 My name is Hilaristo Williams. I'm a research manager in the Farquhar Laboratory at the Australian National University. We're a well-known laboratory that works primarily on stable isotopes in plants, concentrating on the major isotopes, which are the main focus of photosynthesis, one that we'll be thinking about. But I'm here to talk to you about plants. They're the green things on the end of sticks that you sort of see all over the place. Most people think about them as just sort of being almost static features. They just sort of grow and live and don't do very much. But of course, like all organisms, they do their best to exploit their environment as fully as they can. And I think that's a good way to start thinking about what the plant does is to think about where it comes from and what it's using. Well, one of the interesting things about plants of course is that they're made of a variety of minor materials, which I've talked more about, but mostly out of carbohydrates, out of cellulose, starch, and sugars that they create by synthesizing them from calm dioxide and water. So you think about a seed, and you realize that the seed has to contain everything the plant needs to get going. So it needs to have enough carbohydrate in it that the plant can put out some leaves and begin to photosynthesize. It needs to have those trace elements that the plant needs to create things like chlorophyll that will get it going. It's like a little island of supplies like being dropped out of an aeroplane with a backpack. So what do plants need? Well, obviously, they need a lot of minor materials, and they get almost all those minor materials from the soil. So the first thing a plant has to think about doing is putting down roots.