(The Brain Scoop Intro plays)

(Piano music plays: (0:05) - (0:31)

Robert Stallard: I am marking what the landscape looks like at this trail point, and just to double check, T4, 0 meters.  T-B-C.  I would call this terra firme.

Emily Graslie: Terra firme.  What does that mean?

Robert: It's a -- just a term used in Amazonia for slightly higher ground.  TF is my initials for terra firme. It's slightly hummocky.

Emily: What does hummocky mean?

Robert: This bumpy ground, it's not flat. 

Emily: OK.

Robert: I will write the note root mat and --

Emily: Root mat. 

Robert: Root mat: you see everywhere here, it's the ground -- is covered, absolutely covered, with roots, it's like 10 to 20 centimeters thick, and these roots are wandering around, growing around, hunting for nutrients.

Emily: Is that what makes the ground spongy when you walk?

Robert: Oh yeah, yeah.  That's the root mat.  I think they grow pretty fast, because you can see roots growing into fairly fresh things, and so that creates the fear of root mat phenomena, where you have to be careful when you sit down, because it may grow into your butt.  That's -- don't take me too seriously, but termites will do that, um. (1:43)

Emily: Termites will grow into your butt? 

Robert: They'll start eating at your rear end. 

Emily: God! 

Robert: But, yeah, everything here is hunting.  Everything here is hunting for something to eat.  (Piano music begins to play faintly in background)

Emily: Yeah, yeah.  That's the stuff of science fiction. 

Robert: Yeah. The jungle is a dark and dangerous place.  No, not really.

Emily: Let's go! (Laughs)

(Piano music plays)

Emily: Is that a termite mound?

Robert: No, it looks like a burl. No, it's termites. (Whack)

Emily: Ooh! Cool. Yeah, that's termites. 

Robert: Sorry about having termites tumbling down on you. They are angry. 

(Music plays)

Emily: What's going on here?

Robert: One of the things we see about this sad former tree is that it doesn't have a tap root, or anything that resembles a tap root. All of its roots are going horizontally, which says, to me, that there is nothing down, down there, that's worth this tree putting roots down for. A tree would put roots down for either moisture or, or nutrients, and there's plenty of moisture -- this place rains all the time. You're left with the question: plenty of nutrients? And... no.

Emily: So it's just -- instead of going down it just goes out.

Robert: Laterally, yes.

Emily: Yeah. That's crazy. In talking about how, how nutrient-deprived this area is, and when you, you know take a soil sample and it comes up and it's just like nutrient-deprived sand, essentially, it seems like an environment more conducive to a beach than it does to something that would facilitate all of the growth around us, so, how -- how can all of this life thrive here, if there are no nutrients in the soil.

Robert: Well, that's getting back to the root mat.  It's helping recycle all the nutrients that happen to be released by plants and animals.  If somebody dies, like a little monkey, let's say, its nutrients get recycled properly through a food chain, it ends up eventually intercepting plant roots and then it goes into trees and other plants.

Emily: So it doesn't necessarily need to get all its nutrients from soil, it could get it--

Robert: Ultimately, it comes from soil.  Once it's extracted, it's recycled, and this recycling allows the ecosystem to build up nutrients, and of course, this is where the whole problem of deforestation, land clearing, and agriculture come in, is that all the ideas to remove nutrients and feed them to people, that in the case of nutrient-poor environments, can lead to quite a collapse of the ecosystem.  Very near here, we went to a site which had very nutrient rich soils.  The difference was spectacular.  Everything was alive.  There are animals everywhere, there are ants everywhere, at night, you could hear the tapirs and the jaguars and stuff--

Emily: WOW.

Robert: --in the forest, yeah.  That's what happens when there's lots of nutrients.  You can support a very viable animal-rich ecosystem.

Emily: I mean, we're still seeing animals everywhere, but it's not--

Robert: yeah, they get their chance to eat tree fruits and leaves and stuff like that, or some animals eat other animals as part of the food chain, it's just not as much, and so everybody has to work a little harder to get their feast. 

(montage)

Emily: Cool.  Alright, Trey, what are we doing now?

Trey: We're going to take a few soil augers, right, and so the idea is to see how deep the organic matter, how deep the--our root mat is, and then see if we can get down to some more eh, mineral soils. You can kinda hear it. 

Emily: Yeah.

Trey: Pretty rooty, right?

Emily: There's tons of roots. 

Trey: You're gunna find. 

Emily: Oh, yeah.

Trey: You're gunna find sand, yeah?

Emily: That's sand.  Is that kind of what you expected to find over here?

Trey: Yeah.

Emily: Yeah?  Alright, so no big surprises.

Robert: That's most cool...

(5:52) Robert: Now, this is the stuff that has not a speck of nutrients in it.  Roots are going through it in that little search for whatever they can find.  If you look at the forest here, it's kind of like, this is a tropical rainforest and it seems to me to be the shortest trees, the most spindly vegetation--

Emily: Yeah, this doesn't really look like rainforest at all.

Robert: No.  I would say that it's probably our most nutrient impoverished zone that we've been in.

Emily: Yeah, it's--you don't hear any birds around here, really.  There's no--so if there's no birds, there's probably not a whole ton of insects, it just doesn't seem like there's a dearth of life.

Robert: These trees are probably really, really old and they've lived long and tried hard to grow, and they're doing a good job, but--

Emily: Good job, trees.

Robert: Yup.

(Endscreen)

Emily: It still has brains on it.