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I took an environmental science class in college years ago. My memory is fuzzy but I do recall these sorts of cycles typically indicate an unhealthy ecosystem,
by beart 3y ago
I took an environmental science class in college years ago. My memory is fuzzy but I do recall these sorts of cycles typically indicate an unhealthy ecosystem, where an outside factor has shifted the balance. I think a commonly referenced example is the wolf population on Isle Royale in Michigan. Whereas a healthy and vibrant ecosystem tends to maintain a more consistent population across most species. I wish I could remember in more detail...
- ars 3y agoThat's not true. "Ruffed grouse populations rise and fall at intervals of about 10 years. Many other species of wildlife such as snowshoe hares also cycle at 10-year intervals." https://www.dnr.state.mn.us/birds/ruffedgrouse.html https://www.dnr.state.mn.us/birds/ruffedgrouse.html These animals have been cycling this way for as long as people have been checking, and presumably before that as well.
- nomel 3y agoLag in a proportional feedback system results in oscillation. This is why the derivative term is added to get rid of it, to catch things before they overshoot. I don't think most of nature has a concept that maps to the derivative term, especially since "greedy" is usually the best option for short term survival.
- beart 3y agoI'll take your word for it. Clearly not my area.
- pepa65 3y agoLooking at bifurcation theory, it seems the 10 year cycle length cannot be the norm for these oscillations.
- ars 3y agoAnd yet the cycle has continued for as long as humans have tracked it. So either the theory is wrong or reality is wrong.
- nerdponx 3y agoIt looks like this particular die-off was more severe than it otherwise would have been, due to unusually warm ocean temperatures and the resulting higher caloric need for the crabs. So the cycle is natural, but the extreme depth of this particular "trough" in the cycle seems like an abnormal event.