- Tree #83.
I don't know...
- Other... - This one? - The other.
- Cut. [laughs]
- So try to smell.
- Oh, it smells spicy!
- Yeah. - Yeah.
- Yeah, so the nutmeg family, mace.
- It smells really good. - Yeah, no, this is a good one.
And it's also in a group that people commonly call "chicken blood"
because the latex is red on this one.
So this is a group that's super diverse.
It's sort of their version of oaks.
- Oh, okay. So it's one of the more common things to see around here?
- Yeah, that family and this genus. You run into it a lot.
- The chicken blood tree.
- Yeah, you can see a little bit of the red latex showing up there.
- When you're locating these trees and they have all these different odors and things like that,
is that just an indicative way to identify different species
or does that tell you anything about the quality of the forest itself?
- It's just one of the characteristics you use to identify species.
So most of the trees on this transect don't smell like anything.
We could cut and cut and try, and it would just smell sort of like wood, right?
But there are a few, the ones that we're showing you—
—the ones that do give you a clue through your nose—
—and those are a small proportion of the whole tree floor.
And the other ones you have to use bark or roots or latex: the other things that we always look at.
- So we were just using our smell skills to identify those.
- Right, right. - Cool.
- Smells like a new car.
If you had a key lime pie in a leather Porsche.
That's what this one smells like.
Nigel, what do you think it smells like?
- I'm gonna go with turpentine.
- Corine, what's the verdict?
- I gotta make sure.
- You gotta make sure?
- Like carrots... dipped in turpentine.
- Carrots dipped in turpentine.
- That's how you're gonna get this family, the Burseraceae.
- How would I have ever come to that conclusion?
- You gotta work. You gotta train. - Oh, wow. I don't get the carrots, though.
- Oh yeah. Totally. - Really? Let me see.
- Think about it.
- So key lime pie in a Porsche wasn't really close? - No, but it's perfect.
That's how you're gonna remember it.
You're gonna come up to one of these and you're gonna cut it,
and you're gonna be like, "Key lime pie. Porsche. Burseraceae."
- The key to becoming a great botanist.
- Totally. You have to make up your own smell associations, because it's totally gonna work.
- That's awesome. - Yeah. - Cool.
- What's incredible here is that we're actually finding rocks.
In the place just north of here, where the Matsés live,
it turns out the Matsés don't even have a word for rock in their language.
So to be finding these little pebbles, these are probably sandstone or quartzite.
And these are creating these really sandy, rocky, pebbly substrates.
This tells us something about what these trees are growing on.
It's very nutrient poor soils.
Even though it's extremely nutrient poor, there's still thousands of species that are making a living on this.
Meanwhile, in the nutrient poor jungle
- One of the interesting things in tropical forests on really poor soils
is that it's expensive for trees to make leaves and fruits and flowers.
So unlike in the temperate zone—
where you make a leaf for the season and then it does its job and it's done—
in the tropics, trees build leaves to last.
So some leaves have been monitored:
Same leaf, on the same tree, doing its job for decades.
- Really? - Yeah.
One thing that leaves need to have in order to last a long time is defense against insects.
So that one, it's one strategy, right?
- Yeah, it's really thick. It's like leather. - Yeah, it's like a credit card.
Imagine trying to take a bit out of that one.
Here's another strategy that's really neat:
So these are young leaves. They're gonna get this big, but they're just emerging now.
And right when they emerge, there's this blob of resin right there.
So as they emerge, they get coated with this resin.
And feel that.
- Ooh. - Isn't that neat?
- That's strange, yeah. It's like it's been crystallized in honey or something.
- Yeah, it's like it's covered with bug spray. So they're really young.
If they didn't have that, they'd be super delicate and soft and perfect for...
- And tasty? - Uh huh.
- That's... insane. Wow, it looks plastic. Like, it doesn't even look like a real leaf.
- (Tom) Okey-dokey.
- Ready? - (Tom) Mhmm.
- Alright, Nigel. What are we doing with these poles?
- When things are too tall to cut with the clippers,
or to climb a little bit and grab a branch,
we put these extendable tubes together and they get us to maybe 8 meters.
- Wow.
- So we have this cutting mechanism up here.
Same thing as tree pruners you use in the States.
- Wow.
- Are you going for that branch? - Yeah.
- Woah. Woah!
Heyyy, I saved you, Tom.
Well that's your branch. So what is this tree?
- So, hmm.
- He's the plant whisperer.
- So they're alternate. The leaflets are opposite, but the leaves are alternate.
So that narrows us down to... maybe 10 families.
This one... I don't know.
- You don't know what it is? - I'm not sure what it is.
I think it's a Sapindaceae.
We've been getting a lot of weird stuff.
And we're wondering how to say that in the report.
"We found lots of weird stuff!"
- Yeah! That's the scientific conclusion that you came to.
- I guess any forest you go to that's incredibly diverse,
you find lots of these unusual species that are really rare.
- It's so incredible to me how you can have so many different species,
like such an incredible, wide variety, that are all existing in the same area.
It just seems like there'd be too much competition.
- Right, so that's one of the big mysteries that gets a lot of people interested in tropical ecology in the first place.
- Why isn't there a winner?
These guys who are better at being Amazonian trees, how come they don't take up 50% of the forest
and knock off the species that aren't so good at being trees?
So there are lots and lots of ideas about that, but we're not really sure what the answer is.
- Wow.