Distribution Of Aquatic Macrophytes Research Articles

Artificial Regulation of Water Level and Its Effect on Aquatic Macrophyte Distribution in Taihu Lake

Management of water levels for flood control, water quality, and water safety purposes has become a priority for many lakes worldwide. However, the effects of water level management on the distribution and composition of aquatic vegetation has received little attention. Relevant studies have used either limited short-term or discrete long-term data and thus are either narrowly applicable or easily confounded by the effects of other environmental factors. We developed classification tree models using ground surveys combined with 52 remotely sensed images (15–30 m resolution) to map the distributions of two groups of aquatic vegetation in Taihu Lake, China from 1989–2010. Type 1 vegetation included emergent, floating, and floating-leaf plants, whereas Type 2 consisted of submerged vegetation. We sought to identify both inter- and intra-annual dynamics of water level and corresponding dynamics in the aquatic vegetation. Water levels in the ten-year period from 2000–2010 were 0.06–0.21 m lower from July to September (wet season) and 0.22–0.27 m higher from December to March (dry season) than in the 1989–1999 period. Average intra-annual variation (CVa) decreased from 10.21% in 1989–1999 to 5.41% in 2000–2010. The areas of both Type 1 and Type 2 vegetation increased substantially in 2000–2010 relative to 1989–1999. Neither annual average water level nor CVa influenced aquatic vegetation area, but water level from January to March had significant positive and negative correlations, respectively, with areas of Type 1 and Type 2 vegetation. Our findings revealed problems with the current management of water levels in Taihu Lake. To restore Taihu Lake to its original state of submerged vegetation dominance, water levels in the dry season should be lowered to better approximate natural conditions and reinstate the high variability (i.e., greater extremes) that was present historically.

Lack of lake augmentation effects on aquatic macrophyte abundance and distribution in west-central Florida lakes, USA

This study tested the hypothesis that lake augmentation with well water impacts the distribution and abundance of aquatic plants in lakes. Water chemistry was measured from 14 wells, 14 augmented lakes, and 14 lakes without augmentation. Nine in-lake aquatic macrophyte abundance and species distribution metrics were measured in all lakes. Net photosynthetic rate (NPR) of nine submersed species was also measured in well and lake water. Augmentation increased alkalinity in receiving lakes, but total phosphorus was significantly lower, which resulted in lower chlorophyll and greater Secchi depths. Although measured NPR was higher for all plants incubated in well water, only one (emergent species richness) in-lake aquatic macrophyte metric was different in lakes with and without augmentation. Lake augmentation significantly changed water chemistry of receiving waters, but effects on aquatic macrophytes were minimal, suggesting that other environmental factors are limiting the distribution and abundance of macrophytes in the study lakes. The lower phosphorus levels in augmented lakes were unexpected because phosphorus concentrations in well water were significantly greater than in lakes with or without augmentation. Precipitation of calcium phosphate likely accounts for the reduced phosphorus levels in augmented lakes.

Distribution and succession of aquatic macrophytes in Chilka Lake - India

Chilka is the largest brackish water lake in Asia and also the second largest lake in the world. It is situated between 19°28' and 19°54' North latitude and 85°05' and 85° 38' East longitude. A mix of estuarine, marine and freshwater ecosystem is observed here and the lagoon has a long history of sustainable fishing. In September 2000 as a part of its management endeavour, the local authority had opened a new mouth at Satpada to facilitate efficient tidal mixing between the lake and the sea. Prior to this (1996 to 1997) salinity in the lake was low, which favoured intense growth of (invasive) macrophytic vegetation (e.g. Potamogeton, Halophila, Gracilaria, Ruppia etc.) and the effect is the greatest in the northern most part of the lake with intense (freshwater) weeds mainly Eichornia, Hydrilla, Chara, etc. Aquatic macrophytes are important in the functioning of the water body. They offer food and shelter for many organisms and promote habitat diversity. The paper seeks to isolate and describe weedy and non weedy zones inside the lake using grid sampling by Gramin® GPS. Key words: Chilka Lake, macrophyte, weeded and nonweeded, global positioning system (GPS), salinity

Spatio-temporal changes in land cover and aquatic macrophytes of the Danube floodplain lake

The aquatic vegetation of Číčov Lake in the Danube floodplain, which is listed in the Ramsar Convention, was investigated to address three main questions: (1) how have landscape composition and the structures of the lake and its buffer zone changed from the mid-20th century; (2) how have species richness and the abundance of the aquatic macrophyte assemblage in this lake ecosystem changed over the last 34 years; and (3) which landscape metrics can best explain these temporal changes for floating-leaved macrophytes? Two methodological approaches, remote sensing and botanical field surveys, were applied. Historical (1949, 1970, 1990) and contemporary (2006) aerial photographs were analysed to determine land cover. Landscape configuration and structure were analysed using eight landscape metrics selected in advance to measure spatio-temporal changes and the fragmentation of the lake ecosystem and its corresponding buffer zone. The species diversity, abundance and distribution of true aquatic macrophytes were surveyed eleven times in five survey stretches between 1973 and 2007. At the landscape level, a decrease in the area covered by floating-leaved macrophytes, as well as an increase in open water surface and fragmentation of the land cover classes in the lake ecosystem, were recorded from 1949 to 2006. Overall, 30 true aquatic macrophytes were found from 1973 to 2007. Species richness did not change considerably, but the abundance of aquatic species fluctuated over the years. Three groups of true aquatic vegetation, based on common structural characteristics, were found in 1973–1983, 1989–2002, and 2004–2007 over the last 34 years. The landscape metrics NP, PD, LPI, and SHDI, which all express patterns of landscape fragmentation mostly indicate temporal changes in floating-leaved macrophytes.

Anatomy of the root of eight species of emergent aquatic macrophytes from the upper Paraná river, Paraná State, Brazil floodplain

The upper Parana River floodplain is characterized by the existence of several aquatic and transitional habitats between the aquatic and terrestrial environment, influencing the presence and distribution of aquatic macrophytes. Samples were taken from different places and permanent slides were prepared for analysis and capture of images with the objective of comparing the anatomy of the roots of eight species of emergent aquatic macrophytes. The species feature uniseriate epidermis with narrow and long cells, cortex composed of uniseriate or biseriate exodermis, with or without thickening, aerenchyma with great gaps, uniseriate endodermis, with or without thickening, continuous or interrupted pericycle, and central cylinder with variable number of xylem poles.

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.

Macrophyte distribution and ecological status of the Turiec River (Slovakia): Changes after seven years

Characteristics of diversity, abundance, distribution, and ecological status of aquatic macrophytes were observed in 2000 and 2007 on a circa 4.5 km long section of the Turiec River using Kohler's method. In comparison to 2000, the total number of macrophytes in 2007 increased markedly (from 25 to 35), although only the numbers of amphi?phytes and helophytes were changed substantially. The number of hydrophytes increased from 11 to 12; an invasive, Elodea canadenis, was the only new species. The relative plant mass of hydrophytes represents the bulk of all recorded species (95 and 80% in 2000 and 2007, respectively), and it was changed for most hydrophytes. The most significant changes were detected for Myriophyllum spicatum (decrease), filamentous algae (decrease), and Potamogeton crispus (increase). In 2007, the mean mass total (MMT) sum of hydrophytes decreased from 16.46 to 14.5. On the other hand, the MMTsum of amphiphytes and helophytes doubled in value (7.4 and 14.1 in 2000 and 2007, respectively). Within hydrophytes, Batrachium species (including B. aquatile and B. trichophyllum), Myriophyllum spicatum, and Potamogeton crispus were ubiquitous (distribution ratio d > 0.5) in 2000, whereas in 2007 only Batrachium species and Potamogeton crispus were ubiquitous. At all times, Batrachium species were the most frequent species in the study area, and their abundance was relatively high (MMT> 2.5). A poor ecological status (MMP = 0.378 and MMP = 0.333 in 2000 and 2007, respectively) of the surveyed river section was found in both years, but a slight decline of quality as determined on the basis of aquatic plants was observed after 7 years.

Distribution of aquatic macrophytes in contrasting river systems: A critique of compositional-based assessment of water quality

A brief summary of the historical developments relating to plant distribution and aquatic macrophyte-nutrient indices provided a means of assessing the general context and validity of previous assumptions. This has particular current relevance because of the prominent use of bioindicators for defining nutrient enrichment. A survey of 161 sites distributed across two broadly contrasting groups of rivers (circum-neutral versus alkaline) recorded 110 species of aquatic macrophytes and these have been statistically analyzed to (i) rank and separate the individual effects of local environmental conditions and spatial isolation on species distribution in the two contrasting groups of sites; (ii) calculate a macrophyte index based on plant cover and species indicator values (Mean Trophic Rank, MTR); and finally (iii) investigate the implications for biomonitoring. Chemical, physical and hydrological site attributes together with spatial isolation, each explained a significant and at least partially independent influence over plant species distribution. It was extremely difficult, however, to separate the single effects of different site attributes on plant distribution. While some plant species are more restricted to certain environmental conditions, many appeared indifferent to the range of those being tested. The role played by nutrients (nitrogen (N) and phosphorus (P)) were either mostly indistinguishable from other site attributes (e.g., nitrate from conductivity) or subordinate (e.g., soluble reactive phosphorus, ammonium). It is therefore very unlikely that macrophyte species composition could provide a reliable bioindicator of the surrounding nutrient (N, P) status. The calculation of the plant index illustrated this unreliability by showing that strong correlations existed with many environmental variables, not just inorganic N and P.

Environmental Parameters Affecting the Species Diversity Along the Aliakmon River, North Greece

The annual distribution of aquatic and coastal macrophytes in five selected sites along the Aliakmon River was studied from January 2005 to December 2005 in Northern Greece. Soil and water chemical parameters in these sites were also evaluated. A total of 75 taxa were recorded belonging to 37 families and 53 genera. The majority of the macrophytes belonged to coastal plants (76%), whereas the rest of the macrophytes belonged to aquatic plants (24%). Species of the family Asteraceae were dominant among coastal plants, whereas species of the family Potamogetonaceae were dominant among aquatic plants. Soil samples from the site of Dam of Veria had higher pH and electric conductivity (80-100 cm depth), whereas CaCO3 contents were significantly higher in soil samples from the area of P. Prodromos (60-80 cm depth). Most physicochemical water parameters as well as selected soil nutrients and major ionic components showed an increase during the low charge period (fall) compared to with the high charge period (spring), especially in parameters associated with agricultural activity. Furthermore, there was an increase in most examined values moving towards the delta of the river.

Aquatic macrophyte classification, distribution, and traits in British lakes

(2008). Aquatic macrophyte classification, distribution, and traits in British lakes. SIL Proceedings, 1922-2010: Vol. 30, No. 3, pp. 477-481.

Global diversity of aquatic macrophytes in freshwater

Aquatic macrophytes are aquatic photosynthetic organisms, large enough to see with the naked eye, that actively grow permanently or periodically submerged below, floating on, or growing up through the water surface. Aquatic macrophytes are represented in seven plant divisions: Cyanobacteria, Chlorophyta, Rhodophyta, Xanthophyta, Bryophyta, Pteridophyta and Spermatophyta. Species composition and distribution of aquatic macrophytes in the more primitive divisions are less well known than for the vascular macrophytes (Pteridophyta and Spermatophyta), which are represented by 33 orders and 88 families with about 2,614 species in c. 412 genera. These c. 2,614 aquatic species of Pteridophyta and Spermatophyta evolved from land plants and represent only a small fraction (∼1%) of the total number of vascular plants. Our analysis of the numbers and distribution of vascular macrophytes showed that whilst many species have broad ranges, species diversity is highest in the Neotropics, intermediate in the Oriental, Nearctic and Afrotropics, lower in the Palearctic and Australasia, lower again in the Pacific Oceanic Islands, and lowest in the Antarctic region. About 39% of the c. 412 genera containing aquatic vascular macrophytes are endemic to a single biogeographic region, with 61–64% of all aquatic vascular plant species found in the Afrotropics and Neotropics being endemic to those regions. Aquatic macrophytes play an important role in the structure and function of aquatic ecosystems and certain macrophyte species (e.g., rice) are cultivated for human consumption, yet several of the worst invasive weeds in the world are aquatic plants. Many of the threats to fresh waters (e.g., climate change, eutrophication) will result in reduced macrophyte diversity and will, in turn, threaten the faunal diversity of aquatic ecosystems and favour the establishment of exotic species, at the expense of native species.

Distribution of aquatic plants in the Northern Vosges rivers: implications for biomonitoring and conservation

1. The continual confusion over the definition of the term ‘trophic status’ has led to ambiguous demonstrations of the influence of alkalinity versus inorganic N and P on aquatic plant distribution. 2. Data from the Northern Vosges rivers (sandstone geology) were reinvestigated to test whether it was possible to separate the effect of (i) spatial isolation from surface water chemistry, and (ii) alkalinity from inorganic N and P on aquatic macrophyte distribution. 3. Alkalinity and pH exerted the strongest influence on plant distribution, soluble reactive phosphorus (SRP) and pCO2 being subordinate. The effect of spatial isolation between catchments was not significant, which may indicate that aquatic plants dispersed well over the area. The effect of longitudinal connectivity on species distribution was strong, although largely confounded by the effects of water chemistry and possibly other physical factors not recorded. The partial effect of SRP (after removing the effect of pH or alkalinity) was still significant. However this was not the case for NH4. 4. The floristic composition was more likely to indicate the role played by alkalinity than inorganic P, with inorganic N being further subordinate. However, the causality of the significant relationships needs to be investigated further. This study questioned the validity of current macrophyte biomonitoring tools striving to indicate the concentrations of inorganic N and P. 5. More work is needed to quantify the role of connected and isolated aquatic habitats in the region, in order to understand how to maintain the species pool and to ensure that recolonization rates compensate for the losses due to disturbances. It is not clear how the vegetation would respond to inorganic P enrichment (or control), based on the individual species response observed here, and river P uptake studies from other rivers. Future monitoring should also include measurements of physical degradation. Copyright © 2007 John Wiley & Sons, Ltd.

Sample Size Requirements for Estimating Species Richness of Aquatic Vegetation in Iowa Lakes

ABSTRACT We described the distribution of aquatic macrophytes sampled from 130 lakes (1997–2005) across Iowa and estimated the number of samples required to determine species richness at various detection levels. Sago pondweed (Stuckenia pectinatus), cattails (Typha spp.), reed canarygrass (Phalaris arundinacea), longleaf pondweed (Potamogeton nodusus), and coontail (Ceratophyllum demersum) were generally the most common species sampled, but several exceptions were observed. For instance, bulrushes (Schnoenoplectus spp.) were among the most common taxa in natural lakes, and American water lotus (Nelumbo lutea) was one of the most common species in oxbow lakes. Sample size estimates were closely related to lake size, with larger systems requiring more samples. Our analysis suggests that lakes smaller than 10 ha require about 12 vegetated transects to have a 95% probability of detecting all of the species present in the lake. Lakes between 10.1 and 40 ha require 13 transects, those between 40.1 and 101 ha require 19 transects, lakes between 101.1 and 202 ha require 25 transects, lakes between 202.1 and 404 ha require 29 transects, and lakes greater than 404.1 ha require 35 transects.

Occurrence and Distribution of Aquatic Macrophytes in Relation to the Nutrient Content in Sediments of Two Freshwater Lake Ecosystems in the Nigerian Savanna

Occurrence and Distribution of Aquatic Macrophytes in Relation to the Nutrient Content in Sediments of Two Freshwater Lake Ecosystems in the Nigerian Savanna

The Distribution and Abundance of Aquatic Macrophytes in Swan Lake and Middle Lake, Minnesota

ABSTRACT Point intercept surveys were conducted on Swan Lake and Middle Lake, Minnesota to quantitatively assess aquatic macrophyte distribution and abundance. A sediment particle size analysis was conducted to determine if sediment particle size influenced sago pondweed (Stuckenia pectinata (L.) Börner) and wild celery (Vallisneria americana Michx.) distribution. Swan Lake had more macrophyte species than Middle Lake. Sago pondweed distribution was different between 2001 and 2002 in Middle Lake. Wild celery was only found in Swan Lake and its distribution was also different between sample years. The presence of sago pondweed was positively related to percentage of clay in Swan Lake sediments. The presence of wild celery was negatively related to the percentage of clay in the sediment. No relationship was found between sediment particle size and sago pondweed growing in Middle Lake.

Effects of Environmental Factors on Ecology and Distribution of Aquatic Macrophytes

Effects of Environmental Factors on Ecology and Distribution of Aquatic Macrophytes

Diversity of aquatic macrophytes in relation to environmental factors in the Slatina river (Slovakia)

Distribution and plant mass of aquatic macrophytes, and their relation to environmental conditions was studied in the submontane-colline Slatina river in 2004. Diversity of macrophytes was low, only 8 vascular plants, 3 mosses and group Algae filamentosae were found. Myriophyllum spicatum is dominant species, Fontinalis antipyretica, Rhynchostegium riparioides and Algae filamentosae are frequent. Interactions between flow class, bed material, depth of water and the first three mentioned macrophytes, as well as Jungermannia leiantha were detected. Sparganium erectum prefers more antrophogenic conditions and Myriophyllum spicatum prefers the light. According to cluster analysis, three distinct and ecologically well separated parts of the river were identified. Based on Reference index, poor ecological status for the studied part of the Slatina river was estimated.

Mäkkýše hlavných typov vôd dolného Hrona [Mollusca in main water bodies in the lower Hron River, Slovakia

The aim of this study is to describe the main types of water bodies in the lower Hron River (Slovakia) using Mollusca as ‘functional describers’ of the ecosystem dynamics. In European context, the Hron River belongs with its average discharge 53.7 m3.s–1 to small rivers; course length is 297 km. Major part of the alluvial plain exhibits strong human impact, though there are still relics of relatively well-preserved main successional stages of water bodies. The sampling (set-time period method) was stratified on the distribution of aquatic macrophytes (if presented). A total of 35 species was found alive (23 gastropods, 12 bivalves). The most constant species were Radix auricularia and Galba truncatula. In eupotamon, 13 species were found; characteristic species were Valvata piscinalis, Gyraulus albus, Unio pictorum, U. tumidus, Pisidium spp., Ancylus fluviatilis, and Radix peregra. In parapotamon, the bivalve Sphaerium corneum was a characteristic species, plesiopotamon had no characteristic species; for paleopotamon were characteristic Planorbis planorbis and Aplexa hypnorum, also a non-indigenous snail Physella acuta was constant. In anthropogenic water bodies no differentiative species were presented; the presence and dominance of Physella acuta is typical.

The relationship between water level fluctuation and distribution of emergent aquatic macrophytes in large, mildly regulated lakes in the Finnish Lake District

The relationship between water level fluctuation and distribution of emergent aquatic macrophytes in large, mildly regulated lakes in the Finnish Lake District