Insects and Plant Diversity-Applications

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ambience: Rainforest, Iquitos, Peru

Here’s a story about plants, the insects that feed on them and the surprising fact that those insects actually help maintain the diversity of the rainforest. I’m Jim Metzner, and this is the Pulse of the Planet.

In the Amazon, there are two main types of soil — nutrient rich red clay, and a less fertile white sand. Each type of soil is host to a different group of plants with different strategies for dealing with munching insects. Plants that grow in white sand typically fend off insects with chemical defenses, while red clay plants grow fast enough to withstand most insect damage. According to Paul Fine, an Assistant Professor of Evolutionary Biology at the University of Michigan, the net result of all this is that red clay plants stay in their own soil, don’t invade white sand habitats and vice versa.

“Clay plants, when they get attacked by insects in the white sand, dont have as many defenses. Theyre more likely to get killed by insects than white sand plants that have a high level of defense. So when a clay plant tries to invade white sand forest, even though it can grow there, and theres nothing about the soil that will keep the clay plant from growing there, if it starts getting attacked by an insect, the insects are going to eat it all up. Thats going to keep a clay plant from expanding its range into white sand forest. Conversely, white sand plants, because they grow slower due to their high defense allocation, are never going to be able to out compete a clay plant in clay soil. So, because of the insects, this allows two different kinds of plants, white sand plants and clay plants. And if insects didnt exist, our data show that clay plants might be able to invade white sand forests, and there would be one half the number of species in this system.”

So in the complex ecology of the rainforest, predatory insect pests actually increase plant diversity.

Pulse of the Planet is presented by the National Science Foundation. I’m Jim Metzner.

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Insects and Plant Diversity-Applications

Predatory insects actually help maintain the diversity of the rainforest.
Air Date:06/13/2008
Scientist:
Transcript:

music
ambience: Rainforest, Iquitos, Peru

Here's a story about plants, the insects that feed on them and the surprising fact that those insects actually help maintain the diversity of the rainforest. I'm Jim Metzner, and this is the Pulse of the Planet.

In the Amazon, there are two main types of soil -- nutrient rich red clay, and a less fertile white sand. Each type of soil is host to a different group of plants with different strategies for dealing with munching insects. Plants that grow in white sand typically fend off insects with chemical defenses, while red clay plants grow fast enough to withstand most insect damage. According to Paul Fine, an Assistant Professor of Evolutionary Biology at the University of Michigan, the net result of all this is that red clay plants stay in their own soil, don't invade white sand habitats and vice versa.

"Clay plants, when they get attacked by insects in the white sand, dont have as many defenses. Theyre more likely to get killed by insects than white sand plants that have a high level of defense. So when a clay plant tries to invade white sand forest, even though it can grow there, and theres nothing about the soil that will keep the clay plant from growing there, if it starts getting attacked by an insect, the insects are going to eat it all up. Thats going to keep a clay plant from expanding its range into white sand forest. Conversely, white sand plants, because they grow slower due to their high defense allocation, are never going to be able to out compete a clay plant in clay soil. So, because of the insects, this allows two different kinds of plants, white sand plants and clay plants. And if insects didnt exist, our data show that clay plants might be able to invade white sand forests, and there would be one half the number of species in this system."

So in the complex ecology of the rainforest, predatory insect pests actually increase plant diversity.

Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.

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