Effects of extreme flooding on aquatic vegetation cover in Shengjin Lake, China

2021 ◽  
Author(s):  
Wenli Guo ◽  
Zhongze Zhou ◽  
Jingwen Chen ◽  
Xudong Zheng ◽  
Xiaoxin Ye
Keyword(s):  
Vegetation Cover ◽  
Aquatic Vegetation ◽  
Extreme Flooding

Quantification of Historical Changes of Submerged Aquatic Vegetation Cover in Two Bays of Lake Ontario with Three Complementary Methods

2007 ◽  
Vol 33 (1) ◽  
pp. 122-135 ◽  
Author(s):  
Bin Zhu ◽  
Dean G. Fitzgerald ◽  
Susan B. Hoskins ◽  
Lars G. Rudstam ◽  
Christine M. Mayer ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
Lake Ontario ◽  
Historical Changes ◽  
Complementary Methods

scholarly journals Interactions between aquatic vegetation, hydraulics and fine sediment

2020 ◽  
Author(s):  
Hamish Biggs ◽  
Arman Haddadchi ◽  
Murray Hicks
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Hydraulic Resistance ◽  
Vegetation Cover ◽  
Aquatic Vegetation ◽  
Fine Sediment ◽  
Suspended Sediment Transport ◽  
Sediment Delivery ◽  
Lowland Streams ◽  
Mechanical Removal

Aquatic vegetation, hydraulics and sediment transport have complex interactions that are not yet well understood. These interactions are important for sediment conveyance, sediment sequestration, phasing of sediment delivery from runoff events, and management of ecosystem health in lowland streams. To address this knowledge gap detailed field measurements of sediment transport through natural flexible aquatic vegetation are required to supplement and validate laboratory results. This paper contributes a field study of suspended sediment transport through aquatic vegetation and includes mechanical removal of aquatic vegetation with a weed cutting boat. It also provides methods to quantify vegetation cover through remote sensing with Unmanned Aerial Vehicles (UAVs) and estimate biomass from ground truth sampling. Suspended sediment concentrations were highly dependent on aquatic vegetation abundance, and the distance upstream that had been cleared of aquatic vegetation. When the study reach was fully vegetated (i.e. cover >80%), the maximum recorded SSC was 14.6 g/m (during a fresh with discharge of 2.47 m/s), during weed cutting operations SSC was 76.8 g/m at 0.84 m/s (weedcutting boat 0.5-1 km upstream from study reach), however following weed cutting operations (4.6 km cleared upstream), SSC was 139.0 g/m at a discharge of 1.52 m/s. The data indicates that fine sediment was being sequestered by aquatic vegetation and likely remobilised after vegetation removal. Investigation of suspended sediment spatial dynamics illustrated changes in particle size distribution due to preferential settling of coarse particles within aquatic vegetation. Hydraulic resistance in the study reach (parameterized by Manning’s n) dropped by over 70% following vegetation cutting. Prior to cutting hydraulic resistance was discharge dependent, while post cutting hydraulic resistance was approximately invariant of discharge. Aerial surveying captured interesting changes in aquatic vegetation cover, where some very dense regions of aquatic vegetation were naturally removed leaving behind unvegetated riverbed and fine sediment.

Mapping the flood-plain vegetation of the Lower Volga River

2000 ◽  
pp. 62-76 ◽  
Author(s):  
N. M. Novikova ◽  
I. S. Iljina ◽  
I. N. Safronova
Keyword(s):  
Phragmites Australis ◽  
Vegetation Cover ◽  
Aquatic Vegetation ◽  
Salt Content ◽  
Flood Plain ◽  
Salix Alba ◽  
Volga River ◽  
Lower Volga ◽  
Elytrigia Repens ◽  
Mapping Units

In the paper the legend for 8 vegetation maps of key polygons s. 1 : 200 000, compiled by unified method, is given. The maps characterize the state of vegetation cover in different parts of the Lower Volga River (Volga-Akhtuba flood-plain and delta) in the late 90th. The Volga-Akhtuba flood-plain is well-divided into 2 morphogenetic types: the river-side flood-plain and the inner (central) one. Delta consists of numerous islands separated by channels and is subdivided into 3 parts: upper, middle and lower ones. At the mapping of flood-plain vegetation it is important to reveal the spatial variations in vegetation cover connected with regime of inundation, topography elevation, structure of surface, ground water table. The generalized legend to all maps is constructed according to ecological-dynamic principle reflecting the composition and structure of vegetation cover. Large divisions correspond to differentiation of vegetation at the level of main topographic types of territory: A. Vegetation of flood-plain, Б. Vegetation of delta. The divisions of the next rank are: I. Vegetation of river-side flood-plain and II. Vegetation of the inner flood- plain. Within the delta the following division are distinguished: 1. Forest-shrub- meadow and riparian-aquatic vegetation; 2. Desert vegetation. Mapping units proper (marked by numerical indices) characterize the phytocoenotical and floristic composition of vegetation as well as different patterns of its spatial structure and dynamics among the different elevation levels and forms of relief. Construction of Data Bases (DB) at mapping process has its specific features. Map organizes and differentiates the process of collecting information itself. The main instrument in this process is the map legend and the contents of mapping units. The botanical-cartographical DB suggests storing already synthesized and classified information, presented in form of mapping types of geobotanical polygons along with indices of environmental factors. The flood-plain vegetation of the Lower Volga River is represented by forests, shrub thickets, meadows, and aquatic-riparian Herbaceous communities. The forests are restricted mainly to the inner gentle ridges flood-plain. Oak forests (Quercus robur) are characteristic of only northern part of the Lower Volga River occuring between city of Volgograd and Kapustin Yar settlement. Willow forests (Salix alba) are spread throughout the all Lower Volga River (from Volgograd down to the Caspian Sea). They predominate in delta. In the middle part of delta the groves of Elaeagnus angustifolia appear. The channel-side natural levers of the lower seaward part of delta are occupied by forests of Salix alba. Shrubs thickets are less characteristic of these habitats; Tamarix ramosissima should be mentioned which appears south of 48°N in Volga- Akhtuba flood-plain in the limits of the Northern desert subzone. Forests of Populus nigra are wide-spread in the Volga-Akhtuba flood-plain from city of Volgograd southward up to Selitrennoye village. However they occupy habitats of middle topographical level. The same level in the river-side flood-plain and delta shrub thickets occupy. They are formed mainly by willows — Salix triandra, S. viminalis, S. acutifolia. Meadow vegetation predominate in the Lower Volga valley. Vegetation of high topographic level is formed by meadows of Calamagrostis epigeios, Bromopsis inermis, Elytrigia repens. Meadows of the middle topographic level are represented by grass-sedge communities. Meadows of the low topographic level are formed by communities of Carex acuta, Eleocharis spp., Elytrigia repens, Phragmites australis, Butomus umbellatus. The riparian-aquatic vegetation is formed by the communities of Phragmites australis, Typha spp., Scirpus lacustris, Phalaroiodes arundinacea, Butomus umbellatus, Sagittaria sagittifolia, Sparganium ramosum along the shores of water bodies and on the bottoms of depressions. Communities-indicators of soils with high salt content are characteristic of delta vegetation. On the overmoistened islands, free of water for a short time, with the surface salinification, the communities of Aeluropus spp., Crypsis aculeata, Bolboshoenus maritimus, Suaeda confusa, Salicornia europaea, Cynodon dactylon are spread.

Predicting submerged aquatic vegetation cover and occurrence in a Lake Superior estuary

2013 ◽  
Vol 39 (4) ◽  
pp. 536-546 ◽  
Author(s):  
Ted R. Angradi ◽  
Mark S. Pearson ◽  
David W. Bolgrien ◽  
Brent J. Bellinger ◽  
Matthew A. Starry ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
Lake Superior

scholarly journals Synergistic Effects of Rooted Aquatic Vegetation and Drift Wrack on Ecosystem Multifunctionality

Ecosystems ◽  
2021 ◽  
Author(s):  
Å. N. Austin ◽  
J. P. Hansen ◽  
S. Donadi ◽  
U. Bergström ◽  
B. K. Eriksson ◽  
...  
Keyword(s):  
Species Richness ◽  
Vegetation Cover ◽  
Aquatic Vegetation ◽  
Synergistic Effects ◽  
Experimental Studies ◽  
Coastal Ecosystems ◽  
Nitrogen Loading ◽  
Predatory Fish ◽  
Anthropogenic Pressures ◽  
Ecosystem Multifunctionality

AbstractEcosystem multifunctionality is an increasingly popular concept used to approximate multifaceted ecosystem functioning, which in turn may help advance ecosystem-based management. However, while experimental studies have shown a positive effect of diversity on multifunctionality, observational studies from natural systems—particularly aquatic—are scarce. Here, we tested the relative importance of species richness and cover of rooted aquatic vegetation, as well as cover of the loose-lying form of the macroalgae bladderwrack (Fucus vesiculosus), for ecosystem multifunctionality in shallow bays along the western Baltic Sea coast. We estimated multifunctionality based on four indicators of functions that support ecosystem services: recruitment of large predatory fish, grazer biomass, inverted ‘nuisance’ algal biomass, and water clarity. Piecewise path analysis showed that multifunctionality was driven by high cover of rooted aquatic vegetation and bladderwrack, particularly when the two co-occurred. This synergistic effect was nearly three times as strong as a negative effect of land-derived nitrogen loading. Species richness of aquatic vegetation indirectly benefitted multifunctionality by increasing vegetation cover. Meanwhile, high bladderwrack cover tended to decrease vegetation species richness, indicating that bladderwrack has both positive and negative effects on multifunctionality. We conclude that managing for dense and diverse vegetation assemblages may mitigate effects of anthropogenic pressures (for example, eutrophication) and support healthy coastal ecosystems that provide a range of benefits. To balance the exploitation of coastal ecosystems and maintain their multiple processes and services, management therefore needs to go beyond estimation of vegetation cover and consider the diversity and functional types of aquatic vegetation.

scholarly journals Role of habitat complexity in predator–prey dynamics between an introduced fish and larval Long-toed Salamanders (Ambystoma macrodactylum)

2016 ◽  
Vol 94 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Erin K. Kenison ◽  
Andrea R. Litt ◽  
David S. Pilliod ◽  
Tom E. McMahon
Keyword(s):  
Vegetation Cover ◽  
Vegetation Structure ◽  
Aquatic Vegetation ◽  
Extinction Risk ◽  
Structural Complexity ◽  
Introduced Fish ◽  
Nonconsumptive Effects ◽  
Ambystoma Macrodactylum ◽  
Predator Prey

Predation by nonnative fishes has reduced abundance and increased extinction risk for amphibian populations worldwide. Although rare, fish and palatable amphibians have been observed to coexist where aquatic vegetation and structural complexity provide suitable refugia. We examined whether larval Long-toed Salamanders (Ambystoma macrodactylum Baird, 1850) increased use of vegetation cover in lakes with trout and whether adding vegetation structure could reduce predation risk and nonconsumptive effects (NCEs), such as reductions in body size and delayed metamorphosis. We compared use of vegetation cover by larval salamanders in lakes with and without trout and conducted a field experiment to investigate the influence of added vegetation structure on salamander body morphology and life history. The probability of catching salamanders in traps in lakes with trout was positively correlated with the proportion of submerged vegetation and surface cover. Growth rates of salamanders in enclosures with trout cues decreased as much as 85% and the probability of metamorphosis decreased by 56%. We did not find evidence that adding vegetation reduced NCEs in experimental enclosures, but salamanders in lakes with trout used more highly vegetated areas, which suggests that adding vegetation structure at the scale of the whole lake may facilitate coexistence between salamanders and introduced trout.

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