Rachel Stubbington

• BSc PhD
• Professor at Nottingham Trent University

Drying river networks include non‐perennial reaches that cease to flow or dry, and drying is becoming more prevalent with ongoing climate change. Biodiversity responses to drying have been explored mostly at local scales in a few regions, such as Europe and North America, limiting our ability to predict future global scenarios of freshwater biodive...

As climatic extremity intensifies, a fundamental rethink is needed to promote the sustainable use of freshwater resources. Both floods and droughts, including water scarcity, are exacerbating declines in river biodiversity and ecosystem services, with consequences for both people and nature. Although this is a global challenge, densely populated re...

Small streams dominate river networks and collectively support high biodiversity, but are rarely included in regulatory biomonitoring programmes. Macroinvertebrate communities are effective biomonitors of ecological condition and are routinely collected using 3-min 'kick' samples. However, this 3-min duration may not be suitable for small streams,...

Aim To determine which riverine invertebrate traits respond consistently to anthropogenic impacts across multiple biogeographic regions. Location Europe. Time Period 1981–2021. Major Taxa Studied Riverine invertebrates. Methods We compiled a database of riverine invertebrate community time series for 673 sites across six European countries span...

Biological assemblages in streams are influenced by hydrological dynamics, particularly in non‐perennial systems. Although there has been increasing attention on how drying impacts stream organisms, few studies have investigated how specific characteristics of drying and subsequent wetting transitions influence biotic responses via resistance and r...

Drought is an increasing risk to the biodiversity within rivers—ecosystems which are already impacted by human activities. However, the long‐term spatially replicated studies needed to generate understanding of how anthropogenic stressors alter ecological responses to drought are lacking. We studied aquatic invertebrate communities in 2500 samples...

More than half of the world’s rivers dry up periodically, but our understanding of the biological communities in dry riverbeds remains limited. Specifically, the roles of dispersal, environmental filtering and biotic interactions in driving biodiversity in dry rivers are poorly understood. Here, we conduct a large-scale coordinated survey of patter...

Climate change is interacting with water resource pressures to alter the frequency, severity and spatial extent of drought, which can thus no longer be considered a purely natural hazard. Although particularly severe ecological impacts of drought have occurred in drylands, its effects on temperate ecosystems, including rivers, are also considerable...

Freshwater macroinvertebrates are a diverse group and play key ecological roles, including accelerating nutrient cycling, filtering water, controlling primary producers, and providing food for predators. Their differences in tolerances and short generation times manifest in rapid community responses to change. Macroinvertebrate community compositio...

Headwater springs and streams often occur in relatively remote areas, reducing their exposure to human influences and thus increasing their collective capacity to support high biodiversity. Their aquatic macroinvertebrate communities can include species of conservation interest, some of which are specialists associated with groundwater inputs, low...

1. Trait-based approaches have received increasing interest among freshwater scientists given their capacity to predict community structure and biodiversity effects on ecosystem functioning. However, the inconsistent development and use of trait concepts and terms across freshwater scientific disciplines may have limited realisation of the potentia...

Non-perennial river segments — those that recurrently cease to flow or frequently dry — occur in all river networks and are globally more abundant than perennial (always flowing) segments. However, research and management have historically focused on perennial river segments. In this Review, we outline how non-perennial segments are integral parts...

Accelerating the design and implementation of environmental flows (e-flows) is essential to curb the rapid, ongoing loss of freshwater biodiversity and the benefits it provides to people. However, the effectiveness of e-flow programs may be limited by a singular focus on ensuring adequate flow conditions at local sites, which overlooks the role of...

Owing to a long history of anthropogenic pressures, freshwater ecosystems are among the most vulnerable to biodiversity loss¹. Mitigation measures, including wastewater treatment and hydromorphological restoration, have aimed to improve environmental quality and foster the recovery of freshwater biodiversity². Here, using 1,816 time series of fresh...

The lack of data from non-perennial rivers, which regularly cease to flow and dry up, poses a significant challenge in understanding river biodiversity. These dynamic ecosystems, accounting for over half of the global river network, remain understudied. To address this gap, we conducted a coordinated experiment and a metabarcoding approach on envir...

Most empirical metacommunity studies rely solely on morphological identification of taxa, precluding the species-level identification of several biotic groups, which can influence the characterization of metacommunities. DNA metabarcoding enables inference of species and even intraspecific diversity from community samples but has rarely been used t...

As alien invasive species are a key driver of biodiversity loss, understanding patterns of rapidly changing global species compositions depends upon knowledge of invasive species population dynamics and trends at large scales. Within this context, the Ponto-Caspian region is among the most notable donor regions for aquatic invasive species in Europ...

Temporal fluctuations in cause the spatial extent of wet and dry habitats to vary in aquatic–terrestrial riverine ecosystems, complicating their biomonitoring. As such, biomonitoring efforts may fail to characterize the species that inhabit such habitats, hampering assessments of their biodiversity and implementation of evidence-informed management...

Rivers that do not flow year-round are the predominant type of running waters on Earth. Despite a burgeoning literature on natural flow intermittence (NFI), knowledge about the hydrological causes and ecological effects of human-induced, anthropogenic flow intermittence (AFI) remains limited. NFI and AFI could generate contrasting hydrological and...

Aim Invasive alien species are a growing problem worldwide due to their ecological, economic and human health impacts. The “killer shrimp” Dikerogammarus villosus is a notorious invasive alien amphipod from the Ponto‐Caspian region that has invaded many fresh and brackish waters across Europe. Understandings of large‐scale population dynamics of hi...

Freshwater Biological Association News 85: 8–11.

The chalk winterbournes of southern England are globally rare temporary stream habitats, and often support Nationally Rare and Scarce drying-tolerant insects (DTIs). However, winterbournes are rarely the focus of routine biomonitoring, and thus the prevalence and distribution of DTIs is not well characterised. This is problematic because their perc...

As alien invasive species are a key driver of biodiversity loss, understanding patterns of rapidly changing global species compositions depends upon knowledge of biological invasion dynamics and trends. The Ponto-Caspian region is among the most notable donor regions for aquatic invasive species in Europe. Using macroinvertebrate time series collec...

Delivered to the Drying freshwaters in the Anthropocene: ecological effects and socio-economic perspectives scientific session. Abstract: Artificial waterbodies such as ditches can support high biodiversity. However, the role of ditches in increasing habitat diversity, and thus catchment-scale biodiversity is often overlooked. Our previous researc...

Globalization has led to the introduction of thousands of alien species worldwide. With growing impacts by invasive species, understanding the invasion process remains critical for predicting adverse effects and informing efficient management. Theoretically, invasion dynamics have been assumed to follow an “invasion curve” (S-shaped curve of availa...

Nonperennial streams dominate global river networks and are increasing in occurrence across space and time. When surface flow ceases or the surface water dries, flow or moisture can be retained in the subsurface sediments of the hyporheic zone, supporting aquatic communities and ecosystem processes. However, hydrological and ecological definitions...

Riparian invertebrate communities are species rich, but variability in sampling methods hampers assessment of their distributions and inference of the quality of their habitats. To reduce this variability, a standardised, multi-method survey protocol was recently developed. Here, riparian beetle community surveys conducted before and after the prot...

Rivers are dynamic ecosystems in which both human impacts and climate‐driven drying events are increasingly common. These anthropogenic and natural stressors interact to influence the biodiversity and functioning of river ecosystems. Disentangling ecological responses to these interacting stressors is necessary to guide management actions that supp...

Freshwater Biological Association News 83: 14–18.

We analysed the aquatic macroinvertebrate communities at two sites with contrasting temporary flow regimes in the River Thames headwaters: Ewen, which typically dries for six months each year, and Somerford Keynes, which stops flowing in late summer and dries only for a few weeks. The dataset spanned 2018, a typical hydrological year, and 2019, in...

River biomonitoring uses biotic indices that assess human-induced degradation, including pollution, by comparison with type-specific static biological reference conditions. However, index scores that indicate pollution may reflect biological responses to natural hydrological variability associated with low flows and drying, leading biomonitoring sc...

In agricultural landscapes, small ditches are artificial watercourses which sometimes stop flowing and may dry out. Despite their artificial nature and exposure to pollution, ditches support high biodiversity, including rare species. Our previous research has shown that the juveniles of a Nationally Scarce, drying tolerant mayfly occurs more freque...

Intermittent rivers and ephemeral streams (IRES) – waterways in which flow ceases periodically or that dry completely – are found worldwide, and their frequency and extent are expected to increase in the future in response to global climate change and growing anthropogenic demand for fresh water. Repeated wet–dry cycles generate highly dynamic sett...

As complex mosaics of lotic, lentic, and terrestrial habitats, intermittent rivers and ephemeral streams (IRES) support high biodiversity. Despite their ecological importance, IRES are poorly represented in routine monitoring programs, but recent recognition of their considerable—and increasing—spatiotemporal extent is motivating efforts to better...

Temporal fluctuations in water levels cause the spatial extent of terrestrial habitats to vary in river channels, especially in temporary streams. These changing water levels - as well as the advanced skills needed to identify terrestrial invertebrates - can hamper habitat quality assessments in aquatic–terrestrial riverine ecosystems. However, hab...

In agricultural landscapes, ditches are artificial watercourses which are typically slow-flowing, and many sometimes stop flowing and dry out. Despite their artificial nature and exposure to pollution, ditches support high biodiversity, including rare species. For example, larvae of the mayfly Paraleptophlebia werneri, considered a temporary-stream...

Temporary streams are increasingly common – including in cool, wet countries, where they often occur in catchments dominated by agricultural land uses. In these landscapes, fertilizer use and livestock grazing introduce nutrients and fine sediment into aquatic ecosystems, but how these pollutants affect temporary stream communities, and how the eff...

Temporary streams are increasingly common – including in cool, wet countries, where they often occur in catchments dominated by agricultural land uses. In these landscapes, fertilizer use and livestock grazing introduce nutrients and fine sediment into aquatic ecosystems, but how these pollutants affect temporary stream communities, and how the eff...

Ecological communities can remain stable in the face of disturbance if their constituent species have different resistance and resilience strategies. In turn, local stability scales up regionally if heterogeneous landscapes maintain spatial asynchrony across discrete populations—but not if large‐scale stressors synchronize environmental conditions...

Climate change is altering the water cycle globally, increasing the frequency and magnitude of floods and droughts. An outstanding question is whether biodiversity responses to hydrological disturbance depend on background climatic context – and if so, which contexts increase vulnerability to disturbance. Answering this question requires comparison...

Riverine ecosystems can be conceptualized as ‘bioreactors’ (the riverine bioreactor) which retain and decompose a wide range of organic substrates. The metabolic performance of the riverine bioreactor is linked to their community structure, the efficiency of energy transfer along food chains, and complex interactions among biotic and abiotic enviro...

This chapter explores intermittent rivers and ephemeral streams (IRES), dynamic ecosystems that are widespread throughout global river networks. Defined by flow cessation, IRES comprise mosaics of flowing, ponded and dry habitats that shift in space and time to support high biodiversity, including both aquatic and terrestrial species that contribut...

Dispersal is an essential process in population and community dynamics, but is difficult to measure in the field. In freshwater ecosystems, information on biological traits related to organisms' morphology, life history and behaviour provides useful dispersal proxies, but information remains scattered or unpublished for many taxa. We compiled infor...

Temporary streams are widespread in global river networks, and hydroecological tools are needed to assess biotic responses to changes in environmental conditions between wet and dry states. Plant communities can be abundant and diverse in temporary streams, and vary in their tolerance of changing water availability and associated habitat conditions...

Disturbance events govern how the biodiversity of ecological communities varies in both space and time. In freshwater ecosystems, there is evidence that local and regional‐scale drivers interact to influence ecological responses to drying disturbances. However, most research provides temporal snapshots at the local scale, whereas few studies encomp...

According to metacommunity theories, the structure of natural communities is the result of both environmental filtering and spatial processes, with their relative importance depending on factors including local habitat characteristics, functional features of organisms, and the spatial scale considered. However, few studies have explored environment...

Section 4.6. Aquatic Plants

Temporary streams are dynamic ecosystems that shift between wet and dry states and include the ‘winterbourne’ chalk streams of south England. Our understanding of temporary stream biodiversity is biased, with most research to date exploring aquatic invertebrate communities in benthic sediments during flowing phases. We surveyed the invertebrate com...

1.Temporary streams are dynamic ecosystems in which mosaics of flowing, ponded and dry habitats support high biodiversity of both aquatic and terrestrial species. Species interact within habitats to perform or facilitate processes that vary in response to changing habitat availability. A natural capital approach recognizes that, through such proces...

Intermittent rivers and Ephemeral Streams (IRES) are river water bodies characterised by temporary flow. They are widespread across the EU and a significant proportion of them is expected to increase due to climate change scenarios and rising water demands. The purpose of this handbook is to help water managers to understand the natural processes...

Chapter 5 from the Intermittent rivers and ephemeral streams: what water managers need to know. Technical report – Cost ACTION CA 15113

In a nutshell: ▪ There is a variety of benefits that IRES provide to our societies, from the provision of materials such as water and timber, to iconic species, the regulation of biogeochemical cycles, and space for cultural manifestation and as a corridor for both wild and herded animals. ▪ Drying and rewetting processes, timing and duration of...

SMIRES is a COST Action addressing the Science and Management of Intermittent Rivers & Ephemeral Streams (coord. T. Datry, INRAE, and G. Singer, University of Innsbruck; http://www.smires.eu). This COST Action had brought together scientists from various research field and stakeholders to develop a European multidisciplinary network for synthesisin...

SMIRES is a COST Action addressing the Science and Management of Intermittent Rivers & Ephemeral Streams (coord. T. Datry, INRAE, and G. Singer, University of Innsbruck; http://www.smires.eu). This COST Action had brought together scientists from various research field and stakeholders to develop a European multidisciplinary network for synthesisin...

The ABCD conference format (All continents, Balanced gender, low Carbon transport, Diverse backgrounds) mixes live-streamed and pre-recorded talks with in-person ones to reflect a diverse range of viewpoints and reduce the environmental footprint of meetings while also lowering barriers to inclusiveness.

Rapid shifts in biotic communities due to environmental variability challenge the detection of anthropogenic impacts by current biomonitoring programs. Metacommunity ecology has the potential to inform such programs, because it combines dispersal processes with niche-based approaches and recognizes variability in community composition. Using interm...

The ABCD conference format (All continents, Balanced gender, low Carbon transport, Diverse backgrounds) mixes live-streamed and pre-recorded talks with in-person ones to reflect a diverse range of viewpoints and reduce the environmental footprint of meetings while also lowering barriers to inclusiveness.

River ecosystems world‐wide are affected by altered flow regimes, and advanced science and practice of environmental flows have been developed to understand and reduce these impacts. But most environmental flows approaches ignore flow intermittency, which is a natural feature of 30% of the global river network length. Ignoring flow intermittency wh...

Prolonged drought leads to the temporary simplification or loss of aquatic biological communities, as surface water is progressively reduced or dry phases are extended in intermittent streams. Using surveys of aquatic and semi‐aquatic plants, and recording non‐aquatic grasses and herbs, we classify the communities within 24 groundwater‐fed streams...

Motivation: Dispersal is an essential process in population and community dynamics but is difficult to measure in the field. In freshwater systems, relevant information on the dispersal of many taxa remains scattered or unpublished, and biological traits related to organisms morphology, life history and behaviour offer useful dispersal proxies. We...

Intermittent rivers and ephemeral streams (IRES) may represent over half the global stream network, but their contribution to respiration and carbon dioxide (CO2) emissions is largely undetermined. In particular, little is known about the variability and drivers of respiration in IRES sediments upon rewetting, which could result in large pulses of...

Drying disturbances are the primary determinant of aquatic community biodiversity in dynamic river ecosystems. Research exploring how communities respond to disturbance has focused on benthic invertebrates in surface sediments, inadequately representing a connected community that extends into the subsurface. We compared subsurface and benthic inver...

Temporary streams are becoming increasingly common, but ecological responses to streambed drying are poorly characterized in the temperate continental region of central Europe. In addition, global research has focused on community responses to drying, whereas effects on individual populations remain unknown. We explored the population structure of...

Many river networks include temporary reaches that stop flowing and may dry during unpredictable droughts (near-perennial) or more frequently (intermittent). A few biological indices have been developed to assess invertebrate community responses to hydrological variability, including the instream conditions associated with drought, but their perfor...

Intermittently freezing and drying lotic systems are common in many parts of the world. These ecosystems provide dynamic habitats for biota, as both freezing and drying processes result in the loss of water flow along stream and river channels. However, research into the ecological effects of intermittent freezing on stream biota has remained relat...

Intermittent streams occur across global regions, and are increasingly recognized to support high biodiversity and perform important ecological roles within catchments. New tools are needed to better characterize biotic responses to the full spectrum of environmental conditions that occur in these dynamic systems, because the biological indices dev...

Many streams in the extensive Central European region have an intermittent flow regime. Conventional hydrological methods used to identify zero-flow conditions, and in particular drying events, have limited use when assessing large areas dominated by low-order streams. We developed a novel multimetric index to recognise antecedent stream drying bas...

Temporary streams constitute a significant proportion of rivers globally and are common in wet, cool, temperate regions. These heterogeneous ecosystems harbour high biodiversity associated with the dynamic turnover of taxa. Despite flow permanence being widely recognised as an important environmental control, few studies have characterised biotic r...

Temporary rivers (TRs) are prevalent, biodiverse ecosystems yet often overlooked and underprotected. This may be because inadequate understanding of their ecosystem services leaves them undervalued by society. However, evidence of negative attitudes towards TRs is scant. We investigated the strength and extent of negative attitudes by surveying und...

Climate change and human pressures are changing the global distribution and extent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (preconditioning), and peri...

Intermittent rivers and ephemeral streams (IRES) are dynamic ecosystems that shift between aquatic and terrestrial states. IRES are widespread, abundant and increasing in extent, but developing biomonitoring programmes to determine their ecological quality is challenging. To date, quality assessments have focused on the aquatic organisms present du...

Field studies have demonstrated that benthic fauna use hyporheic sediments during drying events in temporary rivers, but the factors influencing the survival of fauna in subsurface sediments remain poorly quantified. Laboratory mesocosm experiments were conducted to determine how the length of drying events (1, 7, 14 and 21 days) influenced the sur...

Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES),which sometimes cease to flow and can dry completely, is largely ignored although theymay represent over half the global river network. Substantial amounts of terrestrialplant...

In the version of this Article originally published, the affiliation for M. I. Arce was incorrect; it should have been: ⁵Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany. This has now been corrected in the online versions of the Article.

Intermittent rivers, which experience periods of flow cessation and streambed drying, occur globally. Given that the frequency and duration of stream drying events is likely to increase as a result of anthropogenic pressures and global climate change, riverbed sediments may become increasingly important as refuge habitat for benthic macroinvertebra...

Perennial rivers and streams make a disproportionate contribution to global carbon (C) cycling. However, the contribution of intermittent rivers and ephemeral streams (IRES), which sometimes cease to flow and can dry completely, is largely ignored although they may represent over half the global river network. Substantial amounts of terrestrial pla...

Intermittent rivers and ephemeral streams (IRES) support diverse and sometimes distinctive aquatic invertebrate communities. Although flow intermittence has been linked to reduced taxa richness, the highly variable environmental conditions that characterize IRES can enhance both taxonomic and functional diversity, with different invertebrates chara...

Intermittent rivers and ephemeral streams (IRES) are temporally and spatially dynamic ecosystems, experiencing alternating wet and dry phases and supporting both aquatic and terrestrial habitats. For aquatic species to persist in these variable habitats, they must be resistant or resilient to disturbances such as flow cessation and drying. Resistan...

Intermittent rivers and ephemeral streams (IRES) are common across Europe and dominate some Mediterranean river networks. In all climate zones, IRES support high biodiversity and provide ecosystem services. As dynamic ecosystems that transition between flowing, pool, and dry states, IRES are typically poorly represented in biomonitoring programmes...