The Roles of Harsh and Fluctuating Conditions in the Dynamics of Ecological Communities

The American Naturalist, Год журнала: 1997, Номер 150(5), С. 519 - 553

Опубликована: Ноя. 1, 1997

Harsh conditions (e.g., mortality and stress) reduce population growth rates directly; secondarily, they may the intensity of interactions between organisms. Near-exclusive focus on secondary effect these forms harshness has led ecologists to believe that importance ecological interactions, such as competition, favor coexistence even ecologically very similar species. By examining both costs benefits, we show alone does not lessen species or limit their role in community structure. Species requires niche differences, itself make more likely. Fluctuations environmental disturbance, seasonal change, weather variation) also have been regarded decreasing favoring coexistence, but argue can only be favored when fluctuations create spatial temporal opportunities. We important diversity-promoting roles for harsh fluctuating depend deviations from assumptions additive effects linear dependencies most commonly found models. Such considerations imply strong diversity a community.

Язык: Английский

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How to make more out of community data? A conceptual framework and its implementation as models and software

Ecology Letters, Год журнала: 2017, Номер 20(5), С. 561 - 576

Опубликована: Март 20, 2017

Abstract Community ecology aims to understand what factors determine the assembly and dynamics of species assemblages at different spatiotemporal scales. To facilitate integration between conceptual statistical approaches in community ecology, we propose Hierarchical Modelling Species Communities ( HMSC ) as a general, flexible framework for modern analysis data. While non‐manipulative data allow only correlative not causal inference, this facilitates formulation data‐driven hypotheses regarding processes that structure communities. We model environmental filtering by variation covariation responses individual characteristics their environment, with potential contingencies on traits phylogenetic relationships. capture biotic rules species‐to‐species association matrices, which may be estimated multiple spatial or temporal operationalise hierarchical Bayesian joint distribution model, implement it R‐ Matlab‐packages enable computationally efficient analyses large sets. Armed tool, ecologists can make sense many types data, including spatially explicit time‐series illustrate use through series diverse ecological examples.

Язык: Английский

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The role of functional traits and trade‐offs in structuring phytoplankton communities: scaling from cellular to ecosystem level

Ecology Letters, Год журнала: 2007, Номер 10(12), С. 1170 - 1181

Опубликована: Окт. 10, 2007

Abstract Trait‐based approaches to community structure are increasingly used in terrestrial ecology. We show that such an approach, augmented by a mechanistic analysis of trade‐offs among functional traits, can be successfully explain composition marine phytoplankton along environmental gradients. Our literature on major traits phytoplankton, as parameters nutrient‐dependent growth and uptake, reveals physiological species abilities acquire utilize resources. These trade‐offs, arising from fundamental relations cellular scaling laws enzyme kinetics, define contrasting ecological strategies nutrient acquisition. Major groups eukaryotic have adopted distinct with associated traits. diverse utilization the distribution patterns size classes availability

Язык: Английский

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Community assembly and invasion: An experimental test of neutral versus niche processes

Proceedings of the National Academy of Sciences, Год журнала: 2003, Номер 100(15), С. 8916 - 8920

Опубликована: Июль 3, 2003

A species-addition experiment showed that prairie grasslands have a structured, nonneutral assembly process in which resident species inhibit, via resource consumption, the establishment and growth of with similar use patterns success invaders decreases as diversity increases. In our experiment, each four functional guilds were introduced, seed, into 147 prairie–grassland plots previously had been established maintained to different compositions diversities. Established most strongly inhibited introduced from their own guild. Introduced attained lower abundances when functionally abundant left levels resources unconsumed, occurred at richness. Residents C4 grass guild, dominant guild nearby native grasslands, reduced major limiting resource, soil nitrate, lowest midsummer exhibited greatest inhibitory effect on species. This simple mechanism greater competitive inhibition are could, theory, explain many observed plant communities.

Язык: Английский

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Trade‐offs in community ecology: linking spatial scales and species coexistence

Ecology Letters, Год журнала: 2003, Номер 7(1), С. 69 - 80

Опубликована: Ноя. 27, 2003

Abstract Trade‐offs in species performances of different ecological functions is one the most common explanations for coexistence communities. Despite potential occurring at local or regional spatial scales, trade‐offs are typically approached a single scale. In recent years, ecologists have increasingly provided evidence importance community processes both and scales. This review summarizes theoretical predictions traits associated with under conditions We provide framework understanding trade‐offs, supportive empirical evidence. Predictions presented that link patterns diversity observed to lead Recent evolution which explores laboratory microcosm studies phylogenetic tests. Examining within can strong approach structure dynamics, while explaining diversity.

Язык: Английский

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Comparative ecology of seed size and dispersal

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 1996, Номер 351(1345), С. 1309 - 1318

Опубликована: Сен. 30, 1996

Seed mass is correlated with a number of other plant traits, including dispersal mode, growth form and specific leaf area. Specific area the main determinant potential relative rate an indicator site quality to which species adapted. The relationships mode have consistent in five datasets from three continents, each account for about 20-30 % variation log seed mass. Thus, there also very substantial within categories. Much, but not all, 20-30% associated shifted family composition between forms or modes. Experiments shown that seedlings larger-seeded are better able survive hazards deep shade, drought, physical damage presence competing vegetation. If common mechanism under these different hazards, it seemingly must be ‘reserve effect’, whereby during deployment early hold bigger percentage reserves uncommitted seedling structure available support respiration repair damage. A reserve effect has yet been demonstrated directly. It remains possible mechanisms operate hazards. Under effect, advantages larger size should temporary, temporary advantage indeed observed regard survival dense shade. Although confers benefits on seedlings, seeds necessarily produced smaller numbers per unit resource allocated. presumed evolved as compromise counterposed pressures. Yet proved surprisingly little difference average vegetation regions, at least temperate climates. Rather, startlingly wide among growing interspersed other. Recent applications game theory may capable accounting this coexisting species, present models driven by competition (as opposed adults). unclear whether decisive influence most world’s types.

Язык: Английский

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A 30-YEAR STUDY OF CORAL ABUNDANCE, RECRUITMENT, AND DISTURBANCE AT SEVERAL SCALES IN SPACE AND TIME

Ecological Monographs, Год журнала: 1997, Номер 67(4), С. 461 - 488

Опубликована: Ноя. 1, 1997

Observations over a 30-yr period revealed considerable degree of natural variation in the abundance corals on Heron Island, Great Barrier Reef, Queensland, Australia. Cover ranged from <0.1% to >80%, with similar large range colony density, at several temporal and spatial scales. Much this was due type, intensity, scale disturbances that occurred. Coral assemblages usually recovered acute disturbances, both Island other Indo-Pacific reefs. In contrast, did not recover chronic either or human origins, gradual declines. Recovery slower after altered physical environment than simply killed damaged corals. The space time scales declines recoveries were much smaller wave-exposed side reef protected storms. Recruitment rates reduced by preemption macroalgae, storms substratum. Thus, dynamics coral community can be largely understood through types occurred, processes took place where rare.

Язык: Английский

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Anthropogenic environmental changes affect ecosystem stability via biodiversity

Science, Год журнала: 2015, Номер 348(6232), С. 336 - 340

Опубликована: Апрель 16, 2015

Human-driven environmental changes may simultaneously affect the biodiversity, productivity, and stability of Earth's ecosystems, but there is no consensus on causal relationships linking these variables. Data from 12 multiyear experiments that manipulate important anthropogenic drivers, including plant diversity, nitrogen, carbon dioxide, fire, herbivory, water, show each driver influences ecosystem productivity. However, productivity only changed by those drivers alter with a given decrease in species numbers leading to quantitatively similar regardless which caused biodiversity loss. These results suggest change be major factor determining how global stability.

Язык: Английский

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Reciprocal interactions and adjustments between fluvial landforms and vegetation dynamics in river corridors: A review of complementary approaches

Earth-Science Reviews, Год журнала: 2007, Номер 84(1-2), С. 56 - 86

Опубликована: Июнь 7, 2007

Язык: Английский

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Invasion, competitive dominance, and resource use by exotic and native California grassland species

Proceedings of the National Academy of Sciences, Год журнала: 2003, Номер 100(23), С. 13384 - 13389

Опубликована: Окт. 31, 2003

The dynamics of invasive species may depend on their abilities to compete for resources and exploit disturbances relative the native species. We test this hypothesis explore its implications restoration ecosystems in one most dramatic ecological invasions worldwide, replacement perennial grasses by exotic annual forbs 9.2 million hectares California grasslands. long-term persistence these annuals has been thought imply that exotics are superior competitors. However, seed-addition experiments a southern grassland revealed species, which had lower requirements deep soil water, nitrate, light, were strong competitors, they markedly depressed abundance fecundity after overcoming recruitment limitations. Native reinvaded grasslands across experimentally imposed nitrogen, disturbance gradients. Thus, not competitors but rather dominate because prior low dispersal extreme current rarity perennials. If our results prove be general, it feasible restore flora at least parts former range.

Язык: Английский

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