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        Remember "the Circle of Life" from the Lion King? Lion cub Simba is told by his father how the animals the lions hunt feed them, but one day they too will die, and will feed the grass, which in turn will feed the grazing animals that the lions hunt and...  Well, you get the picture.

        But that's a fairly simple picture. In nature, the relationships between all the organisms (plants, animals, microbes, etc.) in a given ecosystem are usually far more complex. Instead of a circle, the phrase "food web" is closer to the truth. Teasing out all of the interconnections, and determining how important each is to the whole is one of the trickier tasks facing scientists.

        Some examples follow below the Orange Omnilepticon.

    The Circle of Life is an appealing concept, but it doesn't do full justice to the intricate interrelationships between all the organisms in an ecosystem. A more accurate metaphor might be to think of an ecosystem as being like a self-assembling puzzle with many pieces. Add or subtract certain pieces from the puzzle, and the whole picture changes, sometimes in unexpected ways. It's not a static picture either - it changes over time.

       The picture we see today might be very different from what it was or will be. There's always a certain degree of change happening in the world - and even more so with global climate patterns changing. What may seem a minor piece today could be critical tomorrow; who knows what the effects are of pieces that have gone missing? Seeing what's no longer there is a difficult task to manage - but we're starting to figure it out.

Cute, Fuzzy - And Important!

           Edges are important, the places where one ecosystem impinges on another, where different habitats interact. Coastal biological communities are one example. In California, the marine ecosystems along the coast are under a lot of stress from human activities. Humans affect the amounts and quality of water that runs off the land into the sea. They fill in coastal marshes that many species need for habitat; they hunt and fish. We're finding out now that one particular species may play a critical role in keeping the near shore ecosystem in balance.

           The BBC has picked up on recent research that indicates the California Sea Otter may be a more important element in the coastal web of life than had been previously realized. As the BBC summary of the study notes, the urbanization of the California coast means there's a lot of nutrients washing into the sea, especially nitrogen from fertilizers. This encourages the growth of algae which in turn suppresses the sea grass that would normally cover the bottom. The algae actually grows on it, keeping the sea grass from getting the sunlight it needs. (This is a problem for sea grass around the world.)

        This matters because the sea grass provides habitat for a lot of other species. It helps protect the shoreline from erosion. It helps soak up CO2. And this is where sea otters come into the picture. Researchers looked at 50 years of data on sea grass growth in a section of Monterrey Bay, and what they found was, the one factor that seemed to correlate with how well the grass was doing was the number of sea otters living in the area.

      The hypothesis, which they tested, is that the sea otters feed on crabs in the area, which means fewer crabs. Fewer crabs in turn means that more of the small invertebrates the crabs would normally eat survive. And those invertebrates just happen to eat algae! Where they keep the algae in check, the sea grass can grow and thrive, despite the increasing amounts of nitrogen in the water.

      Sea otters turn out to be the missing piece in this puzzle. They were nearly hunted to extinction over the past 200 years, but have been recovering with the end of the fur trade. More recently there have been restrictions on where they've been allowed to recolonize their former habitat because of fears from fishermen that they would hurt fishing. The implication now seems to be that they should actually improve it, if their presence means sea grass can flourish. (Of course, it will also help if the problem of run off can be addressed too.)

The Landscape of Fear

        Another example of a missing piece is better known: wolves in Yellowstone. But what's becoming clearer is that the presence of wolves is more than just a matter of how many animals they eat. Their presence also changes the behavior of those animals that are their prey - and those changes have a larger impact on the whole landscape. There's a detailed account here of what wolves have meant for Yellowstone.

       Elk numbers have dropped. It's not just a matter of wolves killing and eating them that explains it. In a landscape with wolves, elk spend more time watching for predators and less time grazing. Their herd behavior changes, and so does their success rate at raising young. This reduces pressure on the plants that elk eat, so there have been changes in the numbers and variety of plants that can now thrive - and this in turn affects all the animals that depend on those plants. Further, with the return of fire to the Yellowstone ecosystem, this affects how the landscape recovers afterwards. As the paper linked above concludes:

...Thus, the preservation or recovery of gray wolves may represent an important conservation need for helping to maintain the resiliency of wildland ecosystems, especially with a rapidly changing climate.
     Humankind has a bias against predators (other than ourselves), and yet ecosystems are shaped by their presence or absence in important ways, at all levels - even down to spiders and grasshoppers.
Last year two ecologists from Yale University released spiders into cages of grasshoppers. However, the spiders didn’t eat even one grasshopper because their mouthparts had been glued shut. Still, the grasshoppers were terrified, and it was noted that their metabolism increased by at least 40 percent. This led to a significant change in their diet, as they ate more carb-heavy goldenrod plants and decreased their protein intake from grasses.

This change in animal behavior signals what might be called a paradigm shift in ecological thinking. Just the mere fear of predation can lead to remarkable changes in an animal’s behavior. And this in turn has a big impact on the landscape. And of course, since ecosystems involve long routes of energy flow, the impact on the landscape then further impacts the lives of other animals.

  The Landscape of Fear is potentially a powerful management tool. Hunting, fishing, forestry - there tends to be a species-centered approach, as in Trout streams, Deer hunting, etc. which may not be as efficient as looking at the whole picture.
... take bighorn sheep. Forest fires keep a lot of areas open and bighorn sheep need open areas. When we suppress the fire [which we want to do] the trees and the shrub grow back. That provides ideal hunting habitat for cougars. Then many say we have to control the cougar. But we don’t need to control the cougar. We need to control the habitat.

We need to look at the land [or habitat] and understand what balance of risky versus safe habitat will provide us a balance of predator and prey.

So landscape becomes a very, very strong management tool. Once we understand what the landscape of fear is for a particular species then we can go in an manage the habitat depending on what our conservation goals are.

Missing Pieces - or Pieces in the Wrong Place?

    The government has a serious problem with an introduced species - the horse. (And burros as well) Horses had been present in the Americas thousands of years ago, but had died out (or been hunted to extinction.) Europeans reintroduced horses and they quickly re-established themselves. The problem is, there's currently a large wild population in the west that is running into conflict with cattlemen who want the range they graze on for their livestock. The region is also in an extended drought which means the animals have less and less food available. This creates a dilemma, as much of the land they roam is under Federal control,so it becomes a question of the Feds trying serve many masters and multiple interests with limited resources.

Since the 1970s, the BLM has gathered thousands of horses each year, trying to prevent them from dying of starvation due to overpopulation. The costs have skyrocketed to $74 million a year, 60 per cent of which is spent on holding facilities that now keep some 49,000 horses and donkeys penned up. Congress is unlikely to increase the BLM budget any further, so this year it is only rounding up horses from the regions experiencing the most dire conditions. But the drought is unlikely to end before the pens reach capacity, expected before the end of 2014. Crunch time looms.
    The fundamental problem is too many horses, more than the land can support. The options are limited to two main choices:
• starvation from overgrazing and drought, which will bring numbers down - and leave the land in bad shape not just for the horses but all the other species that share it.
• round ups, to capture horses and reduce the number of free-roaming animals. Problems include protests from pro-wild horse groups, what to do with captured horses (adoption can't keep up with supply and selling them for slaughter isn't very popular), and the costs of feeding and caring for them when federal budgets are under attack.

       One solution that is being proposed is to use birth control on wild horses. Bringing down the birth rate is certainly one method to bring wild equine populations into a better balance. The two big problems with this approach are logistics and budgets. Tracking down all of the wild horses spread over thousands of square miles, let alone administering birth control measures is neither cheap nor easy. (And there's also the question of what kind of selection bias humans might have when picking out horses for  birth control.)

      The missing piece in this puzzle is horse predators: wolves, bears, cougars, wolves, coyotes. The long-standing western crusade against 'varmints' has given horses free rein to multiply in the absence of predators, to the ultimate detriment of themselves and their habitat. Given the hostility to increasing wolf numbers, it's not likely that the ranching interests will look favorably on any efforts to reintroduce any predators to their historic former range, especially given the knee-jerk rejection of anything smacking of environmentalism in western red states. Given the wide-ranging response of Yellowstone ecosystems to the return of wolves though, it's likely such a restoration would be far more effective and with greater benefits than trying to treat the horse problem as an isolated puzzle piece.

The Long Result of Time

      Speaking of missing pieces, recent research suggests the Amazon rainforest is still suffering the effects of an extinction event thousands of years earlier. The arrival of humans into the Americas seems to coincide with the disappearance of many large mammals (collectively called megafauna) - but there were also some climate changes going on that also affected vegetation. There's no single smoking gun that explains it all; it may well have been a combination of several things coming together.

      The disappearance of really large herbivores had consequences that are still manifesting today.

Vast regions of the Amazon are growing more slowly than they were several thousand years ago because they lack the fertilising effect provided by South America’s distinctive “mega-fauna” – the very large mammals that went extinct soon after the arrival of humans.

A study of how soil nutrients are distributed within the Amazon basin has revealed there is a dearth of vital minerals such as phosphorus because large mammals no longer roam the region to fertilise the soil with their dung.

      Given that we are rather counting on the Amazon in its role as a carbon sink, this is perhaps not good news for climate change. It also suggests that surviving large mammals may be carrying out a similar role today - which means their conservation is important far beyond their own individual roles. It's possible the fertility of the plains states today might in part be derived from millions of buffalo in vast herds redistributing nutrients during the course of their wanderings. In the case of the Amazon,
The study, published in Nature Geoscience, calculated 98 per cent of nutrient-dispersal has been lost since the extinction of the mega-fauna, which happened around the same time that humans first colonised South America from the north.

“While 12,000 years may be a timescale that is beyond most people’s understanding, through this model we show that extinctions back then still affect the health of the planet to this day,” Dr Doughty said. “Put simply, the bigger the animal, the bigger its role in distributing nutrients that enrich the environment.

“Most of the planet’s large animals have already gone extinct, thereby  severing the arteries that carried  nutrients far beyond the rivers into  infertile areas,” he said.

      It should be noted that large mammals may be important to the oceans as well, by transporting and releasing iron in their poo.

Meanwhile, Much Much Closer to Home...

        The matter of missing pieces has a very intimate connection for humans at a gut level - literally. The human digestive tract - indeed most of the human body - plays host for entire microbial ecosystems. We're just beginning to appreciate how these complex ecosystems affect us. It turns out the mix of bacteria we have living in our intestines have direct effects on our health.

Individuals with fewer numbers of so-called “good” bacteria are more likely to be obese and develop obesity-related ailments such as type 2 diabetes, high cholesterol, and heart disease. That’s according to research conducted by the international MetaHIT consortium published Thursday (August 29) in Nature.
       In fact, it appears the critters living inside us (gut flora) affect the way our immune systems function, the way food gets digested as it passes through us, and more. There are studies that suggest bacteria may even move in with us before birth. Sorting out exactly what's inside us is tricky, because some of the bacteria are so interdependent, they can't be isolated and grown in pure cultures - and pure cultures don't show us how they interact with each other. It's DNA sequencing that's giving us a better idea of who's living in there.

        This is one of the factors that makes the use of antibiotics something that should be managed carefully. A serious infection may require antibiotics to knock it down - but there can be collateral damage to the 'good guys' who actually help us. Worse, it makes things easier for bacteria that are resistant to a particular antibiotic, because they thrive while competitors die back. It turns out an effective way to treat Clostridium difficile infections is to give the afflicted person a stool transplant so they can be recolonized by helpful bacteria that have gone missing from the gut after antibiotics wiped them out. In a healthy gut, they keep C. difficile from taking over.

        It would be fair to say that modern medicine isn't just about treating patients anymore - it's also about treating ecosystems. Like it or not, we're never alone - and it helps to have all the right pieces in place.

The Bigger Picture

        It's one of the more rewarding elements of modern biology and science in general, to discover approaches that scale, that have general application. Understanding the way a particular ecosystem functions is likely to have applications across ecosystems in general. Understanding gained in one place may open doors in others. The importance of individuals within a species, within an ecosystem, transcends their individuality - it's their roles as members of a greater whole that makes them matter in ways we can't appreciate if we only look at them in isolation. If you can't see the forest for the trees, it's as apt to say you can't see the trees without the forest.

Originally posted to xaxnar on Sun Sep 01, 2013 at 04:06 PM PDT.

Also republished by Headwaters and Community Spotlight.

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Comment Preferences

  •  Tip Jar (36+ / 0-)

    Thank you for working your way down here. Hope you enjoyed this - and as a bonus reward, here's a link to a spectacular picture of Serengeti lions in the rain. (Click on the image for a larger version.)

    "No special skill, no standard attitude, no technology, and no organization - no matter how valuable - can safely replace thought itself."

    by xaxnar on Sun Sep 01, 2013 at 04:05:48 PM PDT

  •  Thanks for this diary (8+ / 0-)

    much to ponder.

  •  A Marxian interpretation (8+ / 0-)

    I know you didn’t want me to get bogged down on The Lion King, but that whole circle of life business was a cheat.  When the lions die, they don’t feed the grass. The hyenas eat them.  So the hyenas, the villains of the movie, were really just as important to the circle of life as all the rest.  Besides, when the lions tell themselves that self-serving crap, it reminds me of the masters telling themselves how they benefit the slaves, or, more recently, CEOs telling themselves how important they are to the economy.

    The Lion King did not merely present an overly simple picture of the ecosystem. It was an ideological justification of the ruling class.  And the dumb herbivores fell for it.

  •  Remember the Horse is an Invasive Species Here Too (4+ / 0-)
    Recommended by:
    xaxnar, LinSea, ban nock, Treetrunk

    We are called to speak for the weak, for the voiceless, for victims of our nation and for those it calls enemy.... --ML King "Beyond Vietnam"

    by Gooserock on Sun Sep 01, 2013 at 04:37:37 PM PDT

  •  Great diary! (5+ / 0-)

    I'm too tired to write more, but I just wanted to say I found it very interesting and it was well put together.

    •  We interfere with every complex (5+ / 0-)

      environmental system on the planet and somehow never see the cost to the health and exquisite balance that the natural world pays for our ignorance.

      The extinction of the top tier predators has been the biggest mistake that our species has visited on our world and it will continue due to short term gain and long term greed.

      In my Celtic druid soul i feel this imbalance every time i leave the garden to venture out into the modern world, filled with 'conveniences' and it breaks my heart every time.

      If only we had stayed hunter/gatherers.....

      'A scarlet tanager broke the silence with his song. She thought of the bird hidden in the leaves somewhere, unseen but nevertheless brilliant red. Nevertheless beautiful.' Barbara Kingsolver/ Prodigal Summer

      by flowerfarmer on Mon Sep 02, 2013 at 06:21:31 AM PDT

      [ Parent ]

      •  remember there is no such thing as "the balance (1+ / 0-)
        Recommended by:

        of nature". It exists only as a belief system.

        “Conservation… is a positive exercise of skill and insight, not merely a negative exercise of abstinence and caution…” Aldo Leopold

        by ban nock on Mon Sep 02, 2013 at 06:47:53 AM PDT

        [ Parent ]

      •  We affect everything by our very existence (5+ / 0-)

        And vice versa. The hunter-gatherer lifestyle is not inherently virtuous. Despite the comparative level of technology, there's plenty of evidence suggesting primitive hunter-gatherers may well have been a major factor in a number of extinctions. Easter Island once was covered by a forest - at some point after humans arrived they cut down the last tree. They did it without high tech.

        The hunter-gatherer lifestyle also comes with some pretty high negative factors: high infant mortality, susceptibility to disease, shorter life spans. Warfare is not precluded, nor is prejudice, xenophobia, ignorance, or all the other failings of humans in groups.

        There are always trade-offs. If our current civilization is wreaking a ghastly toll on the Earth, it also contains the seeds redemption and the power to change things for the better - IF we develop the understanding and will to do something about it.

        That's one of the major themes in David Brin's novel Existence. Every increase in knowledge also seems to come with a potential new way to disaster. We've started down this road though, and going back doesn't seem to be an option we can take voluntarily.

        "No special skill, no standard attitude, no technology, and no organization - no matter how valuable - can safely replace thought itself."

        by xaxnar on Mon Sep 02, 2013 at 07:48:14 AM PDT

        [ Parent ]

        •  We have seen, even in our very short (2+ / 0-)
          Recommended by:
          xaxnar, RiveroftheWest

          lifetimes, that greed ultimately outweighs the seeds of redemption.

          There are the valiant few who fight with mighty intent to save us from ourselves, to achieve one step forward but the greed monsters haul us 3 steps back.

          I miss the time when i was young and awash in the bright force of peace, love and understanding.

          I love your diary, tho, so there's that.

          'A scarlet tanager broke the silence with his song. She thought of the bird hidden in the leaves somewhere, unseen but nevertheless brilliant red. Nevertheless beautiful.' Barbara Kingsolver/ Prodigal Summer

          by flowerfarmer on Mon Sep 02, 2013 at 08:47:54 AM PDT

          [ Parent ]

  •  Fascinating. (5+ / 0-)

    Thanks for putting all that together.

  •  The horse wasn't actually reintroduced, it never (0+ / 0-)

    existed in the wild and has no natural predators. Cougars can take some during or shortly after birth but wolves and bears are shown to have almost zero affect on what is a domestic species.

    Ripple and Bechta have mostly retreated somewhat from their earlier simplistic ideas about wolves in Yellowstone. There's just too much conflicting data. Despite that they remain the most famous scientist advocates.

    Science is self correcting on Wolves the very least, scientists now disagree about whether wolf related behaviorally mediated trophic cascades in Yellowstone are really occurring..........  At most, that well-publicized claim may not be correct at all.

    A study recently completed last winter showed just about no movement from elk due to wolves or disruption of eating.

    Wildlife lives in a very complex space and often defies initial explanations.

    “Conservation… is a positive exercise of skill and insight, not merely a negative exercise of abstinence and caution…” Aldo Leopold

    by ban nock on Mon Sep 02, 2013 at 06:38:34 AM PDT

    •  Which is why science funding is critical (4+ / 0-)

      Some things only become apparent if you have a long baseline of observations to sift through. There's always a certain amount of 'noise' in any system that may obscure subtle interactions - and then there's major disruptions that can occur, knocking everything into a new pattern, i.e.: a wildfire.

      Fire isn't an everyday event, but it happens enough that many ecosystems are adapted to it. And then there's events like the infanticide observed in Chimpanzees that changed the entire understanding of what constitutes a range of 'normal' behavior in Chimps.

      There is very seldom a final answer to any question in science - theories are constantly re-examined, challenged, refined, and even discarded if a new hypothesis does a better job explaining what appears to be happening. Partly this is simply the way science should work - but there's also a very human tendency on one hand to challenge established 'truths' for a variety of reasons just as on the other hand there's a very human tendency to defend those 'truths' without questioning them.

      Over at Salon, an article looks at a recent paper in which two researchers tried to duplicate a number of findings in some pre-clinical cancer research efforts - and failed. The original work had been peer-reviewed, and seemed to meet standards for judging its validity.  A lot of additional work took those findings as a starting point for further work, but failed to pan out. It's not known what the problems are with that original research yet, but it seems clear we don't know as much as we think we did. Further inquiries seem to suggest this isn't a minor problem either.

      The important thing is to give scientists the resources needed to keep the basic research going for the long term. It's not just about coming up with answers - it's about coming up with better questions as we refine our 'ignorance' to a higher level of understanding.

      "No special skill, no standard attitude, no technology, and no organization - no matter how valuable - can safely replace thought itself."

      by xaxnar on Mon Sep 02, 2013 at 07:29:37 AM PDT

      [ Parent ]

  •  This is a very good article to wake up to (4+ / 0-)

    I hope it gets lots of recs!

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