29 results on '"Martinez, Neo D."'
Search Results
2. Artifacts or Attributes? Effects of Resolution on the Little Rock Lake Food Web
- Author
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Martinez, Neo D.
- Published
- 1991
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3. Ecogeographical rules and the macroecology of food webs.
- Author
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Baiser, Benjamin, Gravel, Dominique, Cirtwill, Alyssa R., Dunne, Jennifer A., Fahimipour, Ashkaan K., Gilarranz, Luis J., Grochow, Joshua A., Li, Daijiang, Martinez, Neo D., McGrew, Alicia, Poisot, Timothée, Romanuk, Tamara N., Stouffer, Daniel B., Trotta, Lauren B., Valdovinos, Fernanda S., Williams, Richard J., Wood, Spencer A., Yeakel, Justin D., and Fortin, Marie‐Josée
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MACROECOLOGY ,FOOD chains ,FOOD portions - Abstract
Aim: How do factors such as space, time, climate and other ecological drivers influence food web structure and dynamics? Collections of well‐studied food webs and replicate food webs from the same system that span biogeographical and ecological gradients now enable detailed, quantitative investigation of such questions and help integrate food web ecology and macroecology. Here, we integrate macroecology and food web ecology by focusing on how ecogeographical rules [the latitudinal diversity gradient (LDG), Bergmann's rule, the island rule and Rapoport's rule] are associated with the architecture of food webs. Location: Global. Time period: Current. Major taxa studied: All taxa. Methods: We discuss the implications of each ecogeographical rule for food webs, present predictions for how food web structure will vary with each rule, assess empirical support where available, and discuss how food webs may influence ecogeographical rules. Finally, we recommend systems and approaches for further advancing this research agenda. Results: We derived testable predictions for some ecogeographical rules (e.g. LDG, Rapoport's rule), while for others (e.g., Bergmann's and island rules) it is less clear how we would expect food webs to change over macroecological scales. Based on the LDG, we found weak support for both positive and negative relationships between food chain length and latitude and for increased generality and linkage density at higher latitudes. Based on Rapoport's rule, we found support for the prediction that species turnover in food webs is inversely related to latitude. Main conclusions: The macroecology of food webs goes beyond traditional approaches to biodiversity at macroecological scales by focusing on trophic interactions among species. The collection of food web data for different types of ecosystems across biogeographical gradients is key to advance this research agenda. Further, considering food web interactions as a selection pressure that drives or disrupts ecogeographical rules has the potential to address both mechanisms of and deviations from these macroecological relationships. For these reasons, further integration of macroecology and food webs will help ecologists better understand the assembly, maintenance and change of ecosystems across space and time. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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4. Environmentally‐induced noise dampens and reddens with increasing trophic level in a complex food web.
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Kuparinen, Anna, Perälä, Tommi, Martinez, Neo D., and Valdovinos, Fernanda S.
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NOISE ,ECOLOGICAL impact ,FOOD chains ,ECOSYSTEM dynamics ,ABIOTIC environment - Abstract
Stochastic variability of key abiotic factors including temperature, precipitation and the availability of light and nutrients greatly influences species' ecological function and evolutionary fate. Despite such influence, ecologists have typically ignored the effect of abiotic stochasticity on the structure and dynamics of ecological networks. Here we help to fill that gap by advancing the theory of how abiotic stochasticity, in the form of environmental noise, affects the population dynamics of species within food webs. We do this by analysing an allometric trophic network model of Lake Constance subjected to positive (red), negative (blue), and non‐autocorrelated (white) abiotic temporal variability (noise) introduced into the carrying capacity of basal species. We found that, irrespective of the colour of the introduced noise, the temporal variability of the species biomass within the network both reddens (i.e. its positive autocorrelation increases) and dampens (i.e. the magnitude of variation decreases) as the environmental noise is propagated through the food web by its feeding interactions from the bottom to the top. The reddening reflects a buffering of the noise‐induced population variability by complex food web dynamics such that non‐autocorrelated oscillations of noise‐free deterministic dynamics become positively autocorrelated. Our research helps explain frequently observed red variability of natural populations by suggesting that ecological processing of environmental noise through food webs with a range of species' body sizes reddens population variability in nature. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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5. On the prevalence and dynamics of inverted trophic pyramids and otherwise top‐heavy communities.
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McCauley, Douglas J., Gellner, Gabriel, Martinez, Neo D., Williams, Richard J., Sandin, Stuart A., Micheli, Fiorenza, Mumby, Peter J., and McCann, Kevin S.
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PYRAMIDS ,BIOMASS ,FOOD chains ,ENERGY transfer ,BIOTIC communities - Abstract
Abstract: Classically, biomass partitioning across trophic levels was thought to add up to a pyramidal distribution. Numerous exceptions have, however, been noted including complete pyramidal inversions. Elevated levels of biomass top‐heaviness (i.e. high consumer/resource biomass ratios) have been reported from Arctic tundra communities to Brazilian phytotelmata, and in species assemblages as diverse as those dominated by sharks and ants. We highlight two major pathways for creating top‐heaviness, via: (1) endogenous channels that enhance energy transfer across trophic boundaries within a community and (2) exogenous pathways that transfer energy into communities from across spatial and temporal boundaries. Consumer–resource models and allometric trophic network models combined with niche models reveal the nature of core mechanisms for promoting top‐heaviness. Outputs from these models suggest that top‐heavy communities can be stable, but they also reveal sources of instability. Humans are both increasing and decreasing top‐heaviness in nature with ecological consequences. Current and future research on the drivers of top‐heaviness can help elucidate fundamental mechanisms that shape the architecture of ecological communities and govern energy flux within and between communities. Questions emerging from the study of top‐heaviness also usefully draw attention to the incompleteness and inconsistency by which ecologists often establish definitional boundaries for communities. [ABSTRACT FROM AUTHOR]
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- 2018
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6. Effects of trophic similarity on community composition.
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Morlon, Hélène, Kefi, Sonia, Martinez, Neo D., and Novotny, Vojtech
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FOOD chains ,ECOLOGICAL niche ,ECOSYSTEMS ,CONSUMERS ,PHYLOGENY ,DISPERSAL (Ecology) ,ECOLOGICAL research - Abstract
Understanding how ecological processes determine patterns among species coexisting within ecosystems is central to ecology. Here, we explore relationships between species' local coexistence and their trophic niches in terms of their feeding relationships both as consumers and as resources. We build on recent concepts and methods from community phylogenetics to develop a framework for analysing mechanisms responsible for community composition using trophic similarity among species and null models of community assembly. We apply this framework to 50 food webs found in 50 Adirondack lakes and find that species composition in these communities appears to be driven by both bottom-up effects by which the presence of prey species selects for predators of those prey, and top-down effects by which prey more tolerant of predation out-compete less tolerant prey of the same predators. This approach to community food webs is broadly applicable and shows how species interaction networks can inform an increasingly large array of theory central to community ecology. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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7. 8.1 HOW DO COMPLEX FOOD WEBS PERSIST IN NATURE?
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Dell, Anthony I., Kokkoris, Giorgos D., Banašek-Richter, Carolin, Bersier, Louis-Félix, Dunne, Jennifer A., Kondoh, Michio, Romanuk, Tamara N., and Martinez, Neo D.
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FOOD chains ,BIOCOMPLEXITY - Abstract
Chapter 8.1 of the book "Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change" is presented. It characterizes the ability of complex food webs to thrive in nature based on complexity and stability. It explores the different methods of studying food webs such as topological, empirical and theoretical analyses. It also cites factors that allow food webs to flourish in nature such as omnivory, the importance of weak links, and change in feeding habits.
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- 2005
8. 7.5 COMMUNICATING ECOLOGY THROUGH FOOD WEBS: VISUALIZING AND QUANTIFYING THE EFFECTS OF STOCKING ALPINE LAKES WITH TROUT.
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Harper-Smith, Sarah, Berlow, Eric L., Knapp, Roland A., Williams, Richard J., and Martinez, Neo D.
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FOOD chains - Abstract
Chapter 7.5 of the book "Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development and Environmental Change" is presented. It discusses a case study done on the mountain lakes of the Sierra Nevada of California. It presents the methods used in collating the data gathered from a survey of feeding information for all species found in about 200 of the Sierra Nevada lakes as well as the results.
- Published
- 2005
9. 2.1 FROM FOOD WEBS TO ECOLOGICAL NETWORKS: LINKING NON-LINEAR TROPHIC INTERACTIONS WITH NUTRIENT COMPETITION.
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Brose, Ulrich, Berlow, Eric L., and Martinez, Neo D.
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FOOD chains ,ECOLOGY ,NUTRIENT cycles ,BIOLOGICAL productivity ,ENVIRONMENTAL sciences - Abstract
Chapter 2.1 of the book "Dynamic Food Webs: Multispecies Assemblages, Ecosystem Development & Environmental Change" is presented. It presents a method for exploring the dynamics of complex trophic interactions and consumption of multiple abiotic resources among producer species with the use of non-linear and non-equilibrium numerical simulations. As stated, this method changes siple food-web models into general models of complex ecological networks. These can expand to systems with many more species and abiotic resources.
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- 2005
10. Parasites Affect Food Web Structure Primarily through Increased Diversity and Complexity.
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Dunne, Jennifer A., Lafferty, Kevin D., Dobson, Andrew P., Hechinger, Ryan F., Kuris, Armand M., Martinez, Neo D., McLaughlin, John P., Mouritsen, Kim N., Poulin, Robert, Reise, Karsten, Stouffer, Daniel B., Thieltges, David W., Williams, Richard J., and Zander, Claus Dieter
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PARASITES ,PESTS ,FOOD chains ,ECOLOGICAL niche ,ERROR - Abstract
: Parasites primarily affect food web structure through changes to diversity and complexity. However, compared to free-living species, their life-history traits lead to more complex feeding niches and altered motifs. [ABSTRACT FROM AUTHOR]
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- 2013
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11. Simple prediction of interaction strengths in complex food webs.
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Berlow, Eric L., Dunne, Jennifer A., Martinez, Neo D., Stark, Philip B., Williams, Richard J., and Brose, Ulrich
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FOOD chains ,SPECIES ,BIOMASS ,BIOLOGICAL extinction - Abstract
Darwin's classic image of an "entangled bank" of interdependencies among species has long suggested that it is difficult to predict how the loss of one species affects the abundance of others. We show that for dynamical models of realistically structured ecological networks in which pair-wise consumer-resource interactions allometrically scale to the ¾ power—as suggested by metabolic theory—the effect of losing one species on another can be predicted well by simple functions of variables easily observed in nature. By systematically removing individual species from 600 networks ranging from 10-30 species, we analyzed how the strength of 254,032 possible pair-wise species interactions depended on 90 stochastically varied species, link, and network attributes. We found that the interaction strength between a pair of species is predicted well by simple functions of the two species' biomasses and the body mass of the species removed. On average, prediction accuracy increases with network size, suggesting that greater web complexity simplifies predicting interaction strengths. Applied to field data, our model successfully predicts interactions dominated by trophic effects and illuminates the sign and magnitude of important nontrophic interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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12. Parasites in food webs: the ultimate missing links.
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Lafferty, Kevin D., Allesina, Stefano, Arim, Matias, Briggs, Cherie J., De Leo, Giulio, Dobson, Andrew P., Dunne, Jennifer A., Johnson, Pieter T. J., Kuris, Armand M., Marcogliese, David J., Martinez, Neo D., Memmott, Jane, Marquet, Pablo A., McLaughlin, John P., Mordecai, Erin A., Pascual, Mercedes, Poulin, Robert, and Thieltges, David W.
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PARASITISM ,PARASITES ,FOOD chains ,ECOLOGICAL niche ,COMMUNICABLE diseases ,ECOLOGY - Abstract
Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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13. Success and its limits among structural models of complex food webs.
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Williams, Richard J. and Martinez, Neo D.
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FOOD chains , *ANIMAL feeding behavior , *AQUATIC animals , *ANIMAL feeds , *ANIMAL species , *HIERARCHIES , *BIRDS of prey , *HERBIVORES , *OMNIVORES , *CANNIBALS - Abstract
1. Following the development of the relatively successful niche model, several other simple structural food web models have been proposed. These models predict the detailed structure of complex food webs given only two input parameters, the numbers of species and the number of feeding links among them. 2. The models claim different degrees of success but have not been compared consistently with each other or with the empirical data. We compared the performance of five structural models rigorously against 10 empirical food webs from a variety of aquatic and terrestrial habitats containing 25–92 species and 68–997 links. 3. All models include near-hierarchical ordering of species’ consumption and have identical distributions of the number of prey of each consumer species, but differ in the extent to which species’ diets are required to be contiguous and the rules used to assign feeding links. 4. The models perform similarly on a range of food-web properties, including the fraction of top, intermediate and basal species, the standard deviations of generality and connectivity and the fraction of herbivores and omnivores. 5. For other properties, including the standard deviation of vulnerability, the fraction of cannibals and species in loops, mean trophic level, path length, clustering coefficient, maximum similarity and diet discontinuity, there are significant differences in the performance of the different models. 6. While the empirical data do not support the niche model's assumption of diet contiguity, models which relax this assumption all have worse overall performance than the niche model. All the models under-estimate severely the fraction of species that are herbivores and exhibit other important failures that need to be addressed in future research. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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14. Compilation and Network Analyses of Cambrian Food Webs.
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Dunne, Jennifer A., Williams, Richard J., Martinez, Neo D., Wood, Rachel A., and Erwin, Douglas H.
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FOOD chains ,BIOTIC communities ,TROPHIC state index ,NETWORK analysis (Planning) ,ECOSYSTEM management ,SCIENCE education - Abstract
Analyses of Chengjiang and Burgess Shale food-web data suggest that most, but not all, aspects of the trophic structure of modern ecosystems were in place over a half-billion years ago. [ABSTRACT FROM AUTHOR]
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- 2008
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15. RESPONSE OF COMPLEX FOOD WEBS TO REALISTIC EXTINCTION SEQUENCES.
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Srinivasan, U. Thara, Dunne, Jennifer A., Harte, John, and Martinez, Neo D.
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BIODIVERSITY ,FOOD chains ,ECOLOGY ,FRESHWATER ecology ,AQUATIC ecology ,FLOODPLAIN ecology ,LIFE cycles (Biology) ,HABITATS ,BIOLOGY - Abstract
Although an ecosystem's response to biodiversity loss depends on the order in which species are lost, the extinction sequences generally used to explore such responses in food webs have been ecologically unrealistic. We investigate how several extinction orders affect the minimum number of secondary extinctions expected within pelagic food webs from 34 temperate freshwater lakes. An ecologically plausible extinction order is derived from the geographically nested pattern of species composition among the lakes and is corroborated by species' pH tolerances. Simulations suggest that lake communities are remarkably robust to this realistic extinction order and highly sensitive to the reverse sequence of species loss. This sensitivity is not well explained by the known sensitivity of networks to the loss of highly connected species but appears to be better explained by our observation that trophic specialists preferentially consume widely distributed species at low risk of extinction. Our results highlight an important aspect of community organization that may help to maintain biodiversity amidst changing environments. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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16. Allometric scaling enhances stability in complex food webs.
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Brose, Ulrich, Williams, Richard J., and Martinez, Neo D.
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FOOD chains ,PREDATORY animals ,BIOTIC communities ,POPULATION dynamics ,POPULATION - Abstract
Classic local stability theory predicts that complex ecological networks are unstable and are unlikely to persist despite empiricists’ abundant documentation of such complexity in nature. This contradiction has puzzled biologists for decades. While some have explored how stability may be achieved in small modules of a few interacting species, rigorous demonstrations of how large complex and ecologically realistic networks dynamically persist remain scarce and inadequately understood. Here, we help fill this void by combining structural models of complex food webs with nonlinear bioenergetic models of population dynamics parameterized by biological rates that are allometrically scaled to populations’ average body masses. Increasing predator–prey body mass ratios increase population persistence up to a saturation level that is reached by invertebrate and ectotherm vertebrate predators when being 10 or 100 times larger than their prey respectively. These values are corroborated by empirical predator–prey body mass ratios from a global data base. Moreover, negative effects of diversity (i.e. species richness) on stability (i.e. population persistence) become neutral or positive relationships at these empirical ratios. These results demonstrate that the predator–prey body mass ratios found in nature may be key to enabling persistence of populations in complex food webs and stabilizing the diversity of natural ecosystems. [ABSTRACT FROM AUTHOR]
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- 2006
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17. CONSUMER-RESOURCE BODY-SIZE RELATIONSHIPS IN NATURAL FOOD WEBS.
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Brose, Ulrich, Jonsson, Tomas, Berlow, Eric L., Warren, Philip, Banasek-Richter, Carolin, Bersier, Louis-Felix, Blanchard, Julia L., Brey, Thomas, Carpenter, Stephen R., Blandenier, Marie-France Cattin, Cushing, Lara, Dawah, Hassan Ali, Dell, Tony, Edwards, Francois, Harper-Smith, Sarah, Jacob, Ute, Ledger, Mark E., Martinez, Neo D., Memmott, Jane, and Mintenbeck, Katja
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FOOD chains ,BODY size ,NUTRIENT cycles ,CARNIVORA ,PREDATORY animals ,BIOLOGICAL productivity ,ANIMAL feeding behavior ,VERTEBRATES ,ANIMAL morphology - Abstract
It has been suggested that differences in body size between consumer and resource species may leave important implications for interaction strengths, population dynamics, and eventually food web structure, function, and evolution. Still, the general distribution of consumer-resource body-size ratios in real ecosystems, and whether they vary systematically among habitats or broad taxonomic groups, is poorly understood. Using a unique global database on consumer and resource body sizes, we show that the mean body-size ratios of aquatic herbivorous and detritivorous consumers are several orders of magnitude larger than those of carnivorous predators. Carnivorous predator-prey body-size ratios vary across different habitats and predator and prey types (invertebrates, ectotherm, and endotherm vertebrates). Predator-prey body-size ratios are on average significantly higher (1) in freshwater habitats, than in marine or terrestrial habitats, (2) for vertebrate than for invertebrate predators, and (3) for invertebrate than for ectotherm vertebrate prey. If recent studies that relate body-size ratios to interaction strengths are general, our results suggest that mean consumer-resource interaction strengths may vary systematically across different habitat categories and consumer types. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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18. The structure of food webs along river networks.
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Romanuk, Tamara N., Jackson, Leland J., Post, John R., McCauley, Ed, and Martinez, Neo D.
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FOOD chains ,RIVERS ,FISHES ,ANIMAL population density ,ZOOGEOGRAPHY - Abstract
Do changes in the species composition of riverine fish assemblages along river networks lead to predictable changes in food-web structure? We assembled empirical “fish-centered” river food webs for three rivers located along a latitudinal gradient in the South Saskatchewan River Basin (SSRB) that differ in land-use impacts and geomorphology but flow through similar mountain, foothill, and prairie physiographic regions. We then calculated 17 food-web properties to determine whether the nine river food webs differed according to physiographic region or river sub-basin. There were no statistically significant differences in the 17 food-web properties calculated among the rivers. In contrast, fish species richness, connectance, the proportion of herbivores, and the proportion of cannibals changed longitudinally along the river network. Our results suggest that regional changes in river geomorphology and physicochemistry play an important role in determining longitudinal variation in food-web properties such as fish species richness and connectance. In contrast, the overall structure of river food webs may be relatively similar and insensitive to regional influences such as zoogeography. Further explorations of river and other food webs would greatly illuminate this suggestion. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
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19. Unified spatial scaling of species and their trophic interactions.
- Author
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Brose, Ulrich, Ostling, Annette, Harrison, Kateri, and Martinez, Neo D.
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MACROECOLOGY ,SPECIES ,FOOD chains ,ECOLOGY ,ANIMAL diversity ,LAKES - Abstract
Two largely independent bodies of scaling theory address the quantitative relationships between habitat area, species diversity and trophic interactions. Spatial theory within macroecology addresses how species richness scales with area in landscapes, while typically ignoring interspecific interactions. Complexity theory within community ecology addresses how trophic links scale with species richness in food webs, while typically ignoring spatial considerations. Recent studies suggest unifying these theories by demonstrating how spatial patterns influence food-web structure and vice versa. Here, we follow this suggestion by developing and empirically testing a more unified scaling theory. On the basis of power-law species-area relationships, we develop link-area and non-power-law link-species models that accurately predict how trophic links scale with area and species richness of microcosms, lakes and streams from community to metacommunity levels. In contrast to previous models that assume that species richness alone determines the number of trophic links, these models include the species' spatial distribution, and hence extend the domain of complexity theory to metacommunity scales. This generality and predictive success shows how complexity theory and spatial theory can be unified into a much more general theory addressing new domains of ecology. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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20. Food-web structure and network theory: The role of connectance and size.
- Author
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Dunne, Jennifer A., Williams, Richard J., and Martinez, Neo D.
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FOOD chains ,SYMBIOSIS - Abstract
Investigates the role of connectance and size on food-web structure and network theory. Properties of food webs; Types of food webs; Factors affecting the distribution of food webs.
- Published
- 2002
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21. Two degrees of separation in complex food webs.
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Williams, Richard J., Berlow, Eric L., Dunne, Jennifer A., László, Albert, and Martinez, Neo D.
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FOOD chains ,HABITATS - Abstract
Examines the mechanisms of the degrees of separation in complex food webs. Properties of empirical and niche model food webs; Types of food webs; Impact of habitats on food web structure.
- Published
- 2002
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22. Network structure and biodiversity loss in food webs: robustness increases with connectance.
- Author
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Dunne, Jennifer A, Williams, Richard J, and Martinez, Neo D
- Subjects
BIODIVERSITY ,FOOD chains ,ROBUST control ,BIOLOGICAL extinction ,TOPOLOGY - Abstract
Food-web structure mediates dramatic effects of biodiversity loss including secondary and `cascading' extinctions. We studied these effects by simulating primary species loss in 16 food webs from terrestrial and aquatic ecosystems and measuring robustness in terms of the secondary extinctions that followed. As observed in other networks, food webs are more robust to random removal of species than to selective removal of species with the most trophic links to other species. More surprisingly, robustness increases with food-web connectance but appears independent of species richness and omnivory. In particular, food webs experience `rivet-like' thresholds past which they display extreme sensitivity to removal of highly connected species. Higher connectance delays the onset of this threshold. Removing species with few trophic connections generally has little effect though there are several striking exceptions. These findings emphasize how the number of species removed affects ecosystems differently depending on the trophic functions of species removed. [ABSTRACT FROM AUTHOR]
- Published
- 2002
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23. Simple rules yield complex food webs.
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Williams, Richard J. and Martinez, Neo D.
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FOOD chains , *ECOLOGICAL niche - Abstract
Shows that a simple model provides the mechanistic explanations missing from earlier empirical studies of food webs. Improvement of existing models of food webs by constraining species to consume a contiguous sequence of prey in a one-dimensional trophic niche; Prediction of key structural properties; Use of species numbers and connectance as empirical parameters.
- Published
- 2000
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24. Effects of sampling effort on characterization of food-web structure.
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Martinez, Neo D. and Hawkins, Branford A.
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FOOD chains , *BIOLOGICAL productivity - Abstract
Evaluates the effects of sampling effort on characterization of food-web structure. Suggestion that comparative analyses of connectance among trophic-species webs constructed with varying degrees of moderate observation effort are generally robust; Quantitative food-web patterns; Sampling effort; Scale dependence.
- Published
- 1999
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25. Scale-dependent constraints on food-web structure.
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Martinez, Neo D.
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FOOD chains - Abstract
Reevaluates the assertion of `scale invariance' of community food webs. Food webs as one of central concepts of ecological organization; Definitions and data on community food webs; Scale dependence among food web comparisons.
- Published
- 1994
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26. Simulated evolution assembles more realistic food webs with more functionally similar species than invasion.
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Romanuk, Tamara N., Binzer, Amrei, Loeuille, Nicolas, Carscallen, W. Mather A., and Martinez, Neo D.
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FOOD chains ,BIOTIC communities ,GLOBAL environmental change ,ABIOTIC environment ,FISH populations - Abstract
While natural communities are assembled by both ecological and evolutionary processes, ecological assembly processes have been studied much more and are rarely compared with evolutionary assembly processes. We address these disparities here by comparing community food webs assembled by simulating introductions of species from regional pools of species and from speciation events. Compared to introductions of trophically dissimilar species assumed to be more typical of invasions, introducing species trophically similar to native species assumed to be more typical of sympatric or parapatric speciation events caused fewer extinctions and assembled more empirically realistic networks by introducing more persistent species with higher trophic generality, vulnerability, and enduring similarity to native species. Such events also increased niche overlap and the persistence of both native and introduced species. Contrary to much competition theory, these findings suggest that evolutionary and other processes that more tightly pack ecological niches contribute more to ecosystem structure and function than previously thought. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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27. The "Goldilocks factor" in food webs.
- Author
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Berlow, Eric L., Broset, Ulrich, and Martinez, Neo D.
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LETTERS to the editor ,FOOD chains - Abstract
A letter to the editor is presented in response to the article "Size, foraging, and food web structure" that appear in this issue.
- Published
- 2008
- Full Text
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28. More than a meal... integrating non-feeding interactions into food webs.
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Kéfi, Sonia, Berlow, Eric L., Wieters, Evie A., Navarrete, Sergio A., Petchey, Owen L., Wood, Spencer A., Boit, Alice, Joppa, Lucas N., Lafferty, Kevin D., Williams, Richard J., Martinez, Neo D., Menge, Bruce A., Blanchette, Carol A., Iles, Alison C., and Brose, Ulrich
- Subjects
FOOD chains ,SPECIES ,HABITATS ,PREDATORY animals ,BIODIVERSITY ,ECOLOGISTS ,EMPIRICAL research - Abstract
Ecology Letters (2012) 15: 291-300 Abstract Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (<3) interaction types. The great diversity of non-trophic interactions observed in nature has been poorly addressed by ecologists and largely excluded from network theory. Herein, we propose a conceptual framework that organises this diversity into three main functional classes defined by how they modify specific parameters in a dynamic food web model. This approach provides a path forward for incorporating non-trophic interactions in traditional food web models and offers a new perspective on tackling ecological complexity that should stimulate both theoretical and empirical approaches to understanding the patterns and dynamics of diverse species interactions in nature. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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29. Food webs: reconciling the structure and function of biodiversity
- Author
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Thompson, Ross M., Brose, Ulrich, Dunne, Jennifer A., Hall, Robert O., Hladyz, Sally, Kitching, Roger L., Martinez, Neo D., Rantala, Heidi, Romanuk, Tamara N., Stouffer, Daniel B., and Tylianakis, Jason M.
- Subjects
- *
FOOD chains , *BIODIVERSITY , *BIOTIC communities , *DATA analysis , *QUANTITATIVE research , *BIOLOGICAL productivity - Abstract
The global biodiversity crisis concerns not only unprecedented loss of species within communities, but also related consequences for ecosystem function. Community ecology focuses on patterns of species richness and community composition, whereas ecosystem ecology focuses on fluxes of energy and materials. Food webs provide a quantitative framework to combine these approaches and unify the study of biodiversity and ecosystem function. We summarise the progression of food-web ecology and the challenges in using the food-web approach. We identify five areas of research where these advances can continue, and be applied to global challenges. Finally, we describe what data are needed in the next generation of food-web studies to reconcile the structure and function of biodiversity. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
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