Distribution of aquatic macrophytes along depth gradients in Lajeado Reservoir, Tocantins River, Brazil

Abstract Aim The present study investigated the diversity of aquatic macrophytes in the littoral zone of Lajeado Reservoir, Tocantins River. We characterized spatial variations in species richness, composition and abundance along depth gradients. Methods Macrophyte sampling occurred at the end of the dry season (September and October 2014) in four sites of the reservoir. We established transects perpendicular to the shoreline, each 25 m long, divided in 3 sections (plots of 5 x 5 m). Results In total, we recorded 18 taxa of aquatic macrophytes, belonging to nine families and four life forms. Najas microcarpa, Echinodorus tenellus. and Chara sp. were the more frequent and abundant taxa. Considering depth gradients, we recorded 18 taxa in the section closer to the shoreline, 13 in the middle section and 10 in the section more distant to the shoreline. Submerged and emergent species were more frequent and abundant, especially in the section close to the shoreline; epiphytes and free-floating species were rare. Plot species richness (total, emergent and submerged) decreased along the gradient, and a Non-Metric Multidimensional Scaling (NMDS) revealed that the plot close to the shoreline had different composition when compared to adjacent sections. Individual species showed particular behaviors, but most tended to decline in abundance and occurrence along the gradient. Conclusions The present study revealed that small-scale environmental gradients affect the distribution of aquatic plants in Lajeado Reservoir, with greater diversity in habitats close to the shoreline.

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Testing biodiversity theory using species richness of reef-building corals across a depth gradient

Biology Letters ◽

10.1098/rsbl.2019.0493 ◽

2019 ◽

Vol 15 (10) ◽

pp. 20190493 ◽

Cited By ~ 2

Author(s):

T. Edward Roberts ◽

Sally A. Keith ◽

Carsten Rahbek ◽

Tom C. L. Bridge ◽

M. Julian Caley ◽

...

Keyword(s):

Species Richness ◽

Large Scale ◽

Coral Species ◽

Environmental Gradients ◽

Abiotic Factors ◽

Empirical Support ◽

Null Model ◽

Local Scale ◽

Small Scale ◽

Energy Availability

Natural environmental gradients encompass systematic variation in abiotic factors that can be exploited to test competing explanations of biodiversity patterns. The species–energy (SE) hypothesis attempts to explain species richness gradients as a function of energy availability. However, limited empirical support for SE is often attributed to idiosyncratic, local-scale processes distorting the underlying SE relationship. Meanwhile, studies are also often confounded by factors such as sampling biases, dispersal boundaries and unclear definitions of energy availability. Here, we used spatially structured observations of 8460 colonies of photo-symbiotic reef-building corals and a null-model to test whether energy can explain observed coral species richness over depth. Species richness was left-skewed, hump-shaped and unrelated to energy availability. While local-scale processes were evident, their influence on species richness was insufficient to reconcile observations with model predictions. Therefore, energy availability, either in isolation or in combination with local deterministic processes, was unable to explain coral species richness across depth. Our results demonstrate that local-scale processes do not necessarily explain deviations in species richness from theoretical models, and that the use of idiosyncratic small-scale factors to explain large-scale ecological patterns requires the utmost caution.

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Floristic survey and species richness of aquatic macrophytes in water supply reservoirs

Check List ◽

10.15560/10.6.1324 ◽

2014 ◽

Vol 10 (6) ◽

pp. 1324 ◽

Cited By ~ 1

Author(s):

Suelen Cristina Alves-da-Silva ◽

Cleusa Bona ◽

Maria Cecília de Chiara Moço ◽

Armando Carlos Cervi

Keyword(s):

Species Richness ◽

Water Supply ◽

Biodiversity Conservation ◽

River Basin ◽

Biological Material ◽

Aquatic Macrophytes ◽

Life Forms ◽

Floristic Survey ◽

Water Supply Reservoirs ◽

Iguaçu River

The present study aimed a floristic survey of aquatic macrophytes in four water supply reservoirs (Iraí, Passaúna, Piraquara I and II) of the Iguaçu River basin, Paraná, Brazil. Sampling and herborization of biological material followed methods described in literature. The species were classified by life forms. We found 90 species in 57 genera and 36 families, were 52.7% are monospecific. The richest reservoir was Passaúna (40 spp.), followed by Iraí, Piraquara I and Piraquara II (36 spp. each). Cyperaceae was the most representative with 17 spp., followed by Asteraceae, Onagraceae and Polygonaceae (7 spp. each). Amphibious and emergent life forms were equally express throughout species (41% each). Since aquatic macrophytes structure and contribute to environment biodiversity, the present study can assist management and implementation of biodiversity conservation efforts.

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Vascular plant and epiphytic lichen communities in Canadian aspen parkland: determinants of small-scale species richness

Community Ecology ◽

10.1556/comec.3.2002.1.8 ◽

2002 ◽

Vol 3 (1) ◽

pp. 69-78 ◽

Cited By ~ 4

Author(s):

H.L. Buckley

Keyword(s):

Species Richness ◽

Vascular Plant ◽

Small Scale ◽

Epiphytic Lichen ◽

Aspen Parkland

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Lack of congruence between terrestrial and epiphytic lichen strata in boreal forests

The Lichenologist ◽

10.1017/s0024282920000407 ◽

2021 ◽

Vol 53 (1) ◽

pp. 149-158

Author(s):

Robert J. Smith ◽

Sarah Jovan ◽

Susan Will-Wolf

Keyword(s):

Species Richness ◽

Boreal Forests ◽

Environmental Gradients ◽

Ground Layer ◽

Global Changes ◽

Layer Versus ◽

Epiphytic Lichen ◽

Incremental Change ◽

Compositional Gradients ◽

Environmental Responses

AbstractLichens occupy diverse substrates across tremendous ranges of environmental variation. In boreal forests, lichen communities co-occur in ‘strata’ defined by terrestrial or arboreal substrates, but these strata may or may not be interchangeable as bioindicators. Do co-occurring lichen strata have similar community structures and environmental responses? Could one stratum serve as a proxy for the other? We assessed variation in species richness and community compositions between ground-layer versus epiphyte-layer lichen strata in boreal forests and peatlands of interior Alaska. Species richness was lower and more spatially structured in the ground layer than the epiphyte layer. Richness of strata was not correlated. The most compositionally unique ground-layer communities were species-poor but contained regionally rare species not common in other plots. Variation in community compositions (ordination scores) were not congruent between strata (Procrustes congruence < 0.16 on 0–1 scale); the largest departures from congruence occurred where ground layers were species-poor. The best predictors of ground-layer community compositions were hydrological and topographic, whereas epiphytes were most associated with macroclimate and tree abundances. We conclude that lichens on different substrates ‘move in different circles’: compositional gradients did not agree and the environmental gradients most important to each lichen stratum were not the same. The conditions which strongly influence one vegetation stratum may have little bearing upon another. As global changes modify habitats, an incremental change in environment may lead community trajectories to diverge among lichen strata.

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Monitoring of small rock pools reveals differential effects of chronic anthropogenic disturbance on birds and mammals in the Calakmul region, southern Mexico

Journal of Tropical Ecology ◽

10.1017/s0266467421000547 ◽

2021 ◽

pp. 1-10

Author(s):

Carlos M. Delgado-Martínez ◽

Fredy Alvarado ◽

Melanie Kolb ◽

Eduardo Mendoza

Keyword(s):

Species Richness ◽

Anthropogenic Disturbance ◽

Forest Cover ◽

Biosphere Reserve ◽

Bird Diversity ◽

Small Scale ◽

Rock Pools ◽

Southern Mexico ◽

Wildlife Species ◽

The Impact

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.

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Response of dry grassland vegetation to fluctuations in weather conditions: a 9-year case study in Prague (Czech Republic)

Biologia ◽

10.2478/s11756-011-0079-1 ◽

2011 ◽

Vol 66 (5) ◽

Cited By ~ 6

Author(s):

Jiří Dostálek ◽

Tomáš Frantík

Keyword(s):

Species Richness ◽

Czech Republic ◽

Weather Conditions ◽

Grass Species ◽

Individual Species ◽

Weather Variability ◽

Grassland Vegetation ◽

Dry Grassland ◽

Local Climate ◽

The Impact

AbstractThe extreme habitats of dry grasslands are suitable for investigations of the response of vegetation to local climate changes. The impact of weather variability on the dynamics of a plant community in a dry grassland was studied. Correlations were found between different functional groups of species and individual species and weather variability. During a 9-year study in five nature reserves in Prague (Czech Republic), the following responses of dry grassland vegetation to weather conditions were observed: (i) wetter conditions, especially in the winter, affected the dominance and species richness of perennial grass species and the decline of rosette plants; (ii) the year-to-year higher temperatures in the winter produced a decline in the dominance of short graminoids and creeping forbs; (iii) spring drought adversely impacted the overall abundance, especially the abundance of dicotyledonous species, and the species richness. However, these relationships may be manifested in different ways in different locations, and in some cases the vegetation of different locations may respond to weather conditions in opposite manners.

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Floristic composition of the Montane Forest in the Almadina-Barro Preto axis, Southern Bahia, Brazil

Biota Neotropica ◽

10.1590/s1676-06033878 ◽

2014 ◽

Vol 14 (1) ◽

Cited By ~ 9

Author(s):

Macielle Macedo Coelho ◽

André Márcio Amorim

Keyword(s):

Species Richness ◽

Tropical Forests ◽

Atlantic Forest ◽

Floristic Composition ◽

Woody Species ◽

Life Forms ◽

Montane Forest ◽

Forest Remnants ◽

Southern Bahia ◽

Arboreal Habit

The aim of this study is to survey the angiosperms of two montane forest remnants in the southern Bahia, Brazil: Corcovado (SCO) and Pedra Lascada (SPL). Both fragments are located in the municipality of Almadina and Barro Preto, respectively, and are 18 km distant from each other. We sampled 899 species of angiosperms distributed in 437 genera and 116 families. The SCO was the richest area with 678 species, distributed in 367 genera and 100 families. SPL showed 466 species in 269 genera and 88 families. The percentage of species identified was 85.8% and of this total, 37.7% are endemic to the Atlantic Forest, 11.2% are endemic to southern Bahia and northern Espírito Santo and 7% are disjunct between the Atlantic Forest and Amazon. The remaining percentages (44.3%) were of species widely distributed. The richest families in the two areas were Orchidaceae (10%), Rubiaceae (7%), Bromeliaceae (5.5%), Melastomataceae (4.2%) and Poaceae (4%). The richest genera were Psychotria (2%),Piper (1.8%), Ocotea (1.6%),Vriesea (1.5%) and Peperomia (1.4%). More than half of the recorded species showed non-arboreal habit, regarding life forms documented. That comes against the assertion that many authors in the tropical forests, where species richness in angiosperms is expected for non-woody species, especially in montane forests. Twelve species have been identified as new, but seven others already described from collections previously obtained in these two areas. Orchidaceae, Rubiaceae, Poaceae and Bromeliaceae showed significant richness in this study these families are commonly reported as the richest in other inventories in the Atlantic Forest in southern Bahia reinforcing their importance to the regional flora. The high levels of richness, endemism, and the growing numbers of new taxonomic discoveries from the SPL and SCO sites indicate the biological importance of these two forest remnants. The implementation of parks or other protected environmental reserves would be essential to the conservation of its species.

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Effects of sediment nutrients and depth on small-scale spatial heterogeneity of submersed macrophyte communities in Lake Pleasant, Pennsylvania

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f04-081 ◽

2004 ◽

Vol 61 (8) ◽

pp. 1493-1502 ◽

Cited By ~ 10

Author(s):

R K Johnson ◽

M L Ostrofsky

Keyword(s):

Organic Matter ◽

Community Structure ◽

Spatial Heterogeneity ◽

Environmental Gradients ◽

Small Scale ◽

Sediment Characteristics ◽

Available Nitrogen ◽

Total N ◽

Available N ◽

Prevailing Paradigm

Sediment concentrations of total and available nitrogen (N), phosphorus (P), and potassium (K) and organic matter from the littoral zone of Lake Pleasant, Pennsylvania, were highly variable. Only organic matter and total N were correlated with depth, however. This result suggests the existence of more complex environmental gradients than the prevailing paradigm of monotonic changes in sediment characteristics with increasing depth. The spatial heterogeneity of submersed aquatic plant communities was significantly correlated with depth, and available N and P. Canonical correspondence analysis demonstrated that these three factors explained 38% of the variance in community structure. Other sediment characteristics (available K, organic matter, and total N, P and K) were not significant by themselves, but all variables combined explained 63% of community-structure variance. Cluster analysis identified species or groups of species typical of endpoints on the depth versus nutrient axes. Myriophyllum exalbescens was typical of deep sites with relatively nutrient-rich sediments, whereas deep nutrient-poor sites were dominated by Vallisneria americana and Megalodonta beckii. Shallow nutrient-rich sites were dominated by several species of Potamogeton and Elodea canadensis, and shallow nutrient-poor sites were dominated by Heteranthera dubia and Najas flexilis. These results demonstrate the importance of sediment characteristics in determining macrophytes' community structure within lakes.

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The pitfalls of biodiversity proxies: Differences in richness patterns of birds, trees and understudied diversity across Amazonia

Scientific Reports ◽

10.1038/s41598-019-55490-3 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Camila D. Ritter ◽

Søren Faurby ◽

Dominic J. Bennett ◽

Luciano N. Naka ◽

Hans ter Steege ◽

...

Keyword(s):

Species Richness ◽

Large Scale ◽

Spatial Scales ◽

Local Environment ◽

Life Forms ◽

Taxonomic Group ◽

Diversity Gradients ◽

Richness Patterns ◽

Taxonomic Groups ◽

Micro Organisms

AbstractMost knowledge on biodiversity derives from the study of charismatic macro-organisms, such as birds and trees. However, the diversity of micro-organisms constitutes the majority of all life forms on Earth. Here, we ask if the patterns of richness inferred for macro-organisms are similar for micro-organisms. For this, we barcoded samples of soil, litter and insects from four localities on a west-to-east transect across Amazonia. We quantified richness as Operational Taxonomic Units (OTUs) in those samples using three molecular markers. We then compared OTU richness with species richness of two relatively well-studied organism groups in Amazonia: trees and birds. We find that OTU richness shows a declining west-to-east diversity gradient that is in agreement with the species richness patterns documented here and previously for birds and trees. These results suggest that most taxonomic groups respond to the same overall diversity gradients at large spatial scales. However, our results show a different pattern of richness in relation to habitat types, suggesting that the idiosyncrasies of each taxonomic group and peculiarities of the local environment frequently override large-scale diversity gradients. Our findings caution against using the diversity distribution of one taxonomic group as an indication of patterns of richness across all groups.

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