Richard G Pearson

Richard G Pearson
James Cook University · School of Marine & Tropical Biology

BSc, PhD

About

196
Publications
47,257
Reads
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7,048
Citations
Additional affiliations
February 1974 - April 2021
James Cook University
Position
  • various
Description
  • Head of School (tropical biology), freshwater centre director, currently professor emeritus

Publications

Publications (196)
Article
The critical role of hydrology in tropical floodplain river systems is well established, but there is limited information on the drivers of larval and juvenile recruitment of freshwater fishes in small tropical rivers. Herein we describe the patterns of occurrence and abundance of fish larvae, juveniles and adults in the lower reaches of a short, d...
Article
We argue for improved conservation of freshwater ecosystems at catchment or eco-regional scales by explicit assignment of values to all river sections and wetlands, recognising current disturbance, and aiming for ‘no further harm’ to the commons. The need is indicated by the global deterioration of biodiversity and ecosystem services of rivers and...
Article
Full-text available
Leaf litter decomposition is a key process in stream ecosystems, the rates of which can vary with changes in litter quality or its colonization by microorganisms. Decomposition in streams is increasingly used to compare ecosystem functioning globally, often requiring the distribution of litter across countries. It is important to understand whether...
Article
There is limited published information on the impact of bathing on stream water quality and ecology, except on human pathogens and health. We investigated the relationships between environmental quality of streams and recreational activity at five sites in the Australian Wet Tropics. The streams normally had very low concentrations of nutrients and...
Chapter
Full-text available
Understanding ecological patterns and processes at the global scale is becoming increasingly important in view of the rapid pace of environmental change and consequent impacts on ecosystems. This chapter reviews current knowledge about how plant litter decomposition—a key stream ecosystem process—and its major biotic and abiotic drivers vary global...
Chapter
Terrestrial litter that decomposes in streams is critical to carbon and nutrient fluxes and aquatic food web dynamics. Litter dynamics is influenced by biogeochemical, morphological, environmental and climatic factors, making it challenging to understand how these factors relate to each other and to litter decomposition across different spatial sca...
Article
Full-text available
The relationship between detritivore diversity and decomposition can provide information on how biogeochemical cycles are affected by ongoing rates of extinction, but such evidence has come mostly from local studies and microcosm experiments. We conducted a globally distributed experiment (38 streams across 23 countries in 6 continents) using stand...
Article
We review the literature on the ecology, connectivity, human impacts and management of freshwater and estuarine systems in the Great Barrier Reef catchment (424,000 km²), on the Australian east coast. The catchment has high biodiversity, with substantial endemicity (e.g., lungfish). Freshwater and estuarine ecosystems are closely linked to the land...
Article
Full-text available
Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low a...
Article
Full-text available
Running waters contribute substantially to global carbon fluxes through decomposition of terrestrial plant litter by aquatic microorganisms and detritivores. Diversity of this litter may influence instream decomposition globally in ways that are not yet understood. We investigated latitudinal differences in decomposition of litter mixtures of low a...
Article
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The relationship between productivity and diversity is controversial because of disparity between unimodal and monotonic patterns, especially when occurring simultaneously at different scales. We used stream-side artificial channels to investigate how the availability of a major resource (leaf litter) affected stream invertebrate abundance and dive...
Article
• 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...
Chapter
Many stream invertebrates consume substantial amounts of plant litter at some time during their life cycle and thus play a key role in plant litter decomposition. These litter-consuming invertebrates include mainly shredders, a functional feeding group defined by their ability to shred litter, but also some scrapers, leaf miners, wood borers, and g...
Article
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Headwater streams drain large proportions of landscapes and represent a large proportion of stream habitat. Understanding their ecology requires more comparative data from the smallest streams. We describe dynamics of benthic organic material (BOM) and invertebrate assemblages in an order-2 Australian tropical stream and compare samples from orders...
Article
There is limited information available on the ecology of planktonic invertebrate assemblages of small tropical lowland rivers, despite zooplankton being a vital resource for larval fish. Herein we describe the spatial patterns and temporal dynamics of invertebrate zooplankton at 8 locations over a 25-month period in the lowland section of a short c...
Article
Waterholes that remain in the dry season in intermittent dryland rivers are important biotic refugia, but detailed ecological descriptions of these habitats and their plankton are scarce. We aimed to determine spatial and temporal variation in phytoplankton assemblages in a tropical Australian dryland river system, their main environmental determin...
Article
Full-text available
Streams draining forested landscapes are fuelled by terrestrial plant litter, which can be transported downstream or retained and broken down locally. However, fluxes of plant litter in streams can vary at multiple spatio‐temporal scales, affecting the availability of this key resource in heterotrophic stream food webs. To explore this question we...
Article
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We identified influences of land-use disturbances on invertebrate assemblages in streams draining eight areas of the Great Barrier Reef catchment in tropical Australia (,15.7-228S), a region of high biodiversity. We used distance-based linear modelling (DistLM) to analyse assemblage data (103 taxa), richness and the SIGNAL2 taxon sensitivity index....
Article
Quantifying the influence of biodiversity on ecosystem function is an increasingly important goal as biodiversity declines. Tadpoles can be important contributors to ecosystem processes in streams, so amphibian declines over recent decades may have far-reaching ecosystem effects. We, therefore, used artificial channels located near an Australian ra...
Article
Full-text available
The seasonal dynamics of leaf litter and associated consumers (“shredders”) in tropical streams are not well documented. We investigated the occurrence of litter (density and age composition) and shredders through late dry, wet and early dry seasons in an Australian rainforest stream. Leaf litter packs of varying density and leaf age covered most o...
Article
• Understanding of the ecology of stream assemblages is enhanced by quantifying colonisation and dispersal rates, but these are difficult to measure at small scales. Using field‐located artificial streams that mirrored natural patches of habitat, we investigated immigration, emigration and stability of invertebrates on leaf‐litter packs over 38 day...
Article
Full-text available
1. Understanding how biodiversity loss influences plant litter decomposition – i.e., the biologically mediated conversion of coarse to fine particulate organic matter – is crucial to predict changes in the functioning of many stream ecosystems, where detrital food webs are dominant. Rates of litter decomposition are influenced by detritivore divers...
Article
While flow regime is widely recognised as an over‐arching feature structuring aquatic ecosystems, the influence of flood events on feeding habits in fish assemblages inhabiting variable environments remains largely unknown. In this study, we investigated how diets of a fish assemblage changed in response to fluctuations in hydrology in a highly var...
Article
Full-text available
Despite much research on the influence of disturbance on stream macroinvertebrates, comparative information on tropical streams is limited. We assessed disturbance influence on assemblages under different conditions of hydrology (aseasonal and seasonal) and hydraulics (pools, riffles and stream morphology) by sampling a stream in the Australian Wet...
Article
Hypoxia can have profound sublethal effects on reproduction and embryonic development of some freshwater fish. In the present study, the effects of diel fluctuating hypoxia on embryo viability were investigated for the eastern rainbowfish Melanotaenia splendida splendida, a small-bodied species common in wetlands of tropical Queensland. After daily...
Article
Full-text available
We identified influences of land-use disturbances on invertebrate assemblages in streams draining eight areas of the Great Barrier Reef catchment in tropical Australia (∼15.7-22°S), a region of high biodiversity. We used distance-based linear modelling (DistLM) to analyse assemblage data (103 taxa), richness and the SIGNAL2 taxon sensitivity index....
Article
Full-text available
Plant litter represents a major basal resource in streams, where its decomposition is partly regulated by litter traits. Litter-trait variation may determine the latitudinal gradient in decomposition in streams, which is mainly microbial in the tropics and detritivore-mediated at high latitudes. However, this hypothesis remains untested, as we lack...
Article
Tadpoles can be abundant consumers in stream ecosystems, and may influence the structure and function of streams through their feeding activities and interactions with other organisms. To understand the contribution of tadpoles to stream functioning, and the potential impact of their loss, it is necessary to determine their diets and how they might...
Article
Full-text available
We are facing major biodiversity loss and there is evidence that such loss can alter ecosystem functioning. However, the effects of plant diversity on decomposition – a key component of the global carbon cycle – are still unclear. A recent study suggested that a plant trait – their nitrogen (N)-fixing capacity – could mediate effects of litter dive...
Article
Full-text available
Bryophytes are known to provide habitat and refugia for stream invertebrates, but there are few reports documenting use of bryophytes in tropical streams. We investigated invertebrate assemblages in moss in pools, runs and riffles from wet to dry seasons in tropical Australian streams. We investigated assemblage dynamics, responses to disturbance,...
Article
Understanding spatial and environmental drivers of undisturbed stream assemblages is important for separating natural and human-induced changes, but has rarely been attempted for an entire tropical bioregion. We sampled riffle macroinvertebrate assemblages and measured associated biophysical variables in post-wet and dry seasons from 68 streams of...
Article
Full-text available
Climate change threatens biodiversity in all ecosystems, and major shifts in species distributions are expected. Freshwater ecosystems are considered particularly vulnerable due to the ectothermic physiology of most freshwater species and their limited habitat extent and capacity to track climate trends. In this study, we examined what broad patter...
Article
Waterholes in intermittent dryland rivers are important biotic refugia, but detailed water-quality descriptions of these habitats are rare. Their possible variability in water quality, due to variable flow regimes, may impede development of appropriate water-quality guidelines. We investigated this issue by describing spatial and temporal variation...
Article
Hypoxia can profoundly affect fish reproduction and larval development, but its effects on fish from tropical Australia are not well understood. In the present study, the effects of diel fluctuating hypoxia on reproduction and embryo viability were investigated for a range-limited tropical freshwater fish, namely the Utchee Creek rainbowfish (Melan...
Article
Individual ecological studies, although suitable for testing hypotheses and developing theory, provide site-or region-specific information that is difficult to extrapolate to provide broad generalizations. Today, emerging globally relevant questions (e.g., climate change, biodiversity loss, invasive species or habitat degradation) require a reconsi...
Article
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There are few studies of the ecology of waterfalls despite their being prominent landscape features and of ecological interest because of their physical characteristics. We compared invertebrate assemblages of 5 waterfalls in the Australian Wet Tropics over 12–18 mo. Waterfall assemblages were distinct from those of riffles and bedrock, with some t...
Article
The Great Barrier Reef (GBR) is a World Heritage site off the north-eastern coast of Australia. The GBR is worth A$ 15-20 billion/year to the Australian economy and provides approximately 64,000 full time jobs. Many of the species and ecosystems of the GBR are in poor condition and continue to decline. The principal causes of the decline are catchm...
Article
Plant litter breakdown is a key ecological process in terrestrial and freshwater ecosystems. Streams and rivers, in particular, contribute substantially to global carbon fluxes. However, there is little information available on the relative roles of different drivers of plant litter breakdown in fresh waters, particularly at large scales. We presen...
Article
Separation of natural and anthropogenic influences is required to identify land-use impacts on stream ecosystems. We investigated the effects of water quality and riparian condition on invertebrate assemblages along streams draining agricultural land by partitioning out changes in geomorphological characteristics. There was a strong negative relati...
Article
Adequate conceptual frameworks that link land use to water quality and ecosystem health are lacking for tropical and subtropical freshwater systems, so we review here extensive water-quality research undertaken in the Great Barrier Reef catchment area (GBRCA) and present conceptual models synthesising the dynamics of agricultural pollutants and the...
Article
Floodplain lagoons in the Queensland Wet Tropics bioregion, Australia, are important and threatened habitats for fish. As part of studies to assess their ecological condition and functions, we examined patterns of occurrence of fish larvae, juveniles and adults in 10 permanent lagoons on the Tully–Murray floodplain. Lagoons contained early life-his...
Chapter
The Australian Wet Tropics biogeographic region is known for its ancient World Heritage rainforests and its proximity to the Great Barrier Reef. It includes ancient mountains and floodplains, and diverse wetlands that support high biodiversity and have important socio-economic and ecological values. Aboriginal people have maintained strong cultural...
Chapter
The Australian Wet Tropics biogeographic region is known for its ancient World Heritage rainforests and its proximity to the Great Barrier Reef. It includes ancient mountains and floodplains, and diverse wetlands that support high biodiversity and have important socio-economic and ecological values. Aboriginal people have maintained strong cultural...
Chapter
We monitored the invertebrate community of leaf litter in and around a drying intermittent pool bed to explore patterns of ecological organisation across a complex environmental gradient, with particular focus on population and community size structure. We measured the body size of 24,609 individuals from 313 taxa ranging over 6 orders of magnitude...
Article
We measured water quality along four Australian tropical streams in two catchments with similar agricultural development (mainly sugarcane growing) but contrasting riparian vegetation (intact native rainforest vs. exotic weeds). There were strong gradients in water quality and consistent differences between streams. The most significant pattern was...
Article
Many forested headwater streams are heterotrophic ecosystems in which allochthonous inputs of plant litter are a major source of energy. Leaves of riparian vegetation entering the stream are broken down by a combination of biotic and abiotic processes and, in most temperate and boreal streams, provide food and habitat for dense populations of detri...
Article
Full-text available
We described invertebrate assemblage composition over a range of spatial and temporal scales in the Burdekin River, one of northern Australia’s large and variable dry-tropical river systems. Invertebrates were abundant but not diverse, and the assemblage structure exhibited considerable variability in space and time. Substratum and historical flow...
Article
Global studies of streams are needed to develop general ecosystem and management models. We reviewed research that tested ecological models in streams of the Queensland Wet Tropics bioregion (QWT), which makes up 0.26% of Australia but supports distinctive and high biodiversity, most of which is of Gondwanan or marine origin. QWT streams have seaso...
Article
Understanding what mechanisms shape the diversity and composition of biological assemblages across broad-scale gradients is central to ecology. Litter-consuming detritivorous invertebrates in streams show an unusual diversity gradient, with α-diversity increasing towards high latitudes but no trend in γ-diversity. We hypothesized this pattern to be...
Article
Full-text available
Remnant habitat patches in agricultural landscapes can contribute substantially to wildlife conservation. Understanding the main habitat variables that influence wildlife is important if these remnants are to be appropriately managed. We investigated relationships between the bird assemblages and characteristics of remnant riparian forest at 27 sit...
Article
Full-text available
Hypoxia in freshwater ecosystems of the Australian wet tropics occurs naturally, but is increasing as a result of anthropogenic influences. Diel cycling of dissolved oxygen (DO) concentration (fluctuating hypoxia) is common in the region. Laboratory experiments sought to identify relationships between severity of fluctuating hypoxia and sublethal e...
Article
Understanding what mechanisms shape the diversity and composition of biological assemblages across broad-scale gradients is central to ecology. Litter-consuming detritivorous invertebrates in streams show an unusual diversity gradient, with α-diversity increasing towards high latitudes but no trend in γ-diversity. We hypothesized this pattern to be...
Article
Regional studies of biotic communities are important for characterising their normal spatial and temporal variation, but there are few such studies of tropical streams. This paper describes changes in invertebrate communities in Yuccabine Creek, a seasonal upland rainforest stream in tropical Australia, over three-year and decadal periods. Inverteb...
Article
The ecological condition and biodiversity values of floodplain wetlands are highly dependent on the hydrological connectivity of wetlands to adjacent rivers. This paper describes a method for quantifying connectivity between floodplain wetlands and the main rivers in a wet tropical catchment of northern Australia. We used a one-dimensional hydrodyn...
Article
Full-text available
Recognition that intermittent pools are a single habitat phase of an intermittent pool bed that cycles between aquatic and terrestrial habitat greatly enhances their usefulness for addressing general questions in ecology. The aquatic phase has served as a model system in many ecological studies, because it has distinct habitat boundaries in space a...
Article
Full-text available
Using the Australian marine-freshwater terapontid fishes as a model system, we examined the role of dietary phenotypic optima in an adaptive macro-evolutionary landscape. Comparative modelling relying on both a priori and data-driven identification of selective regimes suggested multi-peak models as best describing much of the dietary phenotypic la...
Data
Data S1. Supplementary methods.
Article
Tropical floodplain wetlands are among the world's most threatened and poorly documented freshwater ecosystems. This paper describes patterns of fish diversity in remnant freshwater lagoons in relation to natural environmental gradients and impacts of agriculture in the Tully–Murray catchment, Queensland Wet Tropics bioregion (QWT), in north-easter...
Article
Full-text available
Kolby et al. (2014) reported the very recent arrival of Asian common toads (Duttaphrynus melanostictus) in Madagascar, most likely arriving inside shipping containers from Asia. The species’ relative, the cane toad (Rhinella marina), has caused widespread ecological destruction in Australia, and there is now concern that an invasion in Madagascar w...
Article
Over the past twelve years the number of papers that explore the impacts of climate change on biodiversity in the conservation literature has grown on average by 20% annually. By categorising these papers on their primary research questions, we show that the vast majority of these articles (88.6%) focus only on those impacts that arise directly as...