Some areas are so destroyed by human activities that they need some help in rewilding, which is definitely possible. Of course, this study does point out that some management of the land that resembles previous human activities could help biodiversity. And of course, as the study mentions, they did not include "Mosses, lichens, mammals and invertebrates—including soil organisms such as nematodes and molluscs".
Keep in mind also that biodiversity is difficult to measure can be counterintuitive. Farmland and managed land creates edge habitats, or a confluence of habitats, where measured biodiversity is higher. Of course, when that edge habitat disappears the measurements can go down. But that does not imply that merging a huge number of farmland back ot a more contiguous wild are won't support biodiversity better in the long run.
People may have generally existed in these regions, but the scope of ecological impact & evolutionary pressure is more recent.
Which is half true, half not.
If you re-introduce certain keystone species, the rest follows automatically - the most well-known and well-studied example being the wolf in Yellowstone [1].
[1] https://www.yellowstonepark.com/things-to-do/wildlife/wolf-r...
There's a lot of bits of biodiversity you don't get without humans putting their thumb on the scale and forcing a different equilibrium.
Climate change is happening everywhere but it is quite noticeable in Japan with summers getting hotter and winters getting milder.
Raleigh used to have more snowy winters from what I was told. Now a days winters have a 1 in 4 chance of giving snow you might see in the morning for most of the area.
Likewise, I don't know if Japan has to deal with wildly aggressive invasive species like I am right now with buckthorn, but there's lots of plants that will simply choke out most others and aren't very beneficial. If nobody's around anymore and they were actively grooming the pastures and such, that will also put a ton of pressure on previously flourishing species.
I didn't see it in the article nor the 2025 study https://www.nature.com/articles/s41893-025-01578-w
Additionally, the article points to Spain and Lake Constance in the Alps exhibiting similar effects.
https://www.nippon.com/en/articles/-/14855
I will look up spain when I get time and get back to you. I have to be somewhere now.
I've also seen some very well secured trash bins in Tokyo, so Japan clearly has wildlife even in urban areas that's very interested in the contents of trash bins.
I used to have a committee of four farm dogs visit my kitchen scrap pile every morning to sniff around. Now they are all in their separate invisible fence boundaries. So, more coyotes, fewer turkeys? I see more turkeys in some closer in suburbs and the neighborhoods of Boston.
That seems reasonable from a study from Europe they quoted. If farmed land, garbage left around, or brush clearing was helping certain species thrive it could mean they will struggle once farm plots and that other stuff goes away. It would be rather silly to have someone dump piles of rotting food in the woods to keep up the wild boar biodiversity that’s now declining.
When you remove these urban centers the same thing happens. You are changing the environment. So of course there is an initial culling as the selection process activates.
We tend to think of depopulating actions in a single unidirectional way. Nature -> Urban = Bad and depopulating. The reality is that nature is neutral. It's Not unidirectional and nothing is bad or good. Believe it or not I'm sure species do go extinct from the conversion from urban to more wild environments. It happens both ways and again, extinction isn't inherently bad either.
First, I live in Japan. Been here for over 25 years. So, here's a first hand point of view, but anecdotal. So, take it as you like...
Most people are growing up and moving to the bigger cities, because of education and because of jobs. If you want a very good job here in Japan, you need to try to go to a very good university.
If you are born just outside of a bigger town, or within 1 to 1.5 hr trip into a bigger town, then you'll likely travel to school by train and bus. You might even stay in this outer circle of homes when you get a job. That seems to be a kind of invisible "circle" where people tend to think "inside this circle, I can travel for school or work, but outside this circle, I'd be better off moving". Mostly that idea comes from two things: the time spent traveling and transportation costs -- you start to spend as much on trains and busses as you might for a cheaper apartment.
The further you are born outside that "invisible circle", you are much more likely to leave home for high school and then college, and then you are more likely to job hunt in bigger cities where there are more choices. It becomes too expensive to travel 2+ hours for every job interview.
So, in short, the countryside IS emptying out. The younger people are leaving for education and work, and the older folks continue to live there until they pass away... so the smaller towns and villages are emptying out. Thus the very large increase in "akiya", empty houses.
NOW, the "people are moving to the countryside" is a kind of YouTube influencer thing where there was a wave of non-Japanese people making videos about how cheap it is to buy one of these akiya in the countryside and improve them. So, those videos make it sound like people are rushing to the countryside to buy houses, but in fact, not many people are. Japanese people generally won't, because it's actually TOO expensive to renovate an old house, the yearly tax on houses is expensive, and then it's a nightmare to travel 30+ minutes every time you want to get groceries or look for new clothes. (I lived in one of these middle-of-nowhere villages for three years. Beautiful place, but took about 40 minutes to go get groceries, get to the nearest train station, or rent a movie!) Japanese people (well middle-age and up) start to worry about retirement and old age... and it's considered general knowledge that living in the countryside makes it extremely hard to visit the doctor, get medical help, get groceries, and such, especially when they are encouraged to turn in their driver's license (for people over 80) and there might only be one bus an hour into town! (Such as in the village I lived in.)
So, yes, there are two narratives on the internet about the Japanese countryside -- it's being bought up and renovated, CHEAP!, and it's emptying out. The later is the reality.
I have bats, barn owls, half a dozen species of song birds, hedgehogs, several variants of mice and the occasional band of racoons (invasive species over here) living on my property. None of these are pets or domesticated in any way. They simply benefit from - and even rely on - the activities of me and my neighbours (I live in a rural community, my neighbours are farmers and I keep livestock myself).
There're just as "wild" as the foxes, storks, deer, cranes, herons, boars, wolves, and all the other critters that live in the area. You'd be hard pressed to actually find animals (and some plants for that matter) that aren't affected by or (sometimes indirectly) depend on human activity in most countries. Some benefit and thrive (like the examples from Japan), others struggle.
Humans built systems to prevent all this from happening, 1000s of little custom ones in 1000s of different little places with 1000s of different functions and kept those systems running. Irrigation. Bringing food (and edible trash). Preventing collapses. Building dams. Removing invasive species from specific areas. Those are probably the big ones. That's why there is the continuous nature across Europe. It's entirely artificial and it's due to farms being so incredibly widespread. Just look at the map. It's absolutely incredible how far and how much there are.
The "natural" Europe is really mostly steppe dotted with swamps and forests, usually next to each other, with vast open spaces, with very few animals, in between. That should be the situation one would expect to return.
Note also in my limited experience there is typically a severe and sudden difference between flat land and mountains, the former being human managed with extreme prejudice and the latter being typically degraded/unnatural/replanted ("Japan's forests are ~44% dense post-war cedar/hinoki plantations with barren understories"). This is one of the most striking features of the Japanese landscape relative to other nearby countries. I would assume the current study focused only on flatland, as the forests are not going to empty out when proximal humans desist: quite the opposite.
The unstated truth here is that Japan apparently raped its physical environment for its war machine.
https://japansociety.org/news/japans-forests-good-days-and-b...