Riverside Vegetation Research Articles

Water Temperature Model to Assess Impact of Riparian Vegetation on Jucar River and Spain

Water temperature is a critical factor for aquatic ecosystems, influencing both chemical and biological processes, such as fish growth and mortality; consequently, river and lake ecosystems are sensitive to climate change (CC). Currently proposed CC scenarios indicate that air temperature for the Mediterranean Jucar River will increase higher in summer, 4.7 °C (SSP5-8.5), resulting in a river water temperature increase in the hotter month; July, 2.8 °C (SSP5-8.5). This will have an impact on ecosystems, significantly reducing, fragmenting, or even eliminating natural cold-water species habitats, such as common trout. This study consists of developing a simulated model that relates the temperature of the river with the shadow generated by the riverside vegetation. The model input data are air temperature, solar radiation, and river depth. The model proposed only has one parameter, the shadow river percentage. The model was calibrated in a representative stretch of the Mediterranean river, obtaining a 0.93 Nash–Sutcliffe efficiency coefficient (NSE) that indicates a very good model fit, a 0.90 Kling–Gupta efficiency index (KGE), and a relative bias of 0.04. The model was also validated on two other stretches of the same river. The results show that each 10% increase in the number of shadows can reduce the river water temperature by 1.2 °C and, in the stretch applied, increasing shadows from the current status of 62% to 76–87% can compensate for the air temperature increase by CC. Generating shaded areas in river restorations will be one of the main measures to compensate for the rise in water temperature due to climate change.

An assessment of maintenance works and their impact on macroinvertebrate communities and long-term recolonization to small lowland watercourses

Due to their small size and high anthropogenic pressure, small watercourses are particularly prone to severe siltation and are densely overgrown with macrophytes. Many of these watercourses are subject to regular maintenance works (RMW), consisting of seasonal desilting and vegetation clearance, in order to ensure unobstructed water flow. The aim of the study was to assess the impact of three types of maintenance works: dredging and mud removal (DMR), river channel vegetation removal (RCVR) and river bank vegetation removal (RBVR) on taxa species richness, macroinvertebrate density and the Shannon-Wiener diversity index, as well as their changes and long-term benthic recolonization one and two years after completion of the works. The study was carried out in 21 habitats on eight rivers in the European Central Plains Ecoregion. A total of 107 zoobenthic taxa were found at all sites, and their species composition was characteristic of highly hydrophytic waters with low hydrological and hydrochemical quality parameters. A significant decrease in macroinvertebrate taxa richness was observed one year after the works, as the average number of taxa had dropped from thirteen to eight, with a further fall to seven taxa two years after the RMW. The same was true for density, which had decreased from an average of 2496 to 786 individuals per square meter one year after the RMW, while, a gradual recolonization was recorded two years after the RMW, with an average density of 1295 individuals per square meter. The Shannon-Wiener index, which had averaged 2.528 before the RMW, also decreased, falling to 1.982 and 1.832 one and two years after. BACI statistical analyses showed that of the three types of maintenance work, desilting and bottom sediment removal had the largest negative impact, significantly reducing taxonomic composition (by an average of 53%), density (by an average of 43%), and ecological index values (by an average of 40%). Over-frequent maintenance can prevent macroinvertebrate populations from recovering, thus depleting the environment of valuable taxa, including those that provide food for fish and other vertebrates.

The Vegetation of Marshes, Ponds and River Banks in Shivpuri, Madhya Pradesh

The paper deals with the aquatic and semi-aquatic vegetation of Shivpuri in Madhya Pradesh. The phenology, distribution in various habitats and ecology have been given. Hydrophytic vegetation of Shivpuri has been compared with that of other investigated parts of M.P. The collection made includes 101 species in 82 genera belonging to 37 families. Ruppia maritima Linn. is a new record for M.P.

The riverbank vegetation for mitigating the adverse effects of sediment dredging

AbstractSediment dredging has been an ever‐growing issue, especially in developing nations with high demand for concrete filler material. River systems are adversely affected by sediment mining, resulting in decreased stability of the riverbed and riverbanks. Nature‐based solutions for riverbank erosion have been a research topic that has led to the proposal of vegetation on the riverbanks. However, little is known about the extent of riverbank vegetation required to negate the devastating effects of sediment mining because dense vegetation severely affects the flow structure and becomes a waste trap. This experimental study uses sparsely dense, flexible, and bladed vegetation to study the annulment effects of vegetation against the existing mining pit. Near‐bed turbulence and sediment transport have increased in the test section in the presence of a mining pit. The increase in near‐bed streamwise and transverse Reynolds shear stresses helped us understand the increased sediment movement in streamwise and lateral directions. The morphology of the test section showed increased riverbed erosion at the beginning of the test segment. The entire cross‐section was levelled at the end of the test section, and aggradation was downstream of the test segment. In contrast, in the vegetated riverbank case, the initial profile of the bank was almost unchanged for the same discharge of flow and upstream sand pit. The sparse vegetation overperformed the intended negation effects. This study establishes that sparse vegetation would perform better in maintaining the channel morphology, which otherwise in dense vegetation would have faced a high erosion rate in the main channel while giving the same protection to the riverbanks.

Livelihood adaptation to changes in River Ekulu depth, channel width and riverbank vegetation cover type by household breadwinners in selected communities in Enugu, Nigeria

Nigeria and most other developing countries need to explore using socio-ecological approaches to address some ecosystem challenges. Changes in river depth, channel width and riverbank vegetation cover type of River Ekulu in Enugu, Nigeria, their causes and effects on biodiversity and livelihood adaptation by household breadwinners, who depended on the river for livelihood activities, were investigated. Snowball sampling technique was adopted. Causes of changes in the river depth, channel width and riverbank vegetation cover type and their effects on biodiversity and livelihood adaptation were obtained from literature with Google Forms administered to purposively selected experts. Factor component analysis was used to select the significant ones. Aerial images of the river were captured with a drone. Questionnaire was used to elicit information from the target household breadwinners to corroborate the images or otherwise, the causes and the effects of the changes on biodiversity and livelihood adaptation. Data were analyzed to test seven null hypotheses bordering on the objectives of the study. Results showed that the observed changes led to adverse effect on biodiversity and the attendant imperative livelihood adaptation. Factors causing the changes in the river depth, width and riverbank vegetation cover type were climate change (factor weight, fw, 0.44–0.54) and increase in population density (fw 0.46–0.63). Recommendations include conscientisation of government and riverine neighbourhood dwellers on the observed ecological changes, their causes and effects, and ways-forward on policies and practices.

Avifaunal assemblage patterns in Bharathapuzha River Basin, Kerala, India

Bharathapuzha, the second largest west-flowing river in the Western Ghats, originates from the northern and southern parts of the Palghat gap and debouches into the Arabian Sea at Ponnani. This river is exposed to high levels of anthropogenic pressures. This study looks into avifaunal assemblage patterns and the factors influencing the structure of bird communities in different ecological zones of the Bharathapuzha River Basin. The syntropic birds and flocking birds contribute variations in the bird community assemblage in the river basin. For the water-dependent and water-associated birds, mudflats, water flow, riverside vegetation, and distance from the forest were found to be the influencing factors in the migratory season. The study also emphasized the importance of protecting these river-associated habitats for the conservation of birds.

Artificially remediated plants impact soil physiochemical properties along the riparian zones of the three gorges dam in China

River ecosystem biodiversity and biogeochemical processes are shaped largely by riverside vegetation and soil. Moreover, river ecosystems provide ecological services influenced by the surrounding vegetation and soil interactions. However, the mechanisms by which artificially remediated plants (ARPs) and riparian soil interact to provide these benefits are still unclear among various ARPs. This study fills this gap and examines the impact of ARPs along the riparian zones of Three Gorges Dam (TGD) in Chongqing City, China. We sampled four varieties of ARPs from the Ruxi River Basin in the TGD. These varieties included Cynodon dactylon, Hemarthria altissima, Taxodium disticum, and Salix mastudana. Our results indicated substantial changes in soil physicochemical parameters. Comparably, T. distigum contains significantly higher soil chemical contents. Interestingly, principal component analysis explained almost 100% of the variance for all plant species in this study. Moreover, different vegetation types and soil chemical properties were positively correlated using Pearson correlation analysis (p < 0.05). Furthermore, all plant species exhibited strong negative correlations with physical characteristics (up to r = −1.00). Specifically, these mechanisms explain the interactions between ARPs and soil from riparian areas in the TGD. Hence, this study may facilitate ecological restoration and land management in degraded riparian areas.

Tall Herb Fringe Vegetation on Banks of Montenegrin Rivers as a Habitat Type of European Importance

River valleys are known to be of high natural value; however, they are exposed to a strong human influence. Anthropogenic changes are evident in the structure and species composition of plant assemblages; therefore, vegetation is a very good indicator of the state of the environment. Convolvuletalia sepium tall herb communities are a natural component of riverside vegetation; they are protected in the EU (habitat 6430), yet have been very poorly studied, especially in SE Europe. Information regarding the geographical distribution of these communities, and their floristic composition and threats, along with effective conservation and restoration strategies, remains insufficient; therefore, this study was aimed at a comprehensive investigation of tall herbs. The paper presents results of the first detailed study of this group of communities in Montenegro. Classification of 70 vegetation samples (relevés) using the UPGMA produced six clusters corresponding to plant communities which were included in the Dorycnio recti-Rumicion conglomerati. Two of them were ranked as associations: Mentho longifolii-Pulicarietum dysentericae and Rubo sancti-Eupatorietum cannabini, the latter new to science. Others (communities of Rubus caesius, Rubus caesius-Eupatorium cannabinum, Helianthus ×laetiflorus, and Helianthus tuberosus) were left without a syntaxonomic rank. The ordination analysis with the CANOCO software confirmed the authors’ hypothesis that the variability of the vegetation patches studied was related to the land use type and river size. Relevés taken in watercourses flowing through built-up areas were dominated by invasive alien species (IAS). Vegetation samples taken in heavily flooded areas, along the Zeta, one of the largest rivers surveyed, had a simplified species composition. Studies in Montenegro should be continued. Moreover, comparative studies of the Convolvuletalia sepium communities described in the Mediterranean region are also necessary. Attention is drawn to the overly narrow interpretation of habitat 6430 in the lowlands, as it lacks a representation of Mediterranean tall herbs.

Experimental study of the effects of riverbank vegetation conditions on riverbank erosion processes

Experimental study of the effects of riverbank vegetation conditions on riverbank erosion processes

The Geographical Analysis of Environmental Threats to Natural Plants in the Sharbazher District

The Sharbazher district is rich in natural vegetation with (49%) of the area consisting of forest and other natural vegetation belts. Protecting this vegetation belt is an environmental necessity, as it has faced several environmental threats in the last two decades. The study identified environmental threats and evaluated the measures and efforts taken to protect this vegetation belt. The research used a (reading) method, followed by analytical and comparative methods. Field surveys of the study area were conducted on several different dates, data were collected and scenes were observed. The study found that along with natural threats, manmade threats are more significantly affecting the vegetation ecology of the region. Rainfall fluctuations have had a more notable impact on short vegetation and pastures. From summer to early winter, an environmental instability occurred that resulted in damaging riverside vegetation and streams, many of which during the years (20172022-) about (2310) trees were cut down, most of which were (Oak) trees, but according to the study’s estimation, more than (16000) trees were cut down during the same period. Until now, charcoal is made in coal furnaces from natural forest trees and this is carried out without official permission, during the years (20172022-) more than (20,000 acres) of weed and natural forests in the region have been burned. Also during the years (20012020-), there have been changes in the vegetation belts and land cover of the region, the area of dense and medium forest belts has increased, but the area of open forest belts has decreased, and there have been major changes in the land area of human settlements. The study outlines ways to protect the vegetation belt and emphasises the enforcement of Implemented laws on the protection of plants and forests. Keywords: Natural plants, Environmental threats, Forest law, Sharbazher district.

Видовой состав прибрежной растительности равнинной территории Республики Адыгея

Представлены результаты исследования по изучению видового состава прибрежной растительности равнинной территории региона. Было выявлено 104 вида, относящиеся к 23 семействам, где среднее число видов на площади 49 м2 изменялось от 13 до 20 и в среднем составляло 18 видов, что свидетельствует о низком флористическом разнообразии фитоценозов долины реки Ульки. В ходе исследования было выявлено пять основных ассоциаций с указанием всех видов, образующих растительные сообщества прибрежной растительности. The paper discusses the results of a study on the species composition of riverside vegetation of the flat land of the region. We identified 104 species belonging to 23 families. The average number of species on an area of 49 m2 varied from 13 to 20 and averaged 18 species. This indicates that a floral diversity of phytocenoses of the Ulka River Valley is low. During the study, we identified five main associations and indicated all the species that formed plant communities of riverside vegetation

Climate Change Risks on Mediterranean River Ecosystems and Adaptation Measures (Spain)

The Mediterranean is one of the most vulnerable regions to climate change impacts. Climate change scenarios predict that water temperature will increase up to 2.2–2.9ºC by the end of the century in Mediterranean rivers. This will cause an impact on water quality (oxygen dissolved reduction), reduce the available habitat of cold-water fish species and affect macroinvertebrates. Risk assessment methodology develops indicators that integrate hazard, exposure and vulnerability. Risk maps are key tools to prioritize the areas in which adaptation measures should be implemented in order to improve the adaptive capacity of ecosystems. The risk of habitat loss and ecosystem damage is very high in Mediterranean rivers. For RCP8.5, the 80% of the waterbodies that currently have brown trout presence are in High Risk (HR) or Very High Risk (VHR) of disappearing in the long term future (2070–2100) and the 35% in the short term (2010–2040). It will affect the middle sections first and the headwaters of the rivers later. The 92% of the waterbodies are in HR-VHR of macroinvertebrate family’s affection (2070–2100) and dissolved oxygen may be reduced by 0.5–0.75 mgO2/l (2070–2100). The restoration of the riverside vegetation is the main adaptation measure. This reduces significantly the stream temperature. Other measures are the groundwater protection and cold-water discharge from the reservoirs.

Small terrestrial mammals (Rodentia and Soricomorpha) along a gradient of forest anthropisation (reserves, managed forests, urban parks) in France.

Understanding the relationships between wildlife biodiversity and zoonotic infectious diseases in a changing climate is a challenging issue that scientists must address to support further policy actions. We aim at tackling this challenge by focusing on small mammal-borne diseases in temperate forests and large urban green spaces. Small mammals are important reservoirs of zoonotic agents, with a high transmission potential for humans and domestic animals. Forests and large urban green spaces are ecosystems where efforts are undertaken to preserve biodiversity. They are put forward for their contribution to human well-being in addition to other ecosystem services (e.g. provisioning and regulating services). Moreover, forests and large urban green spaces are environments where small mammals are abundant and human/domestic-wildlife interactions are plausible to occur. These environments are, therefore, focal points for conservation management and public health issues. The European Biodiversa BioRodDis project (https://www6.inrae.fr/biodiversa-bioroddis) aims at better understanding the relationships between small terrestrial mammal biodiversity and health in the context of global change and, in particular, of forest anthropisation and urbanisation. Here, we present the data gathered in France. The dataset will enable us to describe the diversity of small terrestrial mammal communities in forested areas corresponding to different levels of anthropisation and to evaluate the variability of this diversity over time, between seasons and years.The dataset contains occurrences of small terrestrial mammals (Rodentia and Soricomorpha) trapped in forested areas in eastern France (administrative Departments: Rhône, Ain, Jura). The sampling sites correspond to different degrees of anthropisation. Forests included in biological reserves are the least anthropised sites. Then, public forests and urban parks experience increasing levels of anthropisation. Data were collected during spring and autumn 2020 (three to four sampling sites), 2021 (six sampling sites) and 2022 (four sampling sites). These variations in the number of sites between years were due to lockdown restrictions in 2020 or to the legal authorisation to trap around biological reserves granted in 2021 only. The capture of animals was carried out in various types of forests (pine, deciduous, mixed) and in different habitats within urban parks (wooded areas, buildings, hay storage yards, riverside vegetation, restaurants, playground for kids, botanical garden, landfills). Animals were captured using live traps that were set on the ground for one to 11 nights. During this study period, 1593 small mammals were trapped and identified. They belong to 15 species, amongst which were nine species of rodents (Muridae, Cricetidae, Gliridae) and six species of shrews (Soricidae). They were weighted (gram) and measured (cm): head-body length, tail length and hind-foot length. Sexual characteristics were also recorded.

A warm and humid paleoecological context for the Neanderthal mountain settlement at the Navalmaíllo rockshelter (Iberian Central System, Madrid)

Neanderthals have been claimed to have had a selective adaptation to rugged, wooded landscapes that would have partially compensate their high basal metabolic rate and locomotor energetic costs through reducing search time and increasing diet breadth. The archaeological site of the Navalmaíllo rockshelter (Pinilla del Valle, Madrid), located in a mountain environment in central Iberian Peninsula, has been interpreted as a repeated short-term occupation hunting camp by Neanderthal groups, mainly focused on primary access to large bovids and cervids. Navalmaíllo rockshelter has also furnished fish, toads, frogs, tortoises, lizards and snakes remains. This association of amphibians and reptiles suggests a much warmer climate (+2.8 °C) for layer F than at present, with similar temperatures during the summer but higher temperatures throughout the remaining months. Rainfall was slightly more abundant (+180.6 mm) than today, with a more contrasted regime during the year, with rainier winters and drier summers. A two-month period of aridity is observed during summer, representing a similar duration to present-day climatic conditions. Reconstructed landscapes are mainly constituted by open areas with dry grassland and rocky or stony areas, evolving laterally to humid meadows, probably close to the aquatic and peri-aquatic areas, such as rivers or ponds with riverside vegetation. Woodland environments are also well represented around the site, with medium scrublands to forest formations. Fish complete this reconstruction by documenting the presence of a pre-mountain well-developed river system characterized by relatively cold, permanent, oxygen-rich, and running waters. Such reconstruction is in disagreement with previous pollen interpretation for Layer F that suggested a very open and cold environment. Our new interpretation suggests that the Neanderthal occupation of the Navalmaíllo rockshelter occurred during a somewhat temperate and humid period, probably within the later part of the Marine Isotope Stage 5, effectively favouring the presence of a high biodiversity around the site.

Analysis of Seasonal Variations in Surface Water Quality over Wet and Dry Regions

Water quality is highly affected by riverside vegetation in different regions. To comprehend this research, the study area was parted into wet and dry regions. The WASP8 was applied for the simulations of water quality profile over both Waterways selected from each region. It was found that the Ara Waterway, located in the wet regions, has a higher water quality variation in seasonal scale than that of the Yamuna Waterway, which is in the dry region. The interrelationship between river water quality variables and NDVI produce higher association for water quality variables with Pearson correlation coefficient values of about 0.66, 0.68 and −0.58, respectively, over the annual and seasonal scales in the energy limited regions. This approach will help in monitoring the seasonal variation and effect of the vegetation biomass on water quality for the sustainable water environment.

Shear layer over floodplain vegetation with a view on bending and streamlining effects

Shrubby and woody vegetation growing on floodplains profoundly influences hydrodynamic and transport processes in riverine systems. Existing hydrodynamic research is mostly focused on conditions with aquatic plants and rigid model vegetation. To appreciate the different hydrodynamic impacts of submerged floodplain and riverbank vegetation, a novel flume investigation was carried out. We simulated conditions found in riparian environments in terms of vegetation density, plant structure and flexibility, and presence of a grassy understory. Four experimental cases were defined so that vegetation exhibited different degrees of bending and streamlining. Extensive set of velocity measurements allowed reliable description of the double averaged flow. Vegetation morphology, with the flexibility-induced streamlining and dynamic motion controlled the magnitude and distribution of the vegetative drag, shaping the shear penetration within the canopy. The flows were highly heterogeneous, thus calling for spatially averaged approaches for the flow field investigation. The relative importance of dispersive momentum fluxes was high in the canopy bottom region where both Reynolds and dispersive stresses were small. The contribution of dispersive fluxes to momentum transport decreased with increasing reconfiguration. The results revealed the shear layers over floodplain vegetation to be dynamically similar to other environmental flows over porous obstructions. However, the velocity-dependent vegetative drag and deflected height introduced additional complexity in the flow simulation. Altogether our findings implied that accurate description of vegetated floodplain flows can be achieved only when plant morphology and flexibility are appropriately described in drag models.Article highlightsA novel experimental setup with flexible woody plants and grasses was used to model the hydrodynamics of vegetated floodplains.Plant morphology and flexibility controlled the vegetative drag, affecting key shear layer features, including the shear penetration.The spatially heterogeneous flows had higher dispersive stresses at the canopy bottom, where the total fluid stress was small.

The load of invasive plant species in the Labe riverbank vegetation

The aim of this article is to summarize actual results of the field research of invasive neophytes’ occurrence in the riverbank vegetation of the Labe River from Špindlerův Mlyn to Těchlovice (Děčin district). In total more than 190 km of the riverbank vegetation was mapped using author’s own method. The occurrence of 22 most important invasive neophytes (17 taxons) was registered for each of the 500 m long segments (in total 284 segments was mapped). The number of specimen was registered using a logarithmical scale and both simple and weighted index of total load of invasive neophytes was calculated for each segment. Results are presented for series (i. e. groups of neighbouring segments with similar geographical and ecological conditions) and also the comparation with other water courses in the Czech Republic is presented. The occurence of invasive neophytes is near of the average for other water courses, but the number of specimen is lower. The most frequent taxons were Solidago sp. and Impatiens glandulifera. Mutual dependence between occurence of invasive species and the vertical position of the segment of the watercourse wasn’t confirmed. Development in the years 2006 and 2007 was compared, but only small changes was discovered in this short time horizon. <b>Zatížení břehové vegetace Labe invazivními rostlinnými druhy</b> Tento příspěvek shrnuje výsledky mapování invazních neofytů (v pojetí Richardsona et al. 2000, Pyška et. al. 2002) v břehové vegetaci Labe. Mapování bylo provedeno pomocí vlastní metodiky (Matějček in Langhammer 2005), a to v předem stanovených 500 m dlouhých úsecích, které byly obvykle vymezeny na základě říční kilometráže nebo byly odměřovány od významných bodů (mosty, jezy apod.). Celkem bylo sledováno 284 segmentů v úseku mezi Špindlerovým Mlýnem a Těchlovicemi (okr. Děčín). Za břehovou vegetaci byl podle Nováka et al. (1986) považován pás vegetace podél vodního toku, omezený na jedné straně vodní hladinou, na druhé straně břehovou hranou. Šířka tohoto pásu se v praxi pohybovala obvykle v rozmezí 5–15 m. Výskyt 22 druhů (resp. 17 taxonů) nejvýznamnějších invazních neofytů byl zaznamenáván pomocí logaritmické stupnice. Pro jednotlivé segmenty a pro jednotlivé části toku byl vypočítán celkový počet zaznamenaných taxonů, celkový počet jedinců, prostý index zatížení invazními neofyty a vážený index zatížení invazními neofyty. Zatímco prostý index zatížení invazními neofyty přikládá podobnou váhu počtu přítomných druhů a počtu jedinců, vážený index zatížení invazními neofyty zohledňuje také velikost jednotlivých druhů, jejich stabilitu na stanovišti a potenciální nebezpečnost pro přirozenou vegetaci nebo pro člověka a jeho aktivity. Počet jedinců jednotlivých taxonů je při výpočtu vážen určitým koeficientem (viz tab. 1). Z celkového počtu 17 sledovaných taxonů bylo v břehové vegetaci Labe nalezeno 15 taxonů. Průměrný počet jedinců na jeden segment byl 516, průměrný počet zaznamenaných taxonů v segmentu činil 2,65. V 11,6 % segmentů nebyl zaznamenán žádný ze sledovaných invazních neofytů. Hodnota prostého indexu zatížení invazními neofyty činila 4,67, hodnota váženého indexu zatížení invazními neofyty činila 2,63. Ve srovnání s ostatními dosud sledovanými vodními toky (Matějček 2008) je v břehové vegetaci Labe spíše podprůměrný počet jedinců na jeden segment, naopak vyšší je průměrný počet zaznamenaných taxonů v jednom segmentu, prostý index zatížení invazními neofyty a vážený index zatížení invazními neofyty. Podíl segmentů bez invazních neofytů je spíše nižší. Nejvyšší podíl obsazených segmentů byl zaznamenán u Solidago sp. (S. canadensis a S. gigantea) a Impatiens glandulifera, nejvyšší průměrný počet jedinců v jednom segmentu byl zaznamenán u Conyza canadensis a Solidago sp., nejvyšší průměrný počet jedinců na jeden obsazený segment byl zaznamenán u Helianthus tuberosus a Conyza canadensis. Ve srovnání s ostatními dosud sledovanými vodními toky v České republice je z hlediska podílu obsazených segmentů pro Labe charakteristické nadprůměrné zastoupení Solidago sp., Conyza canadensis, Erigeron annuus a Robinia pseudacacia, výrazně podprůměrné je naopak zastoupení Impatiens parviflora a Reynoutria sp. Průměrný počet jedinců v obsazeném segmentu byl u většiny taxonů podprůměrný. Poměrně značná je diferenciace výskytu invazních neofytů v jednotlivých částech toku, který byl pro přehlednost rozdělen do sérií (obr. 3). Jako úseky s nejvyšším zastoupením invazních neofytů byly shledány úsek těsně pod Kolínem a úsek u Těchlovic. Zcela zanedbatelný počet jedinců i taxonů invazních neofytů byl naopak zaznamenán v úseku nad Špindlerovým Mlýnem. S výjimkou těchto extrémních poloh však nebyla závislost zastoupení invazních neofytů na pořadí segmentu v rámci toku potvrzena. V období let 2006–2007 došlo k relativně malým změnám v zastoupení invazních neofytů v břehové vegetaci Labe. Výraznější změny byly zaznamenány pouze u některých početně slaběji zastoupených taxonů.

The role of increasing riverbank vegetation density on flow dynamics across an asymmetrical channel

Over the last two decades, the role of vegetation in the environmental and ecological restoration of surface water bodies has received much attention. In this context, the momentum exchange between the flow through the main channel and the riparian zone is a key mechanism. The primary goal of this study is to investigate the role of bank vegetation density on flow dynamics across the whole channel. This experimental study presents the major findings from a series of flow measurements across a channel having a sloping bank with vegetation at varying densities. The experiments are conducted under the same, uniform flow and fixed bed conditions, for a range of six linear and rectilinear arrangements of incremental streambank vegetation densities. A set of ten velocity profiles is obtained across the test cross-section of the channel, including the riverbank, for each vegetation density. These flow measurements are analyzed to derive roughness coefficients, which are related to the bulk flow velocities through the main channel and the riverbank and discuss the redistribution of flow velocities. An approximate doubling for the estimates of time-averaged boundary shear stress at the main channel, is observed for the case of no to dense vegetation, which enable further discussing implications for the stability of bed surface material. It is found that the vegetation arrangement, in addition to vegetation density, can have a strong impact in modifying the mean flow velocity at the main channel, for low riparian densities (φ < 0.6%).HighlightsFlow dynamics are measured across the whole channel, including the vegetated riverbank.As stem density increases, mean flow velocity in the main channel increases while mean flow at the riverbank decreases.The arrangement of riparian vegetation can be as important as that of the density, in modifying the mean flow field of the main channel, for low riparian densities.Bed shear stresses at the main channel are estimated to increase with riverbank vegetation, reducing the stability of the stream’s bed surface.

MANAGEMENT OF KUIN RIVER USING THE ECO-HYDRAULIC APPROACH

River management using the eco-hydraulic approach is aimed at preserving the ecological components in the river environment through hydraulic engineering. This study aims to identify the existing conditions on Kuin River border, analyze the relationship and influence of community activities on the banks of Kuin River on the water quality of Kuin River, and study the river development pattern with the concept of eco-hydraulic on Kuin River. Data were collected based on the results of field surveys and laboratory tests for water and soil. The results showed that the current condition of the riverbank of Kuin River has not fulfilled its function as a buffer space between the river and the mainland, due to the large number of community settlements rather than vegetation that functions to protect the river. Kuin River is polluted because several ecological indicators such as pH, Fe, BOD, and COD have exceeded the maximum allowable limits. This occurs due to social activities and development along the river, which have an impact on biotic and abiotic aspects of the river. The type of soil on the banks of the Kuin River is silt mixed with clay with moderate to high plasticity. Based on this condition, there is an assumption that the cliffs on the banks of Kuin River have the potential for landslides. Therefore, a pattern for developing cliff protection using riverbank vegetation components is recommended

PENATAAN KAWASAN TEPIAN SUNGAI SEBAGAI RUANG TERBUKA DI MURUNG KENANGA, MARTAPURA

Riverbanks in Murung Kenanga have the potential to be developed as green open space on the banks of a river that can maintain sustainability the function of the river and becomes a forum for community outreach. This potential has not been fully developed. The existing condition of the river bank which is used as shelter and disposal, causing edge damage river. The conditions of slums around the area become an obstacle to additional handling of this area. Therefore, this area requires the arrangement is right on target and has a positive impact on the surrounding environment. The urban acupuncture method was chosen by making the riverbank area in Murung Kenanga as an open green space and a positive activity point for the surrounding community. The principle of the application of urban acupuncture used in design points in the region is the target focus, low cost applies in every situation, instant effects, facilitate needs, and simple actions. The method supports the concept of environmental &amp; recreation waterfront that is applied by making the area river banks as open spaces that are creative and considerate of the environment. Application of concepts and methods applied through, 1) Quality improvement regional environment through exploiting the natural potential and returning functions rivers with the development of pond areas, the use of riverbank vegetation and ecological plaster 2) Utilization of river banks as recreation areas with designing playgrounds &amp; reading for children, relaxing parks, sports parks, and areas culinary 3) Triggering positive community activities by providing open space green equipped with supporting facilities therein.