Someone logged a 500 hectare plot in Borneo. They split this into 125 sections and planted 0, 1, 4, or 16 "tree species that are frequently targeted for logging". After 20 years, satellite imagery shows that the more tree species you planted, the more recovered the land appears to be.
I'm left wondering:
1. Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
2. Is the satellite imagery actually representative of on-the-ground truth? A lot of logging land in western America gets replanted with logging-friendly trees in very regular grid patterns. These areas may look like forests from satellites (or to uninformed ground-level visitors), but the regrown tree farms do not behave like forests. The dense growth crowds out the ground-level plants, which in turn makes the entire tree farm a poor habitat for local fauna. If your goal is to grow more trees for lumber, tree farms are great. But I'm not sure the claims about "forest restoration" are honest/true here.
> Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
Because that is what private land owners will do, they'll want to plant primarily what they can sell. This research likely intended to reduce the immediate damage from logging.
> Why did they plant only tree species that are frequently targeted for logging?
Because the main purpose of replanting trees to is be able to harvest them again in the next few decades. Private land owners generally aren't interested in creating old-growth forests, they're trying to make money.
It's not exactly ideal, but ending up with more biodiversity is likely a good thing even if it will be logged again later.
If you want more old-growth forests there's going to have to be a _lot_ more subsidies to private owners to literally pay them to not log their land.
> Private land owners generally aren't interested in creating old-growth forests, they're trying to make money.
To be clear, in the western US this is by design. Large swaths of private land are zoned for forest. Aside from a few niche instances of grandfathering, you cannot build on them. They're useful for recreation and logging, and that's all that's allowed.
The gov't wants them to be logged regularly. If they really wanted old growth forests they'd make it public land (it's not especially expensive land, either, right after a patch gets logged it's not uncommon for the owner to put it on the market fairly cheap).
Old growth forward have a range of incredible ecosystem benefits, including a big effect on river health.
The 'Timber Wars' podcast was a six part story on the Pacific Northwest, including a lot of the history of the science on logging and forest health, as it evolved from the eighties through to today.
Actually I've heard that the best ecological and economic outcome is to manage an old growth forest and log it selectively using patterns that mimic tree loss from non-human activity.
Maximizing ecological advantage also maximizes economic advantage, even in the short-medium term.
> I've heard that the best ecological and economic outcome is to manage an old growth forest and log it selectively using patterns that mimic tree loss from non-human activity
I don't see how this is supposed to be accomplished. For that concept to make any sense, you'd need to prevent the tree loss from non-human activity, which is all but impossible to do.
If you can't do that, then the existing pattern of loss already looks like "loss from non-human activity", and any logging you do will look like "a lot more loss than typical of non-human activity".
> I don't see how this is supposed to be accomplished
Peter Wohlleben has written about this approach. The Menominee tribe also practices a similar method; they only log sick or weak trees. However, because these are from old growth forests, the wood quality is superior to that of trees from monoculture forests.
Between clear-cut horror and ideal pristine old growth, there is a world of managed forests that fix carbon with an economically sustainable model. Not the best biodiversity but mixing sixteen species makes the initiative top tear already.
And generally, these forests are subdivided in plots of different 'age'. Every year, they will log 1/20th of the forest or so. The wildlife might be able to move from an affected area to one of the bordering areas.
In fact, this model comes quite close to natural destruction of forests, where old trees would fall over, and wildfires would rage.
The only difference is that the process is not random, but nicely planned and managed to allow _humans_ instead of _wildfires and storms_ to reap the full-grown timber.
This is an aside.
This [0] is what an attempt at balancing logging, locals, and forest conservation ~150 years ago looked like.
The checkerboard effect [1] is pretty striking.
This strategy ended up being a disaster for some animals, famously the Northern Spotted Owl.
Re satellite. At Sentinel resolution (10-20m) not much, maybe enough to distinguish plantation from natural forest spectrally. At Planet (3m) and below you can start to see large individual trees.
It's very difficult to accurately measure biodiversity from space. Drone imagery might get you species visually but until we have widespread hyperspectral (see ESA CHIME) 12-13 bands is what most people work with.
> 1. Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
Because forest management is for logging. They will log those trees once they mature to the best value when considering DBH, the market, and opportunity cost.
> 1. Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
Because the whole point of tree planting is forest management. That's why whenever there's a forest fire they spray it with glyphosate so that other trees don't grow, then they plant GMO trees that can live in glyphosate doused soil.
Glyphosate is not soil active, so there are no "trees that can grow in glyphosate-doused soil."
The primary reason for broad herbicide treatment as part of site prep is to avoid low-value, or ecologically opportunist species that thrive in disturbed soil/land, and prevent either the target species from growing, or create an environment which lacks the diversity necessary for the region. For example, sweetgum, huisache, black locust, chinese tallow (as examples from specific regions in the US), will all take over and completely dominate a deforested section and prevent oaks, pines, etc. and appropriate forb for wildlife without consistent, ongoing burns.
FWIW, there are no "trees which are GMOd to live with glyphosate application" - you're thinking non-tree crops. Nearly every softwood and hardwood tree is susceptible to damage from Glyphosate.
Only one of the trees I listed was invasive, the others are opportunistic natives to their regions that will outgrow everything else.
The nice "diverse" forest you're thinking of in your mind took a long time to become that way, the normal state of nature is to not create a perfect balance out of the gate, but for constant competition and regularly have to cycle through multiple iterations of configuration which are, by all means, not as productive or valuable for wildlife/nature as their final states. None of that means that using a herbicide is sufficient, but without, you're looking at potentially hundreds of years to get back a usable environment for wildlife that is well-balanced vs 10's of years.
Outside of a few soil-active herbicides, most of what they use is one-and-done and can be applied selectively to only problem plants with minimal unintended consequences.
Where I live in germany, there used to be extensive spruce monocultures forests everywhere.
They are mostly chopped down now and replaced with a mixed young forest, all without herbicides. (But with some planted trees, cleansing and fences to protect the young forest from deers) So after 15 years they surely are not comparible to old grown forests, but they are very diverse and alive. So I strongly question the assumption that herbicides are necessary or beneficial to create a diverse forest.
Most of the dominating species in the first years will be (were) replaced by something else eventually.
To be clear: herbicides are not essential in every area, but in some areas it is completely cost-ineffective to promote appropriate diversity and wildlife habitat without some use of it.
FWIW, in the region I'm currently managing a 100-acre habitat that was previously a pine plantation, it would be sacrosanct to "fence out deer." Early stage re-growth is wonderful deer habitat, lots of sunlight generates lots of forbs. However, in the same region I am in, any area left to its own devices becomes quickly overgrown to the point of making poor habitat for wildlife (no viable food, no viable cover, even though it's "thick" it is not useful to species such as deer, rabbits, quail, turkeys, etc. lacking the right kinds of food and cover).
Mechanical and fire (prescribed burns) are our primary tool we use, along with appropriate canopy thinning. However, when dealing with opportunistic species (the most aggressive here being sweetgum and chinese tallow), these methods are not effective. As each of these species re-sprout and spread via roots as well as seed, mechanical and fire only top-kill, resulting in them coming back thicker again within months. Repeated mechanical control presents significant issues both for valuable forb and impacts on land (a skid-steer is very heavy and results in significant compaction of soil, for example) and is incredibly expensive at about $1,000/acre when following proper selective practices.
We were also very much against the use of herbicides, but after numerous conversations with local biologists and forestry management professionals (our state provides them as a service), we finally realized that we were in a losing battle and selective application was the way to go. With basal spraying for larger stems of unwanted species and selective foliar for seedlings, we've reduced our costs to a fraction, reduced the damage to land and erosion, and we're seeing higher value (ecologically, not monetary) habitat with a faster turn time. Our approach is to eliminate all non-native, invasive species, develop the mix of pine savannah and hardwood bottoms our region has historically represented, and we're seeing the returns we expected much quicker than mechanical methods were providing us.
None of the "chemicals" we use are soil-active, and all of them have a half-life measured in days. We don't use them where girdling or sawing are sufficient to open canopy or create snags, and we don't broadly apply them.
I'm glad you live in a region where there are no opportunistic trees and shrubs which will crowd out other species, and where mechanical control is sufficient to restore traditional diversity, but alas, it still doesn't have the same reward everywhere. Anything left to its own devices in this region will rapidly, I mean within 5 years, become what we call the "pine curtain," useless to both wildlife and man. For centuries even the indigenous tribes had to practice regular controlled burning to fight this.
Well, we do have invasive species as well (and other problems, like too much acid from the spruce in the soil), but fortunately not your kind, which seem indeed tricky to deal with.
This I found interesting (on wikipedia):
"Herbivores and insects have a conditioned behavioral avoidance to eating the leaves of Chinese tallow tree, and this, rather than plant toxins, may be a reason for the success of the plant as an invasive"
So the main problem is, for whatever reasons, animals could eat the chinese tallow tree, but don't? That is a problem indeed, but I think one that evolution would sort out eventually. Might take more time, though.
"restore traditional diversity"
And this is a common debate here as well, but I don't think it makes sense to try to restore the "pristine condition". Things have changed too much and they will continue to change. So yes also here we have invasive species that achieved local domination. But it won't last. If there is a monoculture, then other species will evolve (or find their way towards it) to make use of that food and space, as there is so much of it. But if you want fast results, well, you have to do more than waiting, I agree on that.
To elaborate on this great answer, the technical term is "ecological succession", defined on Wikipedia as "the process of change in the species that make up an ecological community over time."
Plants do not just fill their niche, they alter the environment over time, which in aggregate alters the ecosystem as a whole. Animals and microbes also play a role in this process. E.g. the way rodents and birds disperse seeds, or how pests can destroy a species, or even how elephants can uproot whole trees.
> the normal state of nature is to not create a perfect balance out of the gate
That is true. Additionally, a balance will never be achieved no matter how long you wait, either. That's the state of nature; some things are always replacing other things.
Ecological stability refers to a concept that is never realized. You can pretend it exists by ignoring the variation that you feel is unimportant. Over time, that variation will make its way into the areas that you thought were stable.
The reason I wrote my remark is the relatively recent uptick in "in nature everything always changed regardless of whether we exist, therefore we're absolved from everything that's happening with the biosphere"-style arguments.
Obviously on the face of it the premise is true, but time scales, operationalisation and causes/responsibilities matter critically there.
Islands of stability exist (like our homeostatic bodies, species that have survived for millions of years, old growth forests, etc) in nature. But whether one cares about (not unnecessarily, prematurely ending) any of this is a very different matter.
> Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
Logging companies typically log a parcel and replant for logging again in the future. They might be convinced to do things differently, especially if the outcome is better for them, but it would be hard to convince them to plant trees that won't be commercially viable when they come back to log again.
If diversity is good for the environment and the loggers, that seems ideal. If diversity is good for the environment and about the same for the loggers, they might be convinced.
Not all the parcels will end up being relogged, but that decision is unlikely to be made at the time of replanting.
I'm left wondering:
1. Why did they plant only tree species that are frequently targeted for logging? This makes the whole experiment very suspect. The linked article talks a lot about restoring forests, but why restrict the tree species to those that are profitable to log?
2. Is the satellite imagery actually representative of on-the-ground truth? A lot of logging land in western America gets replanted with logging-friendly trees in very regular grid patterns. These areas may look like forests from satellites (or to uninformed ground-level visitors), but the regrown tree farms do not behave like forests. The dense growth crowds out the ground-level plants, which in turn makes the entire tree farm a poor habitat for local fauna. If your goal is to grow more trees for lumber, tree farms are great. But I'm not sure the claims about "forest restoration" are honest/true here.