Biodiversity assessment shows 40% of U.S. ecosystems in danger of collapse.

I’ve mentioned in the past that I spent a couple years working as a field ecologist for the Wisconsin DNR. Most of what I did was catch snakes all over the southern half of the state (as part of a team), measure them, take metadata, and release them. For the garter snakes, we took DNA samples, and noted which subspecies they were. The purpose of this research wasn’t to discover anything new, so much as to assess the status of the garter snake population in that state. It was a fun job, I got to see a lot of the Wisconsin landscape, and it was neat to know that we were part of a larger effort. Not just in every state, but in pretty much every country, there are people doing the slow, daily work of counting organisms.

This is how the scientific community builds a picture, in data, of what’s happening in the world around us. It’s basically an ongoing physical check-up for the biosphere as a whole. Instead of checking temperature, heart rate, blood pressure, and all that jazz, we check snake levels, and tree count, and do bug inventories. I’ve taken part in a few studies like this on different reptile species, and been peripheral to similar work on plants, birds, and insects. I sometimes run into people who’re incredulous that scientists can claim to know that a species is in decline, or that an ecosystem is falling apart, and I think it’s because they don’t realize that we really do have people whose job it is to go out into the middle of nowhere and just… count everything.

I think it’s rare that a study will literally count every tree in a forest, but they absolutely will get a representative sample. Designate strips of forest a couple meters wide and a few dozen meters long, and count every plant in that strip. Do it a hundred more times in different parts of the forest, and you get data that lets you form a sort of impressionist image of the forest’s health. Do it year after year, at consistent times of year, and you can see how things are changing. Unfortunately, the result of all that work is that we know that 40% of ecosystems in the United States are in danger of collapse.

“This grim assessment adds to the mountain of science showing that we’re creating an extinction crisis,” said Tierra Curry, a senior scientist at the Center for Biological Diversity. “It’s suicidal of us to pretend that business as usual is more important than safeguarding the natural world we all depend on.”

The study is the most comprehensive to date on the status of U.S. ecosystems. It found that 51% of grasslands and 40% of forests and wetlands are at risk of range-wide collapse. Only 12% of U.S. lands are currently protected.

“Grassland loss is the biggest U.S. environmental disaster that gets the least attention,” said Curry. “Conversion of grasslands to suburban sprawl and pesticide-intensive agriculture is a primary reason we’ve lost 3 billion birds and why we could lose monarch butterflies and vital pollinators.”

Among animals, the evaluation found that freshwater species such as mollusks, crayfish and amphibians are the most threatened groups because of water pollution and dams. Insects like butterflies, bees and dragonflies are also highly imperiled, with 37% of U.S. bee species facing extinction.

For plants, nearly half of cactus species are vulnerable, making them the most jeopardized plant group. Around 30% of ferns and orchids are at risk, as are 20% of tree species.

“By taking nature for granted we’ve pushed natural systems to the brink of collapse,” said Curry. “We’ve been so neglectful for so long, but we can create a different world that doesn’t exploit nature and vulnerable human communities for never-ending sprawl and consumption.”

It’s not fair to say that nothing is being done, but as with climate change, if enough was being done, then we wouldn’t be at this point.

I think it’s worth discussing what “collapse” means, when it comes to ecosystems. It doesn’t mean that a blight falls upon the land, and everything dies, leaving only withered desert behind. I mean, that can happen, but even when it does, it’s not “the end”, but rather a shift to a new kind of ecosystem. The report itself describes collapse as involving

[…]a transformation of identity, loss of defining features, and/or replacement by a novel ecosystem. It occurs when all ecosystem occurrences lose defining biotic or abiotic features, and when when native biota are no longer sustained.

It might well be the end of the world for species dependent on the old ecosystem, but it’s both more complicated, and less final than what you might see in fiction. The problem is that a change like that can absolutely devastate connected human populations.

We’re worried about ecosystem collapse not just because we mourn the species lost, though I think we should do that, but also because we depend on those ecosystems, often in ways that most of us don’t even notice. I’ve talked before about ecosystem services – the myriad of ways in which natural ecosystems support all of humanity – and while the shift to a different ecosystem won’t necessarily remove all of those benefits, the loss in biodiversity will reduce them. During COVID, we’ve seen how our just-in-time supply chain fails in a crisis, and there’s no reason to think that that weakness is limited to our medical and medical supply systems.

As Dr. Curry says, trying to continue business as usual would be suicide for humanity. Well, most of it would be murder, since most of humanity has had little to no say in the course of events over the last couple centuries. The upside of this report is that “in danger” does not mean “doomed”. We’re on course to “doomed”, but we have the means and understanding to change course, if only we can disempower those working to prevent us from doing so.

If you want to get involved in this kind of work, look for “community science” or “citizen science” happening near you. Local nature centers or university biology departments are likely to have information. If you want to get involved in counteracting this, then look into stuff like pollinator gardens, seed bombing, and community groups that do trash pickup and tree planting and the like. The unfortunate reality is that our institutions have failed us, and are continuing to fail us. It may be that through organizing and hard work we can gain control of those institutions, but until then, doing what we can, where we can, with whom we can, can only lead us in the right direction.

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  1. planter says

    This is an interesting report; thanks for bringing it to our attention Abe. I am disappointed in how the report mixes two different issues together. The processes for assessing extinction risk for individual species are very robust and well developed. I am familiar with the process because I spent 8 years on a committee in Canada tasked with asessing the strength of evidence for species risk of extinction.

    Assesing risk of ecosystem collapse is a whole separate kettle of fish. The report appears to use a criteria of %conversion as a threshold. While this is a good way to assess the risk of diversity loss in a system, it is likely not a good way to assess loss of ecosystem function, which is probably what people think of when we use the word “collapse”. Abe alludes to this in the post, but I suspect most readers of the headline and linked article would miss this. I think such language is not advisable because overstating a problem can lead to cynicism. Focus on the 40% species loss which is calamity enough on its own.

    For those without deep schooling in ecology, you should know that there have been decades of studies and debate on the links between the diversity of an ecological community and the provision of ecosystem function (e.g. growth of biomass or storage of carbon). While studies in experimental (i.e. artificially created communities) often show a positive diversity – function relationship, the findings from natural communities are much more complex.. A blanket assumption that diversity loss = loss of ecosystem function, while likely true for some ecosystems, cannot be extrapolated at a continential scale.

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