Forest Ecologist Answers Tree Questions | Tech Support | WIRED

[00:00] Let's answer your questions from the internet. [upbeat music] "I wish there actually was a mother tree

[00:15] I watched that movie too that connected everything in ecosystems And I had a similar experience

[00:29] The fungi were all lit up in bioluminescent colors. to walk through that rainforest that night And those trees are very unique

[00:43] When they are cut down, they don't come back because they have very specific pollinator relationships. "How do forests regenerate after fires naturally?

[00:56] One of the fascinating things about forest is it's not an ecological catastrophe. like the serotinous cones of Lodgepole pine

[01:13] There are trees that will sprout after a fire, of this nutrient-rich environment

[01:25] so that their progeny will develop into the next forest. and are both needed for the healthy systems to function.

[01:39] LeoPsy asks, "What did ancient forests look like?" trees were a lot different. had not really developed at that time.

[01:54] It has all kinds of needles on it. and was puzzled by how it was gonna climb that tree "How do trees access the internet on a camping trip?

[02:11] Well, there is some reality to that, Trees are connected through their mycorrhizal networks. to the roots of plants

[02:26] There has been some really interesting work done where she actually described connections that allowed them to communicate chemically to one another.

[02:42] between mother and progeny, the more connected the underground network was So trees have a lot of different ways to communicate.

[02:54] When there is an infestation coming, that are landing on the surface of the tree trunk. that they're under attack

[03:09] @richardbis asks, Seems like we have a lot there?" If you're living in Southern California,

[03:23] the Santa Ana winds. That will propagate fires through chaparrals, shrubby, you're going to get fires in forests

[03:38] to these ecosystems. and to allow their seeds to develop into larger trees There are unfortunate consequences

[03:53] and there are ways that we can prepare for that. that your roof is a composite or metal Make sure that your open vents for ventilation

[04:08] Make sure that you're clearing a defensible space so that your flames will not carry from the wild areas

[04:21] @zentreya asks, "My tree exploded. There is a tree that sort of explodes. and its leaves and its spine are toxic to humans.

[04:36] those seeds can be projected at high velocities and cause a lot of damage to people and animals. "What the [beep] do you know about forest management?

[04:49] and fallen trees from the forest floor. Well, no, it's not simple in cleaning up the forest floor.

[05:02] or the forest floor that get the leaves off the ground. that actually will make fire more prevalent There's about 760 million acres of forest

[05:17] most of which are under private ownership. of the national forest system. Most of them are open for a whole variety of uses,

[05:31] a lot of that logging slash, Some of it's treated, for these fast-moving fires.

[05:45] which is directing the federal agencies is actually gonna make them more prone to forest fires that are the most fire resistant parts of the forest

[06:00] and leaving a lot of flammable logging slash behind. "What do tree rings really prove?" of the tree's growth patterns.

[06:12] when I count up all the rings. it means that the conditions for growth during that year The wider the rings means that the tree was doing better,

[06:27] and the living part is the outermost section which is the tree circulatory system to different parts of the tree and water.

[06:42] So the bigger the tree, The more insulated it is from most forest fires. that have been laid down across the rings

[06:57] what year the fire was occurring in So Pundit Review ask, Nine out of 10 wildfires are caused by humans.

[07:11] When you add up all the fires across the nation, and it's associated with high road densities, that can cause a fire accidentally.

[07:27] Smokey Bear would appear in posters and logos and his motto was, "Only you can prevent forest fires." but then it got blown out of proportion

[07:42] to put out every fire start by 10 AM the next day, which is destructive and catastrophic to ecosystems and rejuvenation and aging processes.

[07:59] will MrBeast's 20 million trees project make?" but it is not going to make as big of a dent

[08:12] in the climate crisis as protecting our existing forest, So an old-growth forest is a biological cathedral. are really important habitat

[08:28] the accumulation of atmospheric carbon There's no replacing those trees to start accumulating that carbon.

[08:43] "I have to do a presentation in biology about the [beep] boreal forest. They are cool forests found in places that are very cold.

[08:59] just below the Arctic Circle is where these forests occur. growing in some extreme conditions

[09:11] You'll get conifer trees like pines They are the places where most of our migratory birds The boreal will support up to a billion birds

[09:27] that exist around the planet. In the United States, most of our forests are temperate. or the Pacific Crest Trail

[09:42] you're in a temperate zone. of really interesting tree species. They're a mixture of oaks, conifers, and aspens.

[09:55] And there's a subportion of the world's temperate forests An example would be the Olympic Peninsula in Washington The trees are enormous.

[10:11] They are as wide as this table. and giving so much habitat to the salmon They'll come up the streams and spawn

[10:26] The eagles will poop out their remains and that will be fertilizer for the rainforest trees. now we're talking tropical rainforests,

[10:40] in a very wet and hot environment. where there are only small fragments of rainforests They only grow to maybe 30 feet tall

[10:58] because they're blanketed by rainy conditions. and the type of tree species there. that is a single living organism?"

[11:15] Arguably, forests are interconnected superorganisms. it could have originated from a single aspen tree that would send out its below-ground runners, its suckers

[11:29] and be an entire group of trees from the single organism. to the Northeastern United States

[11:41] The Northeastern forests were almost completely deforested and that led to almost the entire elimination However, there's been a century or so

[11:58] that are now maturing So most of the forests that you get in the Adirondacks had been logged over a century ago,

[12:12] And that's the beauty of forests. if we don't log them the second time through, that make them uniquely old.

[12:26] that there are more trees on the planet right now Well, yeah, it is [beep]. The scale of that deforestation has increased.

[12:42] of what the forests were on the planet before all of this widespread deforestation had taken place. only about 28% are considered primary forests.

[12:56] So that's why you can't just say we're planting trees than ever in history. You can't plant an old-growth forest.

[13:12] It takes centuries for those forests to develop. "Do rainforests create rain It's actually both.

[13:24] Trees are remarkable because they take in rain and use it and then they go through evapotranspiration and becomes the water cycle again.

[13:38] And so when rainforests are cut down, But when that rainforest is removed, @seahaze55 asked,

[13:51] So this is a pretty general map of the Amazon rainforest. You can see in green color areas that are still intact. And then you see these other areas in orange

[14:06] Rainforests are being cut down, burned, and that then triggers these droughts because we don't have the return of water

[14:21] So if that keeps happening, into a drought-stricken savanna That could happen within the next couple of decades

[14:35] depending on the speed at which climate change progresses "Without cheating, Approximately 180 million years old."

[14:49] which has trees that are hundreds of millions of years old. They can be over 300 feet tall.

[15:01] which is an endangered animal in the upper canopies of these rainforests. "Trees suck in CO2, right?

[15:16] Through the miracle of photosynthesis, When it's absorbed by the tree, it makes its food. we store it.

[15:31] like a Sitka spruce in Alaska's rainforest, That carbon has been stored in its trunk and in its roots

[15:43] during the current climate crisis. why do pine forests smell of air freshener?"

[15:55] So trees will produce a terpene It's a chemical that you smell in the forest The really interesting thing about this is

[16:08] that can detect those terpenes accelerated towards the tree's death, it's creating habitat for all this wildlife.

[16:24] it is being recycled into the nutrients in the soil. on anthropogenic natural disturbances which is a fancy way of saying things that [beep] up trees."

[16:40] are clear-cut logging. that causes a major unnatural disturbance which causes all kinds of problems for wildlife habitat,

[16:56] because the trees are no longer storing it. because you need to have a road system and those roads are funneling

[17:10] And when there's a lot of trees dying in the forest will trigger an outbreak of insects,

[17:22] and turn the forest a kind of red coloration Trees also will experience natural mortality agents.

[17:35] The American chestnut is functionally extinct in the wild. that is very specific to American chestnut trees and become part of the old-growth forest.

[17:51] "Do you know the layers of a forest?" of a tropical rainforest. and you start at the top level, the penthouse,

[18:06] then you move down a couple of floors and that is where most of the trees are. They're the trees that have been suppressed

[18:20] Sometimes there's a tree that dies creating a gap as plants try to fill that gap in, And then we've got even more complexity

[18:36] You kind of think of that as the basement of the forest. and mycorrhizal fungi in some of these forests that we see in these older forests.

[18:52] why do trees stop growing at the same height? Trees will stop growing at a certain height. Really good example in California is the coast redwoods.

[19:06] and they stop growing up to the top of the tree canopy. by living in the fog belt.

[19:20] so that they don't have to figure out because they've already got water there from fog. all the way up to their stem

[19:34] It's like a series of tubes that allows them and out to their twigs and their branches.

[19:46] It's like the tree circulatory system. "What the difference between a tree farm and a forest?" where all the trees are planted in rows like a crop,

[20:01] that are grown mostly for timber yield. It's trees interacting with other vegetation,

[20:14] The trees are different ages. When you go into a Franken forest, There's hardly any structure.

[20:26] So you lose all of those special benefits that we get from the natural forest. "How do controlled burns work?"

[20:38] We like to call them prescribed fires. is they might light a fire under certain conditions in a low-intensity burn

[20:53] that need frequent fire in a low-intensity way. "Do trees compete with each other in nature?" When trees come back after like a natural disturbance,

[21:10] will give you a lot of tightly spaced trees and light levels in a forest because there are winners and losers

[21:26] eliminating those that are less fit Some plants will release a chemical called an allelopath so that plant will prosper

[21:42] So those are all the questions for today. [upbeat music]