, investigating: (i) the changes in species richness, composition and phylogenetic diversity during the succession; (ii) whether the trends in species loss and species turnover in taxonomic diversity matched those in phylogenetic diversity. We performed a stratified random sampling, in a full factorial design between habitat type and succession stage (60 sampled plots, 10 × 2 types of habitat × 3 stages of succession). We constructed a phylogenetic tree of the plant communities and compared the differences in taxonomic/phylogenetic α- and β-diversity between these two habitats and during their succession. We identified indicator species for each succession stage and habitat. Looking at α-diversity, both habitats displayed a decrease in species richness, with a random process of species selection in the earlier succession stages from the species regional pool. Nevertheless, in the latter stage of dry grasslands we recorded a shift towards phylogenetic overdispersion at the higher-level groups in the phylogenetic tree. In both habitats, while the richness decreased with succession stage, most species were replaced during the succession. However, the hay meadows were characterized by a higher rate of new species’ ingression whereas the dry grasslands became dominated with Juniperus communis. Accordingly, the two habitats showed similar features in phylogenetic β-diversity. The main component was true phylogenetic turnover, due to replacement of unique lineages along the succession. Nevertheless, in dry grasslands this trend is slightly higher than expected considering the major importance of difference in species richness of dry grasslands sites and this is due to the presence of a phylogenetically very distant species (J. communis).

scholarly journals Climatic drivers of dry grassland phylogenetic diversity in the Republic of Macedonia

2019 ◽  
Vol 78 (1) ◽  
pp. 25-34
Author(s):  
Marco Antonio Batalha ◽  
Renata Ćušterevska ◽  
Vlado Matevski
Keyword(s):  
Phylogenetic Tree ◽  
Evolutionary History ◽  
Phylogenetic Diversity ◽  
Global Climate ◽  
Climatic Variables ◽  
Dry Grassland ◽  
Species Sorting ◽  
Dry Grasslands ◽  
Global Climate Changes ◽  
The Republic

Abstract Climatic gradients can be used to predict the extent to which climate drives biodiversity and to which biodiversity may be affected by global climate changes. Climate and evolutionary history are linked by the ecological adaptations of species and the history of Earth’s climate. If so, phylogenetic diversity may be a good metric to estimate biodiversity. We aimed to test whether the phylogenetic diversity of Macedonian dry grasslands was related to climatic variables. We sampled 575 plots, identifying the species and building a phylogenetic tree for them. We calculated two metrics of phylogenetic diversity and regressed them against climatic variables. We also tested whether there were nodes in the tree responsible for the main observed spatial patterns of phylogenetic diversity. We found a strong signature of evolutionary history in species sorting across a gradient driven by climate in Macedonian dry grasslands. First, the amount of evolutionary history decreased towards drier and more seasonal climates, suggesting a phylogenetic niche conservatism. Second, there was an air temperature filter and a temperature seasonality filter, acting in opposite directions and leading to phylogenetic clustering. Third, there were few nodes in the phylogenetic tree with high degrees of allopatry, associated with clades that differed not only in their geographic distribution, but also in their climatic preferences. Macedonian dry grassland communities developed over centuries of traditional land use but are threatened nowadays by human activities. The use of phylogenetic approaches may lead to more effective conservation policies and help us preserve this highly diverse vegetation.

scholarly journals Arthropod community structure in pastures of an island archipelago (Azores): looking for local–regional species richness patterns at fine-scales

2004 ◽  
Vol 94 (2) ◽  
pp. 111-121 ◽  
Author(s):  
P.A.V. Borges ◽  
V.K. Brown
Keyword(s):  
Species Richness ◽  
Regional Scale ◽  
Local Scale ◽  
Local Species Richness ◽  
Β Diversity ◽  
Arthropod Species ◽  
Α Diversity ◽  
Local Species ◽  
Richness Patterns

AbstractThe arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local–regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= α diversity) and regional species richness was estimated at the pasture level (= γ diversity) with the ‘first-order-Jackknife’ estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of α and β diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing β-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

Diversity metrics, species turnovers and nestedness of bird assemblages in a deep karst sinkhole

2017 ◽  
Vol 63 (2) ◽  
pp. 8-16 ◽  
Author(s):  
Corrado Battisti ◽  
Marco Giardini ◽  
Francesca Marini ◽  
Lorena Di Rocco ◽  
Giuseppe Dodaro ◽  
...  
Keyword(s):  
Species Richness ◽  
Random Distribution ◽  
Diversity Index ◽  
Species Turnover ◽  
Floristic Composition ◽  
Bird Assemblages ◽  
Β Diversity ◽  
Stick Model ◽  
Karst Sinkhole

We reported a study on breeding birds occurring inside an 80 m-deep karst sinkhole, with the characterization of the assemblages recorded along its semi-vertical slopes from the upper edge until the bottom. The internal sides of the sinkhole have been vertically subdivided in four belts about 20 m high. The highest belt (at the upper edge of the cenote) showed the highest values in mean number of bird detections, mean and normalized species richness, and Shannon diversity index. The averaged values of number of detections and species richness significantly differ among belts. Species turnover (Cody’s β-diversity) was maximum between the highest belts. Whittaker plots showed a marked difference among assemblages shaping from broken-stick model to geometric series, and explicited a spatial progressive stress with a disruption in evenness towards the deepest belts. Bird assemblages evidenced a nested subset structure with deeper belts containing successive subsets of the species occurring in the upper belts. We hypothesize that, at least during the daytime in breeding season, the observed non-random distribution of species along the vertical stratification is likely due to (i) the progressive simplification both of the floristic composition and vegetation structure, and (ii) the paucity of sunlight as resources from the upper edge to the inner side of the cenote.

scholarly journals Potential and Limitations of Grasslands α-Diversity Prediction Using Fine-Scale Hyperspectral Imagery

2021 ◽  
Vol 13 (14) ◽  
pp. 2649
Author(s):  
Hafiz Ali Imran ◽  
Damiano Gianelle ◽  
Michele Scotton ◽  
Duccio Rocchini ◽  
Michele Dalponte ◽  
...  
Keyword(s):  
Species Richness ◽  
Well Being ◽  
Hyperspectral Data ◽  
Hyperspectral Images ◽  
Grassland Species ◽  
Biodiversity Indices ◽  
Grassland Ecosystems ◽  
Natural Grasslands ◽  
Α Diversity ◽  
Diversity Metrics

Plant biodiversity is an important feature of grassland ecosystems, as it is related to the provision of many ecosystem services crucial for the human economy and well-being. Given the importance of grasslands, research has been carried out in recent years on the potential to monitor them with novel remote sensing techniques. In this study, the optical diversity (also called spectral diversity) approach was adopted to check the potential of using high-resolution hyperspectral images to estimate α-diversity in grassland ecosystems. In 2018 and 2019, grassland species composition was surveyed and canopy hyperspectral data were acquired at two grassland sites: Monte Bondone (IT-MBo; species-rich semi-natural grasslands) and an experimental farm of the University of Padova, Legnaro, Padua, Italy (IT-PD; artificially established grassland plots with a species-poor mixture). The relationship between biodiversity (species richness, Shannon’s, species evenness, and Simpson’s indices) and optical diversity metrics (coefficient of variation-CV and standard deviation-SD) was not consistent across the investigated grassland plant communities. Species richness could be estimated by optical diversity metrics with an R = 0.87 at the IT-PD species-poor site. In the more complex and species-rich grasslands at IT-MBo, the estimation of biodiversity indices was more difficult and the optical diversity metrics failed to estimate biodiversity as accurately as in IT-PD probably due to the higher number of species and the strong canopy spatial heterogeneity. Therefore, the results of the study confirmed the ability of spectral proxies to detect grassland α-diversity in man-made grassland ecosystems but highlighted the limitations of the spectral diversity approach to estimate biodiversity when natural grasslands are observed. Nevertheless, at IT-MBo, the optical diversity metric SD calculated from post-processed hyperspectral images and transformed spectra showed, in the red part of the spectrum, a significant correlation (up to R = 0.56, p = 0.004) with biodiversity indices. Spatial resampling highlighted that for the IT-PD sward the optimal optical pixel size was 1 cm, while for the IT-MBo natural grassland it was 1 mm. The random pixel extraction did not improve the performance of the optical diversity metrics at both study sites. Further research is needed to fully understand the links between α-diversity and spectral and biochemical heterogeneity in complex heterogeneous ecosystems, and to assess whether the optical diversity approach can be adopted at the spatial scale to detect β-diversity. Such insights will provide more robust information on the mechanisms linking grassland diversity and optical heterogeneity.

scholarly journals Flower‐visitor communities of an arcto‐alpine plant—Global patterns in species richness, phylogenetic diversity and ecological functioning

2018 ◽  
Vol 28 (2) ◽  
pp. 318-335 ◽  
Author(s):  
Mikko Tiusanen ◽  
Tea Huotari ◽  
Paul D. N. Hebert ◽  
Tommi Andersson ◽  
Ashley Asmus ◽  
...  
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Alpine Plant ◽  
Flower Visitor ◽  
Global Patterns ◽  
Ecological Functioning

scholarly journals Intrauterine Hypoxia Changed the Colonization of the Gut Microbiota in Newborn Rats

2021 ◽  
Vol 9 ◽  
Author(s):  
Yan Sun ◽  
Lei Li ◽  
Jiayu Song ◽  
Wei Mao ◽  
Kaihao Xiao ◽  
...  
Keyword(s):  
Species Richness ◽  
Gut Microbiota ◽  
Biological Information ◽  
Control Group ◽  
Neonatal Rats ◽  
Newborn Rats ◽  
Β Diversity ◽  
Significant Difference ◽  
Intrauterine Hypoxia ◽  
Abundance And Diversity

Background: Accumulating evidence suggests a connection between the gut microbiota and neonatal diseases. Hypoxia may play an important role in the intestinal lesions in neonates.Objective: This study aims to determine whether the gut microbiota differs between intrauterine hypoxic rats and healthy controls and to identify the factors that influence the changes in the gut microbiota.Methods: We constructed an intrauterine hypoxia model in rats and collected the intestinal contents of intrauterine hypoxic newborn rats and normal newborn rats within 4 h and on the seventh day after birth. They were divided them into the intrauterine hypoxia first-day group (INH1), intrauterine hypoxia seventh-day group (INH7), normal first-day group (NOR1), and normal seventh-day group (NOR7). The contents of the intestines were sequenced with 16S rRNA sequencing, the sequencing results were analyzed for biological information, and the differences in the diversity, richness, and individual taxa among the groups were analyzed.Results: The abundance of the gut microbiota of neonatal rats with intrauterine hypoxia was higher than that of the control group rats. Intrauterine hypoxia altered the structural composition of the gut microbiota in neonatal rats. The INH1 group showed increased species richness, phylogenetic diversity, and β-diversity, and altered relative abundance in several taxa compared to those in the control group. The differences in the microbiota among the four groups were significantly higher than those within the group, and the differences in the abundance and diversity of the INH7 and NOR7 groups decreased after 7 days of suckling. Functional analysis based on the Cluster of Orthologous Groups (COG) suggested that 23 functional COG categories. There was no significant difference in the functional categories between the hypoxia group and the normal group.Conclusion: Intrauterine hypoxia changed the initial colonization of the gut microbiota in neonatal rats. It could increase the species richness and β-diversity of the gut microbiota, and altered relative abundances of several taxa.

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