4.2.3 The Rainforest

Sloths have less muscle than other mammals their size in order to __________. A) conserve energy B) maintain a lower body weight C) digest their food faster D) maintain a higher body temperature

A) conserve energy

If less than 1% of tropical rainforest plants have been tested for their medicinal properties and half of the 3000 plants known to have anti-cancer properties were discovered in tropical rainforests, how many are still waiting to be discovered? A) 1,500 B) 15,000 C) 150,000 D) 1,500,000

C) 150,000

Which of the following best describes the Lianas vine? A) It only grows in the canopy. B) It is a ground-dwelling vine. C) It climbs a tree to the canopy then spreads to other trees. D) It climbs a tree then spreads through that tree's canopy.

C) It climbs a tree to the canopy then spreads to other trees.

Which of the following are you more likely to have in temperate rainforests rather than tropical rainforests? A) insects B) high annual rainfall C) pine cones D) limited ground vegetation

C) pine cones

This climate is considered tropical wet with temperatures between 68°F to 93°F and an annual precipitation of 50-260 inches. There is often a short season of less rain, or sometimes in areas with monsoon seasons, a short period of no rain. The soil contains very little nutrients because the trees quickly absorb all the nutrition out of the ground. A great amount of sunlight reaches the upper canopies, but very little sunlight filters down to the understory and forest floor. These are all characteristics of the __________ biome. A) deciduous forest B) alpine forest C) rainforest D) savanna

C) rainforest

The least amount of air movement in tropical rainforests is found in (the) __________. A) top canopy B) second layer of the canopy C) third layer of the canopy D) none of the above

C) third layer of the canopy

section one We're going to talk about the different types of rainforest that there are in the world and how organizations interact in those ecosystems.

Section 1 00:00:02PROFESSOR: Imagine walking on this bridge, suspended nearly 100 feet above the forest floor of a rainforest. These are some of the things that tourists can do these days when they go visit a rainforest. We're going to talk about the different types of rainforest that there are in the world and how organizations interact in those ecosystems. The Rainforest Section One. 00:00:23We're going to identify the characteristics of the rainforest biome. And looking ahead to the next section, we'll evaluate ways organisms have adapted to that ecosystem. So we'll talk about the different types of rainforest that we have first. There are two types of rainforest biomes. The first one is tropical. 00:00:40Tropical rainforests. I'm sure you've all heard that before. They're located around the equator, and if we take a look at this map, you'll see that all of the tropical rainforests are right near the equator, which is that center line that goes right through the middle of our planet. There's constant precipitation. And as we're going to learn in just a little bit, they 00:00:58actually have 10 to 14 feet of rain per year. Then we have temperate rainforests. They're located closer to a coastal area. And they don't have to be located near the equator. They may be, but that's not a defining characteristic. So if we look at a map of our temperate rainforests, we'll see that they are all close to a coastal area. The temperatures are not as consistent as our tropical 00:01:24rainforests, but they are still fairly warm for a majority of the year. So let's talk a little bit more about our tropical rainforest. They are found near the equator, which we mentioned. And they have mild climate, about 70 degrees year round. The temperature actually ranges between 70 and 90 degrees throughout the year. 00:01:43They cover about 2% of the earth. But even though they only cover 2% of the earth, they actually have more than half of the species in the world. So such a small area of the world to possess such a large biodiversity is pretty amazing. As I mentioned, they receive 10 to 14 feet of rain every year. And this high biodiversity-- 00:02:08or the high number of organisms living in a small area-- has led to great specialization of the organisms in those areas. So all of these organisms are very specialized to filling a specific niche in that area. Now, another thing that we've gotten from the rainforest are many of the foods that we eat. 00:02:26Avocados, coconuts, figs, oranges, bananas, guavas, pineapples, and many other fruits that we eat on a regular basis all originated from the rainforest. We also get several medicines that we use daily in our population and in our world, and a lot of those have come from places like the rainforests. Now the rainforests are being destroyed through many practices, burning for farming and grazing, 00:02:52and logging for wood. However, only 1% of the plants in the rainforest have been tested for their medicinal uses. And so with this disappearing ecosystem, it's a shame that we're going to be losing so many possible cures for diseases and sickness in our world. The tropical rainforest is divided into two three canopy layers. 00:03:17The ground is usually absent of much vegetation, because there's so little sunlight. Also, there's very little moisture because most of that moisture is filtered out through the dense canopy above it. The first layer is 120 feet high, and it is the most biodiverse layer that we have in the rainforest. Many animals inhabit that top canopy layer. 00:03:38The second and third layer make up the understory, and sunlight is reduced as we get to that third layer. The third layer is also an area with the least amount of air movement in that location. Temperate rainforests cover a smaller area than the tropical rainforest but they have more biomass. If you ever go to the areas of temperate rainforest, such as the great redwoods or the giant sequoias, those trees 00:04:05are huge and very, very massive. Because of that, even though they make up a smaller area, they have more biomass than we do in the tropical rainforests. The temperate rainforests are found in North America, Chile, New Zealand, and Australia. The precipitation is about the same as a tropical rainforest, but as we mentioned, the temperature might not be quite 00:04:29as warm and quite as consistent in areas like that. The main portion that we have of our temperate rainforest is located in North America, the Western coast of Canada, and even parts of Alaska are actually part of the temperate rainforests. These trees are more pine cone bearing trees. So they're not going to be the broad leafed trees that we have in the tropical rainforests. 00:04:53And it's filled with many organisms that are very specifically adapted to living in that area. And as I mentioned, they are slightly cooler than the tropical rainforests. So getting real with science. The Canopy Inkaterra in the Amazon. This is a place where you can go, as I mentioned, and walk across a bridge that is 1,135 feet long. 00:05:21And it's 95 feet above the rainforest floor. So you get a really rare view of the floor, or the flowers and plant life in a rainforest, and the fauna, or the animals that live up in that canopy that you would never be able to get unless you were a bird or some sort of organism that had the ability to climb those trees. So it gives you a very unique perspective of the rainforest that wasn't possible until recent times. 00:05:44So thinking ahead to the next section. Think about the climate and terrain of the rainforest biomes, and what adaptations do the plants and animals need in order to survive there?

section two The Rainforest Section two, we're going to identify the characteristics of the rainforest biome and evaluate ways organisms have adapted to that rainforest.

Section 2 00:00:00PROFESSOR: I bet I know what you're thinking. Why are we looking at a piece of chocolate in Environmental Science? Well as you may or may not have known, chocolate originated from the rainforest. Chocolate, along with many other foods that we eat on an everyday basis, originate in the rainforest. And we're going to mention a couple of those in just a minute. 00:00:19But we're also going to talk about some of the organisms that live in rainforests and how they are adapted to surviving there. The Rainforest Section two, we're going to identify the characteristics of the rainforest biome and evaluate ways organisms have adapted to that rainforest. So the climate is very agreeable in the rainforest and it has very dense vegetation. 00:00:42And this creates a very unique environment that's very welcoming to many types of species. So because of this, we have the largest biodiversity on Earth in our rainforests. As we mentioned, we have 2% of the Earth covered by rainforests but it has over half of the world's species living there. That's a huge biodiversity. 00:01:01It has optimum conditions for life to exist. So organisms are going to survive there very well but there is a lot of competition for those resources. So because of that, organisms are going to become very specialized. So what does that mean, to become very specialized? Well, to be specialized means that you're a specialist. A specialist is someone that concentrates on something very 00:01:24unique and very individualized. So parrots and toucans for example have very unique and adapted beaks for breaking open certain types of seeds that may have a very hard and tough shell. So they're very specialized in fitting that specific niche within that environment. The leaf-cutter ant as another great example of an organism that is very specialized. 00:01:45It goes around and cuts leaves in a very little, tiny sections and carries them down into their holes. But they don't eat them. They bury them, and they spin on them, and then a fungus grows on that material. So maybe they shouldn't be called leaf-cutter ants, they should be called farming ants because really they're farming their own food. 00:02:03Now this is another example of a symbiotic relationship where two organisms are working together. So the fungus is grown by the ant, obviously it's being supplied with food, so the fungus is going to benefit. And the ant is eating the fungus so it benefits as well. So this is a great example of mutualism because they're both benefiting from one another. Sloths are another great example of an organism that 00:02:25are very specialized. Now sloths are very slow. They don't move very fast so they're not very strong. They eat a very low nutritional diet and they sleep all day long. So how are they specialized? Well they're specialized because they are masters in conserving energy. 00:02:41They have less muscle mass than any other mammal their size. In fact, they have half the muscle mass of what a normal mammal their size should have. They're very slow. They also spend a lot of time sleeping. They digest their food very slowly and they have a very low body temperature. All of these things contribute together to use very little 00:03:01energy for survival. So that is their strategy. They don't need to eat more to survive, they just need to burn less energy. Now the tree kangaroo is another example of an organism that's very specialized. It lives in Australia, as many of the other kangaroos and wallabies do. 00:03:16But it is very adapted to living in trees, specifically has an extra long tail for balance. It has very strong forearms to help climb in trees. And it has rubbery soles on the bottom of it's feet for better grip. They are very clumsy on the ground but very agile in the trees. And they've actually been recorded jumping 29 and a half 00:03:36feet from tree to tree. Pretty amazing and pretty specialized. So the major flora or plants in a rainforest, we have several different types. We have the canopy trees, which are going to be the trees that grow up to the top and fill in that entire top canopy, the one on top. Then we have our bromeliads and those actually create 00:04:00little mini ecosystems by collecting water and creating an ecosystem for things like insects to survive in those in the pools of water. Then we have our lianas which are like vines. And they start on the ground and they can grow up to 3,000 feet up into the canopy and attach on to several trees at once. Now this doesn't just help the vine, who's growing up there 00:04:21so it can get sunlight on the top of the canopy. It also helps to grab on to several trees and it keeps the structure of the canopy intact when big winds and storms come through. Saprophytes are another example of a flora that would live in a rainforest. Saprophytes are things like fungus that break down dead material. So that's what fungus do. 00:04:43They're decomposers and they break down that dead material. So it's also a great environment for fungus to survive in the rainforest. Especially the tropical rainforest because it's very warm and moist there, which is a great climate for fungus to survive And of course we have one of the most interesting type of organisms in the rainforest is the meat-eating plants. Now meat-eating plants are exactly what they sound like. 00:05:08They don't eat people but they're going to eat things like insects and they actually create a little trap, such as this pitcher plant right here. And they have a very nice aroma coming out of here that's very attractive to insects. And when they go in there they fall in this juice, this digestive fluid and they're actually able to be digested by that plant. 00:05:28And that plant is able to gain nutrients that way. In a place where sunlight is so fought over, getting your nutrients in any way you can is a very important thing. So getting real with science, the cacao tree which is how we get our cocoa. The pulp of this fruit is actually edible. And it's said that it tastes like mangoes. I can't say that for myself because I've never tried it. 00:05:53But inside there it contains a bean. And that bean is what we use to make our cocoa or how we make our chocolate. Now it takes 300 to 600 of these beans to make two pounds of chocolate. So as you might imagine, the chocolate that we eat today is really only about 10% actual cocoa because it would actually be really expensive to make it any higher 00:06:16percentage than that. So it's kind of interesting that this along with many other of the foods that we eat such as pineapples, avocados, oranges, many other fruits that we have all originated from places like the rainforest. So I think we've accomplished our mission just well. With the rainforest we have decided that the rainforest has the largest amount of biodiversity on the planet. 00:06:41Over half of the species of plants and animals are found in this biome. Animals such as the sloth have become specialized in order to survive highly competitive environments of the rainforest. And plants must compete for sunlight and many other form a mutualistic relationship with other plants or animals filling a specialized niche.

Compared to the trees in tropical rainforests, the trees in temperate rainforests are generally: A) older B) heavier C) smaller D) younger

B) heavier

How does the meat eating plant attract its prey? A) colorful flowers B) nice aroma C) broad leaves D) sweet sap

B) nice aroma

The rainforest contains half of the Earth's wildlife and at least two thirds of its plant species. It can hold great quantities of water and is very important to the planet's water cycle. Rainforests remove vast amounts of CO2 from the atmosphere and replace it with oxygen. Which of the following statements best summarize the above information about rainforests? A) The majority of the planet's oxygen is generated from the rainforest. B) Two-thirds of all plants originated from the rainforest. C) The rainforest is a major catalyst for the planet's water cycle. D) The rainforest is important to life as a whole on the planet.

D) The rainforest is important to life as a whole on the planet.

Which of the following is not a characteristic of the rainforest biome? A) high year-round rainfall B) consistent year-round temperatures C) wide diversity of plant and animal species D) always found along coasts

D) always found along coasts

What adaptations of the harpy eagle allow it to be such a successful rainforest predator? (Site 1)

The harpy eagle has had to adapt in order to compete with a great number of species. These are huge birds with gigantic wings that help them to fly with great speed. They sit quietly looking for prey and pounce at speeds up to 50 miles per hour. They sink their giant talons into the prey and kill it.

Identify some abiotic characteristics of the rainforest biome. (Site 1)

The rainforest is warm to hot with temperatures ranging from the 60s to the 90s. There is an incredible amount of rainfall, 50 to 260 inches annually. They are wet and humid. They have 4 layers. The forest floor receives almost no sunlight due to the tall trees and the canopy layer that blocks the sun.