Researchers rethink ‘natural’ habitat for wildlife

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

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 Natureand 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.

Written By: Science Daily
continue to source article at sciencedaily.com

13 COMMENTS

  1. Orangutans and palm oil fields.

    to make agricultural lands more hospitable to to wildlife by reducing chemical inputs

    This was Rachel Carson’s basic message – vastly reduce indiscriminate use of pesticides. Can’t remember the crop whose pests can be effectively controlled by hoards of ladybugs (ladybirds).

  2. Try it this way:

    “Protecting wildlife while feeding a human population resuced to a sustanable 1 billion will require … absolutely nothing.”

    II also find it interesting that Gretchen Daily considers the primary attribute of human well-being to be “economic prosperity”. With that attitude, the tigers (and much else) are doomed.

  3. The elephant in the room (or the farmyard) is the issue of a planet-killing population. There are a lot of problems to address, of course, but let’s not lose sight of the fact that one of them is population. Much better to control it mercifully, with contraception and changes in cultural traditions, rather than with famine.

    • In reply to #7 by justinesaracen:

      The elephant in the room (or the farmyard) is the issue of a planet-killing population.

      Quite.

      Furthermore, I’ve never believed that you could negotiate with humans on behalf of the rest of the planet’s life. It’s one thing in theory to say we want to preserve other species, but when it comes down to the individual and it is him and his chickens v that fox – the human gets his gun out.

      Secondly, I don’t believe that human population will be controlled through environmental pressure or some sort of disater – at least not until the wildlife we need to save has also mostly been destroyed.

      For me, the only solution is to create vast country-sized reserves and prohibit humans from living there. These would have to be chosen to cover all types of habitat and climate. The world outside these reserves could/would be sacrificed on the human altar.

      I’d start with relocating the population of the UK and Ireland, designate the land as the first of these new mega wildlife sanctuaries and, having first reintroduced some wolves and bears, let nature take its course. By the way, I am serious.

      Geoff

  4. ‘conservation policy recommendations…overly pessimistic’

    I wonder, how does being more optimistic help the hundreds, or thousands, of species terminated in the current mass extinction. How is the human species served by killing so much of the biosphere that it relies on for survival?

    I agree, population excess is considered a taboo, which if not confronted will result in environmental collapse.

  5. @OP – “If we’re valuing coffee fields and other human-made habitats at zero, we’re doing a disservice to ourselves and wildlife,” Mendenhall said.

    Stawman! – I’m not aware of anyone valuing agricultural fields at zero as wildlife habitats. Some may be very low, but zero?????? Coffee fields which are trees with undergrowth, (surrounded by strips of woodland according to the photo) as an example, looks like (coffee-picking?) cherry-picking, when compared to say wheat prairies or oil palm plantations.

    @OP – 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.

    They have not “assumed”! They have produced detailed studies (Can Ecological Corridors Heal Fragmented Landscapes?) showing the genetic isolation of communities all over the world, where the “islands of wild habitat” are small, or connecting corridors are broken by large man-made gaps or obstructions. (eg. Some conservation projects provide tunnels under roads for use by particular species).

    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.

    So the lead author is a basic biology graduate?? who has not yet achieved a doctorate! MMMmmmmmmm!

    “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

    With a recently qualified associate!!

  6. @OP – “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.

    They tested a theory on island isolation and human constructed obstructions using FLYING SPECIES??????

    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.

    Did that theory even apply to animals capable of extensive flight? – and on what basis can this be extrapolated to be relevant to the terrestrial or aquatic species which in so many other studies, are affected by being in isolated pockets with restricted mixing of populations?

    @OP link – The above story is based on materials provided by Stanford University.

    The original article was written by Rob Jordan.

    Clearly the author of this article has no idea about genetically isolated “island populations” or wildlife corridors.

    To what extent the original authors or Stamford University share his views, is unclear.

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