8 votes

What is a keystone species, and why are they so important?

3 comments

  1. UTDoctor
    Link
    As is the concept of keystone species that the author of this article fails to sufficiently shed light on. Something that I thought was interesting when getting my ecology degree was research into...

    These strong, top-down effects are known as “trophic cascades” – and they can be much more complex than you might realize.

    As is the concept of keystone species that the author of this article fails to sufficiently shed light on.

    Something that I thought was interesting when getting my ecology degree was research into the area of biodiversity. Specifically, there is evidence that biodiversity in itself isn't necessarily an indicator of the health of any particular ecosystem. We often see in the news that having a plurality of species within an ecosystem is a net positive and should be sought regardless of other factors. This is a simplistic view of the complexities of ecosystems and what makes one healthy vs. not.

    Back to the topic at hand: keystone species. I wish the author would have discussed that it's not about the species themselves, but about the roles they can play. A species may be a keystone player in one ecosystem but not another. Some ecosystems might have redundant species that perform similar ecological roles. If multiple species can fulfill the same ecological role, the loss of one species - even if "keystone" - might not lead to deleterious trophic cascades. Focusing solely on individual species is less important than understanding the interactions and dynamics within ecological networks at large.

    This is a good surface level article, but I do wish it explained more along these points I outlined above.

    4 votes
  2. [2]
    rosco
    Link
    Whenever keystone species come up I like to point out how the concept was discovered. Robert Paine was an emerging ecologist back in the 60s and wanted to better understand relationships between...

    Whenever keystone species come up I like to point out how the concept was discovered. Robert Paine was an emerging ecologist back in the 60s and wanted to better understand relationships between species in the rock intertidal, usually inhabited by starfish, mussels, barnacles, urchins, anemone and things like that. So Robert decides the best way to do this is to go to different, largely isolated tidepools and just start picking out certain species and winging them out to sea. Like just monster throws of all kinds of creatures into the deeper ocean. I find the image of that hilarious. And he continues doing this for years! The trend that emerges is that in the tide pools that sea stars have been removed from start seeing explosions in mussel populations to the point where they largely out compete the other species. He didn't observe the same impacts from doing the same thing with other species, thus the sea star is the keystone. It's so funny to me that such a foundational theory can come from such a chaotic experiment. I love it!

    Today we see issues with the loss of keystone species across the Pacific coast in the USA. In California we lost my favorite keystone species and all around badass predator the Sunflower Sea Star. Outside of being one of he wackiest things to come across in the deep, the Sunflower star was (and in Washington/British Colombia still is) a prolific predator. They got this with a double whammy of sea star wasting disease and "the Blob" (a absolutely abnormal warm water event) back from 2014-2016 and have literally been eradicated from our shores. Other large starfish species, like Pisaster were also effected but have since started to rebound. However the loss of the Sunflower star, aka the grabage disposal of the sea, has had a devastating impact on our kelp forests, particularly our bull kelp forests that experienced greater than 95% loss in kelp canopy from 2014 to 2019. That's insane!

    In any case there are restoration and reintroduction projects underway for our favorite of the sea stars, and while they aren't going great, it give us some hope for their return. When we talk about the impacts of climate change this is one that is often left out. Not all species will die or even have adverse effects from climate change. But, if a few of the key ones do it still can have an enormous effect on the ecosystems they live in. Anyway, three cheers for this sexy bastard.

    2 votes