Fractured Forests Are Endangering Wildlife, Scientists Find | Hacker News Reader

Fractured Forests Are Endangering Wildlife, Scientists Find

nytimes.com

148 pointspseudolus48 comments

This is not exactly a new finding, and one of the reasons the ecoduct was invented.

https://en.wikipedia.org/wiki/Wildlife_crossing

They work just as well for forests as for other biotopes but the countries where the forests end up slashed into pieces tend not to have the funds to reconnect them.

The article does clear up why different studies found the effects of fragmentation differs:

> While many studies have shown that extinctions are more common in fragmented environments, others haven’t documented much effect.

> A study published on Thursday may help resolve what has been a strident debate, showing why many species are vulnerable to the fragmenting of forests while others are not. Animals in places with a long history of disturbances are relatively resilient, the researchers found. Species that have existed in stable habitats for thousands of years are far more sensitive.

This may affect where you decide to put wildlife crossing or justify building such crossing.

Countries may want to build those but may not be able to afford them.

And, as the article writes, the forests in regions with a long history of undisturbed forests (Java, Brazil) contain species that will not leave the twilight of the forest canopy, so I doubt a wildlife crossing would benefit them. Apparently even birds that could easily fly from one "segment" to the next will not do it because they shy away from the open areas.

I like the idea of wilderness corridors: narrow connective parks linking larger undeveloped areas.

It's a good idea with one major problem, predators soon figure out that other wildlife has to pass this choke point and they will treat it like a walking buffet.

Not sure that's a major problem? Predators are generally the animals with the larger territorial requirements for a home range, and thus more reliant on the presence of these corridors to feed and disperse into new territory.

It negates the usefulness of the concept.

The concept is still useful but without the travel corridors when it comes to birds. Here it is encouraged to put even small blocks of land into a permanent wildlife covenant. Birds can use them as oases.

To some extent, plenty of bird species do not like to overfly humanity at low altitude and if the area isn't large enough to gain altitude or if the motivation isn't strong enough to expend that much energy then there might was well be a cloud high fence.

True, perhaps this approach would not work for condors, eagles etc.

However for most native birds in my country even a spot of an acre or two can be a good bird habitat for nesting and feeding and birds will happily overfly humanity to get to and fro.

The risk is it solves just one of the multiple issues from fragmentation and rather than preserve you develop something entirely and completely different. We will have to see in a century or three whether what results is desirable.

The smaller species of plants and animals in the forest food chain migrate slowly - perhaps a few inches or feet a year, and forest edges are different. Not least they have vastly more light than within the depths of the forest. The carbon uptake is less - thanks to that increased light, the decomposition cycle is different, and less of the dead wood gets broken up to go deep into the soil. By creating lots of little islands with only edge forest, you no longer have the true forest - that far enough into the canopy that deep forest rules apply - the forest that in theory we wanted to save. A connecting strip between areas risks multiplying that edge forest effect dramatically - trapping deep forest species just as surely as an eight lane road or city in the way.

Without a contiguous forest in which to exist, those isolated islands start to evolve differently. In the case of tropical and temperate rainforest you need the huge expanse or you lose the climate impacting effects. e.g. one tree takes up some number of litres of water in the growing season, and you need n trees to seed enough clouds to remain rain forest, or put enough terpines in the air (particularly coniferous) to preserve the right balance of insects.

It's these climate impacting effects - the water uptake and cloud seeding, that is one of the main reasons many studies are claiming the Amazon is nearing a tipping point into catastrophic drying.

TL;DR we really need to develop the will to preserve and remake unfragmented, untouched - or at least limited - wilderness forest - for the benefit of all of us.

Reading The Overstory right now, which is a Man Booker winning fictional exploration into the survival mechanisms? consciousness? endangered status? of forests.

Edit: I read the title as “fractured forests are endangered wildlife”... which goes to show what this book has me thinking about.

That book is incredible, and still relevant to this topic! One big thing in the book is that humans don't understand the complexity of forest ecosystems and it shows when we try to change or recreate them. If we expect that we can just put a highway through a forest and not cause damage because the highway is relatively small (in surface area) we are fools.

I remember learning in elementary school in the 90s that cow birds, which are parasitic breeders(they lay their own eggs in other bird's nests and their offspring pushes other chicks out), live closer to the forest edge, so fragmented forests meant other birds were being wiped out.

Doesn’t that lead to the cow birds being wiped out too?

There was a popular book about this written over 20 years ago, The Song of the Dodo.

https://www.amazon.com/Song-Dodo-Island-Biogeography-Extinct...

This was a great book. I live in the pacific northwest and one thing that boggles my mind is just how cheap forest land is. Weyerhaeuser owns 12.4 million acres and only has a market cap of 21 billion. Crazy to me that for 0.5% of the national budget you could buy out this company and increase the size of the national forests in the lower 48 by nearly 10%.

Everyone wants to spend mental energy on being green and helping the environment, but nobody wants to allow wild places to recover. I would argue any politician proposing a green new deal is proposing a plan that would get less done than simply using eminent domain to form new national forests out of timberland. Much of this land was never proved and was simply granted to railroads, many of which no longer even exist.

If much of the most valuable timberland in North America is this cheap, then what about deserts with no energy prospects?

There are still places in the US that should even be national parks such as the Ruby Mountains in Nevada, which the book mentions briefly as having an island like effect due to how isolated they are from other high alpine mountains.

What can I do to make this better? I would really like to stop ruining earth but it does seem that there is a lot of momentum in that direction.

I've been thinking about this a lot and I think our car-focused construction patterns are to blame. In my state we have a grid of roads (whether paved or unpaved) that covers pretty much the entire state. It seems like where the roads go, people will go build. Everyone wants to have their own quiet area and when everyone does it (enabled by the automobile), we end up with incredibly fractured habitat. I think the only real solution is for governments to stop allowing sprawling, car centric, development and possibly get rid of some roads in rural areas. Doing that without impacting wealth might be tough. However, there are plenty of places where roads go that do not need roads. At a personal level though? People underestimate the impact they can have in their local government.

If you are in the US:

https://wildlandsnetwork.org/ https://rewilding.org/

You can also contribute to local and regional land trusts:

https://www.landtrustalliance.org/

If you own land, you can will it to a conservation land trust. Encourage friends that own land to will it to a land trust.

Have less/no children. Donate to family planning organizations.

at your level? consuming less resources. It's quite easy to lower your environmental footprint by a half, by changing and reducing consumption habits (eating less or no meat, no pets, avoiding to own a car if possible or at least not a heavy/polluting one, no cosmetics, soap bars instead of bottles, reusing, repairing everything, ..). If everyone in developed countries do that, it's virtually twice less people on the planet, and the environment will be much more likely to catch up in the short and long term

and voting for the right people, but I don't believe much in politics for the moment, on this problem

You've a very sane reaction I want to say, I hope most people will do too as quickly as possible

It's only a matter of time before the only places that wildlife can really thrive, is true wildernesses. National forests, big state parks, dedicated wildernesses, and the like. Little community forests are just not good environments and there's little hope for small, isolated ecosystems to have much diversity.

I am all for maintaining large true wilderness. Even so, I think it would be great to have many more "little community forests". My guess is that such forests would improve the diversity of all animal life the size of (say) a hawk and smaller. I also guess that the best path to a medium-sized community forest in an area without one is to start with a "little" one.

I'm the steward of a small (10 acres or so) piece of land - small enough that I can hear human activity from most of it - and my leisure activity is trapping for introduced pests like rats, possums, stoats and weasels. It's hard to say exactly how effective my efforts are, but last month I spotted a wild kiwi on a trail camera which was truly exhilarating https://youtu.be/e_9bSw5yniA. Anecdotally I've also noticed an increase in birdlife during the day. That's given me the incentive to try for total pest eradication next year. Rats are the biggest problem.

we are decades past that point. The biodiversity in national parks that have existed for longer are completely different to what an average person considers wilderness.

Cant read this. Does anyone have a working link?

https://outline.com/4FBeKG

>Animals in places with a long history of disturbances are relatively resilient, the researchers found.

Figures... the species that were less resilient are probably already gone, so the remaining ones are the resilient ones.

Yes, this would be natural selection in action, with the selective pressure being human disturbance and incursion.

I'm not sure what point you are trying to make, but in that way you can put almost everything under the umbrella of natural selection. That does not mean that it is natural or desirable.

It such a weird thing to classify some things as natural and some things as not. Humans and everything we do is of course natural and a direct result of nature taking its course.

Why would that be weird? That is literally the definition of Natural

>existing in or caused by nature; not made or caused by humankind

https://www.lexico.com/en/definition/natural

Right, but I bet very few new species have emerged in the last few hundred years because of habitat fragmentation.

More likely we caused the population of many animals to decrease or extirpated them entirely (if not drove them to extinction).

The coywolf isn't a species (and wolves and coyotes only "diverged" ~100k years ago anyway, IIRC), but they surely became much more common in the exurban northern US after the 1960s. More generally, I believe that there's been an increase in many mid-size mammals in the northeast US as habitats became too small for the large carnivores. So it's not just extirpation and decreasing numbers, but it's also not good.

Would we even call them new species within a few hubdred years or would they be seen as “just variations”?

Many species are absolutely thriving under human invasion and forming new behavioral and breeding patterns that in some cases are even leading to physical changes. Many burds like crows and sparrows love human environments. Trash pandas love us too. Hawks love cities almost as much as mountains. So many tall places to survey from.

There’s also fish who have started being smaller in adult size due to sports fishing and size regulation. Stuff like that.

Oh and crowd are known to have branched into novel food sources because they can use cars to break hard nuts they otherwise couldn’t open.

It’s not all doom and gloom. Nature is hella robust.

This is a well written article on the topic.

It argues that human pressures may be selecting out only the hardiest most adaptable species such as rats, mice, pigeons, sparrows, etc...

If this goes on unabated, we'll be left with an ecosystem with much lower diversity.

http://www.davidquammen.com/sampler/18-planetofweeds

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I think technically you are correct. The earth could become essentially a farm, with a bunch of giant monoculture croplands that provide feed, oxygen, mulch, etc.

The downside is that the lush, unfathomable nature documentaries of the present will be a curiosity from the past.

But there is a pretty large population of humans who is already on board with something quite close to this transition. They live between farms and ranches deserts and cities and don’t see nature as anything but raw material to groom.

So I think your sarcasm is misplaced.

We need a real story for those people. Why should they care that everything over a kilogram could go extinct and ConAgra become responsible for seeding formerly wild spaces with geo-engineering products that maximize economic growth?

But money itself is made of plant-based matter, so the plants have snuck their way into the heart of our economy. It's almost as if they knew about job security.

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I feel like capitalism here was used in place of the current regime

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Ive been to ex “2nd world countries. They’re attitude towards the environment was a bit more man vs nature than what we see in the West. See the gigantic sometimes failed exercises in diverting rivers building dams etc. one of the more spectacular examples is the Aral Sea, connecting the Arctic rivers and in China the three gorges dam... which while a twinkle in Yatsen Sun’s eye, became a windmill in Zedong Mao’s policies, and finally realized by the current regime.

I think we need to get out of this "capitalist" vs "communist" mindset. There are not just two economic possibilities: "everything is an unregulated market" and "everything is top-down planned".

There exist possible future economic systems which use markets where appropriate. Centrally plan where appropriate. And regulate where appropriate.

That’s a common strategy to defend the status quo and scare people from making Any changes. I think only offering extreme options is especially popular in the US with its two party system. Happens in almost every political discussion.

Sure but people seem to have the impression that the “bad things” happen especially in capitalist systems of the west and that other alternate systems like communism would have s different attitude toward the same issues. My experience tells me they had the same attitude but with fewer safeguards and oversight.

Well my view is that both capitalism and communism have these problems, but that other alternate systems (which are neither capitalism or communism) could have better solutions.

Specifically:

- Pure capitalist systems all but rule out strong market regulation. It's not technically incompatible with a market-based system, but in practice people tend to start shouting "but that's not capitalism" as soon as you start proposing regulation as an expected norm as opposed to an unusual exception

- Communist systems all but rule out market-based solutions, which is just dysfunctional as it centralises power too much, and makes it difficult to efficiently distribute resources

I think it's unhelpful (bordering on obtuse) to assume that people criticising capitalism in 2019 are advocating for communism. Very few people would advocate for communism. What people are calling for is:

- A recognition that market failures are not an exception: they are common. And strong regulation is needed to counteract that.

- Large wealth equalities distort markets, and that we need limits on the amount of wealth individuals can control.

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