Stream Floodplain Research Articles

Small stream floodplains have high conservation value for riparian carabid beetles but less for ground‐dwelling spiders

Abstract Floodplains along rivers and streams are characterised by a high habitat heterogeneity and a large biodiversity. However, floodplains are highly threatened by anthropogenic activities such as channelisation and bank enforcement of watercourses. While floodplains along rivers are well known for their importance for riparian biodiversity, the conservation value of floodplains along small streams is less understood. We studied carabid beetles (Coleoptera: Carabidae) and ground‐dwelling spiders (Arachnida: Aranea) along forested small streams (~ up to 5 m width) in Rhineland‐Palatinate (Germany). We investigated 16 pairs of floodplains (natural stream sites with shallow bank and regular flooding events) and controls (deeply cut stream sites without regular flooding), where we sampled carabid beetles and spiders at different distances to the stream bank (0, 5 and 10 m). We found that floodplains along small streams had contrasting value for carabid beetles and ground‐dwelling spiders. For carabid beetles, we observed several typical floodplain species and distinct species assemblages and 2.7 times more individuals across species of conservation concern in floodplain sites. Moreover, species richness and total number of individuals of carabid beetles were highest directly at the stream bank (0 m distance) of floodplains compared with the more distant locations, while the opposite was found for the control stream sites. The spider composition also differed between floodplains and control steam sites, but only one typical floodplain species was detected. Species richness and number of individuals in ground‐dwelling spiders were lower in floodplains than in control stream sites. We conclude that the conservation value of floodplains of small streams is taxa‐dependent and that they appear less relevant for ground‐dwelling spiders but provide important habitats for riparian carabid beetles.

Mountainous Floodplain Connectivity in Response to Hydrological Transitions

AbstractIn mountainous watersheds, floodplain sediments are typically characterized by gravel bed layers capped by an overlying soil unit that serves as a hotspot for biogeochemical reactivity. However, the influence of soil biogeochemistry on gravel bed underflow composition remains unclear, especially during hydrological transitions that alter the vertical connectivity between overlaying soils and the underlying gravel bed. This study investigates these dynamics by measuring hydraulic gradients and water compositions over three hydrological years in a typical mountainous, low‐order stream floodplain in the Upper Colorado River Basin. Results indicate that the timing of hydrological conditions strongly influences the vertical exchanges that control water quality. Specifically, during flooding events such as beaver ponding, that induce downward flushing of the soil, anoxic conditions prevalent in the biogeochemically active soil are transferred downstream via gravel bed underflow. Conversely, snowmelt and drought conditions increase oxic conditions in the gravel bed due to diminished hydrological connectivity with the overlying soil. To compare water quality response to hydrological transitions across similar floodplain environments, we propose a conceptual model that quantifies the inundation‐induced flushing of soil porewater to measure solute exchange efficiency with the gravel bed solute convergence efficiency (SCE). This model provides a framework for quantifying biogeochemical processes in hydrological underflow systems, which is critical for water and elemental budgets in these globally important mountainous ecosystems.

An overview of the current state of the beaver’s environmental activity

A review of scientific publications devoted to the study of the impact of beaver foraging and construction activities on the plant communities of small rivers in different natural zones has been conducted. Based on the analysis of publications devoted to the study of the beaver's environmental activity, its key role in the successional processes of phytocenoses of riverine biotopes in all natural zones within the native and acquired range is noted. The stages of succession transformations initiated by the beaver's vital activity are considered. The degree of succession transformations depends, first of all, on the density of populations and their stages of maturity. The successions are highly intensive, multidirectional and do not reach the final stage, but are concentrated in the floodplains of small rivers and streams, in the coastal strip of other reservoirs. The vital activity of beavers determines the floristic, faunal, and ecologicaltopological diversity of coastal biogeocenoses. An increase in the proportion of groups of aquatic and wetland plant species was noted, and an increase in biological diversity was revealed in the beaver pond backup zone, regardless of zonal factors. However, being strongly transformed, the coastal vegetation remains zonally conditioned, does not become azonal.

Recognizing the ephemeral stream floodplain: Identification and importance of flood zones in drylands

AbstractPrevious syntheses of the hydrologic, geomorphic and biotic functions of floodplains have largely integrated research conducted along perennial stream networks, despite a growing body of literature on analogous functional floodplain zones along ephemeral streams. Although variable inundation characteristic of ephemeral streams complicates the delineation between channel and floodplain, ephemeral stream floodplains are distinct landforms that are hypothesized to host similar ecosystem functions as perennial stream floodplains, including the attenuation of downstream fluxes and provision of habitat to diverse flora and fauna. Here, we review the literature on dryland ephemeral stream floodplains in order to identify: (1) common definitions and styles; (2) unique hydrologic, geomorphic and biotic functions separate from uplands or channels; (3) current and future anthropogenic and natural stressors to such functions; and (4) knowledge gaps regarding research on ephemeral stream floodplains. Although active floodplain definitions follow criteria commonly used in perennial stream corridors, the extent of ephemeral stream floodplains is typically defined by less frequent floods. A set of floodplain styles emerges from the literature dependent on confinement and the presence of channelized streamflow. Functions related to attenuation and storage are typically concentrated in unconfined, channelled floodplains. The temporary storage of sediment and subsurface water in ephemeral stream floodplains makes them disproportionately important for biogeochemical cycling and hosts to richer, denser and more diverse vegetation communities compared with surrounding uplands. Many functions of ephemeral stream floodplains are also found in perennial counterparts, but variable flow regimes and sediment loads in ephemeral streams can potentially impact rates and magnitudes of comparable processes and functions. Future research needs to incorporate a holistic view of the ephemeral stream corridor—including channels and floodplains—to better understand current and future fluvial processes and cascading impacts in drylands globally.

Spatiotemporal patterns of multiple pesticide residues in central Argentina streams

Pollution of surface waters is a global threat, with particular concern about pesticides due to their severe negative effects on ecosystem functioning and human health. The aims of this study were to identify the spatiotemporal patterns of water and sediment quality, and the key variables related to the variation in pesticide pollution (122 compounds), in headwater streams (surrounding land uses: crop or mixed crop-livestock systems) and floodplain streams (surrounding land uses: urban development or natural wetland) of the Paraná River basin in the central area of Argentina. We found significant differences in water and sediment quality related to local land uses among headwater streams, but not among floodplain streams. These differences were more noticeable during spring than during autumn. Pesticides were widespread in all the streams, independently of the surrounding land use, reflecting the combination of local inputs and the role of floodplain hydrological connectivity in transporting pollutants from upstream sources. The most frequently detected compound was atrazine (75 %), whereas the highest concentration of an individual compound was observed for the glyphosate metabolite aminomethylphosphonic acid (AMPA, up to 4 μg L−1). The significant explanatory variables for pesticide pollution were turbidity, chromophoric dissolved organic matter (CDOM), sub-basin area, side slope of streams (positive relations), wetland cover, and precipitations (negative relations). Our results can be useful for the design of monitoring programs that capture the spatial and temporal variability of pesticide pollution.

Homogeneous Environmental Selection Structures the Bacterial Communities of Benthic Biofilms in Proglacial Floodplain Streams.

In proglacial floodplains, glacier recession promotes biogeochemical and ecological gradients across relatively small spatial scales. The resulting environmental heterogeneity induces remarkable microbial biodiversity among proglacial stream biofilms. Yet the relative importance of environmental constraints in forming biofilm communities remains largely unknown. Extreme environmental conditions in proglacial streams may lead to the homogenizing selection of biofilm-forming microorganisms. However, environmental differences between proglacial streams may impose different selective forces, resulting in nested, spatially structured assembly processes. Here, we investigated bacterial community assembly processes by unraveling ecologically successful phylogenetic clades in two stream types (glacier-fed mainstems and non-glacier-fed tributaries) draining three proglacial floodplains in the Swiss Alps. Clades with low phylogenetic turnover rates were present in all stream types, including Gammaproteobacteria and Alphaproteobacteria, while the other clades were specific to one stream type. These clades constituted up to 34.8% and 31.1% of the community diversity and up to 61.3% and 50.9% of the relative abundances in mainstems and tributaries, respectively, highlighting their importance and success in these communities. Furthermore, the proportion of bacteria under homogeneous selection was inversely related to the abundance of photoautotrophs, and these clades may therefore decrease in abundance with the future "greening" of proglacial habitats. Finally, we found little effect of physical distance from the glacier on clades under selection in glacier-fed streams, probably due to the high hydrological connectivity of our study reaches. Overall, these findings shed new light on the mechanisms of microbial biofilm assembly in proglacial streams and help us to predict their future in a rapidly changing environment. IMPORTANCE Streams draining proglacial floodplains harbor benthic biofilms comprised of diverse microbial communities. These high-mountain ecosystems are rapidly changing with climate warming, and it is therefore critical to better understand the mechanisms underlying the assembly of their microbial communities. We found that homogeneous selection dominates the structuring of bacterial communities in benthic biofilms in both glacier-fed mainstems and nonglacier tributary streams within three proglacial floodplains in the Swiss Alps. However, differences between glacier-fed and tributary ecosystems may impose differential selective forces. Here, we uncovered nested, spatially structured assembly processes for proglacial floodplain communities. Our analyses additionally provided insights into linkages between aquatic photoautotrophs and the bacterial taxa under homogeneous selection, potentially by providing a labile source of carbon in these otherwise carbon-deprived systems. In the future, we expect a shift in the bacterial communities under homogeneous selection in glacier-fed streams as primary production becomes more important and streams become "greener".

Automation algorithms for water bodies characteristics calculation on the example of the Volga-Akhtuba floodplain

Introduction. Organization and implementation of a special spring release, carried out annually in the interests of the agriculture and fisheries of the Lower Volga, is the most important and complex problem of the Volga-Kama cascade management. The way to increase the efficiency of solving this problem is to use of mathematical models for calculating the movement of water along the Volga-Akhtuba floodplain. However, the currently functioning mathematical hydrodynamic models of the Lower Volga do not provide enough accuracy and speed. It is planned to create an algorithm for modeling the movement of water masses, combining the use of nomograms of dynamic volumes and a tank model. The characteristics of water bodies and streams that form the water system of the Lower Volga should be obtained at the first stage.
 
 Materials and methods. The materials for the work were a raster digital elevation model with 30 m resolution, obtained from Earth remote sensing data. Algorithms for determining the position and boundaries of water bodies and calculating their characteristics are implemented in the Fortran programming language.
 
 Results. The description of algorithms of smoothing the digital elevation model, searching for local minima, and determining the boundaries of floodplain reservoirs developed to prepare information structures using in the created mathematical model of a water system with a developed network of floodplain streams and lakes is given on the example of the Volga-Akhtuba floodplain. The results of testing the developed algorithms are shown.
 
 Conclusions. The results of the algorithms for searching for local minima on the digital elevation model and determining the position and boundaries of floodplain reservoirs make it possible to calculate the characteristics of water bodies, building a model graph, and developing a data storage system at the next stages of work.

Deciphering natural and anthropogenic nitrate and recharge sources in arid region groundwater

Recently, the subsoils of ephemeral stream (arroyos) floodplains in the northern Chihuahuan Desert were discovered to contain large naturally occurring NO3− reservoirs (floodplain: ~38,000 kg NO3-N/ha; background: ~60 kg NO3-N/ha). These reservoirs may be mobilized through land use change or natural stream channel migration which makes differentiating between anthropogenic and natural groundwater NO3− sources challenging. In this study, the fate and sources of NO3− were investigated in an area with multiple NO3− sources such as accidental sewer line releases and sewage lagoons as well as natural reservoirs of subsoil NO3−. To differentiate sources, this study used a large suite of geochemical tools including δ15N[NO3], δ18O[NO3], δ15N[N2], δ13C[DIC], 14C, tritium (3H), dissolved gas concentrations, major ion chemistry, and contaminants of emerging concern (CEC) including artificial sweeteners. NO3− at sites with the highest concentrations (25 to 229 mg/L NO3-N) were determined to be largely sourced from naturally occurring subsoil NO3− based on δ15N[NO3] (<8 ‰) and mass ratios of Cl−/Br− (〈100) and NO3−/Cl− (>1.5). Anthropogenic NO3− was deciphered using mass ratios of Cl−/Br− (>120) and NO3−/Cl− (<1), δ15N[NO3] (>8 ‰), and CEC detections. Nitrogen isotope analyses indicated that denitrification is fairly limited in the field area. CEC were detected at 67 % of sites including 3H dead sites (<1 pCi/L) with low percent modern carbon-14 (PMC; <30 %). Local supply wells are 3H dead with low PMC; as 3H does not re-equilibrate and 14C is very slow to re-equilibrate during recirculation through infrastructure, sites with low PMC, 3H < 1 pCi/L, and CEC detections were interpreted as locations with substantial anthropogenic groundwater recharge. Neotame was used to identify locations of very recent (<15 years before present) or ongoing wastewater influxes to the aquifer. This work shows the important influence of naturally occurring subsoil NO3− reservoirs on groundwater in arid regions and the major contribution of artificial recharge.

Home range and movement patterns of male dwarf caimans (Paleosuchus palpebrosus and Paleosuchus trigonatus) living in sympatry in Amazonian floodplain streams

ABSTRACT Dwarf caimans (Alligatoridae: Paleosuchus palpebrosus and Paleosuchus trigonatus), are small crocodilians exhibiting cryptic behaviour and complex habitat use that occur throughout the Amazon region. Our goals were to evaluate individual home range, habitat occupancy and movement patterns where they occur in sympatry in relation to seasonal water-level variation. We tracked five P. palpebrosus and seven P. trigonatus using VHS radio transmitters along the shores of two streams directly influenced by the flooding pulse of the Purus River. Paleosuchus palpebrosus individuals moved greater distances on a daily basis and had larger home ranges than P. trigonatus, and the species had different responses to increases in water levels. Paleosuchus palpebrosus moved into flooded forests, as do their principle prey species. Conversely, larger P. trigonatus individuals usually remained near the main stream, and were relatively sedentary. Intraspecific home-range overlap was higher than interspecific overlap in both species. Thus, habitat occupancy patterns as a function of water-level variation might facilitate coexistence of the two species of dwarf caimans in the same location. This study shows that when living in sympatry under a seasonal flooding regime, Paleosuchus species show a degree of habitat partitioning evidenced by different daily movement rates, home-range sizes and home-range locations.

Assessment of Quality of Wastewater Being Used in Irrigating Soils under Urban Agriculture in Zaria Urban Area

The cultivation of food crops in open spaces of cities in the developing world is very common but has not attracted the research attention it deserves. In most areas, the practice relies on the use of wastewater derived from urban sources (houses, industries, markets, public institutions etc) to irrigate soils along the floodplains of streams that drain an urban area. Because such wastewater may be containing some pollutants, concerns are increasingly been raised as to whether urban agriculture is not a threat to public health. There are valid reasons to be so concerned because a wastewater typically contains some pollutants like heavy metals, with tendency to cause several health problems. To ascertain this, a study was conducted to evaluate the quality of wastewater being used in irrigating soils under urban agriculture in Kubanni basin of Zaria area. The results obtained indicate that though there is a presence of As, Fe, Cr, As, Cu, Zn, Mn and Pb in wastewater being used in UPA irrigation practices in the area, their concentrations are generally below the maximum permissible limits set by Nigeria’s Federal Environmental Protection Agency for irrigation. However because of the tendency of the metals to accumulate in soils, it is expected that the metals could possibly have been accumulating in the irrigated soils and the crops being grown on them. Thus further studies are required to establish the extent to which this is so. Nonetheless, it would be worthwhile for the farmers to start some significant purification of wastewater in the area to make it safe for irrigating the soils since there are valid fears to be concerned about possibility of heavy metals build up in the soil.

Are natural floods accelerators for streambank vegetation development in floodplain restoration?

AbstractRiverbanks are very dynamic habitats for riparian vegetation strongly influenced by fluvial and geomorphic processes. This habitat type was severely reduced in the past by river straightening and bank stabilisation. Restoration and establishment of new floodplain streams promote this habitat, but a directed succession to later stages was observed many times. Our study aimed to analyse whether the often observed directed succession of the streambank vegetation after restoration implementation could be reversed by a natural flood along a newly created floodplain stream. We investigated the effects of a natural flood in 2013 and different prerestoration conditions on species development in the riparian zone. Vegetation was studied along 12 transects in four different sections from 2011 to 2014. Species composition differed strongly between the sections. Species richness was lowest in a newly dug steep section with high morphological dynamics and highest on wider flat streambanks. Changes during the years reflecting different hydrological events varied between sections. The high natural flood in 2013 reduced the cover of the herb layer and increased bare ground, which led in most sections to a loss of nontarget species. Total target species richness did not change due to the natural flood, while target species showed a high turnover rate. In the following year, however, the flood‐induced development of species composition, in general, was reversed. Natural floods changed abiotic and biotic conditions along the streambank, but they did not accelerate ecological restoration towards predefined target ecosystems. However, they were necessary to preserve the needed dynamic vegetation changes and species turnover to hinder the succession to later stages dominated by a few species. Our study shows that riparian vegetation near the streambank can be monitored most effectively in cross‐profile transects, both in the long‐term and event‐related.

Ensuring the integrity of the road network as the key to solving the problems of highway capacity in cities

Broadband highways are being built in major cities around the world to combat traffic congestion. At the same time, existing buildings are demolished or powerful overpasses are raised above them. However, it often turns out that newly created highways quickly exhaust their capacity, and traffic jams are formed on them again. This situation indicates that increasing the capacity of the highway does not solve the problem of traffic jams, but often aggravates it, since as a result of this increase, even more cars are drawn to the highway from adjacent territories, often exceeding their current capacity. At the same time, the streets in the surrounding areas are empty and their potential is not used to the full extent. This situation has arisen due to the disruption of the city road network by lengthy obstacles in the form of ravines, rivers, floodplains of small rivers, and railways. This situation can be corrected by "stitching" the streets over the gaps by building bridges and overpasses with a capacity corresponding to the capacity of the "stitched" streets. Most of the gaps fall on relatively small streets, which approach the banks of fairly wide floodplains of small rivers and streams, and this makes it advisable to build mainly small (with a span of 20-25 m) and relatively inexpensive bridges, with the number of spans sufficient to cover the floodplain and reach the levels of road surfaces of connected streets. There will be several hundred such bridges over the river barriers in a large city, for example, Moscow, and several hundred more, taking into account the required number of them over the railways, and in the end, about a thousand. It is proposed to erect bridge buildings instead of simple road bridges. Such structures combine two city functions; the first of them is transport, the second is public, residential, or economic, depending on the needs of the city and the environmental situation at the construction site. An important requirement for the second function is a quick return on the financial assets invested in the construction and income from the operation of the building acceptable to the investor. The bridge part of a bridge building should become the property of the city.

Discovery of a large subsoil nitrate reservoir in an arroyo floodplain and associated aquifer contamination

AbstractIn an area of elevated nitrate (NO3) groundwater concentrations in the northern Chihuahuan Desert in central New Mexico (United States), a large reservoir of nitrate was found in the subsoil of an arroyo floodplain. Nitrate inventories in the floodplain subsoils ranged from 10,000 to 38,000 kg NO3-N/ha—over twice as high as any previously measured arid region. The floodplain subsoil NO3 reservoir was over 100 times higher than the adjacent desert (59–95 kg NO3-N/ha). Chloride mass balance calculations of subsoils indicate arroyo floodplain subsoils have undergone negative recharge since 2600–8600 yr ago, while the surrounding desert has had negative recharge since 13,000–17,000 yr ago. Compared to the adjacent desert, plant communities are larger and more abundant in the floodplain, though subsoil NO3 is apparently not utilized. We demonstrate that NO3 accumulates in the subsoil of the floodplain through evaporation of monsoon season precipitation funneled into the arroyo. Through a one-dimensional vadose zone model, we show that the NO3 inventories in the arroyo floodplain could be acquired 8 to 75 times faster than through atmospheric deposition through the lateral movement of water from the arroyo channel to the adjacent unsaturated zone. As aquifer recharge occurs through the arroyo, channel migration across the floodplain likely flushes subsoil NO3 to the aquifer. High NO3 concentrations and molar ratios of NO3 to Cl in monitoring wells beneath the arroyo floodplain indicate a subsoil NO3 source. These results have major implications for land-use planning in arroyo and ephemeral stream floodplains as well as arid region soil biogeochemistry.

Erosion and accumulative processes in river valleys of the Upper Angara region (as exemplified by the catastrophic floods in 2019 on the rivers of Irkutsk Oblast)

The article considers development features of erosion-accumulative processes during catastrophic floods in 2019 on the rivers of Irkutsk oblast, in the Angara river basin (as exemplified by the Bol’shaya Belaya river). Considering the combination of morphodynamic channel types we preliminary determined main types, interaction degree of flood waters and floodplain-channel complexes in different areas. We revealed that the most intensive transformations of the floodplain-channel relief are associated with engineering and construction structures that hinder the natural exchange of floodplain and channel flows. The rates of coastal recession during the flood period were revealed; on average, they amounted to 2 m. The processes of coastal erosion-tearing away of bank are typical of sandy loam deposits composing the upper part of floodplain surfaces. The most dynamic areas of bank destruction correspond to the concave parts of the channel bends. Note is taken that the presence of linear infrastructure objects (roads) within the floodplain massifs often caused the flow rates increase and an increase in the volume of transported material, as well as formation of accumulative landforms, which can hinder water exchange between channel and floodplain streams in the future, and also serve as an additional development factor of processes that are negative for a person and can lead to total destruction of infrastructures, or cause significant damage to them.

Распространение, состояние популяций и охрана редких эфемероидов в Республике Коми

Here, we report the data on modern state and protection prospects of plant species Anemone altaica Fisch. ex C.A.Mey., Anemone nemorosa L., Anemone ranunculoides L., Ficaria verna Huds. (Ranunculaceae), Corydalis solida (L.) Clairv. (Papaveraceae) and Gagea samojedorum Grossh. (Liliaceae) in the taiga zone of the Komi Republic. These ephemeroid species require a special research due to their biological features (short periods of vegetation in the spring and subtle presence in communities at later dates) and geographic localization. One of the species, Gagea samojedorum is an endemic of the Urals, other species are presented by populations on the border of their distribution areas. Until recently, studies of early-flowering ephemeroids in the north-east Russia have not been performed. However, such studies become more and more important due to an active industrial development of the North. To assess the prospects for the conservation of rare early-flowering ephemeroids, we carried out work to clarify the number of locations of species on the territory of the Komi Republic, compiled maps of their distribution (See Fig. 1), collected and summarized information about the area, the number and the structure of 44 coenopopulations (See Tables 1 and 2), as well as identified limiting factors. It is shown that at the edge of the distribution area, ephemeroid species often have fragmented habitat range due to ecological and phytocoenotical preferences. They occur sporadically in the river and stream floodplains (sometimes at limestones) where soils are moist and fertile. In the floodplain meadows and forests, ephemeroids can form one-two species ecotopical assemblages. The populations of ephemeroids are linear, often with a high number of individuals. Self-recovering of short-root Anemone altaica, A. nemorosa, A. ranunculoides and root-tuber Ficaria verna is made, mainly, by vegetative reproduction. Tuber species Corydalis solida is propagated only by seeds. The ontogenetic structure of populations indicates a decline in seed and vegetative reproduction rate in these species at the edges of distribution areas (See Fig. 2 and 3). The Ural endemic Gagea samojedorum occurs in herbal habitats and sparse forests in foothill and mountain areas of the Ural Mountains, where it forms abundant populations with the prevalence of young individuals. A high reproduction rate of Gagea samojedorum is due to the variability of vegetative reproduction. In the Komi Republic, the anthropogenic impact on the ephemeroid species is low due to a low level of industrial development and population. Natural abiotic and biotic factors are more significant here and may weaken species positions in plant communities, as well as limit the growth, development and self-recovering of the populations. By now, Anemone altaica, A. nemorosa, A. ranunculoides, Corydalis solida, Ficaria verna and Gagea samojedorum have been included in regional Red Books of plants with the protection category 3 (rare). The main reasons for their inclusion are the edge location, small number, isolation of the local populations and often relic origin. Gagea samojedorum is also an endemic species. The object of the UNESCO World Heritage List “Virgin Komi Forests” and the number of regional reserves are important for the preservation of ephemeroid plants in the North.

Аnalysis of underflowing of residential areas and protection from urban groundwater

The article discusses the main provisions for the protection of urban buildings from groundwater and the main causes of flooding of residential areas. Also known and proposed by us ways of solving the problem are analyzed. In recent years, intensive construction has been going on in areas that were previously considered unsuitable for construction: wetlands, floodplains of rivers and streams, ravines, etc. without deep study of changes in the hydrological regime of the adjacent territory. Activities are offered in flooded areas: elimination of the causes of flooding - channel lining; sealing of water pipes and collectors, installation of storm sewers; sealing of buried structures: basement walls, foundations; drainage - lowering groundwater to a safe depth. With our participation, a drainage system has been developed, with drainage water diversion to the floodplain of the Oka River.

The ichthyofauna of the Rio Carinhanha basin, one of the main tributaries of the Rio São Francisco

The ichthyofauna of the Rio São Francisco basin is relatively well-documented. However, most of this knowledge is concentrated at the upper stretch of its catchment area. In this study, we compile a list of species encompassing almost the entire length of the Rio Carinhanha, an important tributary from upper-middle section of the Rio São Francisco, including a comprehensive diversity of environments. A total of 99 species from 8 orders and 27 families were recorded. Five species are considered non-native, six classifieds as long distance migrants, and three as vulnerable. The orders with the greatest richness of native species were Characiformes and Siluriformes. Characidae was the most represented family, followed by Loricariidae. The main river channels were the richest environments sampled, followed by floodplain lagoons, veredas, and streams. The Carinhanha basin has important lotic remnants, thus it has several migratory fish populations as well as endangered species. This study demonstrates the importance of cataloguing the still poorly explored tributaries of the upper-middle section of the Rio São Francisco basin.

A new naturalized plant in Korea: Carex molestiformis Reznicek and Rothrock (Cyperaceae)

국내 ë¯¸ê¸°ë¡ì¢ ê°€ëŠ”íƒ€ëž˜ì‚¬ì´ˆ(Carex molestiformis Reznik and Rothrock)를 강원도 평창군 ë²½íŒŒë ¹ 일대 에서 처음으로 발견하였다. 본 분류군의 원산지는 북아메리카 미국의 남부지역(Missouri, Oklahoma, Arkansas등 11개 주)으로, 자생지에서는 주로 개활지나 강둑, 범람원 등에서 무리지어 밀생한다. íƒ€ëž˜ì‚¬ì´ˆì ˆ (sect. Ovales)에 속하며, ìžì› ì„± 소수를 갖는 ë‹¤ë „ìƒ 초본으로, 한 화서에 달리는 소수의 수가 2–4개로 ì ê³ , 과낭의 폭이 2.6–3.4 mm로 넓으며, 과낭 배면의 맥이 6–9개로 많아 국내에 자생하는 ê·¼ì—°ì¢ ì¸ 타래사초(C. maackii Maxim.) 및 ê·€í™”ì¢ ì¸ 한석사초(C. scoparia)와 ëª í™•ížˆ 구별된다. êµ­ëª ì€ 본 분류군이 í˜•íƒœì ìœ¼ë¡œ 타 래사초와 ìœ ì‚¬í•˜ë©°, 식물체가 ì „ì²´ì ìœ¼ë¡œ 가늘어 ‘가는타래사초’로 ì‹ ì¹­í•˜ì˜€ê³ , 분류군에 대한 기재문, 화상 자료 및 도해 ê·¸ë¦¬ê³ ìœ ì‚¬ì¢ ì— 대한 검색표를 ì œì‹œí•˜ì˜€ë‹¤. 또한, 가는타래사초와 ê·¼ì—°ì¢ ì˜ ìœ ì „ì  차이를 확 ì¸í•˜ê³ ìž 3개(chloroplast DNA matK, ndhF, nuclear ribosomal DNA internal transcribed spacer) DNA barcode 지역의 부분 염기서열을 비교하여, 총 8개의 가는타래사초의 ì¢ íŠ¹ì´ì  단일염기다형성(single nucleotide polymorphisms)을 확인하였다. 주요어: ë¯¸ê¸°ë¡ì¢ , 가는타래사초, íƒ€ëž˜ì‚¬ì´ˆì ˆ, 사초과

Integrating freshwater wetland science into planning for Great Barrier Reef sustainability

Abstract The paper ‘Biodiversity values of remnant freshwater floodplain lagoons in agricultural catchments: evidence for fish of the Wet Tropics bioregion, northern Australia’, published in Aquatic Conservation: Marine and Freshwater Ecosystems in 2015, has contributed in several ways to the integration of freshwater wetland science within new catchment management policies and practices for Great Barrier Reef (GBR) sustainability. The Tully–Murray biodiversity study developed novel protocols to sample larval, juvenile, and adult fish life‐history stages in floodplain lagoons using a combination of boat‐based backpack electrofishing and fyke netting. In addition, hydrological and hydrodynamic models were applied in a completely new way to quantify the timing, extent, and duration of water connectivity across floodplain streams, cane drains, and wetlands. Combining the two novel approaches enabled an analysis of lagoon fish assemblage patterns in relation to environmental gradients, especially floodplain hydrology, connectivity patterns, and measures related to agricultural land use. In demonstrating the importance of different levels of connectivity for different biodiversity outcomes in freshwater floodplain lagoons of the Tully–Murray catchment, the subject paper established that floodplain connectivity needs to be taken into consideration in wetland management practices. The timing of the subject publication was fortuitous. It coincided with the preparation of the evidence‐based 2017 Scientific Consensus Statement on land‐based water quality impacts on the GBR. As one of the few freshwater wetland ecology publications for the catchments of the GBR at that time, this paper played an important role in demonstrating freshwater wetland values, fish conservation options, and management imperatives to sustain wetland ecological health and services in GBR catchments. By advancing the understanding of factors driving biodiversity patterns, and the importance of connectivity and ecohydrological processes in freshwater floodplain wetlands of the GBR catchment, the Tully–Murray study helped to drive new policy directives for the protection and restoration of catchment, floodplain, and estuary functions, and connectivity, now embedded in the Reef 2050 Long‐Term Sustainability Plan 2018, an overarching strategy for managing the GBR over the next 35 years, and complementary Queensland environmental legislation.

Floodplain Inundation and Salinization From a Recently Restored First‐Order Tidal Stream

AbstractThe systematic response of coastal ecosystems to inundation and salinity exposure is fundamental to their ecology and biogeochemical function. Here we observe and model freshwater‐seawater interactions in a first‐order stream—floodplain system where tidal access was recently restored. Subsurface flow and transport modeling were used to quantify and better understand the interplay of processes, properties, and conditions that control water level and salinity in the floodplain to the tidal stream. Water levels in the stream were highly correlated with tidal forcing, which resulted in episodic inundation of the floodplain at quasi‐monthly frequency. The tidal stream is the only source of salinity to the floodplain, yet shallow groundwater salinity was considerably higher than average stream salinity. The low‐permeability clay floodplain soils limit lateral groundwater flow and transport, resulting in floodplain groundwater and salinity dynamics driven almost exclusively by infiltration during inundation events. As inundation occurs during high tide, estuarine waters reach the floodplain with minor attenuation in salinity from the stream's freshwater discharge. Infiltration and salinity exposure are topography controlled and regulated by ponding depth and duration, seasonal ground saturation, and depth to water table. The model suggests that floodplain salinity is currently in an early stage of transition from pre‐restoration freshwater conditions and will not reach equilibrium for ~20 years. These findings have broad relevance for understanding how and over what time scales coastal ecosystems will respond to increasing seawater exposure from sea level rise, ocean‐originating storms, and changes in natural and man‐made barriers.