hatchway t1_isw3qso wrote on October 19, 2022 at 3:04 AM

Reply to comment by Bewaretheicespiders in Phantom Forests: Why Ambitious Tree Planting Projects Are Failing by filosoful

Gardener / urban farmer here. You can't just put a random baby tree in dirt and expect it to thrive, especially with heavily depleted or polluted soil (which I imagine they're planting in). Baby trees are also extremely sensitive to changes in temperature and humidity, to the extent that about 3/4 of the ones I plant are guaranteed to die without continuous attention. Not possible for a whole forest.

The answer isn't to plant baby trees - it's to spread tree seeds, if possible with mulch and light tilling / harrowing. In my experience, plants that grow from seed have a much better chance in a low care / unsupervised situation, because they'lll adapt to the surrounding moisture, fertility, PH balance, and micro-organisms right from sprouting.

remi_pan t1_iswrm37 wrote on October 19, 2022 at 7:24 AM

The article has a similar conclusion:

In fact, many forest ecologists say creating space to allow nature to do its thing is usually a better approach to restoring forests thanplanting. “Allowing nature to choose which species predominate … allowsfor local adaptation and higher functional diversity,” argues oneadvocate, Robin Chazdon of the University of Connecticut, in her book Second Growth. For mangroves, Wetlands International now recommendsabandoning widespread planting and instead creating areas of slackwater along coastlines, where mangroves can naturally reseed and grow.

hatchway t1_isyq3a5 wrote on October 19, 2022 at 5:55 PM

The Hidden Lives of Trees dives deeper into the mechanics of forest ecology and this is 100% in agreement with its insights.

One of the issues to be aware of with allowing re-growth, though, is that certain species tend to absolutely dominate in clear-cut situations, so you need to selectively harvest to allow partial shade to exist.

Douglas Fir, for example, grows super-fast in sunlight, so most second-growth forest you see around here (western Washington) is like 60-95% Doug. Monoculture forests are bad because insects and diseases can jump from tree to tree much more easily, and different species accommodate different environment conditions better (allowing a portion of the forest to hold groundwater during droughts, for example).

However, this is better than no trees, and the issue generally solves itself overtime as species that grow better in shade (hemlock, maple, cedar) start to sprout and grow to full size, giving a diverse forest.

Just need to be careful, because sun-grown Dougs (and many other trees) are softer and spongier than shade-grown counterparts. Far less resistant to fire, bugs, and fungus... meaning there's a decent chance a careless accident can destroy a second-growth Doug-dominant forest before other species have the chance to start sharing the space. (Forest Dreams, Forest Nightmares covers forest succession as it applies to PNW forestry and it's fascinating, if a little more dense and academic)

Despite those caveats, this approach is still superior to planting baby trees raised in greenhouses and utterly lacking an "immune system" for the soil and climate in the particular spot they're planted.

Clearly I have a lot to say on this, but I'm too stupid to be a scientist and too lazy to podcast, so I'm stuck making Reddit comments.