Species Richness Of Aquatic Macrophytes Research Articles

Impact of nutrient enrichment on habitat heterogeneity and species richness of aquatic macrophytes: evidence from freshwater tropical lakes of Central Ganga Plain, India

Impact of nutrient enrichment on habitat heterogeneity and species richness of aquatic macrophytes: evidence from freshwater tropical lakes of Central Ganga Plain, India

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

Abstract The coastal rivers of the São Paulo State in SE Brazil have different lengths and seawater influence. We evaluated whether: (1) environmental heterogeneity (EH) is associated with the species and life‐form richness of aquatic macrophytes; and (2) EH and geographical distance influence species composition in these coastal rivers. We recorded the macrophyte species and life form occurrence and collected explanatory variables characterising the water, sediment, and river channel at 100 sampling sites over 8 rivers. We applied a principal component analysis to the explanatory variables and calculated the rivers' EH using the range of principal component 1 scores. We also determined the position of each river mouth along the coastline to measure the distance between the rivers. We used quasi‐Poisson generalised linear models to evaluate the effects of EH on richness of species and life forms. To determine the effect of EH and geographical distance (Euclidean distance matrices) on the variation in species composition (Jaccard dissimilarity matrix) among the rivers, we applied multiple regressions on distance matrices. The most heterogeneous river had heterogeneity score about five times greater than the least heterogeneous river. Sediment salinity, river width, total phosphorus concentration of water and distance from river mouth were the most important variables contributing to the rivers' EH. We found that EH did not explain variation in species richness; however, it had a significant positive relationship with life‐form richness. The effect of EH was greater than that of the geographical distance on the variation in species composition among the rivers. The pairs of rivers with the most similar EH were the most similar in species composition, but not all of them were geographically close. We conclude that EH influences life‐form richness but does not influence species richness of aquatic macrophytes in the coastal rivers we studied; however, EH does influence species composition regardless of geographical distance among rivers.

Response of benthic algae to environmental conditions in an urban lake recovered from eutrophication, China

Benthic algae communities dominate the primary production in littoral zone of shallow lake. To understand the long-term effect of alteration in the composition of benthic algae community assemblage in such as a lake in China, we analyzed the benthic algae developments and indicators in the Donghu Lake in Wuhan, central China in 2004 and 2014. We compared the benthic algae biomass, compositions, and species richness of aquatic macrophytes and the changes of primary physicochemical parameters. The results show that in the 10-year period, chl a and conductivity declined significantly but nutrient level of the whole lake remained largely stable. The benthic algae biomass doubled and the relative proportion of green algae increased, whereas the benthic diatom ratio decreased. The benthic diatom assemblages and taxa differed in a number of ways, showing more epiphytic diatom species, and the relative abundance and species richness changed markedly. The number of aquatic macrophyte species increased from 3 in 2004 to 15 in 2014, presenting a remarkable recovery from previous eutrophication conditions. The changes of water level, chl a, and conductivity played a crucial role in governing aquatic macrophytes re-colonization in the littoral zones in the period. The ecological characteristics of littoral benthic diatoms reflect habitat coupling as indicated by redundancy analysis. Therefore, the close link between benthic algae and macrophyte recovery demonstrates that the benthic algae metrics are much more useful than nutrient levels to quantify the process of restoration in the lake.

Relationships of macrophyte species richness and environment in different water body types in the Central European region

Individual types of waterbodies are characterised by their specific environmental conditions controlling growth of aquatic macrophytes. We focused on effects of environmental factors on macrophyte species richness in canals, ponds, rivers and streams within Central European region. We employed generalised linear models (GLM) to assess separately overall macrophyte species data and data on wetland species (true aquatic plants and helophytes). No significant difference was revealed by comparing species richness among water body types, though canals were the richest water bodies and streams supported the lowest diversity of macrophytes. The models for all the waterbodies, except streams, contained at least two variables and the explained variability ranged from 37% to 77%. The most recurring variables were the coverage of fine substrate, turbidity, shading by bank and shore trees and shrubs, and altitude. Nevertheless, no obvious pattern of factors was observed for particular water body types. Our study confirmed that aquatic macrophyte species richness is shaped by a complexity of factors and necessity of targeting survey and further generalisation of results not only on one specific water body.

Main predictors of periphyton species richness depend on adherence strategy and cell size.

Periphytic algae are important components of aquatic ecosystems. However, the factors driving periphyton species richness variation remain largely unexplored. Here, we used data from a subtropical floodplain (Upper Paraná River floodplain, Brazil) to quantify the influence of environmental variables (total suspended matter, temperature, conductivity, nutrient concentrations, hydrology, phytoplankton biomass, phytoplankton species richness, aquatic macrophyte species richness and zooplankton density) on overall periphytic algal species richness and on the richness of different algal groups defined by morphological traits (cell size and adherence strategy). We expected that the coefficients of determination of the models estimated for different trait-based groups would be higher than the model coefficient of determination of the entire algal community. We also expected that the relative importance of explanatory variables in predicting species richness would differ among algal groups. The coefficient of determination for the model used to predict overall periphytic algal species richness was higher than the ones obtained for models used to predict the species richness of the different groups. Thus, our first prediction was not supported. Species richness of aquatic macrophytes was the main predictor of periphyton species richness of the entire community and a significant predictor of the species richness of small mobile, large mobile and small-loosely attached algae. Abiotic variables, phytoplankton species richness, chlorophyll-a concentration, and hydrology were also significant predictors, depending on the group. These results suggest that habitat heterogeneity (as proxied by aquatic macrophytes richness) is important for maintaining periphyton species richness in floodplain environments. However, other factors played a role, suggesting that the analysis of species richness of different trait-based groups unveils relationships that were not detectable when the entire community was analysed together.

Remarkable richness of aquatic macrophytes in 3-years old re-established Lake Fil, Denmark

In August 2014, we discovered a surprisingly high species richness of aquatic macrophytes (33 species) in Lake Fil only two years after the large, shallow lake had been re-established following land reclamation and 60 years of intense agricultural use. In 2015, plant richness had increased even further (to 40 species). Some rare, oligotrophic species, which formerly were common in the historical lake, have re-established populations (e.g. Elatine hydropiper and Lythrum portula). However, a larger number of meso- and eutrophic species have colonized the re-established lake, changing the character of aquatic macrophyte flora as compared to the historical lake. The very rare Baldellia repens, considered extinct species in Denmark, has become re-established with at least 13 subpopulations in the new Lake Fil. Also two species recently discovered in Denmark (Callitriche obtusangula and Lemna turionifera) were found. Half of the species may have colonized the re-established lake from now submerged drainage canals and from an upstream lake, while the other half presumably have colonized from more distant lakes. The high richness of aquatic macrophytes in the re-established Lake Fil is matched by only a few natural lakes in Denmark. According to predictions of species richness from environmental conditions and colonized area in 56 natural Danish lakes, the observed richness in Lake Fil is two-fold the expected. We attribute the high plant richness to: shallow waters, large open areas on grazed or physically exposed lake shores and high likelihood of species recruitment from neighboring lakes via dense populations of migratory waterfowl. High plant richness was established despite low transparency due to high release of dissolved organic matter and particles from flooded soils. We conclude that suitable bathymetry, physical disturbance, grazing by cattle and waterfowl in the littoral zone and high dispersal capacity of propagules may ensure rapid establishment of a rich aquatic vegetation in new lakes, even when nutrient-rich farmland is the starting point.

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

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.

Geographic patterns of lake macrophyte communities and species richness at regional scale

AbstractQuestionsAre community composition and species richness of aquatic macrophytes determined primarily by local (habitat heterogeneity and water quality) or regional (climate) patterns at regional scale? Do two macrophyte functional groups (i.e. emergent and submerged macrophytes) respond similarly to local and regional patterns? Are lake macrophytes and explanatory variables geographically structured?LocationThe US state of Minnesota.MethodsThe community composition and species richness of aquatic flora was studied using presence–absence data in 454 lakes, covering the entire US state of Minnesota. In addition, community composition and species richness of emergent and submerged macrophytes was investigated separately. Variation partitioning based on partial redundancy analysis and partial linear regression was used to study the relative roles of water quality, habitat heterogeneity, climate and sampling effort in explaining community composition and species richness of lake macrophytes, respectively.ResultsMacrophyte community composition and species richness (all taxa and two functional groups) were explained by water quality and climate. Alkalinity and total phosphorus were water quality variables that most affected community composition of aquatic flora, and macrophyte species richness decreased with increasing concentrations of these two variables. Maximum temperature of the warmest month and mean annual temperature most affected plant community composition, whereas species richness had a negative relationship with minimum temperature of the coldest month. Most significant explanatory variables (e.g. alkalinity, total phosphorus and temperature) were geographically structured, showing a latitudinal change.ConclusionsCommunity composition and species richness of macrophytes were congruently influenced by regional (climate) and local patterns (water quality) at regional scale. Community composition and species richness of helophytes and submerged macrophytes were equally explained by environmental gradients. The latitudinal change in these most significant environmental variables was related to calcareous soils and intensive agriculture, which were situated in the southern part of the state. Macrophyte species richness showed a reverse latitudinal gradient, which was likely due to high nutrient concentrations in southern latitude lakes. Water quality primarily filters species from the regional species pool, allowing only species tolerating high nutrient concentrations, e.g. invasive plants, to survive at southern latitudes.

Richness and distribution of aquatic macrophytes in Brazilian semi-arid aquatic ecosystems

AIM: The aim of this study was to evaluate the richness and distribution of the aquatic macrophytes in the basin of the Apodi/Mossoró River, in the semi-arid region (caatinga) of Rio Grande do Norte, Brazil; METHODS: A survey of the floristic composition of the aquatic macrophytes was made at 20 sampling stations in the basin at four seasons (August/2007, November/2007, February/2008, May/2008). Specimens of each species were collected and deposited in the Dárdano de Andrade Lima Herbarium of the Universidade Federal Rural do Semi-Árido; RESULTS: We found 40 species of aquatic macrophytes, in 33 genera and 22 families. The families with the most species were Poaceae and Cyperaceae, and the most species-rich genera were Cyperus and Eleocharis. The most common plant form was amphibian (42.5%), followed by emergent (27.5%), free-floating (12.5%), rooted-submersed (10.0%), and floating-leaved (7.5%). The lowest richness was observed at the estuarine region (3 species), and the highest richness in the upper basin (17 species). The rooted-submersed Hydrothrix gardneri Hooker f. and Ceratophyllum demersum L. were observed in great abundance and frequency in the Santa Cruz Reservoir of Apodi, especially in areas close to cage farms of Nile tilapia (Oreochromis niloticus) (Linnaeus, 1758). The most common free-floating species were Eichhornia crassipes (Mart.) Solms., Pistia stratiotes L., and Salvinia auriculata Aubl., predominantly in stretches that run through urban centers; CONCLUSION: The species richness of aquatic macrophytes in aquatic environments of the caatinga is similar to that observed in other basins of Brazil. Because of the many dams and reservoirs in the semi-arid Northeast, inventory and monitoring of aquatic macrophytes have become essential, especially in basins that will receive water from the diversion of the São Francisco River.

Richness and distribution of aquatic macrophytes in Brazilian semi-arid aquatic ecosystems

AIM: The aim of this study was to evaluate the richness and distribution of the aquatic macrophytes in the basin of the Apodi/Mossoro River, in the semi-arid region (caatinga) of Rio Grande do Norte, Brazil; METHODS: A survey of the floristic composition of the aquatic macrophytes was made at 20 sampling stations in the basin at four seasons (August/2007, November/2007, February/2008, May/2008). Specimens of each species were collected and deposited in the Dardano de Andrade Lima Herbarium of the Universidade Federal Rural do Semi-Arido; RESULTS: We found 40 species of aquatic macrophytes, in 33 genera and 22 families. The families with the most species were Poaceae and Cyperaceae, and the most species-rich genera were Cyperus and Eleocharis. The most common plant form was amphibian (42.5%), followed by emergent (27.5%), free-floating (12.5%), rooted-submersed (10.0%), and floating-leaved (7.5%). The lowest richness was observed at the estuarine region (3 species), and the highest richness in the upper basin (17 species). The rooted-submersed Hydrothrix gardneri Hooker f. and Ceratophyllum demersum L. were observed in great abundance and frequency in the Santa Cruz Reservoir of Apodi, especially in areas close to cage farms of Nile tilapia (Oreochromis niloticus) (Linnaeus, 1758). The most common free-floating species were Eichhornia crassipes (Mart.) Solms., Pistia stratiotes L., and Salvinia auriculata Aubl., predominantly in stretches that run through urban centers; CONCLUSION: The species richness of aquatic macrophytes in aquatic environments of the caatinga is similar to that observed in other basins of Brazil. Because of the many dams and reservoirs in the semi-arid Northeast, inventory and monitoring of aquatic macrophytes have become essential, especially in basins that will receive water from the diversion of the Sao Francisco River.

Species richness of aquatic macrophytes in ponds related to number of species in neighbouring water bodies

The number of species of aquatic macrophytes and the number of neighbouring water bodies (within 500 m) were counted for three botanically rich ponds and three botanically poor ponds in north-east England. The number of species and the sum of records of aquatic macrophytes in the neighbouring water bodies were also determined. The linear regression model of number of species in the ponds against number of species in neighbouring water bodies closely fitted the data. This model suggested that ponds contain both a baseline number of taxa representing long-distance migrants and/or introductions, and a number of species which have come from neighbouring water bodies.

Species richness and ß-diversity of aquatic macrophytes in the Upper Paraná River floodplain

In this paper, we estimated the aquatic macrophyte species richness in the Upper Parana River floodplain using non-parametric estimators. Fifty species were recorded in intensive surveys of several floodplain habitats. Based on a random sample of 20 lagoons, 6 connected to the Parana River, 6 to one tributary and 8 to another, all estimators gave values very similar to the true number of species recorded in intensive surveys. The comparison among the lagoons connected with these rivers showed that the species richness was different, after controlling for sampling effort. Correspondence analysis and Mantel's test showed that the beta diversity was significantly higher among the groups of lagoons than within groups of lagoons connected with the same river. The high connectivity among the lagoons of the same river can account for such results. Within the groups of lagoons, the highest species turnover (beta diversity) was found for Parana River lagoons, which are predominantly temporary and more variable. This result is in accordance with a general ecological prediction, which stresses that beta diversity should increase with environmental variability.

Species Richness of Aquatic Macrophytes in Former Channels Connected to a River: A Comparison between Two Fluvial Hydrosystems Differing in Their Regime and Regulation

This paper compares the plant species richness and distribution of two flowing water systems located in functional alluvial forests subject to different hydrodynamics. The study areas are located in the Alsace Rhine floodplain and the braided and anastomosed sector of the upper Rhine. The substrates, through which substantial flows of groundwater occur, are calcareous Rhine gravels, 200 m deep in places. The first sector selected consists of two lateral side arms which are connected to the Rhine and receive highly mineralized bicarbonated waters (conductivity of 500-1000 ,uS cm-'). The second sector is connected to the river Ill, the main tributary of the Rhine in the Alsace floodplain. This sector receives inputs of more acidic waters and of sediments from the Vosges rnountain, and the waters are less highly mineralized (conductivity of 250-600 itS cm-'). The waters of both sectors are classified as eutrophic to hypertrophic. Comparison of the aquatic macrophytes of the flowing waters near the Rhine and the side arms located in the Ill forest shows that the former has greater species richness (43 versus 25 species), greater biomass, as estimated by percentage cover, and a more complex structure (4-5 versus < 3 strata). Plant community structure and diversity are closely related to habitat variability and in turn to the hydrological conditions and fluvial dynamics. In order to maintain the floristic and phytosociological diversity of these ecosystems, it is necessary first to preserve the fluvial dynamics which create and maintain the variation of habitats.

Species richness of aquatic macrophyte communites in Central Canada

Aquatic macrophyte species richness (SR) was examined at 430 sites in the central Canadian region in relation to water body type, bottom substrate and 8 water chemistry parameters. SR was highest in rivers and lakes, intermediate in creeks, and lowest in ponds. The highest values occurred where granitic bedrock, highly organic substrates or sand predominated. SR was significantly inversely correlated in the study area as a whole with 7 of the water chemistry parameters; of these, total alkalinity was the most important. However, the relative importance of the respective parameters differed for various water body types. The relationship between SR and phosphorus was positive in ponds, but negative for all other water body types. Stepwise sultiple regression analysis identified phosphorus, total alkalinity and dissolved organic matter as important factors in ponds; sulphate, total alkalinity and chloride in lakes, and sulphate and phosphorus in lotic habitats. Log transformations improved the correlations for some variables. However, the water chemistry parameters examined accounted for less than half of the total variability in SR. Apparently SR depends on many different factors, including surface areaand bottom type, whose relative contributions vary with situation.

Biomass and species richness of aquatic macrophytes in four Maine (U.S.A.) lakes of different acidity

Macrophyte communities of 2 pairs of oligotrophic head-water lakes of different acidity were described. The acidic lakes had fewer species of macrophytes than the circumneutral lakes. Biomass in the circumneutral lakes ranged from 14.0 to 157.86 g m −2; values for the acidic lakes were intermediate (33.8 and 74.6 g m −2).

Comparison of Species Composition and Richness of Fish Assemblages in Altered and Unaltered Littoral Habitats

ABSTRACT Species composition and richness of fish assemblages in altered and unaltered littoral habitats in Lake St. Clair, Michigan, differed between areas. A percid-cyprinid-cyprinodontid assemblage dominated in the unaltered area, Muscamoot Bay, which has a natural shoreline (with almost no alteration due to dredging or bulkheading), high water quality, and high species richness of aquatic macrophytes. A centrarchid assemblage dominated in the altered area, Belvidere Bay, which has a bulkheaded shoreline, many dredged areas, reduced water quality due to inputs of nutrients from a nearby river, and relatively low species richness of aquatic macrophytes. Habitat factors, species richness and abundance of aquatic macrophytes, had the most influence on fish community structure in both areas. The percid-cyprinid-cyprinodontid assemblage was significantly correlated with six species of macrophytes whereas the centrarchid assemblage was significantly correlated with only four. These patterns suggested that pr...