Matthew F Johnson

• BSc; MSc; PhD
• Lecturer at University of Nottingham

Rising water temperature (Tw) due to anthropogenic climate change may have serious consequences for river ecosystems. Conservation and/or expansion of riparian shade could counter warming and buy time for ecosystems to adapt. However, sensitivity of river reaches to direct solar radiation is highly heterogeneous in space and time, so benefits of sh...

Animals make decisions based on the sensory information that they obtain from the environment and other organisms within that environment. In a river, this information is transported, transmitted, masked, and filtered by fluvial factors and processes, such as relative roughness and turbulent flow. By interpreting the resultant signals, animals deci...

Physical modelling is a key tool for generating understanding of the complex interactions between aquatic organisms and hydraulics, which is important for management of aquatic environments under environmental change and our ability to exploit ecosystem services. Many aspects of this field remain poorly understood and the use of physical models wit...

There is growing acknowledgement of the interaction between animals and the river bed on which they live and the implications of biological activity for geomorphic processes. It has been observed that signal crayfish (Pacifastacus leniusculus) disturb gravel substrates, potentially promoting sediment transport and impacting ecological communities....

We examined the impact of Hydropsychidae caddisfly larvae on the incipient motion of two sizes of narrowly graded fine-gravel (4–6 and 6–8 mm). This impact was assessed relative to the collective impact of other abiotic and biotic processes that are potentially important conditioning agents of fine-gravels. Trays of gravel were placed in the River...

An understanding of the spatiotemporal behaviour of Meteorological drought (MD) and Hydrological drought (HD) is crucial for analysing how drought propagation occurs. Here, drought events were treated as three-dimensional grid structures spanning space (latitude and longitude) and time. 31 years (1971–2001) of global MD and HD events were analysed...

The collective influence of animals on the processes shaping the Earth’s surface remains largely unknown, with most studies limited to individual species and well-known exemplars. To establish the global geomorphic significance of animals, we systematically reviewed and synthesized evidence across freshwater and terrestrial ecosystems. Over 600 ani...

The Pantanal wetland ecosystem of Brazil is experiencing unprecedented local challenges from anthropogenic pressures, as well as from global climate change. These pressures escalate the zoonotic risks from wildlife populations, whose own susceptibility to disease is enhanced by stressors including habitat loss and fragmentation with the resulting d...

Bisphenol A (BPA) is a high-production-volume plastic chemical, with ∼98% of its usage in China allocated to producing polycarbonate and epoxy resin, and its fugitive release threatens ecosystems. However, knowledge of its anthropogenic cycles, environmental emissions, and ecological risks remains incomplete, hindering effective plastic lifecycle m...

Lateral connectivity between rivers and terrestrial landscapes is critical for both river and landscape health. Due to widespread anthropogenic degradation of riverscapes, river management is aiming to connect rivers to floodplains, riparian zones, and wetlands, putting a spotlight on lateral connectivity. However, there is currently no consensus o...

Trace metal pollution is globally widespread, largely resulting from human activities. Due to the persistence and high toxicity of trace metals, these pollutants can have serious effects across ecosystems. However, few studies have directly assessed the presence and impact of trace metal pollution across ecosystems, specifically across multiple env...

Nature-based solutions (NbS), including China's Sponge City Program (SCP), can address the challenges urban communities face due to surface runoff and flooding. The current capacity of SCP facilities in urban environments falls short of meeting the demands placed on communities by climate change. Bioswales are a form of SCP facility that plays an i...

River channels, riparian and floodplain forms and dynamics are all influenced strongly by biological processes. However, the influence of macroinvertebrates on entrainment and transport of river sediments remains poorly understood. We use an energy‐based approach to explore the capacity of benthic animals to move surficial, gravel‐bed particles in...

Streams systems draining upland landscapes provide valuable ecosystem services, but they are vulnerable to incision and channelization caused by anthropogenic disturbance. Restoring a degraded stream to its pre‐disturbance condition by reconnecting the channel to its historical floodplain aims to recover lost hydro‐morphological processes and funct...

Rising water temperatures in rivers due to climate change are already having observable impacts on river ecosystems. Warming water has both direct and indirect impacts on aquatic life, and further aggravates pervasive issues such as eutrophication, pollution, and the spread of disease. Animals can survive higher temperatures through physiological a...

The need to reconcile food production, the safeguarding of nature, and the protection of public health is imperative in a world of continuing global change, particularly in the context of risks of emerging zoonotic disease (EZD). In this paper, we explored potential land use strategies to reduce EZD risks using a landscape approach. We focused on s...

Roadside green swales have emerged as popular stormwater management infrastructure in urban areas, serving to mitigate stormwater pollution and reduce urban surface water discharge. However, there is a limited understanding of the various types, structures, and functions of swales, as well as the potential challenges they may face in the future. In...

Understanding the links between environmental and wildlife elemental concentrations is key to help assess ecosystem functions and the potential effects of legacy pollutants. In this study, livers from 448 European badgers (Meles meles) collected across the English Midlands were used to investigate the relationship between elemental concentrations i...

Landscapes and ecosystems are the result of two-way interactions between hydro-geomorphic and biological processes. Many animals, particularly those that build structures or transport sediment, are important biogeomorphic agents. Glossosomatidae caddisfly larvae (Insecta, Trichoptera) are globally widespread and abundant inhabitants of gravel-bed r...

Microplastic contamination in the sediment of marine bays has attracted widespread attention, whereas the distribution, sedimentation, morphology and risk of microplastics at regional scale remain poorly understood. By introducing a data mining framework into microplastic research, we compiled a microplastic dataset of 649 samples from 24 bays to e...

Flooding of the town of Forres, Scotland prompted the implementation of a flood alleviation scheme (FAS) featuring a low earth‐fill dam constructed upstream of the town to create a flood retention area, limiting peak discharges entering the urban area. Flow through the dam is controlled by a weir, and it was recognised that if coarse sediment, larg...

Background Historically, wildfire regimes produced important landscape‐scale disturbances in many regions globally. The “pyrodiversity begets biodiversity” hypothesis suggests that wildfires that generate temporally and spatially heterogeneous mosaics of wildfire severity and post‐burn recovery enhance biodiversity at landscape scales. However, riv...

Microplastics are the newly identified pollutant of this century, yet they are already detected everywhere worldwide. Microplastic pollution in global marine environments has been intensively reported. Evidence of microplastic pollution is emerging in other environments, including land, freshwater, atmosphere, and organisms. Public concerns were al...

Microplastics are one of the most well-known types of environmental pollution. A microplastic is any piece of plastic smaller than 5 mm (about the size of one of the circles on top of a Lego ® block). Microplastics come in a variety of shapes and they can be eaten by even the smallest animals, blocking their stomachs and intestines. Many of the clo...

Lead pollution from metalliferous mines can have major environmental and health effects long after the mines have closed. Animals living near derelict mine sites can inadvertently ingest lead-contaminated soils, causing them to accumulate lead and potentially experience significant adverse health effects. Human food products, such as eggs, produced...

Anthropogenic Litter (AL) is ubiquitous in distribution and diverse in type and impact. Citizen science AL clean-ups engage citizens with the environment and have the potential to generate data that can inform policy. Here we present a detailed citizen science survey of AL across freshwater, terrestrial, and coastal environments of the United King...

Although global- and catchment-scale hydrological models are often shown to accurately simulate long-term runoff time-series, far less is known about their suitability for capturing hydrological extremes, such as droughts. Here we evaluated simulations of hydrological droughts from nine catchment scale hydrological models (CHMs) and eight global sc...

The importance of two‐way interactions between animals and the physical hydraulic and sedimentological environment are increasingly recognized (e.g., zoogeomorphology). Caddisflies (Trichoptera) are a group of aquatic insects known for their bioconstructions, particularly cases built from fine sediment and silk. Caddisfly cases differ in size, shap...

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Nature-based solutions are widely advocated for freshwater ecosystem conservation and restoration. As increasing amounts of river restoration are undertaken, the need to understand the ecological response to different measures and where measures are best applied becomes more pressing. It is essential that appraisal methods follow a sound scientific...

Microplastics are being widely discussed as an emerging global environmental contaminant. Microplastic pollution usually originates from land-based sources, which are then mainly transported through hydrological and atmospheric pathways and accumulated in terrestrial, freshwater and marine ecosystems. Urban environments represent a condensed area o...

Urban flooding is a key global challenge which is expected to become exacerbated under global change due to more intense rainfall and flashier runoff regimes over increasingly urban landscapes. Consequently, many cities are rethinking their approach to flood risk management by using green infrastructure (GI) solutions to reverse the legacy of hard...

Invertebrates are the most diverse and abundant organisms on the planet. The importance of invertebrates as sediment engineers has been recognised for many decades. However, research has primarily been concerned with terrestrial, lentic or marine systems. We understand very little about the potential importance of invertebrates to fluvial geomorpho...

Natural Flood Management (NFM) is now well established as a paradigm for reducing flood risk. It is characterised by adopting a catchment-wide hydrological perspective and implementing solutions that work with natural processes such as wetlands, riparian vegetation and river channel rehabilitation. However, despite substantial attention in the rive...

Although global- and catchment-scale hydrological models are often shown to accurately simulate long-term runoff time-series, far less is known about their suitability for capturing hydrological extremes, such as droughts. Here we evaluated runoff simulations from nine catchment scale hydrological models (CHMs) and eight global scale hydrological m...

As a consequence of accelerated and excessive use of pesticides in tropical regions, wilderness areas are under threat; this includes the Pantanal wetlands in the Upper Paraguay River Basin (UPRB). Using a Land Cover Land Use Change (LCLUC) modelling approach, we estimated the expected pesticide load in the Pantanal and the surrounding highlands re...

Microplastic pollution of freshwaters is known to be a great concern in China and these pollutants can be discharged into the coastal environment through fluvial processes, posing threats to the global marine ecosystem. This paper reviewed the literature measuring microplastic pollution in the Chinese freshwater environment and found that microfibr...

Mismanaged plastic waste poses a complex threat to the environments that it contaminates, generating considerable concern from academia, industry, politicians, and the general public. This concern has driven global action that presents a unique opportunity for widespread environmental engagement beyond the immediate problem of the persistence of pl...

• Anthropogenic litter (solid manufactured waste) is an understudied but pervasive element of river systems worldwide. Its physical structure generally differs from natural substrates, such as gravel and cobbles (hereafter rocks). Consequently, anthropogenic litter could influence ecological communities in urban rivers by providing novel habitats....

Microplastic pollution is an emerging threat to global freshwater ecological security. The emission and discharge of microplastic pollutants is highly associated with human activities and, therefore, cities are particularly at risk of microplastic pollution because they are a concentrated zone of plastic industry and use. Urban rivers may also be s...

Water temperature (Tw) is a primary determinant of river ecosystem health and function that is strongly controlled by climate variability and change but mediated by catchment properties. We apply a nested analysis to: (1) evaluate how annual and seasonal mean Tw varied across England during the period 2000–2018; (2) assess the extent to which these...

Climate change and invasive species are among the biggest threats to global biodiversity and ecosystem function. Although the individual impacts of climate change and invasive species are commonly assessed, we know far less about how a changing climate may impact invading species. Increases in water temperature due to climate change are likely to a...

Freshwater systems are vitally important, supporting diversity and providing a range of ecosystem services. In China, rapid urbanization (over 800 million urban population) has led to multiple anthropogenic pressures that threaten urban freshwater environments. Microplastics (<5 mm) result from intensive production and use of plastic materials, but...

Dredging is a globally important aquatic system management activity, used for navigation improvement, contamination removal, aggregate production and/or flood risk mitigation. Despite widespread application, understanding of the environmental effects of some dredging types remains limited. Field campaigns in 2016 and 2017 in the River Parrett estua...

Plastic pollution represents one of the most salient indicators of society's impact on the environment. The microplastic component of this is ubiquitous, however, microplastic studies are seldom representative of the locations they sample. Over 12 months we explored spatiotemporal variation in microplastic prevalence across a freshwater system and...

Nutrient enrichment represents one of the most important causes of detriment to river ecosystem health globally. Monitoring nutrient inputs can be particularly challenging given the spatial and temporal heterogeneity of nitrogen and phosphorus concentrations and the indirect and often lagged effects on instream communities. The objective of this pa...

The presence of microplastic particles (<5 mm) in the environment has generated considerable concern across public, political, and scientific platforms. However, the diversity of microplastics that persist in the environment poses complex analytical challenges for our understanding of their prevalence. The use of the dye Nile red to quantify microp...

River management based solely on physical science has proven to be unsustainable and unsuccessful, evidenced by the fact that the problems this approach intended to solve (e.g., flood hazards, water scarcity, and channel instability) have not been solved and long‐term deterioration in river environments has reduced the capacity of rivers to continu...

The complex surface topography of river substrates controls near‐bed hydraulics and drives the exchange of subsurface and surface flow. In rivers, the topographic structures that are studied are usually formed by the flow, but it is known that many animals also create biogenic bedforms, such as pits and mounds. Here, a large‐eddy simulation model o...

Caddisfly (Trichoptera) larvae are an abundant and widespread aquatic insect group characterised by the construction of silk structures, including nets and cases. Case‐building caddisfly have the potential to modify the sorting and mobility of sand and fine gravel via; 1) case construction, resulting in altered sediment properties; 2) transporting...

Observed and simulated hydrological drought events were identified using the Standardised Runoff Index (SRI) and were classified based on intensity. It is one of the most used drought index. SRI is based on long-term runoff records that are fitted to a probability distribution. This distribution is then transformed to a normal distribution, ensurin...

The potential role of natural textile fibres as environmental pollutants has been speculated upon by some environmental scientists, however, there is a general consensus that their biodegradability reduces their environmental threat. Whilst the risks that they pose remain poorly understood, their environmental prevalence has been noted in several r...

The Somerset Levels (‘The Levels’ hereafter) are a low-lying and flood-prone agricultural landscape in South West England. The rivers, rhynes and ditches of The Levels are heavily managed for navigation and flood relief purposes and there is a legacy of dredging, typically excavation (using large mechanical digging / dredging apparatus), to help mi...

There is growing recognition that manipulation of sediments by animals can have significant consequences for river geomorphology and ecosystem functioning, but the biogeomorphic effects of aquatic invertebrates remain poorly understood. Caddisfly (Trichoptera) are a widespread, abundant and diverse group of aquatic insects, many of which construct...

The ecological effects of interacting stressors within lotic ecosystems have been widely acknowledged. In particular, the ecological effects of elevated fine sediment inputs and phosphate have been identified as key factors influencing faunal community structure and composition. However, while knowledge regarding adult and larval life stage respons...

Aquatic macroinvertebrates have been the basis for one of the primary indicators and a cornerstone of lotic biomonitoring for over 40 years. Despite the widespread use of lotic invertebrates in statutory biomonitoring networks, scientific research and citizen science projects, the sampling methodologies employed frequently vary between studies. Rou...

Sound water policy and management rests on sound hydrometeorological and ecological data. Conversely, unrepresentative, poorly collected, or erroneously archived data introduce uncertainty regarding the magnitude, rate, and direction of environmental change, in addition to undermining confidence in decision‐making processes. Unfortunately, data bia...

Sediment transport is regarded as an abiotic process driven by geophysical energy, but zoogeomorphological activity indicates that biological energy can also fuel sediment movements. It is therefore prudent to measure the contribution that biota make to sediment transport, but comparisons of abiotic and biotic sediment flux are rare. For a stream i...

River flow and water temperature are fundamental controls of freshwater ecosystems. Hence, future warming could impact valued habitats and species, particularly those with cold water preferences (such as salmonids). Warming could also exacerbate existing environmental pressures or diminish the effectiveness of management interventions. Climate mode...

1. Rising water temperatures under climate change are expected to affect the phenology of aquatic insects, including the mayfly E phemera danica M üller which is widespread throughout E urope. 2. To assess temporal and spatial variability in mayfly emergence, E . danica were monitored at two thermally contrasting reaches in the R iver D ove, E ngli...

The role of biotic forcing in fluvial geomorphology is understudied. This paper investigates the suggestion that the activities of signal crayfish (Pacifastacus leniusculus) can increase suspended sediment fluxes in rivers. Previous field work, supported by mesocosm experiments, suggests that crayfish nocturnalism can cause night time increases in...

Nocturnal water temperature (Tw) affects the behaviour of aquatic biota and metabolism of whole rivers. However, night-time water temperature (nTw) is poorly understood because spot samples are typically taken during daylight hours, or Tw series are aggregated in ways that mask sub-daily properties. This paper examines 15-minute measurements of Tw...

Invertebrate animals have an important and complex role in altering the physical and biochemical environment of marine and freshwater sediments. A database has been compiled which aims to include all published articles that consider how macroinvertebrates alter aquatic systems. The database contains 2300 entries spanning over 120 years of study and...

Signal crayfish (Pacifastacus leniusculus) are an invasive species of global significance because of their detrimental impacts on freshwater environments and native organisms. The movement of signal crayfish was continuously monitored for 150-days through a 20-m reach of an alluvial stream in the UK. Passive integrated transponder-tags were attache...

When investigating or quantifying the interaction of organisms with the hydrodynamic environment, it is often necessary or desired to use surrogates instead of the prototype organisms. In order not to derogate the results, it is important to design surrogates to represent the essential properties of the prototype organism correctly. To do so, sever...

Temperature sensors are potentially susceptible to errors due to heating by solar radiation. Although this is well known for air temperature (Ta), significance to continuous water temperature (Tw) monitoring is relatively untested. This paper assesses radiative errors by comparing measurements of exposed and shielded Tinytag sensors under indirect...

Water temperature (Tw) is a key determinant of freshwater ecosystem status and cause for concern under a changing climate. Hence, there is growing interest in the feasibility of moderating rising Tw through management of riparian shade. The Loughborough University Temperature Network (LUTEN) is an array of 36 water and air temperature (Ta) monitori...

The signal crayfish (Pacifasticus leniusculus) is a formidable invasive species that has had a deleterious impact on native freshwater fauna across Europe. We contend that the impact of this animal extends beyond ecology into geomorphology and hypothesise that crayfish are significant agents of fine sediment recruitment and mobilisation, with poten...

Deeper consideration of the meaning and relevance of habitat is necessary and inevitable as interdisciplinary river science reveals the interactive nature of the relation between fluvial environments and the organisms that live in them. Following some embellishment of Lapointe's critique of ‘habitat’ we illustrate this interaction by reviewing the...

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Sediment quantity and quality are key considerations in the sustainable management of fluvial systems. Increasing attention is being paid to the role of aquatic biota as geomorphic agents, capable of altering the composition, mobilization and transport of fluvial sediments at various spatiotemporal scales. In this paper invasive species are present...

The impact of signal crayfish (Pacifastacus leniusculus) on the topography and fabric of six narrowly graded, gravel substrates was investigated using repeat laser scanning of sediment surfaces in still-water aquaria. Digital Elevation Models (DEMs) of the gravel surfaces were obtained before and after exposure to crayfish for five predetermined pe...

The reworking of substrates by organisms, termed bioturbation, is considered a fundamental processes in marine and terrestrial environments but has remained relatively unstudied in fluvial environments. This studies looks at the bioturbation of fluvial gravel substrates by signal crayfish, an internationally important invasive species. We investiga...

A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University. Signal crayfish are an internationally widespread invasive species that can have important detrimental ecological impacts. This thesis aims to determine whether signal crayfish have the potential to also impact t...