Trophic Downgrading of Planet Earth

Science, Journal Year: 2011, Volume and Issue: 333(6040), P. 301 - 306

Published: July 14, 2011

Until recently, large apex consumers were ubiquitous across the globe and had been for millions of years. The loss these animals may be humankind's most pervasive influence on nature. Although such losses are widely viewed as an ethical aesthetic problem, recent research reveals extensive cascading effects their disappearance in marine, terrestrial, freshwater ecosystems worldwide. This empirical work supports long-standing theory about role top-down forcing but also highlights unanticipated impacts trophic cascades processes diverse dynamics disease, wildfire, carbon sequestration, invasive species, biogeochemical cycles. These findings emphasize urgent need interdisciplinary to forecast downgrading process, function, resilience global ecosystems.

Language: Английский

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Status and Ecological Effects of the World’s Largest Carnivores

Science, Journal Year: 2014, Volume and Issue: 343(6167)

Published: Jan. 9, 2014

Large carnivores face serious threats and are experiencing massive declines in their populations geographic ranges around the world. We highlight how these have affected conservation status ecological functioning of 31 largest mammalian on Earth. Consistent with theory, empirical studies increasingly show that large substantial effects structure function diverse ecosystems. Significant cascading trophic interactions, mediated by prey or sympatric mesopredators, arise when some extirpated from repatriated to Unexpected cascades various taxa processes include changes bird, mammal, invertebrate, herpetofauna abundance richness; subsidies scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; crop damage. Promoting tolerance coexistence is a crucial societal challenge will ultimately determine fate Earth's all depends upon them, including humans.

Language: Английский

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Resilience and Sustainable Development: Building Adaptive Capacity in a World of Transformations

AMBIO, Journal Year: 2002, Volume and Issue: 31(5), P. 437 - 440

Published: Aug. 1, 2002

Language: Английский

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Ecological Resilience—In Theory and Application

Annual Review of Ecology and Systematics, Journal Year: 2000, Volume and Issue: 31(1), P. 425 - 439

Published: Nov. 1, 2000

▪ Abstract In 1973, C. S. Holling introduced the word resilience into ecological literature as a way of helping to understand non-linear dynamics observed in ecosystems. Ecological was defined amount disturbance that an ecosystem could withstand without changing self-organized processes and structures (defined alternative stable states). Other authors consider return time state following perturbation. A new term, adaptive capacity, is describe modify resilience. Two definitions recognize presence multiple states (or stability domains), hence property mediates transition among these states. Transitions have been described for many ecosystems, including semi-arid rangelands, lakes, coral reefs, forests. systems, maintained by keystone structuring across number scales, sources renewal reformation, functional biodiversity. practice, maintaining capacity dynamic environment provides buffer protects system from failure management actions are taken based upon incomplete understanding, it allows managers affordably learn change.

Language: Английский

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The Identification, Conservation, and Management of Estuarine and Marine Nurseries for Fish and Invertebrates

BioScience, Journal Year: 2001, Volume and Issue: 51(8), P. 633 - 633

Published: Jan. 1, 2001

seagrass meadows, marshes, and mangrove forestsserve many important functions in coastal waters.Most notably, they have extremely high primary secondary productivity support a great abundance diversity of fish invertebrates.Because their effects on the macrofauna, these estuarine marine ecosystems are often referred to as nurseries numerous papers, textbooks, government-sponsored reports (Boesch Turner 1984, NRC 1995, Butler Jernakoff 1999).Indeed, role nearshore is an established ecological concept accepted by scientists, conservation groups, managers, public

Language: Английский

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Novel ecosystems: theoretical and management aspects of the new ecological world order

Global Ecology and Biogeography, Journal Year: 2006, Volume and Issue: 15(1), P. 1 - 7

Published: Jan. 1, 2006

ABSTRACT We explore the issues relevant to those types of ecosystems containing new combinations species that arise through human action, environmental change, and impacts deliberate inadvertent introduction from other regions. Novel (also termed ‘emerging ecosystems’) result when occur in relative abundances have not occurred previously within a given biome. Key characteristics are novelty, form potential for changes ecosystem functioning, agency, these or action. As more Earth becomes transformed by actions, novel increase importance, but relatively little studied. Either degradation invasion native ‘wild’ abandonment intensively managed systems can formation systems. Important considerations whether persistent what values they may have. It is likely it be very difficult costly return such their previous state, hence consideration needs developing appropriate management goals approaches.

Language: Английский

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Kelp forest ecosystems: biodiversity, stability, resilience and future

Environmental Conservation, Journal Year: 2002, Volume and Issue: 29(4), P. 436 - 459

Published: Dec. 1, 2002

Kelp forests are phyletically diverse, structurally complex and highly productive components of coldwater rocky marine coastlines. This paper reviews the conditions in which kelp develop globally where, why at what rate they become deforested. The ecology long archaeological history examined through case studies from southern California, Aleutian Islands western North Atlantic, well-studied locations that represent widest possible range forest biodiversity. Global distribution is physiologically constrained by light high latitudes nutrients, warm temperatures other macrophytes low latitudes. Within mid-latitude belts (roughly 40–60° latitude both hemispheres) well-developed most threatened herbivory, usually sea urchins. Overfishing extirpation valued vertebrate apex predators often triggered herbivore population increases, leading to widespread deforestation. Such deforestations have profound lasting impacts on species-depauperate systems, such as those Alaska Atlantic. Globally urchin-induced deforestation has been increasing over past 2–3 decades. Continued fishing down coastal food webs resulted shifting harvesting targets their invertebrate prey, including kelp-grazing herbivores. recent global expansion urchin led this herbivore, returned some but, for first time, these devoid predators. In large predatory crabs recently filled void new predator system. Similar shifts fish- crab-dominance may occurred zones United Kingdom Japan, where finfish were extirpated ago. Three American determine with humans project status future year 2025. Fishing systems much longer duration than previously thought. Archaeological data suggest peoples exploited organisms thousands years, occasionally resulting localized losses predators, outbreaks populations probably small-scale Over two centuries, commercial exploitation export otter Pacific fishes like cod large-scale removal markets increased abundances promoted decline vast areas. Despite California having one longest known associations forests, rare. It functional redundancies among herbivores make diverse system stable. biodiverse also resist invasion non-native species. introduced algal competitors carpet benthos threaten dominance. There, established dominant Climate changes had measurable ecosystems efforts control emission greenhouse gasses should be a priority. However, overfishing appears greatest manageable threat 2025 time horizon. Management focus minimizing restoring functionally important species systems.

Language: Английский

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Response diversity, ecosystem change, and resilience

Frontiers in Ecology and the Environment, Journal Year: 2003, Volume and Issue: 1(9), P. 488 - 494

Published: Nov. 1, 2003

Biological diversity appears to enhance the resilience of desirable ecosystem states, which is required secure production essential services. The responses environmental change among species contributing same function, we call response diversity, critical resilience. Response particularly important for renewal and reorganization following change. Here present examples from both terrestrial aquatic ecosystems across temporal spatial scales. provides adaptive capacity in a world complex systems, uncertainty, human-dominated environments. We should pay special attention when planning management restoration, since it may contribute considerably desired states against disturbance, mismanagement, degradation.

Language: Английский

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THE ECOLOGICAL CONSEQUENCES OF CHANGES IN BIODIVERSITY: A SEARCH FOR GENERAL PRINCIPLES¹⁰¹

Ecology, Journal Year: 1999, Volume and Issue: 80(5), P. 1455 - 1474

Published: July 1, 1999

This paper uses theory and experiments to explore the effects of diversity on stability, productivity, susceptibility invasion. A model resource competition predicts that increases in cause community stability increase, but population decrease. These opposite are, a great extent, explained by how temporal variances species abundances scale with mean abundance, differential impact this scaling vs. stability. Community also depends negative covariance effect (competitive compensation) overyielding (ecosystem productivity increasing diversity). long-term study Minnesota grasslands supports these predictions. Models predict, field confirm, greater plant leads primary productivity. diversity–productivity relationship results both from chance more productive would be present at higher (the sampling effect) better "coverage" habitat heterogeneity caused broader range traits diverse niche differentiation effect). Both complete utilization limiting resources diversity, which retention, further Finally, lower levels available are predicted decrease an ecosystem invasion, supporting diversity–invasibility hypothesis. mechanism provides rules for assembly invasion resistance. In total, biodiversity should added composition, disturbance, nutrient supply, climate as major controller dynamics structure. By their increasingly directional impacts all controllers, humans likely changes functioning ecosystems worldwide. understanding is needed if ecologists provide society knowledge essential wise management earth its biological resources.

Language: Английский

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Long-Term Ecosystem Response to the Exxon Valdez Oil Spill

Science, Journal Year: 2003, Volume and Issue: 302(5653), P. 2082 - 2086

Published: Dec. 18, 2003

The ecosystem response to the 1989 spill of oil from Exxon Valdez into Prince William Sound, Alaska, shows that current practices for assessing ecological risks in oceans and, by extension, other toxic sources should be changed. Previously, it was assumed impacts populations derive almost exclusively acute mortality. However, Alaskan coastal ecosystem, unexpected persistence subsurface and chronic exposures, even at sublethal levels, have continued affect wildlife. Delayed population reductions cascades indirect effects postponed recovery. Development ecosystem-based toxicology is required understand ultimately predict chronic, delayed, long-term impacts.

Language: Английский

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