Navigation Links
Stanford researchers rethink 'natural' habitat for wildlife
Date:4/18/2014

Protecting wildlife while feeding a world population predicted to reach 9 billion by 2050 will require a holistic approach to conservation that considers human-altered landscapes such as farmland, according to Stanford researchers.

Wildlife and the natural habitat that supports it might be an increasingly scarce commodity in a world where at least three-quarters of the land surface is directly affected by humans and the rest is vulnerable to human-caused impacts such as climate change. But what if altered agricultural landscapes could play vital roles in nurturing wildlife populations while also feeding an ever-growing human population?

A new study, published April 16 in the journal Nature and co-authored by three Stanford scientists, finds that a long-accepted theory used to estimate extinction rates, predict ecological risk and make conservation policy recommendations is overly pessimistic. The researchers point to an alternative framework that promises a more effective way of accounting for human-altered landscapes and assessing ecological risks.

Current projections forecast that about half of Earth's plants and animals will go extinct over the next century because of human activities, mostly due to our agricultural methods. "The extinction under way threatens to weaken and even destroy key parts of Earth's life-support systems, upon which economic prosperity and all other aspects of human well-being depend," said co-author Gretchen Daily, the Bing Professor in Environmental Science at Stanford and senior fellow at the Stanford Woods Institute for the Environment.

But that grim future isn't a foregone conclusion.

"Until the next asteroid slams into Earth, the future of all known life hinges on people, more than on any other force," Daily said.

Nature is not an island

Conservationists have long assumed that once natural landscapes are fractured by human development or agriculture, migration corridors for wildlife are broken, blocking access to food, shelter and breeding grounds. A scholarly theory was developed to estimate the number of species in such fractured landscapes, where patches of forest surrounded by farms resemble islands of natural habitat.

The "equilibrium theory of island biogeography" is a pillar of biological research its elegant equation to estimate the number of species in a habitat has almost reached the status of a scientific law, according to Chase Mendenhall, a Stanford doctoral student in biology and the study's lead author. The theory drives the default strategy of conserving biodiversity by designating nature reserves. This strategy sees reserves as "islands in an inhospitable sea of human-modified habitats" and doesn't adequately account for biodiversity patterns in many human-dominated landscapes, according to the Stanford study.

"This paper shows that farmland and forest remnants can be more valuable for biodiversity than previously assumed," said Daniel Karp, who earned his PhD in biology at Stanford in 2013 and is currently a NatureNet postdoctoral fellow at the University of California, Berkeley.

"If we're valuing coffee fields and other human-made habitats at zero, we're doing a disservice to ourselves and wildlife," Mendenhall said.

To test the island theory against a more holistic theory of agricultural or countryside biogeography, the researchers turned to bats acutely sensitive to deforestation. The study focused on bat populations within a mosaic of forest fragments and farmland in Costa Rica and on islands in a large lake in Panama. The researchers also did a meta-analysis of 29 studies of more than 700 bat species to bolster and generalize their findings globally.

Island biogeographic theory accurately predicted bats' responses to forest loss on the Panamanian islands system, but didn't come close to accurately forecasting similar responses in the Costa Rican countryside landscape. For example, the island theory predicted that the Costa Rican coffee plantations would have inadequate habitat to sustain a single species of bat. In reality, plantations in the countryside typically supported 18 bat species, compared to the 23 to 28 supported by tropical forest fragments and nature reserves.

"Conservation opportunities for tropical wildlife are tightly linked to adequate management of these human-modified habitats," said co-author Christoph Meyer, a researcher at the University of Lisbon's Center for Environmental Biology.

Overall, as forest cover disappeared, the rate of species loss was "substantially and significantly higher" in the island ecosystem, and species abundances were "increasingly uneven" compared to the countryside ecosystem, the study found.

The reason for the discrepancies, according to the study's authors, is that island biogeographic theory was originally based on actual islands surrounded by water, and does not account for factors such as a countryside landscape's ability to support more species and slow extinction rates compared to true island ecosystems. Especially in the tropics, island biogeographic theory's application is "distorting our understanding and conservation strategies in agriculture, the enterprise on which the future of biodiversity most critically hinges," the study's authors wrote.

"Not only do more species persist across the 'sea of farmland' than expected by island biogeographic theory, novel yet native species actually thrive there," said co-author Elizabeth Hadly, the Paul S. and Billie Achilles Professor in Environmental Biology at Stanford and senior fellow at the Stanford Woods Institute for the Environment. "This indicates that human-altered landscapes can foster more biological diversity than we anticipated."

A new approach

The fate of much of the world's wildlife is playing out in human-altered landscapes that are increasingly threatened by chemical inputs such as herbicides and pesticides. Biodiversity is not the only loser. People are losing many of nature's benefits such as water purification provided by forests and wetlands and pest control provided by birds and bats.

The study's findings point to the need for new approaches that integrate conservation and food production, to make agricultural lands more hospitable to wildlife by reducing chemical inputs, preserving fragments of forest and other natural habitats and rewarding farmers and ranchers for the benefits that result.

"A theory of countryside biogeography is pivotal to conservation strategy in the agricultural ecosystems that comprise roughly half of the global land surface and are likely to increase even further in the future," the researchers wrote.


'/>"/>

Contact: Rob Jordan
rjordan@stanford.edu
650-721-1881
Stanford University
Source:Eurekalert  

Related biology news :

1. Stanford scientists develop gene therapy approach to grow blood vessels in ischemic limbs
2. Keck award enables Carnegie Mellon and Stanford to dramatically expand crowdsourced RNA design
3. Climate change may create price volatility in the corn market, say Stanford and Purdue researchers
4. Stanford and MIT scientists win Perl-UNC Neuroscience prize
5. Americas clean energy policies need a reality check, say Stanford researchers
6. Support for climate change action drops, Stanford poll finds
7. Stanford scientists document fragile land-sea ecological chain
8. Stanford researchers help predict the oceans of the future with a mini-lab
9. Stanford marine biologist Barbara Block wins Rolex Award for Enterprise
10. Stanford scientists find molecule to starve lung cancer and improve ventilator recovery
11. Stanford researchers calculate global health impacts of the Fukushima nuclear disaster
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Stanford researchers rethink 'natural' habitat for wildlife
(Date:11/29/2016)... , Nov. 29, 2016   ... identification and object recognition technologies, today released ... for fingerprint recognition solutions that run on ... fingerprint template using less than 128KB of ... compact devices that have limited on-board resources, ...
(Date:11/28/2016)... 2016 "The biometric system ... The biometric system market is in the growth ... near future. The biometric system market is expected to ... a CAGR of 16.79% between 2016 and 2022. Government ... technology in smartphones, rising use of biometric technology in ...
(Date:11/22/2016)... 2016 According to the new market research report ... Vein, Signature, Voice), Multi-Factor), Component (Hardware and Software), Function (Contact and Non-contact), ... market is expected to grow from USD 10.74 Billion in 2015 to ... 2016 and 2022. Continue Reading ... ...
Breaking Biology News(10 mins):
(Date:12/8/2016)... Dec. 8, 2016  Anaconda BioMed S.L., a pre-clinical ... the next generation neuro-thrombectomy system for the treatment of ... G. Jovin, MD to join its Scientific Advisory Board ... strategic network of scientific and clinical experts to Anaconda ... the ANCD BRAIN ® to its clinical phase. ...
(Date:12/8/2016)... ... December 08, 2016 , ... ... their exceptionally efficient human mesenchymal stem/stromal cell (hMSC) expansion medium. This ... products engineered to radically streamline culture processes, minimize processing time, significantly decrease ...
(Date:12/8/2016)... Ames, Iowa (PRWEB) , ... December 08, 2016 , ... ... of asynchronous approvals for biotech crops. The authors focus on the economic effects in ... the global approval of new biotech crops and the resultant risk of low level ...
(Date:12/8/2016)... -- Soligenix, Inc. (OTCQB: SNGX) (Soligenix or the Company), ... products to treat rare diseases where there is an ... hosting an Investor Webcast Event Friday, December 16, 2016, ... defense regulators (IDRs) as a new drug class, as ... recently announced and published Phase 2 clinical data for ...
Breaking Biology Technology: