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Ecosystems that are coupled by reciprocal flows of energy and nutrient subsidies can be viewed as a single "meta-ecosystem." Despite these connections, the reciprocal flow of subsidies is greatly asymmetrical and seasonally pulsed. Here, we synthesize existing literature on stream-riparian meta-ecosystems to quantify global patterns of the amount of subsidy consumption by organisms, known as "allochthony." These resource flows are important since they can comprise a large portion of consumer diets, but can be disrupted by human modification of streams and riparian zones. Despite asymmetrical subsidy flows, we found stream and riparian consumer allochthony to be equivalent. Although both fish and stream invertebrates rely on seasonally pulsed allochthonous resources, we find allochthony varies seasonally only for fish, being nearly three times greater during the summer and fall than during the winter and spring. We also find that consumer allochthony varies with feeding traits for aquatic invertebrates, fish, and terrestrial arthropods, but not for terrestrial vertebrates. Finally, we find that allochthony varies by climate for aquatic invertebrates, being nearly twice as great in arid climates than in tropical climates, but not for fish. These findings are critical to understanding the consequences of global change, as ecosystem connections are being increasingly disrupted.

Concern over rising water temperatures for freshwater ectotherms has led to application of experimentally derived thermal thresholds to stream temperature models for estimation of streams at high risk of exceeding thermal thresholds under current and future climate conditions. We optimised an approach that links field‐relevant thermal maxima experiments to corresponding stream temperature models and identifies opportunities to reduce stream temperatures through riparian tree growth.We conducted a thermal maxima experiment on cold‐water adapted juvenile Chinook (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) that reflected natural temperatures by using incremental temperature ramping with diel fluctuations (IT‐Dmax) and refit a regionally specific stream temperature model for British Columbia, Canada to directly relate to lab‐derived thresholds. Salmon‐bearing streams across British Columbia were categorised by threshold exceedance risk (i.e., low, moderate, high, severe) based on risk tolerance scenarios for management decision making (i.e., considering a range of prediction intervals [PIs] and stream thermal sensitivities to air temperature). We linked these results directly to riparian management and restoration actions by estimating the potential for riparian tree growth to reduce threshold exceedance risk.Lab‐derived IT‐Dmax endpoints were consistently 24°C (based on the median value between the 7‐day average of the daily maximum and the mean weekly average temperature) across acclimation treatments for both species. Under current conditions, most stream reaches (99.6% using an intermediate risk tolerance scenario) were below the thermal threshold; streams with moderate to high risk of threshold exceedance were projected to increase from 0.4% to 1.5% (total linear stream length of 6,929 km) by end of century. The risk‐averse (high sensitivity, 75% PI) and risk‐tolerant (low sensitivity, 95% PI) scenarios differed by 1,107 km of streams predicted to have a moderate to severe risk of exceeding thresholds by end of century. Maximal riparian tree growth was predicted to shift 670 km of streams from moderate to low exceedance risk under end‐of‐century conditions and intermediate risk tolerance, showing the potential for mitigation from thermal impacts.Our integrative approach tackled several key considerations in identifying streams at high temperature risk for freshwater ectotherms that to date have not been addressed. Furthermore, we showcased the delineation of spatially comprehensive estimates that identify where management mitigation and a specific restoration activity may be most needed to reduce impacts of rising temperatures on rearing salmonids across an extensive region. [ABSTRACT FROM AUTHOR]

Abstract Riparian forests are crucial for biodiversity, but dam construction for hydroelectric power disrupts these ecosystems, causing habitat loss and altering river dynamics. Our study investigates the impacts of dams on tree diversity in the southern Brazilian Atlantic Forest. We sampled trees along riverbanks and uplands across 15 dam-affected fragments, analysing the relationship between habitat loss (i.e. loss of riparian zones by permanent flooding due to dam filling), elevation difference, fragment size, and dam implementation time with alpha and beta diversity using mixed models and redundancy analyses. Habitat loss had a more significant impact on beta diversity, leading to shifts in species composition and reduced uniqueness of communities as the impact’s intensity, spatial extent, and duration increased. Alpha diversity only increased in response to local elevation differences between plots located on uplands and riverbanks. Our sampling design can be applied to other inadequately monitored systems to provide insights into beta diversity, a component often neglected in dam licensing and mitigation processes. Our findings reveal a transient local heterogenisation, transitioning into regional homogenisation due to dam-induced habitat loss in riparian forests of the Brazilian Atlantic Forest.

Freshwater and terrestrial biodiversity are linked through spatial resource flows. Key examples are detrital subsidies from the riparian vegetation that form the base of food webs in small streams. Despite the central role of detritivores in these food webs, the consequences of altered riparian vegetation type and resource availability on their trophic strategies are less known.Therefore, we experimentally tested direct and indirect effects of riparian vegetation type (i.e. riparian forests present vs. absent) on trophic interactions and dietary imbalances of aquatic detritivores. To characterise trophic strategies, we used stoichiometric and isotopic differences between consumers and resources as functional measures of trophic link strength in leaf litter bags naturally colonised by stream decomposers and detritivores.Our results show that an absence of riparian forests affected stoichiometric and isotopic properties in stream detrital food webs. Where local riparian forests were absent, leaf litter showed lower C:N ratios, which only trichopteran detritivores mirrored, whereas plecopteran and crustacean detritivores showed differences in their isotopic signatures. Diverging patterns between resources and consumers could lead to a rewiring of energy flow paths and weaken the coupling between aquatic detritivores and terrestrial detritus.Consequently, our findings demonstrate that riparian forests are essential for aquatic food webs by not only influencing organisms themselves but also their trophic interactions and energy flow paths. Aquatic detritivores depending on terrestrial subsidies can be highly sensitive to local changes in their resource environment. Therefore, functionally divergent patterns between resources and consumers in recipient systems highlight how habitat properties of the donor system can affect food webs connected across ecosystem boundaries. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Considerable parts of riparian forests around the world are covered by deciduous trees and tall shrub species with rigid trunk and flexible-broadleaf. Experiments are conducted on artificial rigid and flexible models to estimate drag coefficient and resistance to flow for deciduous trees in forest floodplains under nonsubmerged condition. The rigid and flexible models with similar size and configuration are tested in a laboratory flume to clearly determine the effects of vegetation flexibility and density, and the flow velocity and depth on the roughness coefficients. Ratios of the flexible to rigid drag forces and drag coefficients indicate considerable effects of flexibility on the roughness coefficients. In this study, the flexural rigidity of the tree leaf is used in the roughness equations to account for vegetation flexibility instead of the traditionally used tree trunk flexural rigidity. This is based on the assumption that foliage flexibility governs tree reaction to the flow for most species of deciduous trees and leafy tall shrub families. The developed roughness coefficient equations are scaled up to determine the variation of Manning's n -value with increase of flow depth for a riparian canopy of black willow. The estimated Manning's n -values are compared with the reported Manning n -values for the same black willow canopy. [ABSTRACT FROM AUTHOR]

This research focuses on developing a multipurpose riparian zone designed to effectively reduce erosion and control nutrient flow into Lake Tondano. The goal is to enhance both conservation and pollution control strategies for sustainable ecosystem management. Conducted at Lake Tondano in Minahasa, Indonesia, the research followed three main stages: data collection, analysis, and design. The data collection included a vegetation survey of riparian species, land use mapping, and measuring nitrogen and phosphorus levels in lake sediments. A total of 91 plant species from 60 genera and 42 families were documented. Based on their Importance Value Index (IVI), non-invasive status, and nutrient absorption capabilities, 15 species were selected for restoration in areas with high nutrient concentrations, with sediment levels recorded at 0.09% nitrogen and 0.06% phosphorus in impacted zones. These plant species were carefully identified and rigorously tested, originating from intact riparian zones. They will be strategically employed in areas facing significant challenges from nutrient overloading. Using QGIS analysis, a riparian zone measuring 100 m x 30 m was designed at coordinates 1.1745604 latitude and 124.8972748 longitude, targeting areas most impacted by nutrient pollution, which poses a risk of eutrophication and negatively affects aquatic ecosystems. The multipurpose riparian zone incorporates distinct wet, transition, and dry zones, employing a zigzag planting pattern to optimize pollutant filtration and nutrient uptake. This design effectively addresses critical issues of erosion and nutrient excessive enrichment, promoting ecological health and biodiversity in the region. The novel contributions of this study include identifying specific plant species capable of thriving in nutrient-rich sediments and quantifying their nutrient absorption capacities, thereby providing a scientifically grounded model for similar conservation efforts in vulnerable ecosystems and enhancing overall resilience. However, long-term impacts on water quality require further research to assess nutrient mitigation efficacy.

Wetland hydrological dynamics often dictate the composition of biological communities found in or near wetlands, either directly or through changes in vegetation composition. However, much remains unknown, particularly regarding how riparian arthropods respond to such dynamics. In this study, we used high-resolution hydrological data, along with presence of grazing livestock and shoreline vegetation height from 41 constructed wetlands in south-western Sweden to explore flood zone areas, flood frequencies, vegetation and grazing as drivers of the resident arthropod communities. The collected material consisted of 26,817 arthropods, where the dominant groups were Diptera (13,258 specimens), spiders (6,207) and Coleoptera (2,858), which were collected using SLAM (Sea Land and Air Malaise) trapping, along with pitfall trapping and vacuum sampling of riparian arthropods. We found group-specific responses to inundation frequencies, where wetlands with higher frequencies had lower abundances of some beetles and tipulids, and where wetlands with longer low-water table periods contained less trichopterans and heteropterans. In contrast, the size of flood zone areas only affected some wolf spider groups, that were more abundant in wetlands with intermediately sized flood zones. Shoreline vegetation height affected multiple groups, spiders, beetles and dipterans, but in different directions, whereas presence of grazing livestock had limited impact on abundances and community compositions. Given the variable responses to wetland hydrological and structural drivers, it seems that wetland arthropod communities would benefit from a high local wetland habitat variability, or wetlandscapes where individual wetlands have differing hydrological dynamics, morphology and vegetation.

Isotopic evidence of groundwater and stream water is frequently used to investigate water exchanges with groundwater. Monthly sampling of rain, stream water, and groundwater was conducted at Tims Branch watershed in South Carolina for the oxygen and hydrogen stable isotope (δ2H and δ18O) measurement, as well as pH and oxidation–reduction potential (ORP). Together with a mass balance perspective, it was determined that it takes a few weeks to one month for groundwater in the hyporheic zone to fully exchange with stream water. From hydrodynamic modelling, we show that substantial (up to 70 %) groundwater exchange occurs at gaining and losing sites. Groundwater exfiltration, i.e. inflow into stream water, contributes up to 4 % to stream water, with the remainder from upstream exfiltration. A 2–4 % per day renewal rate of adjacent groundwater would indirectly indicate a groundwater residence time in the order of half a month to a full month (assuming either a well-mixed case or large dispersion rate in pulse flow case), in agreement with a greatly reduced variability of δ2H and δ18O of groundwater compared to stream water and rain. This reduced variability of stable isotope signal from groundwater confirms our hypothesis that riparian groundwater mixing at Tims Branch is more of a mixed type rather than a pulse flow type. A monthly time scale is sufficient for groundwater to become anoxic at exit points into stream water resulting in the episodic production of natural organic matter- and iron-rich flocs upon oxidation. [ABSTRACT FROM AUTHOR]

Abstract The normal operation of the Three Gorges Reservoir, which involves periodic water storage and discharge, has led to strong disturbances in environmental conditions that alter soil microbial habitats in the riparian zones. Riparian zones are an important part of controlling pollution in the Three Gorges Reservoir area, since they act as a final ecological barrier that intercepts pollutants. Meanwhile, monitoring the health of microbial communities in the riparian zone is crucial for maintaining the ecological security of the reservoir area. We specifically investigate the Daning River, which are tributaries of the Three Gorges Reservoir and have typical riparian zones. Soil samples from these areas were subjected to high-throughput sequencing of 16S rRNA genes and 18S rRNA genes, in order to obtain the characteristics of the present microbial communities under strong disturbances in the riparian zones. We studied the characteristics and distribution patterns of microbial communities and their relationship with soil physicochemical properties. The study results indicate that microbial communities exhibit high diversity and evenness, and spatial heterogeneity is present. The ASV dataset contains many sequences not assigned to known genera, suggesting the presence of new fungal genera in the riparian zone. Redundancy analysis (RDA) revealed that pH and $${NH}_{4}^{+}$$ NH 4 + -N were the primary environmental factors driving bacterial community variation in the riparian zone, while pH, total carbon (TC) content, and $${NO}_{3}^{-}$$ NO 3 - -N were identified as the main drivers of soil archaeal community variation.

Abstract [Objective] The relationship between species diversity and soil factors in riparian zone is important to maintain the stability of riparian ecosystems. The purpose of the study is to reveal the relationship between species diversity and soil factors in riparian zone and provide references and theoretical guidance for the ecological restoration, protection, and high-quality development of the middle and lower reaches of the Yellow River. [Methods] The study examined the relationship between plant distribution, species diversity, and soil factors in the transition zone of the middle and lower reaches of the Yellow River in He􀆳nan Province by means of quadrat survey, experimental analysis, and CCA ranking. [Results] (1) Soil organic matter, available potassium, and available phosphorus in the transition zone of the middle and lower reaches of the Yellow River were moderate variability, water content, the coefficient of total nitrogen was strong variability, and the spatial distribution of soil nutrients was uneven. (2) There was a significant negative correlation between the dominance index of riparian plants and soil total nitrogen (P < 0.05). Soil pH, available potassium, and available phosphorus had no obvious effects on species richness index. The evenness index, Shannon-Wiener index, and six soil factors did not reach a significant level. (3) The distribution of Polygonum polygonatum , Cyperus capitatum , Echinochloa crusgalli, Echinochloa cristatum , and Eclipta prostrata communities was affected by water content. The distribution of Artemisia annua, Ziziphus jujuba, and Populus tomentosa was mainly affected by total nitrogen, which were mainly distributed in areas with high total nitrogen content. Humulus scandens and Amaranthus retroflexus were affected by available potassium. However, Cynodon dactylon, Xanthium strumarium , Phragmites australis, Setaria viridis, Polygonum persicaria, Vigna radiata, and other communities were less affected by soil factors. [Conclusion] The soil moisture content, available potassium, and total nitrogen in the transitional zone of the middle and lower reaches of the Yellow River are the main factors affecting plant distribution. Different plants have different requirements for soil conditions, which can reflect the relationship between vegetation and soil environment.

River and lake health assessment (RLHA) is an important approach to alleviating the conflict between protecting river and lake ecosystems and fostering socioeconomic development, aiming for comprehensive protection, governance, and management. Vegetation, a key component of the riparian zone, supports and maintains river and lake health (RLH) by providing a range of ecological functions. While research on riparian zone vegetation is ongoing, these studies have not yet been synthesized from the perspective of integrating RLHA with the ecological functions of riparian zone vegetation. In this paper, based on the bibliometric method, the relevant literature studies on the topics of RLHA and unmanned aerial vehicle (UAV) remote sensing of vegetation were screened and counted, and the keywords were highlighted, respectively. Based on the connotation of RLH, this paper categorizes the indicators of RLHA into five aspects: water space: the critical area from the river and lake water body to the land in the riparian zone; water resources: the amount of water in the river and lake; water environment: the quality of water in the river and lake; water ecology:aquatic organisms in the river and lake; and water services:the function of ecosystem services in the river and lake. Based on these five aspects, this paper analyzes the key role of riparian zone vegetation in RLHA. In this paper, the key roles of riparian zone vegetation in RLHA are summarized as follows: stabilizing riverbanks, purifying water quality, regulating water temperature, providing food, replenishing groundwater, providing biological habitats, and beautifying human habitats. This paper analyzes the application of riparian zone vegetation ecological functions in RLH, summarizing the correlation between RLHA indicators and these ecological functions. Moreover, this paper analyzes the advantages of UAV remote sensing technology in the quantitative monitoring of riparian zone vegetation. This analysis is based on the high spatial and temporal resolution characteristics of UAV remote sensing technology and focuses on monitoring the ecological functions of riparian zone vegetation. On this basis, this paper summarizes the content and indicators of UAV quantitative remote sensing monitoring of riparian zone vegetation for RLHA. It covers several aspects: delineation of riparian zone extent, identification of vegetation types and distribution, the influence of vegetation on changes in the river floodplain, vegetation cover, plant diversity, and the impact of vegetation distribution on biological habitat. This paper summarizes the monitoring objects involved in monitoring riparian zones, riparian zone vegetation, river floodplains, and biological habitats, and summarizes the monitoring indicators for each category. Finally, this paper analyzes the challenges of UAV quantitative remote sensing for riparian zone vegetation at the current stage, including the limitations of UAV platforms and sensors, and the complexity of UAV remote sensing data information. This paper envisages the future application prospects of UAV quantitative remote sensing for riparian zone vegetation, including the development of hardware and software such as UAV platforms, sensors, and data technologies, as well as the development of integrated air-to-ground monitoring systems and the construction of UAV quantitative remote sensing platforms tailored to actual management applications. [ABSTRACT FROM AUTHOR]

The study is focused on measures put in place to restore the degraded riparian vegetation of the Black Volta Basin in the Lawra Municipality. The study is necessitated by the fact that much attention has not been given to rehabilitation of degraded riparian flora species in the Upper West Region by scholars and researchers. The current study aims at filling the knowledge gaps on restoration measures of degraded riparian flora species in the Lawra Municipality in particular and Upper West Region in general. Going by pragmatism as a research philosophy, the study employed the mixed methods research approach in data collection, analysis, and presentation. Computed values of the Shannon Wiener Index (0.686) and Simpson's Index (1.5328) show that the riparian vegetation of the Black Volta Basin in the Lawra Municipality has dwindled due to livelihood activities as compared to the Shannon Index (1.6406) and Simpson's Index (3.5511) of the riparian vegetation of the Burkina Faso site across the Black Volta Basin. The reduction in vegetative cover of the Black Volta Basin in the Lawra Municipality is confirmed by satellite images which demonstrate dwindling riparian vegetation in the years 2020 and 2021 as compared to the years 2000 and 2001. The current study also discloses that restoration of the riparian vegetation of the Black Volta Basin in the Lawra Municipality is a collaborative effort of local and external stakeholders using measures such as complete ban on farming activities within the riparian zone, creating a buffer zone, promoting natural regeneration and a total ban on logging in the riparian zone. The study concludes that restoration of the degraded riparian vegetation of the Black Volta Basin of the study area is a panacea for sustainable development. It is recommended that by-laws to prevent logging of riparian tree species should be enforced by local and external stakeholders of the riparian vegetation of the study area.

Riparian soils, together with vegetation, play a crucial role in supporting biodiversity and driving biogeochemical processes within river ecosystems. Conservation of riparian soils and artificial planting are essential for river ecosystem recovery following land degradation. Researchers focus on examining soil nutrients, microbial biomass, and organic acid metabolism in the interactions between plants and soil along riverbanks. However, the seasonal responses of riparian soils to artificial plantations have been infrequently reported in the existing literature. This study investigates the influence of seasonal variations on soil conditions and the growth of artificially planted species in the riparian zones of the Three Gorges Dam Reservoir (TGDR) in China. The species sampled include Cynodon dactylon, Hemarthria altissima, and Salix matsudana. These species provide valuable insight into soil properties along riparian zones, assessing interactions across different seasons: T1 (spring), T2 (summer), and T3 (autumn). The results demonstrated significant seasonal changes in soil organic matter, ammonium nitrogen, nitrate nitrogen, and other indicators between T1 and T3. Apart from invertase activity in H. altissima soil, enzyme activity peaked during T1. Dominant soil bacteria were examined using high-throughput 16S rDNA sequencing, revealing that the available bacteria belong to 62 phyla and 211 classes. Among the most abundant were Proteobacteria and Actinobacteria, averaging over 60 % across all soil samples. Principal component analyses accounted for 62.81 % (T1), 50.57 % (T2), and 54.08 % (T3) of the variation observed in the study, indicating that soil properties were predominantly influenced by the different seasonal phases, assuming all other factors remained constant. Pearson correlation analysis (p < 0.05) identified strong positive correlations between physical properties and all three plant species during T1 (r ≤ 0.94), as well as significant negative correlations with bacterial communities in T2 and T3 (r ≤ −1.00). These findings suggest that the selected plant species are well-suited to cultivation in the riparian zone of the TGDR. This study enhances our understanding of seasonal dynamics in riparian environments, offering practical insights into their management.

Study Region, Shanghai, China, Study FocusUrban riparian zones can mitigate or even control nitrogen pollution in rivers through nitrification and denitrification processes. However, these processes also produce N2O, a potent greenhouse gas. During urbanization, various types of revetments have been constructed in riparian zones. These revetments alter the exchange of materials and energy between the riparian zone and the river, which in turn affects the nitrification and denitrification processes in the riparian zone. However, the mechanisms by which revetments impact nitrogen removal and N2O emissions in riparian zones are not yet clear, and the ways in which revetments balance nitrogen removal and N2O emissions remain unknown. Therefore, in a single river section, natural (NR), permeable (PR), and impervious revetment (IR) types were replicated. Measurements are taken of nitrogen removal, N2O emissions, and related environmental indicators in both the river-riparian interface (RRI) and the riparian zone area outside the RRI (RZ). The study analyzes the differences in environmental factors, nitrification and denitrification potentials, and N2O emission rates among the different revetments to identify the main factors affecting nitrogen removal and N2O emissions in the riparian zone. It also explores the potential mechanisms by which revetments influence the spatial distribution of nitrogen removal and N2O emissions in the summer riparian zone.New Hydrological Insights for the Region: PR exhibit greater denitrification potential and lower N2O emission rates. The denitrification potential is higher in the RRI compared to RZ, while the N2O emission rate is lower than in RZ. nirK is the primary factor influencing denitrification potential, whereas nosZII predominantly affects N2O emissions. The lower soil carbon-to-nitrogen ratio in PR increases the abundance of nirK, thereby enhancing the riparian zone's denitrification potential. Moreover, greater aboveground vegetation biomass increases the abundance of nosZII, reducing the N2O emission rate. The study results could provide guidance for urban ecological restoration and greenhouse gas emission reduction.