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Sun X, Hu S, He R, Zeng J, Zhao D. Ecological restoration enhanced the stability of epiphytic microbial food webs of submerged macrophytes: Insights from predation characteristics of epiphytic predators. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174547. [PMID: 38992355 DOI: 10.1016/j.scitotenv.2024.174547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/13/2024]
Abstract
The application of various submerged macrophytes for ecological restoration has gained increasing attention in urban lake ecosystems. The multitrophic microbial communities that colonized in various submerged macrophytes constitute microbial food webs through trophic cascade effects, which affect the biogeochemical cycles of the lake ecosystem and directly determine the effects of ecological restoration. Therefore, it is essential to reveal the diversity, composition, assembly processes, and stability of the microbial communities within epiphytic food webs of diverse submerged macrophytes under eutrophication and ecological restoration scenarios. In this study, we explored the epiphytic microbial food webs of Vallisneria natans and Hydrilla verticillata in both eutrophic and ecological restoration regions. The obtained results indicated that the two regions with different nutrient levels remarkably affected the diversity and composition of epiphytic multitrophic microbial communities of submerged macrophytes, among them, the community composition of epiphytic predators were more prone to change. Secondly, environmental filtering effects played a more important role in driving the community assembly of epiphytic predators than that of prey. Furthermore, the generality and intraguild predation of epiphytic predators were significantly improved within ecological restoration regions, which increased the stability of epiphytic microbial food webs. Additionally, compared with Hydrilla verticillata, the epiphytic microbial food webs of Vallisneria natans exhibited higher multitrophic diversity and higher network stability regardless of regions. Overall, this study focused on the role of the epiphytic microbial food webs of submerged macrophytes in ecological restoration and uncovered the potential of epiphytic predators to enhance the stability of microbial food webs, which may provide new insights into the development of ecological restoration strategies.
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Affiliation(s)
- Xiaojian Sun
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Siwen Hu
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Rujia He
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jin Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Sino-Danish Centre for Education and Research, University of Chinese Academy of Sciences, Beijing 100039, China; Poyang Lake Wetland Research Station, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Jiujiang 332899, China
| | - Dayong Zhao
- Joint International Research Laboratory of Global Change and Water Cycle, the National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China; College of Geography and Remote Sensing, Hohai University, Nanjing 210098, China.
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2
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McIntosh AR, Greig HS, Warburton HJ, Tonkin JD, Febria CM. Ecosystem-size relationships of river populations and communities. Trends Ecol Evol 2024; 39:571-584. [PMID: 38388323 DOI: 10.1016/j.tree.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/05/2023] [Accepted: 01/25/2024] [Indexed: 02/24/2024]
Abstract
Knowledge of ecosystem-size influences on river populations and communities is integral to the balancing of human and environmental needs for water. The multiple dimensions of dendritic river networks complicate understanding of ecosystem-size influences, but could be resolved by the development of scaling relationships. We highlight the importance of physical constraints limiting predator body sizes, movements, and population sizes in small rivers, and where river contraction limits space or creates stressful conditions affecting community stability and food webs. Investigations of the scaling and contingency of these processes will be insightful because of the underlying generality and scale independence of such relationships. Doing so will also pinpoint damaging water-management practices and identify which aspects of river size can be most usefully manipulated in river restoration.
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Affiliation(s)
- Angus R McIntosh
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - Hamish S Greig
- School of Biology and Ecology, University of Maine, Orono, ME, USA; Rocky Mountain Biological Laboratory, Gothic, CO, USA
| | - Helen J Warburton
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; New Zealand's Biological Heritage National Science Challenge, Lincoln, New Zealand
| | - Jonathan D Tonkin
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand; Te Pūnaha Matatini Centre of Research Excellence, University of Canterbury, Christchurch, New Zealand; Bioprotection Aotearoa Centre of Research Excellence, University of Canterbury, Christchurch, New Zealand
| | - Catherine M Febria
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, ON, Canada; Department of Integrative Biology, University of Windsor, Windsor, ON, Canada
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3
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Schlenker A, Brauns M, Fink P, Lorenz AW, Weitere M. Long-term recovery of benthic food webs after stream restoration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171499. [PMID: 38453075 DOI: 10.1016/j.scitotenv.2024.171499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 02/12/2024] [Accepted: 03/03/2024] [Indexed: 03/09/2024]
Abstract
The assessment of restoration success often neglects trophic interactions within food webs, focusing instead on biodiversity and community structure. Here, we analysed the long-term recovery of food web structure based on stable isotopes (δ13C and δ15N) of benthic invertebrates and quantified responses of food web metrics to time since restoration. The samples derived from twelve restored sites with different restoration ages, sampled annually from 2012 to 2021, and covering an investigation period of up to 28 years after restoration for the whole catchment. Temporal developments of the restored sites were compared to the development of two near-natural sites. The restoration measures consisted of the cessation of sewage inflow and morphological restoration of the channels. As a clear and consistent result over almost all sites, trophic similarity (proportion of co-existing species occupying similar trophic niches) increased with time since restoration, and reached values of near-natural sites, suggesting an increase in the stability and resilience of the food webs. Surprisingly, resource diversity decreased at most restored sites within 10 years after restoration, probably due to the removal of wastewater-derived resources, and a shift towards leaf litter as the dominant resource following the regrowth of the riparian vegetation. Food chain length showed no consistent pattern over time at the different sites both increasing and decreasing with time since restoration. Overall, restoration had clear effects on the food web structure of stream ecosystems. While some effects such as the increase in trophic similarity were consistent at almost all sites, others such as response of the food chain length were context dependent. The study demonstrates the potential of utilizing food web metrics, particularly trophic similarity, in restoration research to achieve a more holistic understanding of ecosystem recovery.
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Affiliation(s)
- Alexandra Schlenker
- Department River Ecology, Helmholtz Centre for Environmental Research - UFZ, Brückstraße 3a, 39114 Magdeburg, Germany.
| | - Mario Brauns
- Department River Ecology, Helmholtz Centre for Environmental Research - UFZ, Brückstraße 3a, 39114 Magdeburg, Germany
| | - Patrick Fink
- Department River Ecology, Helmholtz Centre for Environmental Research - UFZ, Brückstraße 3a, 39114 Magdeburg, Germany; Department of Aquatic Ecosystem Analysis and Management, Helmholtz Centre for Environmental Research - UFZ, Brückstraße 3a, 39114, Magdeburg, Germany
| | - Armin W Lorenz
- Department of Aquatic Ecology, Faculty for Biology, University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany
| | - Markus Weitere
- Department River Ecology, Helmholtz Centre for Environmental Research - UFZ, Brückstraße 3a, 39114 Magdeburg, Germany
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4
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Gutiérrez-Fonseca PE, Pringle CM, Ramírez A, Gómez JE, García P. Hurricane disturbance drives trophic changes in neotropical mountain stream food webs. Ecology 2024; 105:e4202. [PMID: 37926483 DOI: 10.1002/ecy.4202] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/17/2023] [Accepted: 09/18/2023] [Indexed: 11/07/2023]
Abstract
Food webs are complex ecological networks that reveal species interactions and energy flow in ecosystems. Prevailing ecological knowledge on forested streams suggests that their food webs are based on allochthonous carbon, driven by a constant supply of organic matter from adjacent vegetation and limited primary production due to low light conditions. Extreme climatic disturbances can disrupt these natural ecosystem dynamics by altering resource availability, which leads to changes in food web structure and functioning. Here, we quantify the response of stream food webs to two major hurricanes (Irma and María, Category 5 and 4, respectively) that struck Puerto Rico in September 2017. Within two tropical forested streams (first and second order), we collected ecosystem and food web data 6 months prior to the hurricanes and 2, 9, and 18 months afterward. We assessed the structural (e.g., canopy) and hydrological (e.g., discharge) characteristics of the ecosystem and monitored changes in basal resources (i.e., algae, biofilm, and leaf litter), consumers (e.g., aquatic invertebrates, riparian consumers), and applied Layman's community-wide metrics using the isotopic composition of 13 C and 15 N. Continuous stream discharge measurements indicated that the hurricanes did not cause an extreme hydrological event. However, the sixfold increase in canopy openness and associated changes in litter input appeared to trigger an increase in primary production. These food webs were primarily based on terrestrially derived carbon before the hurricanes, but most taxa (including Atya and Xiphocaris shrimp, the consumers with highest biomass) shifted their food source to autochthonous carbon within 2 months of the hurricanes. We also found evidence that the hurricanes dramatically altered the structure of the food web, resulting in shorter (i.e., smaller food-chain length), narrower (i.e., lower diversity of carbon sources) food webs, as well as increased trophic species packing. This study demonstrates how hurricane disturbance can alter stream food webs, changing the trophic base from allochthonous to autochthonous resources via changes in the physical environment (i.e., canopy defoliation). As hurricanes become more frequent and severe due to climate change, our findings greatly contribute to our understanding of the mechanisms that maintain forested stream trophic interactions amidst global change.
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Affiliation(s)
- Pablo E Gutiérrez-Fonseca
- Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, USA
| | | | - Alonso Ramírez
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Jesús E Gómez
- Department of Environmental Sciences, University of Puerto Rico-Río Piedras, San Juan, Puerto Rico
- Department of Biological Sciences, Florida International University, Miami, Florida, USA
| | - Pavel García
- Escuela de Biología, Universidad de San Carlos de Guatemala, Guatemala City, Guatemala
- Ecology and Evolution Program, University of Montana, Missoula, Montana, USA
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5
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Guo G, Barabás G, Takimoto G, Bearup D, Fagan WF, Chen D, Liao J. Towards a mechanistic understanding of variation in aquatic food chain length. Ecol Lett 2023; 26:1926-1939. [PMID: 37696523 DOI: 10.1111/ele.14305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023]
Abstract
Ecologists have long sought to understand variation in food chain length (FCL) among natural ecosystems. Various drivers of FCL, including ecosystem size, resource productivity and disturbance, have been hypothesised. However, when results are aggregated across existing empirical studies from aquatic ecosystems, we observe mixed FCL responses to these drivers. To understand this variability, we develop a unified competition-colonisation framework for complex food webs incorporating all of these drivers. With competition-colonisation tradeoffs among basal species, our model predicts that increasing ecosystem size generally results in a monotonic increase in FCL, while FCL displays non-linear, oscillatory responses to resource productivity or disturbance in large ecosystems featuring little disturbance or high productivity. Interestingly, such complex responses mirror patterns in empirical data. Therefore, this study offers a novel mechanistic explanation for observed variations in aquatic FCL driven by multiple environmental factors.
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Affiliation(s)
- Guanming Guo
- Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang, China
| | - György Barabás
- Division of Theoretical Biology, Department IFM, Linköping University, Linköping, Sweden
- Institute of Evolution, Centre for Ecological Research, Budapest, Hungary
| | - Gaku Takimoto
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Daniel Bearup
- School of Mathematics, Statistics and Actuarial Sciences, University of Kent, Parkwood Road, Canterbury, UK
| | - William F Fagan
- Department of Biology, University of Maryland, College Park, Maryland, USA
| | - Dongdong Chen
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Jinbao Liao
- Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang, China
- Centre for Invasion Biology, Institute of Biodiversity, School of Ecology and Environmental Science, Yunnan University, Kunming, China
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6
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Guo G, Zhao F, Nijs I, Liao J. Colonization-competition dynamics of basal species shape food web complexity in island metacommunities. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:169-177. [PMID: 37275541 PMCID: PMC10232389 DOI: 10.1007/s42995-023-00167-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/28/2023] [Indexed: 06/07/2023]
Abstract
Exploring how food web complexity emerges and evolves in island ecosystems remains a major challenge in ecology. Food webs assembled from multiple islands are commonly recognized as highly complex trophic networks that are dynamic in both space and time. In the context of global climate change, it remains unclear whether food web complexity will decrease in a monotonic fashion when undergoing habitat destruction (e.g., the inundation of islands due to sea-level rise). Here, we develop a simple yet comprehensive patch-dynamic framework for complex food web metacommunities subject to the competition-colonization tradeoff between basal species. We found that oscillations in food web topological complexity (characterized by species diversity, mean food chain length and the degree of omnivory) emerge along the habitat destruction gradient. This outcome is robust to changing parameters or relaxing the assumption of a strict competitive hierarchy. Having oscillations in food web complexity indicates that small habitat changes could have disproportionate negative effects on species diversity, thus the success of conservation actions should be evaluated not only on changes in biodiversity, but also on system robustness to habitat alteration. Overall, this study provides a parsimonious mechanistic explanation for the emergence of food web complexity in island ecosystems, further enriching our understanding of metacommunity assembly. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00167-0.
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Affiliation(s)
- Guanming Guo
- Ministry of Education’s Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang, 330022 China
| | - Fei Zhao
- Ministry of Education’s Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang, 330022 China
| | - Ivan Nijs
- Research Group in Plants and Ecosystems, Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium
| | - Jinbao Liao
- Ministry of Education’s Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Nanchang, 330022 China
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7
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Mestre F, Rozenfeld A, Araújo MB. Human disturbances affect the topology of food webs. Ecol Lett 2022; 25:2476-2488. [PMID: 36167463 PMCID: PMC9828725 DOI: 10.1111/ele.14107] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 08/16/2022] [Accepted: 08/21/2022] [Indexed: 01/12/2023]
Abstract
Networks describe nodes connected by links, with numbers of links per node, the degree, forming a range of distributions including random and scale-free. How network topologies emerge in natural systems still puzzles scientists. Based on previous theoretical simulations, we predict that scale-free food webs are favourably selected by random disturbances while random food webs are selected by targeted disturbances. We assume that lower human pressures are more likely associated with random disturbances, whereas higher pressures are associated with targeted ones. We examine these predictions using 351 empirical food webs, generally confirming our predictions. Should the topology of food webs respond to changes in the magnitude of disturbances in a predictable fashion, consistently across ecosystems and scales of organisation, it would provide a baseline expectation to understand and predict the consequences of human pressures on ecosystem dynamics.
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Affiliation(s)
- Frederico Mestre
- ‘Rui Nabeiro’ Biodiversity Chair, MED – Mediterranean Institute for Agriculture, Environment and Development & CHANGE – Global Change and Sustainability Institute, Institute for Advanced Studies and ResearchUniversidade de ÉvoraÉvoraPortugal
| | - Alejandro Rozenfeld
- ‘Rui Nabeiro’ Biodiversity Chair, MED – Mediterranean Institute for Agriculture, Environment and Development & CHANGE – Global Change and Sustainability Institute, Institute for Advanced Studies and ResearchUniversidade de ÉvoraÉvoraPortugal,Centro de Investigaciones en Física e Ingeniería del CentroUniversidad Nacional del Centro de la Provincia de Buenos Aires, Consejo Nacional de Investigaciones Científicas y TécnicasTandilBuenos AiresArgentina,CONICET‐CIFICEN‐Universidad del Centro de la Provincia de Buenos AiresTandilBuenos AiresArgentina
| | - Miguel B. Araújo
- ‘Rui Nabeiro’ Biodiversity Chair, MED – Mediterranean Institute for Agriculture, Environment and Development & CHANGE – Global Change and Sustainability Institute, Institute for Advanced Studies and ResearchUniversidade de ÉvoraÉvoraPortugal,Department of Biogeography and Global Change, National Museum of Natural SciencesCSICMadridSpain
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8
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Zhang J, Xu J, Tan X, Zhang Q. Nitrogen loadings affect trophic structure in stream food webs on the Tibetan Plateau, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 844:157018. [PMID: 35772539 DOI: 10.1016/j.scitotenv.2022.157018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic activities, such as agricultural and industrial development, have increased nutrient inputs into waterways, which affect trophic interactions and the flow of energy through food webs in the aquatic ecosystems. However, the responses of food web structure and function to specific anthropogenic stressors in the alpine stream systems remain unclear. Here, we studied the stream food webs in the Lhasa River on the Tibetan Plateau, China. We measured the isotopic ratios (δ13C and δ15N) of macroinvertebrate and fish functional feeding groups (FFGs) and their basal resources in the streams. Dietary contributions of basal resources to consumers and food web metrics including trophic length, diversity, and redundancy were used to quantify changes in stream food webs in response to anthropogenic disturbance. Dietary analysis showed that allochthonous resources contributed more than autochthonous resources to macroinvertebrate primary consumers regardless of the disturbance intensity in the adjacent land areas. Anthropogenic activities increased the δ15N values in epilithic algae and isotopic variation in basal resources and fish but reduced the trophic length and redundancy (i.e., fewer species or taxon at each trophic level) in food webs. Additionally, the total nitrogen concentration in waters was the most important environmental variable affecting trophic diversity and redundancy. Therefore, the reduction of nitrogen inputs into streams is critical for sustainable river management and biodiversity conservation in the streams on the Tibetan Plateau.
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Affiliation(s)
- Jian Zhang
- Research Center for Ecology and Environment of Qinghai-Tibetan Plateau, Tibet University, Lhasa 850000, Tibet, China; College of Science, Tibet University, Lhasa 850000, Tibet, China; Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan, Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
| | - Jilei Xu
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan, Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
| | - Xiang Tan
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan, Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
| | - Quanfa Zhang
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan, Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China
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9
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Barrett IC, McIntosh AR, Febria CM, Graham SE, Burdon FJ, Pomeranz JPF, Warburton HJ. Integrative analysis of stressor gradients reveals multiple discrete trait‐defined axes underlie community assembly. Ecosphere 2022. [DOI: 10.1002/ecs2.4164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Isabelle C. Barrett
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- Department of Environmental Management Lincoln University Lincoln New Zealand
| | - Angus R. McIntosh
- School of Biological Sciences University of Canterbury Christchurch New Zealand
| | - Catherine M. Febria
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- Great Lakes Institute for Environmental Research (GLIER) Windsor Ontario Canada
| | - S. Elizabeth Graham
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- National Institute of Water and Atmosphere Hamilton New Zealand
| | - Francis J. Burdon
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- School of Science University of Waikato Hamilton New Zealand
| | - Justin P. F. Pomeranz
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- Department of Biology University of South Dakota Vermillion South Dakota USA
| | - Helen J. Warburton
- School of Biological Sciences University of Canterbury Christchurch New Zealand
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10
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Mor JR, Muñoz I, Sabater S, Zamora L, Ruhi A. Energy limitation or sensitive predators? Trophic and non-trophic impacts of wastewater pollution on stream food webs. Ecology 2021; 103:e03587. [PMID: 34792187 DOI: 10.1002/ecy.3587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 08/20/2021] [Indexed: 11/11/2022]
Abstract
Impacts of environmental stressors on food webs are often difficult to predict because trophic levels can respond in divergent ways, and biotic interactions may dampen or amplify responses. Here we studied food-web level impacts of urban wastewater pollution, a widespread source of degradation that can alter stream food webs via top-down and bottom-up processes. Wastewater may (i) subsidize primary producers by decreasing nutrient limitation, inducing a wide-bottomed trophic pyramid. However, (ii) wastewater may also reduce the quality and diversity of resources, which could decrease energy transfer efficiency by reducing consumer fitness, leading to predator starvation. Additionally, (iii) if higher trophic levels are particularly sensitive to pollution, primary consumers could be released from predation pressure. We tested these hypotheses in 10 pairs of stream sites located upstream and downstream of urban wastewater effluents with different pollutant levels. We found that wastewater pollution reduced predator richness by ~34%. Community Size Spectra (CSS) slopes were steeper downstream than upstream of wastewater effluents-in all except one impact site where predators became locally extinct. Further, variation in downstream CSS slopes were correlated with pollution loads: the more polluted the stream, the steeper the CSS. We estimate that wastewater pollution decreased energy transfer efficiencies to primary consumers by ~70%, limiting energy supply to predators. Additionally, traits increasing vulnerability to chemical pollution were overrepresented among predators, which presented compressed trophic niches (δ15 N- δ13 C) downstream of effluents. Our results show that wastewater pollution can impact stream food webs via a combination of energy limitation to consumers and extirpation of pollution-sensitive top predators. Understanding the indirect (biotically-mediated) vs. direct (abiotic) mechanisms controlling responses to stress may help anticipating impacts of altered water quantity and quality-key signatures of global change.
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Affiliation(s)
- Jordi-René Mor
- Catalan Institute for Water Research (ICRA), Girona, Spain.,Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona (UB), Barcelona, Spain
| | - Isabel Muñoz
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona (UB), Barcelona, Spain
| | - Sergi Sabater
- Catalan Institute for Water Research (ICRA), Girona, Spain.,Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Lluís Zamora
- Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Albert Ruhi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley Berkeley, CA, USA
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11
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Greig HS, McHugh PA, Thompson RM, Warburton HJ, McIntosh AR. Habitat size influences community stability. Ecology 2021; 103:e03545. [PMID: 34614210 DOI: 10.1002/ecy.3545] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 12/18/2020] [Accepted: 03/15/2021] [Indexed: 11/06/2022]
Abstract
Mechanisms linked to demographic, biogeographic, and food-web processes thought to underpin community stability could be affected by habitat size, but the effects of habitat size on community stability remain relatively unknown. We investigated whether those habitat-size-dependent properties influenced community instability and vulnerability to perturbations caused by disturbance. This is particularly important given that human exploitation is contracting ecosystems, and abiotic perturbations are becoming more severe and frequent. We used a perturbation experiment in which 10 streams, spanning three orders of magnitude in habitat size, were subjected to simulated bed movement akin to a major flood disturbance event. We measured the resistance, resilience, and variability of basal resources, and population and community-level responses across the stream habitat-size gradient immediately before, and at 0.5, 5, 10, 20, and 40 d post-disturbance. Resistance to disturbance consistently increased with stream size in all response variables. In contrast, resilience was significantly higher in smaller streams for some response variables. However, this higher resilience of small ecosystems was insufficient to compensate for their lower resistance, and communities of smaller streams were thus more variable over time than those of larger streams. Compensatory dynamics of populations, especially for predators, stabilized some aspects of communities, but these mechanisms were unrelated to habitat size. Together, our results provide compelling evidence for the links between habitat size and community stability, and should motivate ecologists and managers to consider how changes in the size of habitats will alter the vulnerability of ecosystems to perturbations caused by environmental disturbance.
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Affiliation(s)
- Hamish S Greig
- School of Biology and Ecology, University of Maine, 5722 Deering Hall, Orono, Maine, 04469, USA
| | - Peter A McHugh
- California Department of Fish and Wildlife, 3637 Westwind Blvd, Santa Rosa, California, 95403, USA
| | - Ross M Thompson
- Centre for Applied Water Science and Institute for Applied Ecology, University of Canberra, Kirinari Street, Bruce, Australian Capital Territory, 2617, Australia
| | - Helen J Warburton
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Angus R McIntosh
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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12
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Danet A, Mouchet M, Bonnaffé W, Thébault E, Fontaine C. Species richness and food-web structure jointly drive community biomass and its temporal stability in fish communities. Ecol Lett 2021; 24:2364-2377. [PMID: 34423526 DOI: 10.1111/ele.13857] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 06/30/2021] [Accepted: 07/15/2021] [Indexed: 01/28/2023]
Abstract
Biodiversity-ecosystem functioning and food-web complexity-stability relationships are central to ecology. However, they remain largely untested in natural contexts. Here, we estimated the links among environmental conditions, richness, food-web structure, annual biomass and its temporal stability using a standardised monitoring dataset of 99 stream fish communities spanning from 1995 to 2018. We first revealed that both richness and average trophic level are positively related to annual biomass, with effects of similar strength. Second, we found that community stability is fostered by mean trophic level, while contrary to expectation, it is decreased by species richness. Finally, we found that environmental conditions affect both biomass and its stability mainly via effects on richness and network structure. Strikingly, the effect of species richness on community stability was mediated by population stability rather than synchrony, which contrasts with results from single trophic communities. We discuss the hypothesis that it could be a characteristic of multi-trophic communities.
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Affiliation(s)
- Alain Danet
- Centre d'Ecologie et des Sciences de la Conservation, UMR 7204 MNHN-CNRS-Sorbonne Université, Muséum national d'Histoire naturelle de Paris, Paris, France
| | - Maud Mouchet
- Centre d'Ecologie et des Sciences de la Conservation, UMR 7204 MNHN-CNRS-Sorbonne Université, Muséum national d'Histoire naturelle de Paris, Paris, France
| | - Willem Bonnaffé
- Ecological and Evolutionary Dynamics Lab, Department of Zoology, University of Oxford, Oxford, UK
| | - Elisa Thébault
- Sorbonne Université, CNRS, IRD, INRAE, Université Paris Est Créteil, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
| | - Colin Fontaine
- Centre d'Ecologie et des Sciences de la Conservation, UMR 7204 MNHN-CNRS-Sorbonne Université, Muséum national d'Histoire naturelle de Paris, Paris, France
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13
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Eagle LJB, Milner AM, Klaar MJ, Carrivick JL, Wilkes M, Brown LE. Extreme flood disturbance effects on multiple dimensions of river invertebrate community stability. J Anim Ecol 2021; 90:2135-2146. [PMID: 34363703 DOI: 10.1111/1365-2656.13576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 07/19/2021] [Indexed: 11/30/2022]
Abstract
Multidimensional analysis of community stability has recently emerged as an overarching approach to evaluating ecosystem response to disturbance. However, the approach has previously been applied only in experimental and modelling studies. We applied this concept to an 18-year time series (2000-2017) of macroinvertebrate community dynamics from a southeast Alaskan river to further develop and test the approach in relation to the effects of two extreme flood events occurring in 2005 (event 1) and 2014 (event 2). Five components of stability were calculated for pairs of pre- or post-event years. Individual components were tested for differences between pre- and post-event time periods. Stability components' pairwise correlations were assessed and ellipsoids of stability were developed for each time period and compared to a null model derived from the permuted dataset. Only one stability component demonstrated a significant difference between time periods. In contrast, 80% of moderate and significant correlations between stability components were degraded post-disturbance and significant changes to the form of stability ellipsoids were observed. Ellipsoids of stability for all periods after the initial disturbance (2005) were not different to the null model. Our results illustrate that the dimensionality of stability approach can be applied to natural ecosystem time-series data. The major increase in dimensionality of stability observed following disturbance potentially indicates significant shifts in the processes which drive stability following disturbance. This evidence improves our understanding of community response beyond what is possible through analysis of individual stability components.
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Affiliation(s)
| | - Alexander M Milner
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK.,Institute of Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Megan J Klaar
- School of Geography and water@leeds, University of Leeds, Leeds, UK
| | | | - Martin Wilkes
- Centre for Agroecology, Water and Resilience, Coventry University, Coventry, UK
| | - Lee E Brown
- School of Geography and water@leeds, University of Leeds, Leeds, UK
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14
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Fraley KM, Robards MD, Rogers MC, Vollenweider J, Smith B, Whiting A, Jones T. Freshwater input and ocean connectivity affect habitats and trophic ecology of fishes in Arctic coastal lagoons. Polar Biol 2021. [DOI: 10.1007/s00300-021-02895-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Fraley KM, Warburton HJ, Jellyman PG, Kelly D, McIntosh AR. The influence of pastoral and native forest land cover, flooding disturbance, and stream size on the trophic ecology of New Zealand streams. AUSTRAL ECOL 2021. [DOI: 10.1111/aec.13028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kevin M. Fraley
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch8140New Zealand
| | - Helen J. Warburton
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch8140New Zealand
| | - Phillip G. Jellyman
- National Institute of Water and Atmospheric Research Ltd Christchurch New Zealand
| | - Dave Kelly
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch8140New Zealand
| | - Angus R. McIntosh
- School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch8140New Zealand
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16
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Chua KWJ, Liew JH, Wilkinson CL, Ahmad AB, Tan HH, Yeo DCJ. Land-use change erodes trophic redundancy in tropical forest streams: Evidence from amino acid stable isotope analysis. J Anim Ecol 2021; 90:1433-1443. [PMID: 33666230 DOI: 10.1111/1365-2656.13462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 12/16/2020] [Indexed: 11/29/2022]
Abstract
Studies have shown that food chain length is governed by interactions between species richness, ecosystem size and resource availability. While redundant trophic links may buffer impacts of species loss on food chain length, higher extinction risks associated with predators may result in bottom-heavy food webs with shorter food chains. The lack of consensus in earlier empirical studies relating species richness and food chain length reflects the need to account robustly for the factors described above. In response to this, we conducted an empirical study to elucidate impacts of land-use change on food chain length in tropical forest streams of Southeast Asia. Despite species losses associated with forest loss at our study areas, results from amino acid isotope analyses showed that food chain length was not linked to land use, ecosystem size or resource availability. Correspondingly, species losses did not have a significant effect on occurrence likelihoods of all trophic guilds except herbivores. Impacts of species losses were likely buffered by initial high levels of trophic redundancy, which declined with canopy cover. Declines in trophic redundancy were most drastic amongst invertivorous fishes. Declines in redundancy across trophic guilds were also more pronounced in wider and more resource-rich streams. While our study found limited evidence for immediate land-use impacts on stream food chains, the potential loss of trophic redundancy in the longer term implies increasing vulnerability of streams to future perturbations, as long as land conversion continues unabated.
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Affiliation(s)
- Kenny W J Chua
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Jia Huan Liew
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR
| | - Clare L Wilkinson
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Amirrudin B Ahmad
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Terengganu, Malaysia.,Institute for Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu, Terengganu, Malaysia
| | - Heok Hui Tan
- Lee Kong Chian Natural History Museum, National University of Singapore, Singapore
| | - Darren C J Yeo
- Department of Biological Sciences, National University of Singapore, Singapore.,Lee Kong Chian Natural History Museum, National University of Singapore, Singapore
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17
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Diesburg KM, Sullivan SMP, Manning DWP. Consequences of a terrestrial insect invader on stream-riparian food webs of the central Appalachians, USA. Biol Invasions 2021. [DOI: 10.1007/s10530-020-02435-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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18
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Wang S, Luo BK, Qin YJ, Zhao JG, Wang TT, Stewart SD, Yang Y, Chen ZB, Qiu HX. Fish isotopic niches associated with environmental indicators and human disturbance along a disturbed large subtropical river in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141667. [PMID: 32871370 DOI: 10.1016/j.scitotenv.2020.141667] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 08/09/2020] [Accepted: 08/10/2020] [Indexed: 06/11/2023]
Abstract
Stable isotopes are increasingly used to detect and understand the impacts of environmental changes on riverine ecological properties. The δ13C and δ15N signatures of fish with different feeding habits were measured in a large subtropical river to evaluate how fish isotopic niches respond to environmental gradients and human disturbance. From basal resources to fish consumers, the high values of epilithic periphyton (biofilm) δ13C and suspended particulate organic matter δ15N concurrently determined the niche ranges and space (e.g., convex hull area) of fish communities. Along a longitudinal gradient (except in the industrial zone), the number of fish trophic guilds identified by Bayesian ellipses continuously increased; meanwhile, higher trophic diversity and less redundancy were observed near the lower reaches and estuary. Variance inflation factors were estimated to detect the multicollinearity of 40 environmental variables, 14 of which were selected as indicators. Relative importance (RI) analysis was used to evaluate the explanatory power of these indicators for the spatial variation in isotopic niche metrics; the results showed that riffle habitat area, water nitrate concentration, gravel-cobble substrate, and riparian buffer width were the 4 key environmental indicators (average RI > 12%) that determined the longitudinal pattern of fish isotopic niches. These findings suggested that community-level δ13C signatures are more responsive to changes in habitats (e.g., riffle) and substrates (e.g., gravel-cobble) supporting the productivity of autochthonous diatoms while δ15N signatures respond to water quality altered by nitrogen pollution from manure-fertilized farming and poultry livestock effluent. Furthermore, δ15N may be more robust and interpretable than δ13C as an isotopic indicator of ecosystem change in rivers exposed to multiple or complex anthropogenic stressors.
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Affiliation(s)
- Sai Wang
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China; Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou 510632, China; Skyte Testing Services Guangdong Co., Ltd., Shenzhen 518101, China
| | - Bang-Ke Luo
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China
| | - Ying-Jun Qin
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China
| | - Jian-Gang Zhao
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China; Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou 510632, China
| | - Tuan-Tuan Wang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Simon D Stewart
- Cawthron Institute, 98 Halifax St East, Nelson 7010, New Zealand
| | - Yang Yang
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China; Research Center of Tropical and Subtropical Aquatic Ecological Engineering, Ministry of Education Engineering, Jinan University, Guangzhou 510632, China.
| | - Zhong-Bing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, 16521 Prague 6, Czech Republic.
| | - Hong-Xin Qiu
- Research Center of Hydrobiology, Department of Ecology, Jinan University, Guangzhou 510632, China
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19
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Nelson SJ, Chen CY, Kahl JS. Dragonfly larvae as biosentinels of Hg bioaccumulation in Northeastern and Adirondack lakes: relationships to abiotic factors. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1659-1672. [PMID: 31883061 PMCID: PMC8418898 DOI: 10.1007/s10646-019-02149-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/05/2019] [Indexed: 05/28/2023]
Abstract
Mercury (Hg) is a toxic pollutant, widespread in northeastern US ecosystems. Resource managers' efforts to develop fish consumption advisories for humans and to focus conservation efforts for fish-eating wildlife are hampered by spatial variability. Dragonfly larvae can serve as biosentinels for Hg given that they are widespread in freshwaters, long-lived, exhibit site fidelity, and bioaccumulate relatively high mercury concentrations, mostly as methylmercury (88% ± 11% MeHg in this study). We sampled lake water and dragonfly larvae in 74 northeastern US lakes that are part of the US EPA Long-Term Monitoring Network, including 45 lakes in New York, 43 of which are in the Adirondacks. Aqueous dissolved organic carbon (DOC) and total Hg (THg) were strongly related to MeHg in lake water. Dragonfly larvae total mercury ranged from 0.016-0.918 μg/g, dw across the study area; Adirondack lakes had the minimum and maximum concentrations. Aqueous MeHg and dragonfly THg were similar between the Adirondack and Northeast regions, but a majority of lakes within the highest quartile of dragonfly THg were in the Adirondacks. Using landscape, lake chemistry, and lake morphometry data, we evaluated relationships with MeHg in lake water and THg in dragonfly larvae. Lakewater DOC and lake volume were strong predictors for MeHg in water. Dragonfly THg Bioaccumulation Factors (BAFs, calculated as [dragonfly THg]:[aqueous MeHg]) increased as lake volume increased, suggesting that lake size influences Hg bioaccumulation or biomagnification. BAFs declined with increasing DOC, supporting a potential limiting effect for MeHg bioavailability with higher DOC.
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Affiliation(s)
- Sarah J Nelson
- School of Forest Resources, University of Maine, 5755 Nutting Hall, Orono, ME, 04469-5755, USA.
- Appalachian Mountain Club, PO Box 298, Route 16, Gorham, NH, 03581, USA.
| | - Celia Y Chen
- Department of Biological Sciences, Dartmouth College, HB 6044, Class of '78 Life Sciences Center, Hanover, NH, 03755, USA
| | - Jeffrey S Kahl
- Thomas College, School of Arts and Sciences, 180 West River Road, Waterville, ME, 04901, USA
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20
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Wilkinson CL, Chua KWJ, Fiala R, Liew JH, Kemp V, Hadi Fikri A, Ewers RM, Kratina P, Yeo DCJ. Forest conversion to oil palm compresses food chain length in tropical streams. Ecology 2020; 102:e03199. [PMID: 32969053 DOI: 10.1002/ecy.3199] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 05/18/2020] [Accepted: 07/20/2020] [Indexed: 11/11/2022]
Abstract
In Southeast Asia, biodiversity-rich forests are being extensively logged and converted to oil palm monocultures. Although the impacts of these changes on biodiversity are largely well documented, we know addition to samples we collected in 201 little about how these large-scale impacts affect freshwater trophic ecology. We used stable isotope analyses (SIA) to determine the impacts of land-use changes on the relative contribution of allochthonous and autochthonous basal resources in 19 stream food webs. We also applied compound-specific SIA and bulk-SIA to determine the trophic position of fish apex predators and meso-predators (invertivores and omnivores). There was no difference in the contribution of autochthonous resources in either consumer group (70-82%) among streams with different land-use type. There was no change in trophic position for meso-predators, but trophic position decreased significantly for apex predators in oil palm plantation streams compared to forest streams. This change in maximum food chain length was due to turnover in identity of the apex predator among land-use types. Disruption of aquatic trophic ecology, through reduction in food chain length and shift in basal resources, may cause significant changes in biodiversity as well as ecosystem functions and services. Understanding this change can help develop more focused priorities for mediating the negative impacts of human activities on freshwater ecosystems.
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Affiliation(s)
- Clare L Wilkinson
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore
| | - Kenny W J Chua
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore
| | - Roswitha Fiala
- School of Biological and Chemical Sciences, Queen Mary University London, London, E1 4DQ, UK
| | - Jia H Liew
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore.,School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Victoria Kemp
- School of Biological and Chemical Sciences, Queen Mary University London, London, E1 4DQ, UK
| | - Arman Hadi Fikri
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, 88400, Malaysia
| | - Robert M Ewers
- Department of Life Sciences, Imperial College London-Silwood Park, Buckhurst Road, Ascot, SL5 7PY, UK
| | - Pavel Kratina
- School of Biological and Chemical Sciences, Queen Mary University London, London, E1 4DQ, UK
| | - Darren C J Yeo
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore.,Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore, 117377, Singapore
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21
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Boddy NC, Booker DJ, McIntosh AR. Heterogeneity in flow disturbance around river confluences influences spatial patterns in native and non-native species co-occurrence. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02334-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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22
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Sánchez-Hernández J. Drivers of piscivory in a globally distributed aquatic predator (brown trout): a meta-analysis. Sci Rep 2020; 10:11258. [PMID: 32647243 PMCID: PMC7347837 DOI: 10.1038/s41598-020-68207-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 06/22/2020] [Indexed: 11/09/2022] Open
Abstract
There is growing interest in the delineation of feeding patterns in animals, but little is known about the interaction of multiple explanatory factors across broad geographical scales. The goal of this study was to identify the factors that together determine population-level patterns in piscivory in a globally distributed aquatic predator, the brown trout (Salmo trutta). A meta-analysis of peer-reviewed studies revealed that the prevalence (frequency of occurrence, %) of piscivory increases from riverine to marine ecosystems, with fish community type and the size-structure (ontogeny) of brown trout populations being the key drivers. Thus, piscivory was related to ecosystem-specific differences in predator body size (increasing in populations with large individuals) and fish community configurations (increasing with fish species richness). Fish species richness imposes important limitations on (i.e. in low diversity scenarios) or facilitate (i.e. in high diversity scenarios) piscivory in brown trout populations, with a low prevalence expected in low-diversity fish communities. In fresh water, piscivory is higher in lentic than lotic ecosystems and, in the former, increases with latitude. Competition in multi-species systems is expected to be higher than in simpler systems because the size-structure and species composition of fish assemblages, explaining cross-ecosystem differences in piscivory.
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Affiliation(s)
- Javier Sánchez-Hernández
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Móstoles, Madrid, Spain.
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23
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Jackson MC, Fourie HE, Dalu T, Woodford DJ, Wasserman RJ, Zengeya TA, Ellender BR, Kimberg PK, Jordaan MS, Chimimba CT, Weyl OLF. Food web properties vary with climate and land use in South African streams. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13601] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Michelle C. Jackson
- Department of Zoology University of Oxford Oxford UK
- Imperial College London, Silwood Park Campus Ascot UK
- Centre for Invasion Biology (CIB), Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | - Hermina E. Fourie
- Centre for Invasion Biology (CIB), Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | - Tatenda Dalu
- Department of Ecology and Resource Management University of Venda Thohoyandou South Africa
- South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
| | - Darragh J. Woodford
- South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
- Centre for Invasion Biology (CIB), School of Animal, Plant and Environmental Sciences University of the Witwatersand Johannesburg South Africa
| | - Ryan J. Wasserman
- South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
- Department of Zoology and Entomology Rhodes University Makhanda South Africa
| | - Tsungai A. Zengeya
- Centre for Invasion Biology (CIB), Department of Zoology and Entomology University of Pretoria Pretoria South Africa
- South African National Biodiversity Institute (SANBI) Kirstenbosch Research Centre Cape Town South Africa
| | - Bruce R. Ellender
- South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
- Upper Zambezi Programme World Wide Fund For Nature Lusaka Zambia
| | | | - Martine S. Jordaan
- South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
- CapeNature Biodiversity Capabilities Unit Stellenbosch South Africa
- Centre for Invasion Biology (CIB) University of Stellenbosch Stellenbosch South Africa
| | - Christian T. Chimimba
- Centre for Invasion Biology (CIB), Department of Zoology and Entomology University of Pretoria Pretoria South Africa
| | - Olaf L. F. Weyl
- DSI/NRF Research Chair in Inland Fisheries and Freshwater Ecology South African Institute for Aquatic Biodiversity (SAIAB) Makhanda South Africa
- Department of Ichthyology and Fisheries Science Rhodes University Makhanda South Africa
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24
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Jackson BK, Stock SL, Harris LS, Szewczak JM, Schofield LN, Desrosiers MA. River food chains lead to riparian bats and birds in two mid‐order rivers. Ecosphere 2020. [DOI: 10.1002/ecs2.3148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Breeanne K. Jackson
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Sarah L. Stock
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Leila S. Harris
- Department of Wildlife, Fish, and Conservation Biology University of California Davis California 95616 USA
| | - Joseph M. Szewczak
- Department of Biological Sciences Humboldt State University Arcata California 95521 USA
| | - Lynn N. Schofield
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
| | - Michelle A. Desrosiers
- Resources Management and Science Division Yosemite National Park El Portal California 95318 USA
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25
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Jellyman PG, McIntosh AR. Disturbance‐mediated consumer assemblages determine fish community structure and moderate top‐down influences through bottom‐up constraints. J Anim Ecol 2020; 89:1175-1189. [DOI: 10.1111/1365-2656.13168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 09/04/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Phillip G. Jellyman
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- National Institute of Water and Atmospheric Research Christchurch New Zealand
| | - Angus R. McIntosh
- School of Biological Sciences University of Canterbury Christchurch New Zealand
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26
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Burdon FJ, McIntosh AR, Harding JS. Mechanisms of trophic niche compression: Evidence from landscape disturbance. J Anim Ecol 2019; 89:730-744. [DOI: 10.1111/1365-2656.13142] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 09/28/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Francis J. Burdon
- School of Biological Sciences University of Canterbury Christchurch New Zealand
- Department of Aquatic Ecology Eawag: Swiss Federal Institute of Aquatic Science and Technology Dübendorf Switzerland
- Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences Uppsala Sweden
| | - Angus R. McIntosh
- School of Biological Sciences University of Canterbury Christchurch New Zealand
| | - Jon S. Harding
- School of Biological Sciences University of Canterbury Christchurch New Zealand
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27
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Moran NP, Wong BBM, Thompson RM. Communities at the extreme: Aquatic food webs in desert landscapes. Ecol Evol 2019; 9:11464-11475. [PMID: 31641486 PMCID: PMC6802011 DOI: 10.1002/ece3.5648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 12/01/2022] Open
Abstract
Studying food webs across contrasting abiotic conditions is an important tool in understanding how environmental variability impacts community structure and ecosystem dynamics. The study of extreme environments provides insight into community-wide level responses to environmental pressures with relevance to the future management of aquatic ecosystems. In the western Lake Eyre Basin of arid Australia, there are two characteristic and contrasting aquatic habitats: springs and rivers. Permanent isolated Great Artesian Basin springs represent hydrologically persistent environments in an arid desert landscape. In contrast, hydrologically variable river waterholes are ephemeral in space and time. We comprehensively sampled aquatic assemblages in contrasting ecosystem types to assess patterns in community composition and to quantify food web attributes with stable isotopes. Springs and rivers were found to have markedly different invertebrate communities, with rivers dominated by more dispersive species and springs associated with species that show high local endemism. Qualitative assessment of basal resources shows autochthonous carbon appears to be a key basal resource in both types of habitat, although the particular sources differed between habitats. Food-web variables such as trophic length, trophic breadth, and community isotopic niche size were relatively similar in the two habitat types. The basis for the similarity in food-web structure despite differences in community composition appears to be broader isotopic niches for predatory invertebrates and fish in springs as compared with rivers. In contrast to published theory, our findings suggest that the food webs of the hydrologically variable river sites may show less dietary generalization and more compact food-web modules than in springs.
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Affiliation(s)
- Nicholas P. Moran
- School of Biological SciencesMonash UniversityClaytonVic.Australia
- Evolutionary BiologyBielefeld UniversityBielefeldGermany
| | - Bob B. M. Wong
- School of Biological SciencesMonash UniversityClaytonVic.Australia
| | - Ross M. Thompson
- Institute for Applied EcologyUniversity of CanberraCanberraACTAustralia
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28
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Palmer M, Ruhi A. Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration. Science 2019; 365:365/6459/eaaw2087. [DOI: 10.1126/science.aaw2087] [Citation(s) in RCA: 187] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
River ecosystems are highly biodiverse, influence global biogeochemical cycles, and provide valued services. However, humans are increasingly degrading fluvial ecosystems by altering their streamflows. Effective river restoration requires advancing our mechanistic understanding of how flow regimes affect biota and ecosystem processes. Here, we review emerging advances in hydroecology relevant to this goal. Spatiotemporal variation in flow exerts direct and indirect control on the composition, structure, and dynamics of communities at local to regional scales. Streamflows also influence ecosystem processes, such as nutrient uptake and transformation, organic matter processing, and ecosystem metabolism. We are deepening our understanding of how biological processes, not just static patterns, affect and are affected by stream ecosystem processes. However, research on this nexus of flow-biota-ecosystem processes is at an early stage. We illustrate this frontier with evidence from highly altered regulated rivers and urban streams. We also identify research challenges that should be prioritized to advance process-based river restoration.
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Zhao Q, Van den Brink PJ, Carpentier C, Wang YXG, Rodríguez-Sánchez P, Xu C, Vollbrecht S, Gillissen F, Vollebregt M, Wang S, De Laender F. Horizontal and vertical diversity jointly shape food web stability against small and large perturbations. Ecol Lett 2019; 22:1152-1162. [PMID: 31095883 PMCID: PMC6852190 DOI: 10.1111/ele.13282] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 02/19/2019] [Accepted: 04/22/2019] [Indexed: 12/30/2022]
Abstract
The biodiversity of food webs is composed of horizontal (i.e. within trophic levels) and vertical diversity (i.e. the number of trophic levels). Understanding their joint effect on stability is a key challenge. Theory mostly considers their individual effects and focuses on small perturbations near equilibrium in hypothetical food webs. Here, we study the joint effects of horizontal and vertical diversity on the stability of hypothetical (modelled) and empirical food webs. In modelled food webs, horizontal and vertical diversity increased and decreased stability, respectively, with a stronger positive effect of producer diversity on stability at higher consumer diversity. Experiments with an empirical plankton food web, where we manipulated horizontal and vertical diversity and measured stability from species interactions and from resilience against large perturbations, confirmed these predictions. Taken together, our findings highlight the need to conserve horizontal biodiversity at different trophic levels to ensure stability.
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Affiliation(s)
- Qinghua Zhao
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Paul J Van den Brink
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands.,Wageningen Environmental Research, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Camille Carpentier
- Research Unit of Environmental and Evolutionary Biology, Namur Institute of Complex Systems, and Institute of Life, Earth, and the Environment, University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
| | - Yingying X G Wang
- Resource Ecology Group, Wageningen University, Droevendaalsesteeg 3a, 6708 PB, Wageningen, The Netherlands
| | - Pablo Rodríguez-Sánchez
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Chi Xu
- School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Silke Vollbrecht
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Frits Gillissen
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Marlies Vollebregt
- Aquatic Ecology and Water Quality Management Group, Wageningen University, P.O. Box 47, 6700 AA, Wageningen, The Netherlands
| | - Shaopeng Wang
- Institute of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, 100871, Beijing, China
| | - Frederik De Laender
- Research Unit of Environmental and Evolutionary Biology, Namur Institute of Complex Systems, and Institute of Life, Earth, and the Environment, University of Namur, Rue de Bruxelles 61, 5000, Namur, Belgium
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30
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Lafage D, Bergman E, Eckstein RL, Österling EM, Sadler JP, Piccolo JJ. Local and landscape drivers of aquatic‐to‐terrestrial subsidies in riparian ecosystems: a worldwide meta‐analysis. Ecosphere 2019. [DOI: 10.1002/ecs2.2697] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- D. Lafage
- Department of Environmental and Life Sciences/Biology Karlstad University Karlstad Sweden
| | - E. Bergman
- Department of Environmental and Life Sciences/Biology Karlstad University Karlstad Sweden
| | - R. L. Eckstein
- Department of Environmental and Life Sciences/Biology Karlstad University Karlstad Sweden
| | - E. M. Österling
- Department of Environmental and Life Sciences/Biology Karlstad University Karlstad Sweden
| | - J. P. Sadler
- School of Geography, Earth and Environmental Sciences The University of Birmingham Birmingham UK
| | - J. J. Piccolo
- Department of Environmental and Life Sciences/Biology Karlstad University Karlstad Sweden
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31
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Doi H, Hillebrand H. Historical contingency and productivity effects on food-chain length. Commun Biol 2019; 2:40. [PMID: 30701205 PMCID: PMC6349908 DOI: 10.1038/s42003-019-0287-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 12/27/2018] [Indexed: 11/10/2022] Open
Abstract
Food-chain length (FCL) is a fundamental ecosystem attribute, integrating information on both food web composition and ecosystem processes. It remains untested whether FCL also reflects the history of community assembly known to affect community composition and ecosystem functioning. Here, we performed microcosm experiments with a copepod (top predator), two ciliate species (intermediate consumers), and bacteria (producers), and modified the sequence of species introduction into the microcosm at four productivity levels to jointly test the effects of historical contingency and productivity on FCL. FCL increased when the top predator was introduced last; thus, the trophic position of the copepod reflected assembly history. A shorter FCL occurred at the highest productivity level, probably because the predator switched to feeding at the lower trophic levels because of the abundant basal resource. Thus, we present empirical evidence that FCL was determined by historical contingency, likely caused by priority effects, and by productivity.
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Affiliation(s)
- Hideyuki Doi
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, 26382 Wilhelmshaven, Germany
- Graduate School of Simulation Studies, University of Hyogo, 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047 Japan
| | - Helmut Hillebrand
- Institute for Chemistry and Biology of the Marine Environment, Carl-von-Ossietzky University Oldenburg, Schleusenstrasse 1, 26382 Wilhelmshaven, Germany
- Helmholtz-Institute for Functional Marine Biodiversity at the University Oldenburg (HIFMB), Ammerländer Heerstrasse 231, 26129 Oldenburg, Germany
- Alfred-Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570 Germany
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32
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Pomeranz JPF, Thompson RM, Poisot T, Harding JS. Inferring predator–prey interactions in food webs. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.13125] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Ross M. Thompson
- Institute for Applied Ecology University of Canberra Bruce ACT Australia
| | - Timothée Poisot
- Département de Sciences Biologiques Université de Montréal Montréal QC Canada
| | - Jon S. Harding
- School of Biological Sciences University of Canterbury Christchurch New Zealand
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33
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Maceda-Veiga A, Mac Nally R, de Sostoa A. Environmental correlates of food-chain length, mean trophic level and trophic level variance in invaded riverine fish assemblages. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:420-429. [PMID: 29981992 DOI: 10.1016/j.scitotenv.2018.06.304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/24/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
Examining how the trophic structure of biotic assemblages is affected by human impacts, such as habitat degradation and the introduction of alien species, is important for understanding the consequences of such impacts on ecosystem functioning. We used general linear mixed models and hierarchical partitioning analyses of variance to examine for the first time the applicability of three hypotheses (ecosystem-size, productivity and disturbance) for explaining food-chain length (FCL) in invaded fish assemblages. We used Fishbase trophic level (TL) estimates for 16 native and 18 alien fish species in an extensive riverine system in north-eastern Spain (99,700 km2, 15 catchments, 530 sites). The FCL of assemblages ranged from 2.7 to 4.42. Ecosystem size-related variables (Strahler stream order, physical habitat diversity) and human-disturbance (conductivity) made the largest contribution to the explained variance in the FCL model after accounting for spatial confounding factors and collinearity among predictors. Within-assemblage TL also was positively associated with Strahler stream order, suggesting that large rivers have the highest trophic diversity. High conductivity was negatively associated with FCL, as did with the mean TL of fish assemblages. However, an inverse association was found between mean TL and Strahler stream order, possibly because the presence of fish species of high TL may be offset by larger numbers of alien species of lower TL in large rivers. Given that there may be trophic replacements among native and alien species, this inference needs to be addressed with detailed trophic studies. However, reducing water conductivity by improved wastewater treatment and better agricultural practices probably would help to conserve the fish species on the apices of aquatic food-webs.
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Affiliation(s)
- Alberto Maceda-Veiga
- Department of Evolutionary Biology, Ecology and Environmental Sciences & Institute of Research in Biodiversity, Universitat de Barcelona (IRBio-UB), 08028 Barcelona, Spain; Department of Integrative Ecology, Estación Biológica de Doñana (EBD-CSIC), 41092 Sevilla, Spain.
| | - Ralph Mac Nally
- Institute for Applied Ecology, University of Canberra, Bruce 2617, ACT, Australia
| | - Adolfo de Sostoa
- Department of Evolutionary Biology, Ecology and Environmental Sciences & Institute of Research in Biodiversity, Universitat de Barcelona (IRBio-UB), 08028 Barcelona, Spain
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34
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McIntosh AR, McHugh PA, Plank MJ, Jellyman PG, Warburton HJ, Greig HS. Capacity to support predators scales with habitat size. SCIENCE ADVANCES 2018; 4:eaap7523. [PMID: 29978038 PMCID: PMC6031369 DOI: 10.1126/sciadv.aap7523] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 05/22/2018] [Indexed: 05/31/2023]
Abstract
Habitat reduction could drive biodiversity loss if the capacity of food webs to support predators is undermined by habitat-size constraints on predator body size. Assuming that (i) available space restricts predator body size, (ii) mass-specific energy needs of predators scale with their body size, and (iii) energy availability scales with prey biomass, we predicted that predator biomass per unit area would scale with habitat size (quarter-power exponent) and prey biomass (three-quarter-power exponent). We found that total predator biomass scaled with habitat size and prey resources as expected across 29 New Zealand rivers, such that a unit of habitat in a small ecosystem supported less predator biomass than an equivalent unit in a large ecosystem. The lower energetic costs of large body size likely mean that a unit of prey resource supports more biomass of large-bodied predators compared to small-bodied predators. Thus, contracting habitat size reduces the predator mass that can be supported because of constraints on predator body size, and this may be a powerful mechanism exacerbating reductions in biodiversity due to habitat loss.
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Affiliation(s)
- Angus R. McIntosh
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Peter A. McHugh
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Michael J. Plank
- Te Pūnaha Matatini and School of Mathematics and Statistics, University of Canterbury, Christchurch, New Zealand
| | - Phillip G. Jellyman
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Helen J. Warburton
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Hamish S. Greig
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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35
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Mor JR, Ruhí A, Tornés E, Valcárcel H, Muñoz I, Sabater S. Dam regulation and riverine food-web structure in a Mediterranean river. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 625:301-310. [PMID: 29289778 PMCID: PMC5861997 DOI: 10.1016/j.scitotenv.2017.12.296] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 12/24/2017] [Accepted: 12/24/2017] [Indexed: 05/24/2023]
Abstract
Flow regimes are a major driver of community composition and structure in riverine ecosystems, and flow regulation by dams often induces artificially-stable flow regimes downstream. This represents a major source of hydrological alteration, particularly in regions where biota is adapted to strong seasonal and interannual flow variability. We hypothesized that dam-induced hydrological stability should increase the availability of autochthonous resources at the base of the food web. This, in turn, should favour herbivorous over detritivorous strategies, increasing the diversity of primary consumers, and the food-web width and length. We tested this hypothesis by studying the longitudinal variation in food-web structure in a highly-seasonal Mediterranean river affected by an irrigation dam. We compared an unregulated reach to several reaches downstream of the dam. Hydrological and sedimentological stability increased downstream of the dam, and altered the type and quantity of available resources downstream, prompting a change from a detritus-based to an algae-based food web. The fraction of links between top and intermediate species also increased, and the food web became longer and wider at the intermediate trophic levels. Food-web structure did not recover 14km downstream of the dam, despite a partial restitution of the flow regime. Our results advance the notion that hydrologic alteration affects riverine food webs via additions/deletions of taxa and variation in the strength and distribution of food-web interactions. Thus, flow regulation by dams may not only impact individual facets of biodiversity, but also food-web level properties across river networks.
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Affiliation(s)
- Jordi-René Mor
- Catalan Institute for Water Research (ICRA), Girona, Spain; Department of Evolutionary Biology, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Spain.
| | - Albert Ruhí
- Catalan Institute for Water Research (ICRA), Girona, Spain; Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA 94720-3114, USA
| | - Elisabet Tornés
- Catalan Institute for Water Research (ICRA), Girona, Spain; Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Héctor Valcárcel
- Institute of Aquatic Ecology, University of Girona, Girona, Spain
| | - Isabel Muñoz
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Sergi Sabater
- Catalan Institute for Water Research (ICRA), Girona, Spain; Institute of Aquatic Ecology, University of Girona, Girona, Spain
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36
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Capmourteres V, Rooney N, Anand M. Assessing the causal relationships of ecological integrity: a re-evaluation of Karr's iconic Index of Biotic Integrity. Ecosphere 2018. [DOI: 10.1002/ecs2.2168] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Virginia Capmourteres
- School of Environmental Sciences; University of Guelph; 50 Stone Road East Guelph Ontario N1G 2W1 Canada
| | - Neil Rooney
- School of Environmental Sciences; University of Guelph; 50 Stone Road East Guelph Ontario N1G 2W1 Canada
| | - Madhur Anand
- School of Environmental Sciences; University of Guelph; 50 Stone Road East Guelph Ontario N1G 2W1 Canada
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37
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Linking DNA Metabarcoding and Text Mining to Create Network-Based Biomonitoring Tools: A Case Study on Boreal Wetland Macroinvertebrate Communities. ADV ECOL RES 2018. [DOI: 10.1016/bs.aecr.2018.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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38
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Ward CL, McCann KS. A mechanistic theory for aquatic food chain length. Nat Commun 2017; 8:2028. [PMID: 29229910 PMCID: PMC5725575 DOI: 10.1038/s41467-017-02157-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/08/2017] [Indexed: 11/10/2022] Open
Abstract
Multiple hypotheses propose an ostensibly disparate array of drivers of food chain length (FCL), with contradictory support from natural settings. Here we posit that the magnitude of vertical energy flux in food webs underlies several drivers of FCL. We show that rising energy flux fuels top-heavy biomass pyramids, promoting omnivory, thereby reducing FCL. We link this theory to commonly evaluated hypotheses for environmental drivers of FCL (productivity, ecosystem size) and demonstrate that effects of these drivers should be context-dependent. We evaluate support for this theory in lake and marine ecosystems and demonstrate that ecosystem size is the most important driver of FCL in low-productivity ecosystems (positive relationship) while productivity is most important in large and high-productivity ecosystems (negative relationship). This work stands in contrast to classical hypotheses, which predict a positive effect of productivity on FCL, and may help reconcile the contradictory nature of published results for drivers of FCL.
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Affiliation(s)
- Colette L Ward
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada.
- National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, 735 State Street, Suite 300, Santa Barbara, CA, 93101-5504, USA.
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
| | - Kevin S McCann
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
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39
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Hanley TC, Kimbro DL, Hughes AR. Stress and subsidy effects of seagrass wrack duration, frequency, and magnitude on salt marsh community structure. Ecology 2017; 98:1884-1895. [DOI: 10.1002/ecy.1862] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/09/2017] [Accepted: 04/05/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Torrance C. Hanley
- Department of Marine and Environmental Science Marine Science Center Northeastern University Nahant Massachusetts 01908 USA
| | - David L. Kimbro
- Department of Marine and Environmental Science Marine Science Center Northeastern University Nahant Massachusetts 01908 USA
| | - Anne Randall Hughes
- Department of Marine and Environmental Science Marine Science Center Northeastern University Nahant Massachusetts 01908 USA
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40
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Ziegler JP, Gregory-Eaves I, Solomon CT. Refuge increases food chain length: modeled impacts of littoral structure in lake food webs. OIKOS 2017. [DOI: 10.1111/oik.03517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Jacob P. Ziegler
- Dept of Natural Resource Sciences, McGill Univ.; Montreal, 21111 Lakeshore Road Ste. Anne de Bellevue; QC H9X 3V9 Canada
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41
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White RSA, McHugh PA, McIntosh AR. Drought survival is a threshold function of habitat size and population density in a fish metapopulation. GLOBAL CHANGE BIOLOGY 2016; 22:3341-3348. [PMID: 26929393 DOI: 10.1111/gcb.13265] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/22/2016] [Indexed: 06/05/2023]
Abstract
Because smaller habitats dry more frequently and severely during droughts, habitat size is likely a key driver of survival in populations during climate change and associated increased extreme drought frequency. Here, we show that survival in populations during droughts is a threshold function of habitat size driven by an interaction with population density in metapopulations of the forest pool dwelling fish, Neochanna apoda. A mark-recapture study involving 830 N. apoda individuals during a one-in-seventy-year extreme drought revealed that survival during droughts was high for populations occupying pools deeper than 139 mm, but declined steeply in shallower pools. This threshold was caused by an interaction between increasing population density and drought magnitude associated with decreasing habitat size, which acted synergistically to increase physiological stress and mortality. This confirmed two long-held hypotheses, firstly concerning the interactive role of population density and physiological stress, herein driven by habitat size, and secondly, the occurrence of drought survival thresholds. Our results demonstrate how survival in populations during droughts will depend strongly on habitat size and highlight that minimum habitat size thresholds will likely be required to maximize survival as the frequency and intensity of droughts are projected to increase as a result of global climate change.
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Affiliation(s)
- Richard S A White
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
| | - Peter A McHugh
- Department of Watershed Sciences, Utah State University and Eco Logical Research Inc., 5210 Old Main Hill, Logan, UT, 84322, USA
| | - Angus R McIntosh
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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42
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Jellyman PG, Harding JS. Disentangling the stream community impacts of Didymosphenia geminata: How are higher trophic levels affected? Biol Invasions 2016. [DOI: 10.1007/s10530-016-1233-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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43
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Culumber ZW, Tobler M. Spatiotemporal environmental heterogeneity and the maintenance of the tailspot polymorphism in the variable platyfish (Xiphophorus variatus). Evolution 2016; 70:408-19. [PMID: 26748941 DOI: 10.1111/evo.12852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 10/29/2015] [Accepted: 12/08/2015] [Indexed: 11/28/2022]
Abstract
Genetic variation is critical for adaptive evolution. Despite its importance, there is still limited evidence in support of some prominent theoretical models explaining the maintenance of genetic polymorphism within populations. We examined 84 populations of Xiphophorus variatus, a livebearing fish with a genetic polymorphism associated with physiological performance, to test: (1) whether niche differentiation explains broad-scale maintenance of polymorphism, (2) whether polymorphism is maintained among populations by local adaptation and migration, or (3) whether heterogeneity in explicit environmental variables could be linked to levels of polymorphism within populations. We found no evidence of climatic niche differentiation that could generate or maintain broad geographic variation in polymorphism. Subsequently, hierarchical partitioning of genetic richness and partial mantel tests revealed that 76% of the observed genetic richness was partitioned within populations with no effect of geographic distance on polymorphism. These results strongly suggest a lack of migration-selection balance in the maintenance of polymorphism, and model selection confirmed a significant relationship between environmental heterogeneity and genetic richness within populations. Few studies have demonstrated such effects at this scale, and additional studies in other taxa should examine the generality of gene-by-environment interactions across populations to better understand the dynamics and scale of balancing selection.
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Affiliation(s)
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, 66506
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44
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Barnum TR, Drake JM, Colón-Gaud C, Rugenski AT, Frauendorf TC, Connelly S, Kilham SS, Whiles MR, Lips KR, Pringle CM. Evidence for the persistence of food web structure after amphibian extirpation in a Neotropical stream. Ecology 2015; 96:2106-16. [DOI: 10.1890/14-1526.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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45
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Sullivan SMP, Hossler K, Cianfrani CM. Ecosystem Structure Emerges as a Strong Determinant of Food-Chain Length in Linked Stream–Riparian Ecosystems. Ecosystems 2015. [DOI: 10.1007/s10021-015-9904-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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46
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Saigo M, Zilli FL, Marchese MR, Demonte D. Trophic level, food chain length and omnivory in the Paraná River: a food web model approach in a floodplain river system. Ecol Res 2015. [DOI: 10.1007/s11284-015-1283-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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47
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Verburg P, Hickey CW, Phillips N. Mercury biomagnification in three geothermally-influenced lakes differing in chemistry and algal biomass. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 493:342-354. [PMID: 24951892 DOI: 10.1016/j.scitotenv.2014.05.097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/30/2014] [Accepted: 05/22/2014] [Indexed: 06/03/2023]
Abstract
Accumulation of Hg in aquatic organisms is influenced not only by the contaminant load but also by various environmental variables. We compared biomagnification of Hg in aquatic organisms, i.e., the rate at which Hg accumulates with increasing trophic position, in three lakes differing in trophic state. Total Hg (THg) concentrations in food webs were compared in an oligotrophic, a mesotrophic and a eutrophic lake with naturally elevated levels of Hg associated with geothermal water inputs. We explored relationships of physico-chemistry attributes of lakes with Hg concentrations in fish and biomagnification in the food web. Trophic positions of biota and food chain length were distinguished by stable isotope (15)N. As expected, THg in phytoplankton decreased with increasing eutrophication, suggesting the effect of biomass dilution. In contrast, THg biomagnification and THg concentrations in trout were controlled by environmental physico-chemistry and were highest in the eutrophic lake. In the more eutrophic lake frequent anoxia occurred, resulting in favorable conditions for Hg transfer into and up the food chain. The average concentration of THg in the top predator (rainbow trout) exceeded the maximum recommended level for consumption by up to 440%. While there were differences between lakes in food chain length between plankton and trout, THg concentration in trout did not increase with food chain length, suggesting other factors were more important. Differences between the lakes in biomagnification and THg concentration in trout correlated as expected from previous studies with eight physicochemical variables, resulting in enhanced biomagnification of THg in the eutrophic lake.
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Affiliation(s)
- Piet Verburg
- National Institute of Water and Atmospheric Research, Hamilton, PO Box 11115, Hamilton 3251, New Zealand.
| | - Christopher W Hickey
- National Institute of Water and Atmospheric Research, Hamilton, PO Box 11115, Hamilton 3251, New Zealand
| | - Ngaire Phillips
- National Institute of Water and Atmospheric Research, Hamilton, PO Box 11115, Hamilton 3251, New Zealand
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48
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Jellyman PG, McHugh PA, McIntosh AR. Increases in disturbance and reductions in habitat size interact to suppress predator body size. GLOBAL CHANGE BIOLOGY 2014; 20:1550-1558. [PMID: 24133009 DOI: 10.1111/gcb.12441] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/20/2013] [Accepted: 09/21/2013] [Indexed: 06/02/2023]
Abstract
Food webs are strongly size-structured so will be vulnerable to changes in environmental factors that affect large predators. However, mechanistic understanding of environmental controls of top predator size is poorly developed. We used streams to investigate how predator body size is altered by three fundamental climate change stressors: reductions in habitat size, increases in disturbance and warmer temperatures. Using new survey data from 74 streams, we showed that habitat size and disturbance were the most important stressors influencing predator body size. A synergistic interaction between that habitat size and disturbance due to flooding meant the sizes of predatory fishes peaked in large, benign habitats and their body size decreased as habitats became either smaller or harsher. These patterns were supported by experiments indicating that habitat-size reductions and increased flood disturbance decreased both the abundance and biomass of large predators. This research indicates that interacting climate change stressors can influence predator body size, resulting in smaller predators than would be predicted from examining an environmental factor in isolation. Thus, climate-induced changes to key interacting environmental factors are likely to have synergistic impacts on predator body size which, because of their influence on the strength of biological interactions, will have far-reaching effects on food-web responses to global environmental change.
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Affiliation(s)
- Phillip G Jellyman
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand; National Institute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand
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49
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Perkins MJ, McDonald RA, van Veen FJF, Kelly SD, Rees G, Bearhop S. Application of nitrogen and carbon stable isotopes (δ(15)N and δ(13)C) to quantify food chain length and trophic structure. PLoS One 2014; 9:e93281. [PMID: 24676331 PMCID: PMC3968125 DOI: 10.1371/journal.pone.0093281] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 03/04/2014] [Indexed: 11/25/2022] Open
Abstract
Increasingly, stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ(15)N, and carbon range (CR) using δ(13)C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ(15)N or δ(13)C from source to consumer) between trophic levels and among food chains. δ(15)N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ(13)C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ(13)C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of ecological systems.
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Affiliation(s)
- Matthew J. Perkins
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Robbie A. McDonald
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, United Kingdom
| | - F. J. Frank van Veen
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Simon D. Kelly
- Food and Environment Research Agency, York, Yorkshire, United Kingdom
| | - Gareth Rees
- Food and Environment Research Agency, York, Yorkshire, United Kingdom
| | - Stuart Bearhop
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, United Kingdom
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50
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Ulanowicz RE, Holt RD, Barfield M. Limits on ecosystem trophic complexity: insights from ecological network analysis. Ecol Lett 2013; 17:127-36. [PMID: 24382355 DOI: 10.1111/ele.12216] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/10/2013] [Accepted: 10/04/2013] [Indexed: 11/29/2022]
Abstract
Articulating what limits the length of trophic food chains has remained one of the most enduring challenges in ecology. Mere counts of ecosystem species and transfers have not much illumined the issue, in part because magnitudes of trophic transfers vary by orders of magnitude in power-law fashion. We address this issue by creating a suite of measures that extend the basic indexes usually obtained by counting taxa and transfers so as to apply to networks wherein magnitudes vary by orders of magnitude. Application of the extended measures to data on ecosystem trophic networks reveals that the actual complexity of ecosystem webs is far less than usually imagined, because most ecosystem networks consist of a multitude of weak connections dominated by a relatively few strong flows. Although quantitative ecosystem networks may consist of hundreds of nodes and thousands of transfers, they nevertheless behave similarly to simpler representations of systems with fewer than 14 nodes or 40 flows. Both theory and empirical data point to an upper bound on the number of effective trophic levels at about 3-4 links. We suggest that several whole-system processes may be at play in generating these ecosystem limits and regularities.
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Affiliation(s)
- Robert E Ulanowicz
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA; Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, 20688, USA
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