Top predators key to extinctions as planet warms

[OKIsItJustMe]

http://www.eurekalert.org/pub_releases/2012-06/yu-tpk061912.php

Public release date: 21-Jun-2012

Contact: David DeFusco
[e-mail]
203-436-4842
Yale University

[font face=Serif][font size=5]Top predators key to extinctions as planet warms[/font]

[font size=3]New Haven, Conn.—Global warming may cause more extinctions than predicted if scientists fail to account for interactions among species in their models, Yale and UConn researchers argue in Science.

"Currently, most models predicting the effects of climate change treat species separately and focus only on climatic and environmental drivers," said Phoebe Zarnetske, the study's primary author and a postdoctoral fellow at the Yale School of Forestry & Environmental Studies. "But we know that species don't exist in a vacuum. They interact with each other in ways that deeply affect their viability."

Zarnetske said the complexity of "species interaction networks" discourages their inclusion in models predicting the effects of climate change. Using the single-species, or "climate envelope," approach, researchers have predicted that 15 percent to 37 percent of species will be faced with extinction by 2050.

But research has shown that top consumers—predators and herbivores—have an especially strong effect on many other species. In a warming world, these species are "biotic multipliers," increasing the extinction risk and altering the ranges of many other species in the food web.

…[/font][/font]

http://dx.doi.org/10.1126/science.1222732 <- Doesn’t seem to work yet.
http://www.sciencemag.org/content/336/6088/1516.full

[GliderGuider]

1. And the top predator on the planet is???

Last edited Thu Jun 21, 2012, 08:48 PM - Edit history (1)

No fair, you peeked.

[OKIsItJustMe]

2. And the point is?

(That if we remove humans from the picture the ecosystem will be destabilized?)

[GliderGuider]

3. Nothing so simple.

It's just a reminder that we should see ourselves not as some sort of apotheosis but as a predator in an ecological web of predator-prey relationships.

What sets us apart from lions and wolves is our incredible predatory efficiency, our preternatural adaptability and our ability to prey on every level in the trophic chain. That makes our presence much more harmful than our removal.

[OKIsItJustMe]

4. However, the point of the study is that removing top predators has negative repercussions

http://dx.doi.org/10.1126/science.1222732

[font size=4]Climate change and species interactions.[/font]

Recent findings suggest that climate change should affect top consumers more strongly, disrupting vertical interactions and thereby affecting many species across trophic levels. In this general example, climate change reduces top predators, leading to an increase in herbivores, and a decrease in plants. As a result, the community experiences an overall decrease in both species diversity and stability.
"CREDIT: ICONS COURTESY OF THE INTEGRATION AND APPLICATION NETWORK, UNIVERSITY OF MARYLAND CENTER FOR ENVIRONMENTAL SCIENCE (IAN.UMCES.EDU/SYMBOLS/)"

So, the analogous concern should be what would the result be of decreased predation on the part of humans.

In my own area, we are seeing this play out, as deer herds increase due to reduced predation, and their grazing adversely affects the forests.