Environmental heterogeneity influences life‐form richness and species composition but not species richness of aquatic macrophytes in tropical coastal rivers

2020 ◽  
Vol 65 (11) ◽  
pp. 1894-1905
Author(s):  
Laís Samira Correia Nunes ◽  
Cristiane Akemi Umetsu ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Aquatic Macrophytes ◽  
Environmental Heterogeneity ◽  
Life Form ◽  
Coastal Rivers

Influence of the environmental heterogeneity of breeding ponds on anuran assemblages from southeastern Brazil

2009 ◽  
Vol 87 (8) ◽  
pp. 699-707 ◽  
Author(s):  
T. S. Vasconcelos ◽  
T. G. Santos ◽  
D. C. Rossa-Feres ◽  
C.F.B Haddad
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Beta Diversity ◽  
Environmental Heterogeneity ◽  
Null Model ◽  
Distinct Species ◽  
Southeastern Brazil ◽  
Similar Species ◽  
Anuran Species ◽  
High Beta

We hypothesized that the environmental heterogeneity of breeding ponds influences the species composition and species richness of anuran assemblages from southeastern Brazil, because it provides humidity, shelter, and breeding microhabitats for anuran species, which can result in an increasing number of species in a given habitat. To begin, we tested whether the occurrence of anuran species in each breeding pond is different from a null model of random placement of species in those ponds. We then performed two tests to evaluate which of the five environmental descriptors of breeding ponds influence (1) the species composition and (2) species richness. Species composition of the 38 breeding ponds was correlated with number of edge types, number of plant types along the edges of the breeding ponds, and the hydroperiod. Neither the percentage of vegetation cover on the water’s surface nor the size of the breeding ponds were correlated with species composition. Only the number of edge types was correlated with species richness of breeding ponds. The correlation of three environmental descriptors with species composition and one environmental descriptor with species richness, as well as the high beta diversity among breeding ponds, suggest that the analyses of environmental heterogeneity on species composition was more informative than was the analysis for species richness, because breeding ponds with similar species richness can have distinct species composition among them (high beta diversity).

scholarly journals Influence of Environmental Heterogeneity on the Species Composition, Species Richness and Species Abundances Unevenness in Reef-associated Conus Communities (Neogastropoda) from Papua New-Guinea

2019 ◽  
pp. 1-21
Author(s):  
Jean Béguinot
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Environmental Heterogeneity ◽  
Species Abundance ◽  
Jaccard Index ◽  
Point Of View ◽  
Fundamental Issue ◽  
Marine Communities ◽  
Surrounding Environment ◽  
Species Abundances

To what extent differences in species composition, species richness and species abundance unevenness between marine communities are attributable to heterogeneities of the surrounding environment and/or to inter-community distance is a fundamental issue to be addressed, in order to more deeply understand the functioning of marine ecosystems. A comparison between six reef-associated Conus communities, differing more or less in both their surrounding environment and their mutual geographical distance, offers a relevant opportunity to address these questions. As expected, environmental heterogeneities prove having a significant influence on the dissimilarity in species composition, whereas distance-decay in similarity reveals comparatively negligible, at least within the investigated range of distances, up to 60 km. Less expectedly, more homogeneous surrounding environments between communities tend, here, to increase the dissimilarity in species richness. At last, here, difference in species abundance unevenness between communities seems unrelated to either environmental heterogeneity or inter-community distance. From a methodological point of view, these results could not have been reliably established without the prior implementation of a least-biased procedure of numerical extrapolation applied to the available incomplete samplings. Also, the relevant assessment of dissimilarity in species composition required using a modified Jaccard index, rendered insensitive to bias-induced differences in communities species richness.

scholarly journals Disentangling the Ecological Determinants of Species and Functional Trait Diversity in Herb-Layer Plant Communities in European Temperate Forests

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 552
Author(s):  
Janez Kermavnar ◽  
Lado Kutnar ◽  
Aleksander Marinšek
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Communities ◽  
Functional Trait ◽  
Forest Stand ◽  
Relative Importance ◽  
Herb Layer ◽  
Bud Bank ◽  
Tree Species Composition ◽  
Stand Characteristics

Forest herb-layer vegetation responds sensitively to environmental conditions. This paper compares drivers of both taxonomic, i.e., species richness, cover and evenness, and functional herb-layer diversity, i.e., the diversity of clonal, bud bank and leaf-height-seed plant traits. We investigated the dependence of herb-layer diversity on ecological determinants related to soil properties, climatic parameters, forest stand characteristics, and topographic and abiotic and biotic factors associated with forest floor structure. The study was conducted in different forest types in Slovenia, using vegetation and environmental data from 50 monitoring plots (400 m2 each) belonging to the ICP Forests Level I and II network. The main objective was to first identify significant ecological predictors and then quantify their relative importance. Species richness was strongly determined by forest stand characteristics, such as richness of the shrub layer, tree layer shade-casting ability as a proxy for light availability and tree species composition. It showed a clear positive relation to soil pH. Variation in herb-layer cover was also best explained by forest stand characteristics and, to a lesser extent, by structural factors such as moss cover. Species evenness was associated with tree species composition, shrub layer cover and soil pH. Various ecological determinants were decisive for the diversity of below-ground traits, i.e., clonal and bud bank traits. For these two trait groups we observed a substantial climatic signal that was completely absent for taxonomy-based measures of diversity. In contrast, above-ground leaf-height-seed (LHS) traits were driven exclusively by soil reaction and nitrogen availability. In synthesis, local stand characteristics and soil properties acted as the main controlling factors for both species and trait diversity in herb-layer communities across Slovenia, confirming many previous studies. Our findings suggest that the taxonomic and functional facets of herb-layer vegetation are mainly influenced by a similar set of ecological determinants. However, their relative importance varies among individual taxonomy- and functional trait-based diversity measures. Integrating multi-faceted approaches can provide complementary information on patterns of herb-layer diversity in European forest plant communities.

Species Composition and Species Richness in the Hetao Irrigation Region Drainage Ditches, Northern China

2013 ◽  
Vol 27 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Yang Zhao ◽  
Xin-rong Li ◽  
Zhi-shan Zhang ◽  
Yi-gang Hu ◽  
Pan Wu
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Northern China ◽  
Drainage Ditches

scholarly journals Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Felipe Augusto Trindade Gondim-Silva ◽  
Alessandra Rodrigues Santos Andrade ◽  
Rafael Oliveira Abreu ◽  
Jamile Santos Nascimento ◽  
Geovane Paixão Corrêa ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Rainy Season ◽  
Dominant Species ◽  
The State ◽  
Northeastern Brazil ◽  
Freshwater Wetland ◽  
Northern Coast ◽  
Anuran Species

Abstract The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the 'main rainy season' and two in a 'lesser rainy season', using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H' indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H'= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H' = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).

A structural gradient in cerrado vegetation of Brazil: changes in woody plant density, species richness, life history and plant composition

2002 ◽  
Vol 18 (5) ◽  
pp. 775-794 ◽  
Author(s):  
Luci Ferreira Ribeiro ◽  
Marcelo Tabarelli
Keyword(s):  
Life History ◽  
Species Richness ◽  
Species Composition ◽  
Woody Plant ◽  
Plant Density ◽  
Lower Layer ◽  
Sensu Stricto ◽  
Life History Strategies ◽  
Cerrado Vegetation ◽  
Structural Types

Four structural types of cerrado vegetation were examined to test the following hypotheses: (1) there are predictable changes in woody plant density, species richness and life-history strategies from one structural type to another; and (2) plant species composition in the less-rich structural types represent particular and impoverished subsets of those found in the richer ones. The study was conducted at Fazenda Palmares (5°33′S, 42°37′W) Piauí State, Brazil. A 47% decrease in woody plant density between cerradão (forest) and the least-dense type of cerrado sensu stricto (scrub) was associated with a 40% decrease in species richness. The percentage of lower-layer species was reduced by 29% in the least dense type of cerrado sensu stricto compared to cerradão. The proportion of species that flower and fruit during the rainy season was also reduced by one third. Species were not distributed as impoverished subsets along the cerradão–cerrado sensu stricto gradient. It is argued that the reduction in woody plant density and richness is partly due to factors limiting the occurrence of species with particular life-history strategies. The species composition of structural types is affected by the ‘mass effect’ and also by surrounding biotas, which provide species that colonize particular types of cerrado vegetation. Both these processes reduce the likelihood that the species composition in the poorer structural types are simple subsets of those present in the richer types.

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Cross Validation ◽  
Strong Relationship ◽  
Distribution Patterns ◽  
Common Species ◽  
Important Variable ◽  
Diatom Species ◽  
Expected Species Richness

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

scholarly journals Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication

2014 ◽  
Vol 26 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Suelen Cristina Alves da Silva ◽  
Armando Carlos Cervi ◽  
Cleusa Bona ◽  
André Andrian Padial
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Indicator Species ◽  
Beta Diversity ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Wiener Index ◽  
Spatial And Temporal Variation ◽  
Macrophyte Community ◽  
Aquatic Macrophyte Community

AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i) through two‑way ANOVAs considering the stand extent (m) and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand); and ii) through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.

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