Publications
140 results found
Woodward G, Perkins DM, Brown LE, 2010, Climate change and freshwater ecosystems: impacts across multiple levels of organization, Philosophical Transactions of the Royal Society B: Biological Sciences, Vol: 365, Pages: 2093-2106, ISSN: 0962-8436
<jats:p>Fresh waters are particularly vulnerable to climate change because (i) many species within these fragmented habitats have limited abilities to disperse as the environment changes; (ii) water temperature and availability are climate-dependent; and (iii) many systems are already exposed to numerous anthropogenic stressors. Most climate change studies to date have focused on individuals or species populations, rather than the higher levels of organization (i.e. communities, food webs, ecosystems). We propose that an understanding of the connections between these different levels, which are all ultimately based on individuals, can help to develop a more coherent theoretical framework based on metabolic scaling, foraging theory and ecological stoichiometry, to predict the ecological consequences of climate change. For instance, individual basal metabolic rate scales with body size (which also constrains food web structure and dynamics) and temperature (which determines many ecosystem processes and key aspects of foraging behaviour). In addition, increasing atmospheric CO<jats:sub>2</jats:sub>is predicted to alter molar CNP ratios of detrital inputs, which could lead to profound shifts in the stoichiometry of elemental fluxes between consumers and resources at the base of the food web. The different components of climate change (e.g. temperature, hydrology and atmospheric composition) not only affect multiple levels of biological organization, but they may also interact with the many other stressors to which fresh waters are exposed, and future research needs to address these potentially important synergies.</jats:p>
WOODWARD GUY, DYBKJAER JOHNB, ÓLAFSSON JS, et al., 2010, Sentinel systems on the razor's edge: effects of warming on Arctic geothermal stream ecosystems, Global Change Biology, Vol: 16, Pages: 1979-1991, ISSN: 1354-1013
LARRAÑAGA A, LAYER K, BASAGUREN A, et al., 2010, Consumer body composition and community structure in a stream is altered by pH, Freshwater Biology, Vol: 55, Pages: 670-680, ISSN: 0046-5070
<jats:title>Summary</jats:title><jats:p>1. Low pH inhibits microbial conditioning of leaf‐litter, which forms the principal energy input to many headwater streams. This reduces food quality and availability for the shredder assemblage, thereby creating a potential bottleneck in the flux of energy and biomass through acidified food webs.</jats:p><jats:p>2. We explored the consequences of acidity on the well‐characterised community of Broadstone Stream in southeast England, by quantifying the physiological condition (protein and lipid content) of three dominant shredder species (<jats:italic>Leuctra nigra</jats:italic>,<jats:italic>L. hippopus</jats:italic>and<jats:italic>Nemurella pictetii</jats:italic>) and relating this to changes in the numerical abundance and biomass of invertebrates across a longitudinal pH gradient (5.3–6.5).</jats:p><jats:p>3. Total taxon richness increased with pH, as did shredder diversity. The acid‐tolerant stonefly,<jats:italic>L. nigra</jats:italic>, exhibited a positive correlation between pH and protein content, but its abundance was suppressed in the less acid reaches. These results suggest that the impacts of environmental stressors might be manifested differently at the population (i.e. numerical and biomass abundance) versus the physiological (i.e. protein content of individuals) levels of organisation. Body composition of<jats:italic>L. hippopus</jats:italic>and<jats:italic>N. pictetii</jats:italic>did not exhibit any significant relationship with stream pH in the field.</jats:p><jats:p>4. The survey data were corroborated with a laboratory rearing experiment using<jats:italic>N. pictetii</jats:italic>, in which survival rate, growth rate, and protein and lipid content of individuals were measured in stream water of differing pH and acid versus circumneutral microbial co
RAWCLIFFE R, SAYER CD, WOODWARD GUY, et al., 2010, Back to the future: using palaeolimnology to infer long‐term changes in shallow lake food webs, Freshwater Biology, Vol: 55, Pages: 600-613, ISSN: 0046-5070
<jats:title>Summary</jats:title><jats:p>1. Shallow lakes are often cited as classic examples of systems that exhibit trophic cascades but, whilst they provide good model systems with which to test general ecological theory and to assess long‐term community change, their food web linkages have rarely been resolved, so changes associated with the structure and dynamics of the ecological network as a whole are still poorly understood.</jats:p><jats:p>2. We sought to redress this, and to demonstrate the potential benefits of integrating palaeolimnological and contemporary data, by constructing highly resolved food webs and stable isotope derived measures of trophic interactions and niche space, for the extant communities of two shallow U.K. lakes from different positions along a gradient of eutrophication. The contemporary surface sediment cladoceran and submerged macrophyte assemblages in the less enriched site, Selbrigg Pond, matched the palaeolimnological assemblages of the more enriched site, Felbrigg Hall Lake, in its more pristine state during the 1920s. Thus, Selbrigg was a temporal analogue for Felbrigg, from which the consequences of long‐term eutrophication on food web structure could be inferred. These data represent the first steps towards reconstructing not only past assemblages (i.e. nodes within a food web), but also past interactions (i.e. links within a food web): a significant departure from much of the previous research in palaeolimnology.</jats:p><jats:p>3. The more eutrophic food web had far fewer nodes and links, and thus a less reticulate network, than was the case for the more pristine system. In isotopic terms, there was vertical compression in δ<jats:sup>15</jats:sup>N range (NR) and subsequent increased overlap in isotopic niche space, indicating increased trophic redundancy within Felbrigg. This structural change, which was associated with a greater channelling of energy through a sm
RIIPINEN MP, FLEITUCH T, HLADYZ S, et al., 2010, Invertebrate community structure and ecosystem functioning in European conifer plantation streams, Freshwater Biology, Vol: 55, Pages: 346-359, ISSN: 0046-5070
<jats:title>Summary</jats:title><jats:p>1. Terrestrial leaf‐litter is the dominant energy input to many headwater streams and consequently the nature of the riparian vegetation can have profound effects on in‐stream processes. The impact of conifer plantations on community structure and ecosystem functioning (litter breakdown) was investigated in field experiments in three countries (Britain, Ireland, Poland), each representing a distinct European ecoregion. Twenty‐six streams were used in the trial: half were bordered with broadleaved and the other half with conifer riparian vegetation.</jats:p><jats:p>2. In a leaf breakdown study using litter bags, two leaf types (oak and alder) were used to assess the impact of resource quality and two mesh sizes (10 and 0.5 mm aperture) were used to gauge the relative importance of invertebrate detritivores and microbial decomposers respectively. Comparisons were made between vegetation types and among regions; pH varied among individual streams but, unlike many previous studies, it was not confounded with vegetation type, enabling us to isolate the effect of vegetation more effectively.</jats:p><jats:p>3. Overall, riparian vegetation type did not affect breakdown rates but strong regional differences were observed. There was also a significant interaction between these two variables, but this disappeared after fitting pH as a covariable, demonstrating its importance in determining breakdown rates and raising the possibility that in previous studies the impacts of conifer plantations might have been confounded with pH.</jats:p><jats:p>4. Shredder species composition differed between vegetation types. Small stoneflies were most strongly associated with conifer streams; broadleaved streams generally had a higher proportion of larger taxa, such as limnephilid caddisflies and gammarid shrimps, although the latter were excluded from sites with low pH. However, breakdown rates
WOODWARD GUY, 2009, Biodiversity, ecosystem functioning and food webs in fresh waters: assembling the jigsaw puzzle, Freshwater Biology, Vol: 54, Pages: 2171-2187, ISSN: 0046-5070
<jats:title>Summary</jats:title><jats:p>1. Dramatic advances have been made recently in the study of biodiversity–ecosystem functioning (B‐EF) relations and food web ecology. These fields are now starting to converge, and this fusion has the potential to improve our understanding of how environmental stressors modulate ecosystem processes and the supply of ‘goods and services’.</jats:p><jats:p>2. Food web structure and dynamics can exert particularly strong influences on B‐EF relations in fresh waters, as consumer–resource interactions (e.g. trophic cascades) are often more important than horizontal interactions within trophic levels. For instance, many freshwater food webs are size structured, with large organisms tending to occupy the higher trophic levels and often exerting powerful effects on ecosystem processes. However, because they are also vulnerable to perturbations, non‐random losses of these large taxa can alter both food web structure and ecosystem functioning profoundly.</jats:p><jats:p>3. Recently, the focus of food web research has shifted away from exploring patterns, towards developing an understanding of processes (e.g. quantifying fluxes of individuals, biomass, energy, nutrients) and how the two interact. Many of the best‐characterized food webs are from fresh waters, and these ecosystems are now being used to address some of the shortcomings of earlier B‐EF studies. I have identified several key gaps in our current knowledge and highlighted potentially fruitful avenues of future B‐EF and food web research.</jats:p><jats:p>4. A major challenge for this newly emerging research is to place it within a unified theoretical framework. The application of metabolic theory and ecological stoichiometry may help to achieve this goal by considering biological systems within the constraints imposed upon them by physical and chemical laws.</jats:p>
Reiss J, Bridle JR, Montoya JM, et al., 2009, Emerging horizons in biodiversity and ecosystem functioning research, Trends in Ecology & Evolution, Vol: 24, Pages: 505-514, ISSN: 0169-5347
HLADYZ S, GESSNER MO, GILLER PS, et al., 2009, Resource quality and stoichiometric constraints on stream ecosystem functioning, Freshwater Biology, Vol: 54, Pages: 957-970, ISSN: 0046-5070
<jats:title>Summary</jats:title><jats:p>1. Resource quality and stoichiometric imbalances in carbon : nutrient ratios between consumers and resources can influence key ecosystem processes. In many streams, this has important implications for food webs that are based largely upon the utilization of terrestrial leaf‐litter, which varies widely among litter types in its value as a food source for detritivores and as a substrate for microbial decomposers.</jats:p><jats:p>2. We measured breakdown rates and macroinvertebrate colonization of leaf‐litter from a range of native and exotic plants of differing resource quality and palatability to consumers [e.g. carbon : nitrogen : phosphorus (C : N : P) ratios, lignin and cellulose content], in a field experiment. We also measured C : N : P ratios of the principal leaf‐shredding invertebrates, which revealed strong stoichiometric imbalances across trophic levels: C : N and C : P ratios typically differed by at least one order of magnitude between consumers and resources, whereas N : P imbalances were less marked. Application of the threshold elemental ratio approach, which integrates animal bioenergetics and body elemental composition in examining nutrient deficiency between consumers and resources, revealed less marked C : P imbalances than those based on the simpler arithmetic differences described above.</jats:p><jats:p>3. Litter breakdown rates declined as nutrient imbalances widened and resource quality fell, but they were independent of whether resources were exotic or native. The principal drivers of total, microbial and invertebrate‐mediated breakdown rates were lignin : N, lignin : P and fungal biomass, respectively. However, multiple regression using orthogonal predictors yielded even more efficient models of litter breakdown, as consumers respond
Reuman DC, Mulder C, Banasek-Richter C, et al., 2009, Allometry of body size and abundance in 166 food webs, Advances in Ecological Research, Vol: In press
Ings TC, Montoya JM, Bascompte J, et al., 2009, Ecological networks - beyond food webs, JOURNAL OF ANIMAL ECOLOGY, Vol: 78, Pages: 253-269, ISSN: 0021-8790
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- Citations: 634
Vaughan IP, Diamond M, Gurnell AM, et al., 2009, Integrating ecology with hydromorphology: a priority for river science and management, Aquatic Conservation: Marine and Freshwater Ecosystems, Vol: 19, Pages: 113-125, ISSN: 1052-7613
<jats:title>Abstract</jats:title><jats:p><jats:list list-type="explicit-label"><jats:list-item><jats:p>The assessment of links between ecology and physical habitat has become a major issue in river research and management. Key drivers include concerns about the conservation implications of human modifications (e.g. abstraction, climate change) and the explicit need to understand the ecological importance of hydromorphology as prescribed by the EU's Water Framework Directive. Efforts are focusing on the need to develop ‘eco‐hydromorphology’ at the interface between ecology, hydrology and fluvial geomorphology. Here, the scope of this emerging field is defined, some research and development issues are suggested, and a path for development is sketched out.</jats:p></jats:list-item><jats:list-item><jats:p>In the short term, major research priorities are to use existing literature or data better to identify patterns among organisms, ecological functions and river hydromorphological character. Another early priority is to identify model systems or organisms to act as research foci. In the medium term, the investigation of pattern–processes linkages, spatial structuring, scaling relationships and system dynamics will advance mechanistic understanding. The effects of climate change, abstraction and river regulation, eco‐hydromorphic resistance/resilience, and responses to environmental disturbances are likely to be management priorities. Large‐scale catchment projects, in both rural and urban locations, should be promoted to concentrate collaborative efforts, to attract financial support and to raise the profile of eco‐hydromorphology.</jats:p></jats:list-item><jats:list-item><jats:p>Eco‐hydromorphological expertise is currently fragmented across the main contributory disciplines (ecology, hydrology, geomorphology, flood risk management, civil engineering), potent
McKie BG, Woodward G, Hladyz S, et al., 2008, Ecosystem functioning in stream assemblages from different regions: contrasting responses to variation in detritivore richness, evenness and density, Journal of Animal Ecology, Vol: 77, Pages: 495-504, ISSN: 0021-8790
Yvon-Durocher G, Montoya J, Emmerson M, et al., 2008, Macroecological patterns and niche structure in a new marine food web, Open Life Sciences, Vol: 3, Pages: 91-103
<jats:title>Abstract</jats:title> <jats:p>The integration of detailed information on feeding interactions with measures of abundance and body mass of individuals provides a powerful platform for understanding ecosystem organisation. Metabolism and, by proxy, body mass constrain the flux, turnover and storage of energy and biomass in food webs. Here, we present the first food web data for Lough Hyne, a species rich Irish Sea Lough. Through the application of individual-and size-based analysis of the abundance-body mass relationship, we tested predictions derived from the metabolic theory of ecology. We found that individual body mass constrained the flux of biomass and determined its distribution within the food web. Body mass was also an important determinant of diet width and niche overlap, and predator diets were nested hierarchically, such that diet width increased with body mass. We applied a novel measure of predator-prey biomass flux which revealed that most interactions in Lough Hyne were weak, whereas only a few were strong. Further, the patterning of interaction strength between prey sharing a common predator revealed that strong interactions were nearly always coupled with weak interactions. Our findings illustrate that important insights into the organisation, structure and stability of ecosystems can be achieved through the theoretical exploration of detailed empirical data.</jats:p>
Woodward G, Warren PH, 2007, Body Size: The Structure and Function of Aquatic Ecosystems, Body Size: The Structure and Function of Aquatic Ecosystems, Editors: Hildrew, Raffaelli, Edmonds-Brown, ISBN: 9780521861724
Brose U, Jonsson T, Berlow EL, et al., 2006, Consumer-resource body-size relationships in natural food webs, ECOLOGY, Vol: 87, Pages: 2411-2417, ISSN: 0012-9658
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- Citations: 484
Emmerson MC, 2005, Dynamic Food Webs, Dynamic Food Webs, Editors: Ruiter, Wolters, Moore, Ruiter, Wolters, Moore, Ruiter, Wolters, Moore, Publisher: Academic Press, ISBN: 9780080460949
Dyanmic Food Webs is a volume in the Theoretical Ecology series. * Relates dynamics on different levels of biological organization: individuals, populations, and communities * Deals with empirical and theoretical approaches * Discusses the ...
WOODWARD G, EBENMAN B, EMMERSON M, et al., 2005, Body size in ecological networks, Trends in Ecology & Evolution, Vol: 20, Pages: 402-409, ISSN: 0169-5347
Woodward G, 2005, Aquatic Food Webs, Aquatic Food Webs, Editors: Belgrano, Publisher: Oxford University Press, ISBN: 9780198564829
Belgrano A, Woodward G, 2005, Aquatic Food Webs, Publisher: Oxford University Press, ISBN: 9780198564829
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