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 Floristic and structure of the arboreal community of an Ombrophilous Dense Forest at 800 m above sea level, in Ubatuba/SP, Brazil

2018 ◽  
Vol 18 (4) ◽  
Author(s):  
Ana Cláudia Oliveira de Souza ◽  
Luís Benacci ◽  
Carlos Alfredo Joly
Keyword(s):  
Sea Level ◽  
Diversity Index ◽  
Floristic Composition ◽  
Strong Similarity ◽  
Breast Height ◽  
Palm Trees ◽  
Tree Community ◽  
Dense Forest ◽  
Metadata Generation

Abstract: Undoubtedly, the publication of floristic lists and phytosociological studies are important tools for metadata generation, quantification and characterization of the megadiversity of Brazilian forests. In this sense, this work had the objective of describing the composition and the structure of the tree community of one hectare of Dense Atlantic Rainforest, at an altitude of 800 m. All individuals, including trees, palm trees, arborescent ferns and dead and standing stems, with a diameter at breast height (DBH) of ≥ 4.8 cm were sampled. After the identification of the botanical material, we proceeded to calculate the usual phytosociological parameters, besides the Shannon diversity index (H') and Pielou equability index (J). A total of 1.791 individuals were sampled, of which 1.729 were alive, belonging to 185 species, 100 genera and 46 families. The results obtained showed a strong similarity of structure and floristic composition with plots of both Montana and Sub Montana Ombrophilous Dense Forest studied in the same region. This reinforces the hypothesis that the transition between the phytophysiognomies of the Atlantic Ombrophylous Dense Forest is gradual, and that the boundaries between them cannot be clearly established.

Holy or Not, Israel is a Palaearctic Biodiversity Hotspot

2011 ◽  
Vol 57 (3) ◽  
pp. 207-211
Author(s):  
Yoni Gavish
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Grid Cell ◽  
Biodiversity Hotspot ◽  
Statistical Prediction ◽  
Β Diversity ◽  
Α Diversity ◽  
Species Area ◽  
Prediction Limits ◽  
Global Biodiversity

In their rebuttal to my comment, Roll et al. (2011) defend their original conclusion, by questioning the theoretical framework on which I based my analysis. They stress the importance of the statistical prediction limits and the treatment of latitudinal location as a covariate. They also add an additional grid-cell-based analysis. Here, I claim that even if provincial species-area relationships (SPAR) are not parallel, they are still different. While relying on Roll et al.'s (2011) analyses, I show that for each taxon there is at least one other provincial SPAR that lies considerably above the Palaearctic SPAR, making Palaearctic countries less favorable to be identified as a global biodiversity hotspot. I further claim that prediction limits should not be used to answer the question in focus and that adding latitude as a covariate does not alter the results. Finally, I address the grid-cell analyses of Roll et al. (2011), claiming that Israel's diversity lies mainly in the species turnover between cells (i.e., β diversity) and not on the average species richness within cells (α diversity). Therefore I hold on to my former conclusion that at least for three taxa—birds, mammals, and reptiles—Israel is indeed a Palaearctic provincial hotspot.

scholarly journals α- and β-Diversity Patterns of Macrophytes and Freshwater Fishes are Driven by Different Factors and Processes in Lakes of the Unexplored Southern Balkan Biodiversity Hotspot

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1984
Author(s):  
Anthi Oikonomou ◽  
Konstantinos Stefanidis
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Biodiversity Hotspot ◽  
Environmental Drivers ◽  
Conservation Strategies ◽  
Compositional Variation ◽  
Related Factors ◽  
Diversity Patterns ◽  
Β Diversity ◽  
Α Diversity

Disentangling the main drivers of species richness and community composition is a central theme in ecology. Freshwater biodiversity patterns have been poorly explored; yet, it has been shown that different freshwater biota have different, often contrasting responses to environmental gradients. In this study, we investigated the relative contribution of geographical and environmental (habitat-, climate- and water quality-related) factors/gradients in shaping the α- and β-diversity patterns of macrophytes and fish in sixteen natural freshwater lakes of an unexplored Balkan biodiversity hotspot, the Southern Balkan Peninsula. We employed generalized linear modeling to identify drivers of α-diversity, and generalized dissimilarity modeling to explore commonalities and dissimilarities of among-biota β-diversity. Species richness of both biota was significantly associated with lake surface area, whereas macrophytes had an inverse response to altitude, compared to fish. Both species turnover and nestedness significantly contributed to the total β-diversity of macrophytes. In contrast, species turnover was the most significant contributor to the total fish β-diversity. We found that the compositional variation of macrophytes is primarily limited by dispersal and ultimately shaped by environmental drivers, resulting in spatially structured assemblages. Fish communities were primarily shaped by altitude, highlighting the role of species sorting. We conclude that among-biota diversity patterns are shaped by different/contrasting factors, and, thus, effective/sustainable conservation strategies should encompass multiple aquatic biota.

scholarly journals CARACTERIZAÇÃO FLORÍSTICA E ESTRUTURAL DE UM FRAGMENTO DE FLORESTA OMBRÓFILA MISTA, EM CURITIBA, PR – BRASIL

FLORESTA ◽  
2002 ◽  
Vol 32 (1) ◽  
Author(s):  
Rubens Marques Rondon Neto ◽  
Carina Kozera ◽  
Regina do Rocio De Andrade ◽  
Adriana Trippia Cecy ◽  
Ana Paula Hummes ◽  
...  
Keyword(s):  
Diversity Index ◽  
Floristic Composition ◽  
Total Density ◽  
Araucaria Angustifolia ◽  
Forest Fragment ◽  
Importance Value ◽  
Important Species ◽  
Casearia Sylvestris ◽  
Index Value

O presente trabalho teve como objetivo conhecer a composição florística e a estrutura dos indivíduos arbóreos com DAP ³ 5cm presentes em um fragmento de Floresta Ombrófila Mista (Floresta com Araucária), denominado “Capão do Tigre”, situado em Curitiba - PR. Em dezoito parcelas de 10 x 20m foram inventariados 710 indivíduos, distribuídos em 77 espécies, pertencentes a 36 famílias e 55 gêneros. O valor do índice de diversidade Shannon para as espécies foi de 3,437. A densidade total estimada foi de 1.972 indivíduos/ha e os valores médios de DAP e altura encontrados foram 11,6 cm e 8,2 m, respectivamente. De acordo com o parâmetro valor de importância ampliado, as espécies mais importantes foram Casearia sylvestris, Allophylus edulis, Luehea divaricata, Araucaria angustifolia, Cupania vernalis, Ocotea corymbosa, Ocotea nutans, Jacaranda puberula, Mollinedia clavigera e Solanum sanctae-catharinae. FLORISTIC AND STRUCTURAL CHARACTERIZATION OF A FRAGMENT OF MIXED OMBROPHYLOUS FOREST IN CURITIBA, PR - BRAZIL Abstract The aim of this paper was to know the floristic composition and the structureof a Mixed Ombrophylous Forest fragment (Araucaria Forest), named “Capão do Tigre”, situated in Curitiba - PR. It was inventoried 710 trees individuous in eighteen 10 x 20 m plots with DBH ³ 5cm, distributed in 77 species from 55 gender and 36 families. The Shannon diversity index value was 3,437 for the species. The total density found was 1.972 individuous/ha, and the medium DBH and height was 11,6 cm and 8,2 m, respectively. Acording to the parameters of Amplieted Importance Value, the most important species are: Casearia sylvestris, Allophylus edulis, Luehea divaricata, Araucaria angustifolia, Cupania vernalis, Ocotea corymbosa, Ocotea nutans, Jacaranda puberula, Mollinedia clavigera e Solanum sanctae-catharinae.

scholarly journals Effects of Landscape Change on Floristic Composition and Structure in the Bale Mountains National Park, Southeastern Ethiopia

2020 ◽  
Author(s):  
Annissa Muhammed ◽  
Eyasu Elias
Keyword(s):  
Species Richness ◽  
Landscape Change ◽  
National Park ◽  
Diversity Index ◽  
Basal Area ◽  
Floristic Composition ◽  
Economic Benefits ◽  
Environmental Data ◽  
Conservation Action ◽  
Shannon Diversity

Abstract BackgroundBale mountains national park (BMNP) is one of the 34 International Biodiversity Hotspots that comprise a variety of life forms. However, it faces a critical challenge from subsistence farming and overgrazing. This study was made to analyze the effects of landscape change on floristic composition, diversity, and structure in BMNP. The vegetation and environmental data were collected from 96 plots that were laid along 8 line transects. Vegetation hierarchical clustering and landscape structural analysis was made using R software version 3.5.2 and FRAGSTATS version 4.2.1, respectively. ResultsA total of 205 species that belongs to 153 genera and 71 families were identified. The overall Shannon diversity and evenness index was 4.34 and 0.81, respectively. Both the species richness and Shannon diversity index were significantly higher (p < 0.05) in the edge habitat (40 ± 0.2 and 2.93 ± 0.2, respectively) than the interior (25 ± 4.5 and 2.43 ± 0.4, respectively). Conversely, the basal area was lower in the interior habitat (173.79 m2 ha-1) than the edge (64.15 m2 ha-1). Moreover, as AREA_MN and COA of patches increases, species richness, diversity, evenness, woody species density, basal area, DBH, and height also increases. Whereas, as PN, SHAPE_MN, ED, ENN_MN, and IJI of patches increases, those floristic compositions and structural variables decrease. ConclusionThis study revealed that BMNP is a biologically diverse and ecologically significant area that provides a variety of ecological and economic benefits to the surrounding communities and the country at large. However, its landscape is changing alarmingly and urgent restoration and conservation action needs to be taken to reverse this condition.

scholarly journals Does Altitude Effect on Species Composition and Diversity on Himalayan Rangeland?

2017 ◽  
Vol 1 ◽  
pp. 26-30
Author(s):  
Dilkumar Limbu ◽  
Madan Koirala ◽  
Zhanhuan Shang
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Altitudinal Gradient ◽  
Diversity Index ◽  
Grazing Intensity ◽  
Floristic Composition ◽  
Diversity Indices ◽  
Altitude Effect ◽  
Wiener Diversity Index ◽  
The Impact

Himalayan rangelands have diverse floristic composition and important ecological services. The floristic diversity and composition play an important role in grassland ecosystem regulation. It is different in altitudinal gradient due to grazing intensity, climatic condition and topography. To reveal the vegetation composition values, this work was conducted on August and September 2011 in Tinjure-Milke mountain ridge, Guphapokhari, Nepal. In the present study we have described the impact of altitude on the species richness, species diversity and dispersion behavior of different plants (grasses) in Himalayan rangeland. The values of community indices were observed to be: RD (0.09 to 49.57), RF (3.57 to 14.71), RA (0.23 to 47.59), IVI (3.89 to 111.87), Shannan-Wiener diversity index (1.09 to 2.23) and species diversity evenness (0.12 to 0.19) at the study area, MilkeJaljale, eastern Nepal. Similarly, Species richness (R) value of 8.87 to 11.86 and Simpson dominant index value of 0.12 to 0.42 were observed. All diversity indices were reversed to altitudinal gradient higher the altitudes lower the values. Species richness of all plants showed a unimodal relationship with altitude. Similarly, negative correlation of density and species richness with altitude and slope was recorded.

scholarly journals Species richness and β-diversity patterns of macrolichens along elevation gradients across the Himalayan Arc

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Subzar Ahmad Nanda ◽  
Manzoor-ul Haq ◽  
S. P. Singh ◽  
Zafar A. Reshi ◽  
Ranbeer S. Rawal ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Elevation Gradient ◽  
Conservation Strategies ◽  
Elevational Gradients ◽  
Elevation Gradients ◽  
Diversity Patterns ◽  
Β Diversity ◽  
Shaped Pattern ◽  
The Himalaya

AbstractUnderstanding the species richness and β-diversity patterns along elevation gradients can aid in formulating effective conservation strategies particularly in areas where local anthropogenic stresses and climate change are quite significant as in the Himalaya. Thus, we studied macrolichen richness and β-diversity along elevational gradients at three sites, namely Kashmir (2200 to 3800 m a.m.s.l), Uttarakhand (2000–3700 m a.m.s.l) and Sikkim (1700 to 4000 m a.m.s.l) which cover much of the Indian Himalayan Arc. In all, 245 macrolichen species belonging to 77 genera and 26 families were collected from the three sites. Only 11 species, 20 genera and 11 families were common among the three transects. Despite the differences in species composition, the dominant functional groups in the three sites were the same: foliose, fruticose and corticolous forms. The hump-shaped elevation pattern in species richness was exhibited by most of the lichen groups, though an inverse hump-shaped pattern was also observed in certain cases. β-diversity (βsor) based on all pairs of comparisons along an elevation gradient varied from 0.48 to 0.58 in Kashmir, 0.03 to 0.63 in Uttarakhand and 0.46 to 0.77 in Sikkim. The contribution of turnover to β-diversity was more than nestedness at all the three transects. Along elevation β-diversity and its components of turnover and nestedness varied significantly with elevation. While species turnover increased significantly along the elevation in all the three transects, nestedness decreased significantly in Kashmir and Sikkim transects but increased significantly in the Uttarakhand transect. Except for the Kashmir Himalayan elevation transect, stepwise β-diversity and its components of turnover and nestedness did not vary significantly with elevation. The present study, the first of its kind in the Himalayan region, clearly brings out that macrolichen species richness, β-diversity, and its components of turnover and nestedness vary along the elevation gradients across the Himalayan Arc. It also highlights that contribution of turnover to β-diversity is higher in comparison to nestedness at all the three transects. The variations in species richness and diversity along elevation gradients underpin the importance of considering elevational gradients in planning conservation strategies.

scholarly journals Changes in the structure and floristic composition of the limestone grasslands after cutting trees and shrubs and mowing

2011 ◽  
Vol 72 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Wojciech Bąba
Keyword(s):  
Species Richness ◽  
Management Practices ◽  
Species Turnover ◽  
Soil Layer ◽  
Floristic Composition ◽  
Grass Species ◽  
Calcareous Grasslands ◽  
Brachypodium Pinnatum ◽  
Shrub Patches ◽  
Trees And Shrubs

<p>The calcareous grasslands belong to the species-rich plant communities in Poland. Most of them are of anthropogenic origin and they need specific management (i.e. periodical cutting suckers of trees and shrubs, grazing or mowing) in order to protect their floristic diversity. Many of calcareous grasslands have been overgrown by shrubs as a result of cessation of traditional management. The aim of this study was to compare the structure and dynamics of xerothermic hazel shrub patches, which were undergoing secondary succession with patches where different management practices aiming at restoration of species-rich limestone grassland were applied. The managed plots had a significantly higher species richness than the control one. However, they strongly differed in their floristic composition from well-preserved limestone grasslands. There were also significant differences observed between both the managed plots. Too intensive management, particularly frequent mowing of herbs resulted in expansion of grass species such as <em>Brachypodium pinnatum</em> and <em>Calamagrostis arundinacea</em> and caused a sharp decline in species richness.</p><p>The species composition and turnover rate strongly depended on succesional stage (soil layer thickness) of plots at the start of the experiment. The deeper was the soil, the higher was the rate of species turnover and the smaller was the share of xerothermic and thermophilous species. The last mentioned group was dominated by species with a persistent seed bank in the soil, frequently colonizing anthropogenic habitats.</p>

scholarly journals Bird Diversity Components in Australian Eucalyptus and North-Temperate Quercus Woodlands

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 443-456
Author(s):  
Martin L. Cody
Keyword(s):  
Species Richness ◽  
Vegetation Structure ◽  
Species Turnover ◽  
Density Variation ◽  
Bird Diversity ◽  
Species Variation ◽  
Vegetation Density ◽  
Β Diversity ◽  
Bird Density ◽  
Α Diversity

Abstract Diversity patterns of breeding bird assemblages (exclusive of raptors and nocturnal species) of western North American oak and Australian eucalypt woodlands are derived from data recorded at 113 census sites distributed over four regions, two on each continent. Regional species richness varies by a factor of 2 among regions. The contribution to regional species totals by various diversity components is examined: α-diversity (species richness within sites), β-diversity (species turnover between sites related to differences in vegetation structure), and γ-diversity (turnover related to distance between sites, independent of habitat change). Mean α-diversity is relatively constant among regions (mean 25.5 to 29.7 species). Variation in α-diversity within regions is related to variation in vegetation structure, and bird-density variation is best predicted by a measure of vegetation density. The relationships between bird diversity and density and vegetation structure are similar in the four regions. With the influence of vegetation structure removed, there is no (Australia) or at best a modest (North America) latitudinal gradient in α-diversity. Within regions, regression analysis shows that species turnover is significantly related to both vegetation structural differences (β-diversity) and distance between sites (γ-diversity), with the latter accounting for a larger proportion of, and correlating strongly with, regional species totals. Identification of factors promoting species turnover between sites, beyond distance and vegetation effects, remains a major challenge to ecologists.

scholarly journals Biogeographic regionalization by spatial and environmental components: Numerical proposal

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253152
Author(s):  
Mayra Flores-Tolentino ◽  
Leonardo Beltrán-Rodríguez ◽  
Jonas Morales-Linares ◽  
J. Rolando Ramírez Rodríguez ◽  
Guillermo Ibarra-Manríquez ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Regional Scale ◽  
Floristic Composition ◽  
Plant Species Richness ◽  
Rare Plants ◽  
Environmental Drivers ◽  
Herbaceous Plant ◽  
Environmental Predictors ◽  
Biogeographic Regionalization

Regionalization through the analysis of species groups offers important advantages in conservation biology, compared to the single taxon approach in areas of high species richness. We use a systematic framework for biogeographic regionalization at a regional scale based on species turnover and environmental drivers (climate variables and soil properties) mainly of herbaceous plant species richness. To identify phytogeographic regions in the Balsas Depression (BD), we use Asteraceae species, a family widely distributed in Seasonally Dry Tropical Forest (SDTF) and the most diverse of the vascular plants in Mexico. Occurrence records of 571 species were used to apply a quantitative analysis based on the species turnover, the rate of changes in their composition between sites (β-Simpson index) and the analysis of the identified environmental drivers. Also, the environmental predictors that influence species richness in the SDTF were determined with a redundancy analysis. We identified and named two phytogeographic districts within the SDTF of the BD (Upper Balsas and Lower Balsas). According to the multi-response permutation procedure, floristic composition of the two districts differs significantly, and the richness of exclusive species in Upper Balsas was higher (292 species) than in the Lower Balsas (32 species). The proportion of Mg and Ca in the soil and the precipitation of the driest three-month period were the environmental factors with greatest positive influence on species richness. The division of geographic districts subordinated to the province level, based on diverse families such as Asteraceae, proved to be appropriate to set up strategies for the conservation of the regional flora, since at this scale, variation in species richness is more evident. Our findings are consistent with a growing body of biogeographic literature that indicates that the identification of smaller biotic districts is more efficient for the conservation of biodiversity, particularly of endemic or rare plants, whose distribution responds more to microhabitats variation.

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