Trophic Downgrading of Planet Earth

  title={Trophic Downgrading of Planet Earth},
  author={James A. Estes and John Terborgh and Justin S. Brashares and Mary E. Power and Joel Berger and William J. Bond and Stephen R. Carpenter and Timothy E. Essington and Robert D Holt and Jeremy B. C. Jackson and Robert J. Marquis and Lauri Oksanen and Tarja Oksanen and Robert T. R. Paine and Ellen K. Pikitch and William J. Ripple and Stuart A. Sandin and Marten Scheffer and Thomas W. Schoener and Jonathan B. Shurin and Anthony R. E. Sinclair and Michael E. Soul{\'e} and Risto Virtanen and David A. Wardle},
  pages={301 - 306}
Until recently, large apex consumers were ubiquitous across the globe and had been for millions of years. The loss of these animals may be humankind’s most pervasive influence on nature. Although such losses are widely viewed as an ethical and aesthetic problem, recent research reveals extensive cascading effects of their disappearance in marine, terrestrial, and freshwater ecosystems worldwide. This empirical work supports long-standing theory about the role of top-down forcing in ecosystems… 

Trophic Cascades

In many ecosystems, apex consumers (top predators) play a crucial role in food web dynamics. Their top-down impacts are known to spread downwards through the food webs in a cascading fashion. Trophic

Biotic responses of canids to the terminal Pleistocene megafauna extinction

The results suggest that loss of megaherbivores and competition with humans likely outweighed advantages conferred from the loss of very large predators.

Learning from Africa's herbivores

  • J. Gill
  • Environmental Science, Geography
  • 2015
Hempson et al. (4) provide a new tool for elucidating the ecological role of large herbivores at continental scales, and help clarify the role of herbivore diversity in grassland ecosystems.

Ecosystem effects of the world's largest invasive animal.

This work examined the impacts on aquatic ecosystems of an emerging population of hippopotamus that has been growing in Colombia over the last 25 years, suggesting that hippos recapitulate their role as ecosystem engineers in Colombia, importing terrestrial organic matter and nutrients with detectable impacts on ecosystem metabolism and community structure in the early stages of invasion.

Exploring the influence of ancient and historic megaherbivore extirpations on the global methane budget

It is suggested that large-bodied mammals have a greater influence on methane emissions than previously appreciated and, further, that changes in the source pool from herbivores can influence global biogeochemical cycles and, potentially, climate.

The megabiota are disproportionately important for biosphere functioning

A prominent signal of the Anthropocene is the extinction and population reduction of the megabiota—the largest animals and plants on the planet. However, we lack a predictive framework for the

Megafauna in the Earth system

The state of knowledge about the environmental legacies of the terminal Pleistocene megafauna extinction, the complex role of modern large-bodied animals and what the ongoing loss of their ecological interactions might mean in terms of ecosystem function are synthesized.

Animal pee in the sea: consumer‐mediated nutrient dynamics in the world's changing oceans

Research is reviewed that underscores the importance of this bottom-up control at local, regional, and global scales in coastal marine ecosystems, and the potential implications of anthropogenic change to fundamentally alter these processes.

Understanding patterns and processes in models of trophic cascades

It is shown that inclusion of processes represented mathematically as density-dependent regulation of either consumer uptake or mortality rates is necessary for the generation of realistic ‘top-down’ cascades in simple food chain models.



Biodiversity loss, trophic skew and ecosystem functioning

The dominant impacts of biodiversity change on ecosystem functioning appear to be trophically mediated, with important implications for conservation.

Cascading Effects of the Loss of Apex Predatory Sharks from a Coastal Ocean

Impacts of chronic overfishing are evident in population depletions worldwide, yet indirect ecosystem effects induced by predator removal from oceanic food webs remain unpredictable. As abundances of

Methane emissions from extinct megafauna

To the Editor: About 13,400 years ago, the Americas were heavily populated with large-bodied herbivores such as mammoths, camelids and giant ground sloths; the megaherbivore assemblage was richer

Trophic Cascades: Predators, Prey and the Changing Dynamics of Nature

Bottom-up or top-down? The debate as to which force drives ecosystem food webs and population dynamics has been ongoing for decades. Are ecosystems stabilized from the top down as proposed by

Catastrophic shifts in ecosystems

Recent studies show that a loss of resilience usually paves the way for a switch to an alternative state, which suggests that strategies for sustainable management of such ecosystems should focus on maintaining resilience.

The Rise of the Mesopredator

An overview of mesopredator release is presented and its underlying concepts can be used to improve predator management in an increasingly fragmented world and it is shown that 60% of mesOPredator ranges have expanded, whereas all apex predator ranges have contracted.

Evidence for top predator control of a grazing ecosystem

Widespread wolf effects on ungulate prey, plants, and microbial activity that have spatially reorganized grassland energy and nutrient dynamics in Yellowstone Park are suggested.

Predator control of ecosystem nutrient dynamics.

Because predator species are disproportionately vulnerable to elimination from ecosystems, the authors stand to lose much more from their disappearance than their simple charismatic attractiveness, and new research is beginning to show that predator effects on nutrient cycling are ubiquitous.


Because most large, terrestrial mammalian predators have already been lost from more than 95-99% of the contiguous United States and Mexico, many ecological communities are either missing dominant