Replanting logged forests with diverse seedlings accelerates restoration
Comments
atoav
asddubs
You just have to look at how utterly the Harz pine forests have been completely destroyed by the bark beetle to see what monocultures get you. It's just huge swaths of lands filled with nothing but dead trees
HarryHirsch
There's the additional complication that when the beetle or the windstorm come there's suddenly an overabundance of wood on the market, which depresses prices. You'd need to do forest maintenance but cannot afford it, market forces are against it. It's like the Schweinezyklus but worse.
robocat
> Schweinezyklus
Translation is probably Boom-bust cycle (literal: swine cycle?)
https://dictionary.reverso.net/german-english/Schweinezyklus for some rather poor usage examples
Biologist123
I have heard estimates of 100 million trees dead in the Harz. The common refrain is that this was caused by climate change, but also choice of monoculture was a major contributing factor as the area was historically covered by mixed deciduous. Furthermore, choice of forest type will affect soil moisture retention, so reduced rainfall would have been buffered by better choice of forest type.
Loss of those trees was an economic disaster. I’m not sure it’s an environmental disaster yet - especially as replanting seems to be with better reference to the agro-climatic zone.
killerpopiller
I‘ve heard from a local that in the onset of the bork beetle infestation, it was decided not to intervene (leaving dead trees there). This contributed to the catastrophe. Not sure if this is true.
Biologist123
The non-managed zone is rewilded, so it will be left to regenerate on its own I guess.
Xylakant
> Loss of those trees was an economic disaster.
Given that most of the trees lost were in the nature reserve, the economic impact is somewhat limited.
Biologist123
Is that the case? I didn’t realise. Although as a tourist draw, dead trees are not exactly that appealing. A couple of years ago, I took my three year old daughter up a mountain, and she earnestly said to me: “the once’ler”. We haven’t been back.
pjc50
I was not aware of this, and found this very informative https://en.harzinfo.de/pure-nature/the-forest-calls-initiati...
saiya-jin
We had in Slovakia in 2004 a small catastrophe in our tiny higher mountains (High Tatras) - wind up to 110 kmh IIRC, and literally large swathes of pine/spruce forests that were on higher grounds were cut like with lawnmower. They often broke in half with bare trunk still standing, not even ripped out of the ground. Then parasitic beetles had a feast and their population exploded.
Main reason was stated as monoculture planted decades ago, since these forests are pretty and they were used also for treating respiratory illnesses (clean mountain air with strong pine sap smell really helps, sort of natural aromatherapy).
Almost 20 years passed, its still a sad sight. More logging, some ad hoc growth but forest definitely didn't regrow in any meaningful form, rather fast growing bushes took over. There was a lot of fight between forest / natural park management and ecologists on how to proceed, and everybody (including forest) lost.
Lutger
In some tree monocultures, you can just see the soil is covered with layers of organic matter that just isn't decomposing fast enough. This is because there isn't the diversity in the soil food web required to process it, reflecting the lack of biodiversity above the ground. Such soils often have a very low ph and poor nutrient cycling.
chiefalchemist
> His focus was looking at resilience against weather, insects etc. and mixed forests fared significantly better throughout all climate zones.
It makes sense. The diversity means that while one genera is suffering from some Hostility X or Y (e.g., insects) the others might not be, or at least as much so.
Diversity is a form of hedging your bet.
Lutger
Hedging your bet is one part, another big one is creating habitat for predators. Pests often arise in monocultures because there just isn't any suitable habitat for the organisms that eat them.
A part of that habitat is food, so ironically and perhaps counter intuitively, a good agro-ecological practice is to farm your pests. This provides a source of food (but not in your main crop) to attract the predators that you want to help control the pest.
This is the reversal of a negative spiral where you control pests by killing them, thus preventing predators to settle in your land and making it a very nice place for the pests to multiple. And they will, because you can never kill them all - unless you keep using massive amounts of pesticides. This is why monocultures often need a lot of pesticides to work, its very hard to do without.
taylorius
No offense meant at all to your brother, it sounds like an interesting investigation. That said, the answer to these sorts of eco-questions always seems to be that the way nature has worked for millions of years is actually the best way (for loads of reasons we didn't know) - and if we mess with it too much, there will be some problems. This just seems kind of inevitable though. If nature's way didn't work, it wouldn't be happening. I suppose finding the reasons behind it being optimal are where the "meat" of such an investigation is. Interesting stuff.
dagmx
Your comment bothers me because it is based on very shaky premises.
Nature doesn’t work in the most optimal way, so it’s not always best to replicate it. Tons of things happen in nature that may wipe out important ecosystems. I suppose one could argue that at a long enough time scale it will even out but that time scale can be millennia. In the meantime, nature can wreak tons of havoc.
Nature (and by that I mean ecosystems because nature is a vague) also doesn’t behave in necessarily intuitive or easily observable ways either. What might seem “obvious” at first can be very wrong.
Nature (and again I mean ecosystems) also doesn’t exist in vacuums. What may have worked for centuries can be upset by even the most subtle of temperature shifts, and those might be caused by effects hundreds of miles away.
Unchecked nature is also not always going to be conducive to human needs either.
The entire field requires constant observation and inference. Even the ways of indigenous people that are fetishized as natures way by many, are scientific in nature. They’re the result of many years of observation, experimentation, learning and modifying how nature works to fit our needs.
taylorius
"but that time scale can be millennia. In the meantime, nature can wreak tons of havoc."
For sure - I suppose I'm questioning humans' ability to mitigate such havoc without causing a load of unintended consequences.
"Nature (and by that I mean ecosystems because nature is a vague) also doesn’t behave in necessarily intuitive or easily observable ways either. What might seem “obvious” at first can be very wrong."
I think I was saying a very similar thing, actually. I certainly agree with you on that.
vintermann
Nothing is "optimal", it's only ever "optimal for". So asking if nature is optimal is nonsense unless we have a firm agreement on what nature is for (which we certainly don't).
But the linked article doesn't have this problem. The "for" there is quite clearly the recovery of forests after logging, so they can be used again for whatever you may be expected to use a forest for (including more logging)
dagmx
I think you’re arguing against a point that I am not making. In fact I think you’re making the same argument that I am, which is “nature isn’t seeking an optimal outcome because that is too abstract”.
The person I was replying to was saying “just do what nature does”. But that doesn’t mean much. My point was you can’t just blindly follow “nature” without observation and study because it can just as easily go and do something catastrophic as it can do something good.
taylorius
Yes, I suppose optimal isn't really the right word - I suppose I mean relatively stable and long lasting.
flakeoil
> "the most optimal way"
Optimum in what sense?
Make as much cash as quickly as possible or have a forrest and a working eco system (or even any trees at all) also in 100+ years from now.
dagmx
Optimal as in preserving life if we’re going based off of the person I was replying to, but in general that is hard to define which is part of my point . Nature can just as quickly extinguish entire ecosystems, just as much as it can make them thrive.
Just trusting nature to do the optimal thing and trust that it’ll turn out okay isn’t sensible unless you also don’t care about the constituent parts of that ecosystem.
Insects can ravage entire populations of trees, rendering them dead and inhospitable to wildlife. Blight can do the same. Those are just as much nature at work as happy trees in a forest.
Lutger
Well, yes and no. Yes, in the sense that 'nature' is what organisms learned in millions of years and the emergent processes of the ecosystems in which they 'learned' things. And because this is so vastly complex, we often don't understand it and our interventions will have unintended consequences.
No, in the sense that humans are actually part of these ecosystems and it is possible for us to understand these processes and work with them. And this is the point of the research posted here: planting native seedlings is superior for restoration than 'just leaving things to nature'.
There's a technical side to this and a 'worldview' side, where there are two competing concepts of 'nature': one defines it as 'everything except humans' and the other includes humans as being part of nature, a useful part even.
taylorius
"No, in the sense that humans are actually part of these ecosystems and it is possible for us to understand these processes and work with them. And this is the point of the research posted here: planting native seedlings is superior for restoration than 'just leaving things to nature'."
I agree with what you're saying - but I think this point is slightly misleading. Planting native seedlings is exactly what nature would do - we are just accelerating nature's own process - not changing it for another process.
Lutger
> we are just accelerating nature's own process
That is well put and also exactly my point. However, you are accelerating something, so there is an intervention. For some people this doesn't count as natural! The word 'just' in your sentence does a lot of work.
The line is, in fact, not always obvious. Would those seedlings have come there naturally? Or would it have been a different mix? If so, is the end result actually the same as would have happened without human intervention, or would it have been different? Maybe there are actually 50 or more species that could and would find a place in this biome.
You can say the same about exotic species, eventually most (or at least some) of them would have come here anyway - via birds for example, but its the pace at which they are introduced which makes all the difference. Well, is it a good thing then to introduce exotic species, after all its just accelerating nature's processes, or is it not? Evidently this one is not always only beneficial, so it depends.
taylorius
Again, I agree entirely with you (yet still feel the need to respond) :-)
To some extent, who can say what exact mix of seedlings would arise if nature were left entirely to it's own devices. But one can imagine the basin of attraction for arriving at such a stable state is somewhat large (perhaps this is the crux of your point - such a basin cannot be mapped, and therefore one never knows if one is in it or not). Nevertheless - I feel able to draw a distinction between something that plausibly may have happened naturally, and, say, a vast grid of identically aged, undifferentiated pine trees. Though who knows, perhaps there is no distinction to be made - other than that of intention.
Lutger
I agree too. That distinction is clear and useful.
I'm interested in creating a plausible-natural agricultural ecosystem, aka a food forest. Such a system draws more criticism from ecologists, probably because where I live almost all of the desirable species aren't native.
On the one hand, this clearly isn't a normal agricultural system and often looks more like nature, on the other hand 'nature people' often do not really understand its ecological value. So thats where I'm coming from, maybe that clears it up a bit.
There's a weird aside to this story though, because what we (Netherlands) generally consider to be desirable nature is often a landscape created by old agricultural practices.
atoav
I just know what he told me about it verbatim, but the "meat" of his investigation was that he did statistical analysis on vast amounts of (LIDAR-based) tree-height data and comparison of storm damages. On top there were many other GIS-data layers included, so in addition to that simple finding the "meat" is that he found multiple concrete combinations of circumstances that are especially benefitial to resilience.
Not that a skilled and experienced ranger might not have known some of these combinations as well, but the data-based approach can help planing better where to plant what specifically, as opposed to just mix it based on chance.
wesapien
I was just listened to a podcast on this and they said planting a bunch of trees don't make a forest especially tropical ones. There's just too much going on there.
rootw0rm
afaik it helps guard against particularly devastating wildfires, too.
mtnGoat
The best way to deal with fires is not to. The problems the west is facing are due to so much fire suppression for tire last century and a half left too much fuel near the ground, we are now learning to let them burn.
atoav
Not to get too political here, but the problem is literally that we have "raked the forest" too much.
If you don't know how this could be political, be prepared to make your day a whole lot dumber if you google it.
dagmx
This is somewhat simplistic. There are many methods to wild fire control, including prescribed burns.
Yes, many forestry practices are antiquated and incorrect, but it’s not as simple as just letting fires burn.
There’s a significant science to forestry and wildfire management. Fire suppression is as important as fire management and fire encouragement. They go hand in hand, and require a measured balance
ccooffee
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.
mschuster91
> 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.
kmeisthax
Interestingly enough, this is also part of the reason for Canada's horrible wildfires a few months back: https://pluralistic.net/2023/09/16/murder-offsets/#pulped-an...
bequanna
[dead]
llbeansandrice
> 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.
rootusrootus
> 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).
voisin
> Private land owners generally aren't interested in creating old-growth forests, they're trying to make money.
In Canada the vast majority of logging is on crown land.
adasdasdas
Why do we want old growth forests over harvestable forests? Is there an ecological advantage
sdenton4
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.
taway_6PplYu5
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.
thaumasiotes
> 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".
myshpa
> 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.
https://en.wikipedia.org/wiki/Peter_Wohlleben
https://e360.yale.edu/features/menominee-forest-management-l...
liotier
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.
unglaublich
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.
harywilke
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.
[0] https://www.google.com/maps/@43.4146826,-123.52657,129879m/d... [1] https://osupress.oregonstate.edu/blog/checkerboard-effect [2] https://en.wikipedia.org/wiki/Northern_spotted_owl
thaumasiotes
> the regrown tree farms do not behave like forests. The dense growth crowds out the ground-level plants
Crowding out ground-level plants is the entire point of being a tree; it's pretty normal for forests to have clear ground.
Here's what a redwood forest looks like: https://www.westwindvistas.com/Redwood%20Forest%20Floor.htm
joshvm
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.
greenie_beans
> 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.
soperj
> 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.
drone
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.
dudeofea
why not plant other species to out-compete the invasive ones?
why do we need to perform chemotherapy on our forests?
drone
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.
hutzlibu
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.
drone
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.
hutzlibu
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.
anon84873628
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.
thaumasiotes
> 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.
RGamma
That's dangerously simplistic, see https://en.wikipedia.org/wiki/Ecological_stability and related topics for a start.
thaumasiotes
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.
RGamma
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.
thaumasiotes
> species that have survived for millions of years
I mean, this is a perfect example of pretending that differences don't exist because you can't see them. There are no such species.
RGamma
Wrong taxon, I guess.
thaumasiotes
I'll use different terminology: there are no such organisms.
toast0
> 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.
atourgates
I did a quick look to see if this only worked in tropical forests, or if this would be true in, say, Western North American forests.
I didn't really find an answer.
A study[1] in Virgina found that planting multiple varieties of trees was beneficial because it allowed the variety that was most suitable for that location to thrive, and survive problems that might affect other varieties.
A study[2] in Washington State tested a couple varities of common conifers planted in pairs, and found more conventional "trees are affected by competition" result.
This study[3] performed in the inter-mountain West found that some conifers _may_ benefit from being mixed with aspens, but didn't seem nearly as conclusive as the Borneo study.
If anyone can find a more conclusive study about temperate Western forests, I'd love to see it.
[1] https://www.si.edu/newsdesk/releases/tree-species-diversity-...
[2] https://cdnsciencepub.com/doi/10.1139/X09-040
[3] https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111...
swader999
BC can have three our four species in play on the coast, interior and east typically has pine and spruce. You could argue for balsam but that is crap wood and it grows back on its own typically. I don't know about tropical reforestation, but in Canada the notion that we are replanting with only mono species isn't true. They leave seed trees standing and source cones directly from the logged blocks. It's very well done and highly regulated. Blocks that don't grow back are replanted again until they do.
Canada replants 600 million trees annually, USA about 1 billion.
Trees grow so much faster than they did a decade ago. CO2 is to 'blame'. I help maintain ski runs at my favorite ski hill and it's ridiculous how much more work it is now. Alpine areas that never in history had trees are beginning to get overrun.
nerpderp82
The sub-alpine line is rising in elevation due to increased warming.
swader999
Is it T or CO2?
1970-01-01
Warm soil causes seed germination. CO2 causes warm soil. So, both.
voisin
Roughly where are you in BC? I am in Cranbrook and haven’t seen the seed trees left standing in logged blocks but maybe I’ve missed them somehow.
Isn’t part of the issue that historically there would’ve been more deciduous trees that acted as natural fire breaks and now loggers only are allowed to replant coniferous?
swader999
I've planted all over BC. Seed trees started being a thing early nineties and they don't do it everywhere. Quite often its because there aren't species needed as seed trees that won't already grow back are already slated for nursery production and replanting.
Smaller block sizes act this way too, the boundaries are seeded from the older growth on the perimeter.
Deciduous trees like poplar, Adler, and birch are like weeds and will grow very quickly and compete for a time with replanted trees. Eventually the evergreens tend to choke them out by taking over the canopy and changing the soil with their needles.
twunde
You may also hear this practice called selective cutting/lumbering. Essentially they leave trees in ones or twos scattered through to reseed the area around it.
swader999
Yeah maybe, selective cutting looks different though, like 1-2 hectare pieces and roads everywhere. This seed trees thing has blocks up to about 90 hectares that are rectangles with ten or twenty trees still standing in it.
rcostin2k2
They grow faster but weaker, with lower density (cf. https://doi.org/10.1016/j.foreco.2018.07.045)
MissingAFew
I would suspect they would gradually evolve to grow stronger?
hosh
There’s a more thoughtful way of designing this. In the permaculture world, these would be called “guilds”. Species are selected with an understanding of canopy layers (so that plants don’t compete for sunlight and can still fill in spaces at each canopy layer), and ecological function (such as, nitrogen fixer, dynamic accumulators, pollinator attractors, habitats, etc)
If you randomly mix up species in temperate forests that are all competing in the same canopy layer, I can see more competition. A study done where say, a mix of overstory, understory, and shrub (such as berries), would be more insightful.
voisin
I’d love to see a resource where someone could select their location and have example guilds like this provided. Every time I’ve looked it seemed like the only way to find out was to take a permaculture design course which is well beyond the limits of my interest.
hosh
This is a good video on the specific design principles for guilds, from Canandian Permaculture Legacy at: https://www.youtube.com/watch?v=XLPUN2wGbwA
And yeah, site analysis is where I would start:
1. "Where Am I?" https://www.youtube.com/watch?v=-XNiacRhzuM
2. "Sectors" https://www.youtube.com/watch?v=233GgYhtoGs&list=PLNdMkGYdEq...
3. "Zones" https://www.youtube.com/watch?v=CaUlnvGhnho&list=PLNdMkGYdEq...
4. "Slope" https://www.youtube.com/watch?v=McopD04XP3s&list=PLNdMkGYdEq...
These will inform you of how everything comes together, and it starts with an understand of your place on earth (particularly, the lat/lng and how that affects the sun cycle; then regional forces that is discussed in "Sectors". Then you designs zones on your site based on how much human contact you have.
You can get the rest of the Oregon State University PDC lectures from Andrew Millison from https://www.youtube.com/playlist?list=PLNdMkGYdEqOCvZ7qcgS3e...
Permaculture is very heavy on design, even if the end result doesn't look like it.
And yes, I had thought of creating a mod for an open source CAD that can pull in knowledge bases and databases as a permaculture design assistant. For example, there is a researcher whose lifetime work was to collect nutritional information for plants from all over the world so that people can select a nutritionally complete set of native plants. It's not more widely known because that knowledge base is locked into a desktop dbms from before web apps.
pstuart
That seems quite reasonable -- I'm guessing the more challenging part is finding economic consensus with the landholders.
comboy
Forest is a complex ecosystem and based on some books [1][2] my understanding is that fungi plays a huge role in them. They provide a lot of things that trees need in exchange for what they need, they also create kind of a market which allows trees even from different species exchange their resources. Different trees have different strong sides and can make use of different conditions. Perhaps this, thanks to the huge forestweb underneath allows them to thrive.
Also, trees like to grow slow and solid. Older trees from the same specie will feed small tree hidden in their shadow and provide it necessary resources so that when some bigger tree falls and it can take it place, it can also grow faster. It's possible that when there's competition between species they grow faster because there's a fight for sunlight. The year's growth will be bigger and wood would be less dense (but it is sold by volume).
1. The Hidden Life of Trees, Peter Wohlleben
2. Entangled Life, Merlin Sheldrake
farnsworth
I strongly recommend "The Hidden Life of Trees". I listened to the audiobook multiple times while hiking/cycling through the woods and it changed the way I will see trees forever.
hinkley
Suzanne Simard has a bunch of chemical analysis that says yes, and most of her testing was in the PNW and western Canada (BC and... Alberta?)
A lot of the other literature on the complex relationship of soils and trees (and trees and trees via soil life) were instigated by her observations.
She was trying to get NW foresters to stop bathing everything in herbicides before replanting clearcuts. They always struggled more than anticipated.
hinkley
I'm a little disappointed that's still an active cause.
myshpa
> If anyone can find a more conclusive study about temperate Western forests, I'd love to see it.
I didn't. But there's no reason why it shouldn't work there.
https://www.scmp.com/news/china/science/article/2167048/fore...
Forest study in China finds mix of trees can absorb twice as much carbon as areas with one species
More than 60 scientists from China, Switzerland and Germany were involved in the research, testing a hypothesis based on observations in the field.
“The study shows that forests are not all the same when it comes to climate protection – monocultures achieve not even half of the desired ecosystem service,” Schmid said. “The full level of mitigation of global warming can only be achieved with a mix of species. In addition, species-rich forests also contribute towards protecting the world’s threatened biodiversity.”
Such forests were also less vulnerable to disease and extreme weather events, which are becoming increasingly frequent as a result of climate change, Schmid said.
RetroTechie
"Such forests were also less vulnerable to disease and extreme weather events, which are becoming increasingly frequent as a result of climate change, Schmid said."
That might well be an underestimated aspect. We don't know how climate will change locally, what pests will spread where, what species will turn out best adapted to future conditions, or what species turn out to be keystones in specific ecosystems. So we should strive for having as diverse a set of flora anywhere. Success factors are varied, complex & interconnected.
Climate changes so fast that past 'performance' of species in an area is of little value. Those trees are going to stand there 20, 50 or 100y from now. What will local climate be then? Take your guess / throw the dice.
hinkley
Simard proved that deep rooted trees pull up water that ends up in shallow rooted plants, and that evergreens share sugars with deciduous trees in early spring, and then the direction reverses during the height of photosynthesis. Specifically in the case of water, the trees cannot transport enough water to keep up with peak transpiration, so they slowly dry out. But all night long they're still pulling up more water, more than they can use, more than they can store, and some of the excess ends up in their neighbors, through capillary action or the rhizosphere.
There’s an implication of intent here, regarding plant-to-plant transport and fairness, that I think is more likely explained by osmotic pressure. Entropy itself is 'fair' in this regard. Fungal hyphae aren’t designed to manage huge nutrient or water gradients. In fact they seem to be designed to communicate information at an alarming speed. Which we still do not entirely understand.
rolph
there was a time when logging an area, and subsequent monospecific replanting had a name.
it was called a tree farm
there was a commercialized ignorance of what forest actually was.
hinkley
There was a scary forest ghost story a few years ago and all of the trailers and the PR shots showed neat, tightly spaced rows of firs.
That’s not a forest it’s a fucking tree farm.
Now is there a Princess Mononoke style paranormal revenge story out there for destroying the forest? Absolutely. But this ain’t it.
screye
I can see benefits tied to wildfire R0 (in infectivity terms). A few fire resistant plants might play a role in decelerating the rate of wildfire spread and limit scope of damage.
karaterobot
I'm not an expert, but I had thought that observing that monocultures created a weak forest ecosystem was one of the foundational concepts behind modern forestry—a centuries old discipline. This seems like an obvious corollary to that. I would have assumed it yesterday, before reading this article, and I assume most people would have thought the same. Again, I'm not an expert, so I'm likely missing something. And sometimes you just need a study to provide evidence for common sense.
Cthulhu_
Yeah, this is one of those "well duh" headlines, doesn't take a scientist to figure it out.
anon84873628
Just one of those situations where science needs to get the ducks in a row and ensure incontrovertible proof.
kderbyma
it's a blinding glimpse of the obvious
jvm___
The Curiosity Daily podcast had a related topic this past week. There are plans to plant 1 billion (or 1 Trillion) trees at various levels of government (WEF is the 1Trillion number). So researchers went out to try to find saplings from local nurseries that could supply the diversity of trees that would be needed. They found that less than half the nurseries could supply saplings - and very few were 'climate change friendly' saplings, most were decorative or other non-climate-friendly trees.
“Plans to plant billions of trees threatened by massive undersupply of seedlings.” by Joshua Brown. 2023. https://www.uvm.edu/news/story/plans-plant-billions-trees-th...
“A lack of ecological diversity in forest nurseries limits the achievement of tree-planting objectives in response to global change.” by Peter W. Clark, et al. 2023. https://academic.oup.com/bioscience/advance-article-abstract...
“Trees Help Fight Climate Change.” Arbor Day Foundation. N.d. “Benefits of Planting Trees.” Tree Advisory Board. N.D. https://www.bgky.org/tree/benefits
destron
... of course the nurseries don't have seedlings to plant one trillion trees. Growing seedlings of the appropriate species would have to be part of that effort.
prawn
There are volunteer efforts in some places to spread the load in starting seedlings. Not sure how effective it would be though in contributing to an effort of that scale where you need commercial scale to make a dent.
Cthulhu_
It can be done though, if anyone that has a balcony or a back yard were to look after a tray of seedlings (25 or so trees?) until they're ready to be planted, it'd quickly add up. The challenge then becomes logistics though. But again, can be done with volunteers.
mym1990
Can you expand on the difference between climate change friendly and non climate change friendly trees, for the noobs like me?
jvm___
The money is in growing saplings of white-pine, the ones commercial re-planters will buy - because they grow fast and can be turned into toilet paper in 25(?) years. Growing saplings of local 'slow' growing, non-harvestable species doesn't make you $$$.
"In essence, forest nurseries tended to maintain a limited inventory of a select few species, electing to prioritize those valued for commercial timber production over species required for conservation, ecological restoration, or climate adaptation."
"Yet, in their 20-state survey, the team only found two tree nurseries that had inventory of red spruce, a species from which many millions of seedlings are needed to meet restoration goals. “Remarkably, only 800 red spruce seedlings were commercially available for purchase in 2022,” the team reports in their new Bioscience study, “—enough to reforest less than one hectare.”
myshpa
Maybe we should plant seeds, same as nature does. Dozens of different seeds per m2, nature would choose what'd survive and flourish.
An example of a forest farm planted with the same approach: https://www.youtube.com/watch?v=_ST9NyHf09M
RetroTechie
I recall some initiative (in Africa, iirc) where locals would collect seeds of random herbs, shrubs, trees etc, mix those up & pack into seed bombs.
Then others who travel around for their work, would toss those in random places. From bicycle thrown some distance from roadside, or a bush pilot dropping some during flight, etc.
Basically as many different seeds in as many different places as possible. Then let nature do its thing.
Note this was still mostly local. So not introducing invasive species from other side of the globe. Just helping native species to spread a bit further & faster.
myshpa
Yes, that's a very effective method. Such initiatives are all over the world.
It's based on ancient method of seedballs, promoted by Fukuoka.
https://www.permaculturenews.org/2014/06/18/making-seedballs...
freedude
The same problem exists at the seed level. Who is collecting the 2 trillion seeds (50% germination rate)?
zo1
Perhaps we could, I dunno, pay people to do it with the millions(billions) of dollars of carbon credits? Isn't that what they're for?
myshpa
It's a similar problem but on a smaller scale (it's easier/cheaper to collect & spread seeds than grow & plant the seedlings).
mvdtnz
If you want to prioritise speedy regeneration then this is not the best approach. Nature is incredibly effective in the slow and steady mode of operation but to maximise efficiency you need to be more deliberate.
myshpa
This method is known as "close planting" or "high-density planting". It's frequently employed in regeneration projects, such as the Green Great Wall in China. Syntropic agriculture, as seen in the video I've posted, and Miyawaki forests also use this approach.
Akira Miyawaki developed a variant of this method, which involves planting a variety of native species in close proximity. The idea is that the trees compete for sunlight, growing upwards more than outwards, leading to a fast-establishing and diverse forest.
https://www.sugiproject.com/blog/the-miyawaki-method-for-cre...
Another example would be Mark Shephard's farm where he's using his Sheer Utter Total Neglect (STUN) method. He describes in his video that the goal is to find a combination of plants that is so resilient, that you can't kill those trees even if you try.
https://www.youtube.com/watch?app=desktop&v=RePJ3rJa1Wg
Sure, it's essential to ensure that the selected species are suitable for the specific soil, climate, and conditions of the site. Additionally, as the forest grows, some form of management, like thinning or selective removal of species, may be required to ensure the forest remains healthy and achieves the desired goals.
mvdtnz
Did you even read your own links? They are carefully preparing soil and planting saplings, not randomly scattering seeds. The exact opposite of what gp is suggesting. They are planting in an intentional manner exactly as I said.
myshpa
> carefully preparing soil and planting sapling
None of that is strictly necessary. While it helps, it's not a requirement. Simply selecting the right seeds, maximizing cover/photosynthesis, and perhaps mowing at the appropriate time are usually sufficient, unless the soil is seriously degraded.
https://www.amazon.com/Sowing-Seeds-Desert-Restoration-Ultim...
Fukuoka spent years working with people and organizations in Africa, India, Southeast Asia, Europe, and the United States, to prove that you could, indeed, grow food and regenerate forests with very little irrigation in the most desolate of places.
By randomly scattering seeds.
Cthulhu_
Supply and demand then; if there's demand for a million of these saplings, the nurseries will adapt. I don't understand why this is posited as a weird finding. Just place an order for X saplings and the nurseries will get to work.
developer93
If a plant isn't native, the insects and animals that eat or use it aren't around, those that are can't use it, and it's of limited use to the ecosystem. Not to mention it's interactions with other plants.
WaitWaitWha
"...plots replanted with a mixture of 16 native tree species showed faster recovery of canopy area and total tree biomass, compared to plots replanted with 4 or just 1 species. However, even plots that had been replanted with 1 tree species were recovering more quickly than those left to restore naturally."
I am not trying to be obtuse or misanthropic.
Please, someone can explain why was this study needed? Was there some hidden new discovery?
Asking, because if I walk down the dirt road and ask any farmer, they will tell me, if I sow seed in a field, it will grow faster, than I leave it to nature's chance. If I sow mixed crops (crop & cover crop), I will get potentially better yield. I thought it was a specific species of trees thing, but the paper does not seem to be stating it.
salynchnew
Shouldn't be surprising.
The Miyawaki method shows success when a few principles are followed: -Planting naturally-occurring communities of plants, not monocultures (bonus points for including microfauna and soil microbes) -Planting locations are semi-randomized, with room for plants to expand and reseed. -Stands of trees are protected/watered for first 3-5 years. -Local communities are engaged and have a vested interest in protecting/maintaining stands of trees for the first few years.
https://www.jstor.org/stable/24577389?mag=the-miyawaki-metho...
meerita
As a reflection of my passion for plants, every time I trek through a forest, I gather seeds and nurture sprouts from them, replanting them each year. Last year, I successfully planted 25 trees, and over the course of four years, I've planted approximately 100. This year, in the upcoming spring, I aspire to plant 50 more.
bluerooibos
Who would have thought that replicating nature would yield the best results...
The Miyawaki method is probably relevant to this discussion - https://www.creatingtomorrowsforests.co.uk/blog/the-miyawaki...
nxobject
Another text I really love as well that focuses on teaching "applied ecology" is "Garden Revolution" by Weaner and Christopher. Since I've never taken biology of any sort, it was a good primer on things like ecological succession (in temperate climates), parameters of plants that might completement each other, etc. The authors have worked on large-scale restoration and sustainable landscaping projects, and it shows.
cookiengineer
I can recommend reading about the reforestation laws in Germany.
Why? Germany was running out of forests to harvest around 1400, and the oldest law that is still in effect is from 1442 (Forstordnung of the Bistum Speyer) . All forests in Germany are artificially created, and there are a lot of things involved to make this happen.
We have rain plans that limit the amount of how much water farmers are allowed to use which are on higher altitudes on the mountains/plains. We have the Wasserwirt which is responsible to flood the farming plains regularly (completely under water), and redistribute their water "lakes" to other fields down to lower altitudes. We also have the Foerster whose job is to decide which trees to harvest, which ones need to be replaced, and what to do with the dead trees.
All of those variables are planned carefully and involve a lot of data, especially the water flooding and rain plan parts.
There are a lot of nice documentaries about this on arte and NDR in case anyone is interested about these kind of topics.
Also about corruption and the forest mafia in Romania, which is a huge discussion topic in Brussels for years, because Ikea and other furniture producers down the line keep buying illegally harvested wood.
prennert
One thing that struck me when visiting Germany in summer was how logging seemed to be selective, leaving much of the trees standing.
I passed a forest by train and despite logs piled up next to it, and logging vehicles around, you could not tell from the train that the forest was being logged. While in Scotland, if they harvest a forest, they do it like harvesting wheat. They just leave a wasteland of stumps behind. Looks horrible, must be bad for the ecosystem and I am wondering if mudslides will be more common now, since a lot of forest is on hillsides.
ovih
Fascinating context, thank you for sharing!
Some other countries whose history has something to say about reforestation/afforestation: Australia, South Korea, UK
swader999
The other way to do this is to leave seed trees on the block in addition to replanting with 3-4 other species. They do this in British Columbia now.
When a block is logged, cones from that block are taken to regrow seedlings to plant there. It doesn't work as well if you try to seed from different elevations or far away areas.
BengineeringELM
Check out the silvicultural guide for the northeast:
https://www.fs.usda.gov/research/treesearch/45874
It turns out most logging in the northeast already yields a diverse ecosystem as quickly as the next year, and no planting is nessesary.
Forresters can target different species mixes in the regeneration by using different harvesting methods.
Pretty cool stuff.
darklycan51
I don't understand why loggers clear entire sections of forests instead of leaving every hectare x amount of old "mother" trees
BengineeringELM
In general they do leave "seed trees " but they only need as few as 3 trees per acre to effect the spaces mix in the regrowth.
Those 3 trees aren't nessesary though. The Forrest floor is loaded with seeds that can survive longer than a decade waiting for the right time to germinate. In many cases the sunlight hitting the ground is the trigger they need, and in most cases a "clear cut" will be a 9 year old forest 10 years later.
CatWChainsaw
If you own property with a lawn, do what you can as well with native plants for native pollinators.
erikhopf
There are companies like Terraformation that have been doing this for a while. Beyond the biodiversity angle, seed banking seems to be very important to the long term success of regrowth projects.
greenie_beans
i invested in their republic.co fundraising: https://republic.com/terraformation
but then did more research, because i've been interested in forestry for a while and was geniunely curious and wanted to understand my investment more.
i pulled my investment once i learned that these sort of projects don't actually work. terraformation targets land in areas that aren't meant to be forests. also decided to pull it because i don't completely understand the space. (sure, "planting trees will solve climate change" seems easy enough and makes me feel good because "i'm planting trees!" but nah, not really, let's maybe rethink this...this is coming from somebody who spends a lot of time in the woods and finds trees to be an important part of my life.)
this person researches this space: https://scholar.google.com/citations?user=DbjysqUAAAAJ&hl=en
this is one of the bigger studies: https://scholar.google.com/citations?view_op=view_citation&h...
elsewhen
In reading the paper, I don’t think that you can conclude that tree planting programs don’t work, just that the details matter.
greenie_beans
correct. they work when they're done in the right place, like where forests existed historically.
iamcasen
How is this not a complete and obvious no-brainer? As advanced as our culture is in some ways, it is clearly quite idiotic in many other ways.
wredue
It always helps having raw experimentation on your side.
AnimalMuppet
Or, to say it in reverse: Replanting logged forests with a monoculture hinders restoration.
Putting it this way emphasizes what "normal" is.
husamia
"diverse" is the key here and I doubt most understand what it really means..
hanniabu
This seems pretty obvious, I'm amazed this is coming as a surprise
sp332
No one said it was a surprise. It's a demonstration.
bradly
It isn't mentioned in this article but one example of this is deforestation of the a Eastern White Pine. They quickly realized the problems deforestation at that scale and attempted to build pack the forests quickly by use a very similar, but much faster growing pine. Turns out that was a really bad idea.
rgrieselhuber
Eventually people will figure out that monoculture was a horrible and anti-nature idea.
grlass
The issues from the Great Green Wall [1] are worth looking at
hasmanean
I’ve heard monoculture forests are worse for forest fires too.
Having dead decaying logs on the forest floor probably helps because fungi are naturally fire resistant.
WalterBright
This is not surprising in the least. Also, genetic variety within a particular species should help a lot.
My brothers MA thesis was about comparing the multiple model forests that have been planted throughout the EUs different climate zones (I didn't even know such a thing existed, bur it makes sense).
His focus was looking at resilience against weather, insects etc. and mixed forests fared significantly better throughout all climate zones.
As someone from the alps, a thing that should not be forgotten is how important a diverse tree structure can be for stabilizing soil, especially in mountain areas. And those areas can expect more extreme wheater conditions due to climate change, especially in the form of rain. Mudslides can become a real economic factor in such regions.
Mixed forests are also better at stabilizing the soil because the root structures are less uniform.
So the best moment to plant mixed forests is 20 years ago, the next best is now.
Edit: For non-wood people, the reason why there aren't more mixed woods is that harvesting is easier in non-mixed environments (although that also has changed with newer methods and tech).