0:00:02 > 0:00:04This is Ecomaths, a brilliant way of looking at
0:00:04 > 0:00:06fascinating, real-life situations
0:00:06 > 0:00:10to understand how maths can be used to help create a sustainable future.
0:00:10 > 0:00:14In the first film we explore renewable energy using algebra.
0:00:14 > 0:00:19Then we look at food production comparing lamb and snails
0:00:19 > 0:00:21using area, fractions and ratios.
0:00:21 > 0:00:24And finally, in a trial of a natural pesticide,
0:00:24 > 0:00:28we calculate volumes and concentrations using standard form.
0:00:30 > 0:00:32VIOLIN MUSIC PLAYS
0:00:43 > 0:00:44Hiya, I'm Stef.
0:00:44 > 0:00:48Now, if you want to keep warm and cook food you need fuel,
0:00:48 > 0:00:52and the oldest fuel known to humans is this stuff - wood.
0:01:05 > 0:01:08You might think that all wood is pretty much the same,
0:01:08 > 0:01:10but what's amazing is that different wood
0:01:10 > 0:01:14contains different amounts of energy, sometimes very different.
0:01:14 > 0:01:16But why does it matter? If we want to get warmer,
0:01:16 > 0:01:18why don't we just stick another log on the fire?
0:01:18 > 0:01:22Well, when we burn any fuel we come across global warming issues
0:01:22 > 0:01:27that affect the entire planet, so it's crucial to understand
0:01:27 > 0:01:29how much energy is in our fuel
0:01:29 > 0:01:31so that we can make the best possible use of it,
0:01:31 > 0:01:33and that's where Ecomaths comes in.
0:01:33 > 0:01:35It's a brilliant way of using maths
0:01:35 > 0:01:38to help make the world a better place.
0:01:38 > 0:01:41'And if you want to know about wood, ask a woodsman.
0:01:41 > 0:01:43'This is Martin Charlton.'
0:01:43 > 0:01:47- Cup of tea.- Hey, top man! - There you go.- So, Martin,
0:01:47 > 0:01:50how come there is energy in wood?
0:01:50 > 0:01:52It's carbon.
0:01:52 > 0:01:55The trees take the carbon dioxide with the sunlight,
0:01:55 > 0:02:00turn it into carbon and oxygen and so it's a carbon fuel.
0:02:00 > 0:02:03So does all wood have the same amount of energy in it?
0:02:03 > 0:02:06Yes, it can. It all depends on the amount of moisture
0:02:06 > 0:02:09you've got in there and the density of the wood,
0:02:09 > 0:02:12but it is the moisture that's the critical thing.
0:02:12 > 0:02:17In an oak tree, for example, you will have 350 litres of water.
0:02:17 > 0:02:21In one of these pine trees there will be anywhere between 15
0:02:21 > 0:02:25and 20 litres of water at any one moment in time.
0:02:25 > 0:02:29So before you can burn it you need to get the water out.
0:02:29 > 0:02:33- So I have here a very damp piece of wood.- Yup.
0:02:33 > 0:02:35I mean, you can literally see the dampness in it,
0:02:35 > 0:02:38and so, if I put that on the fire, what happens?
0:02:38 > 0:02:41It will only smoulder, it won't burn,
0:02:41 > 0:02:44because the energy in the fire, the heat in the fire,
0:02:44 > 0:02:45is going to dry the wood out first,
0:02:45 > 0:02:48it will drive the water off as steam, before it can actually burn the wood.
0:02:48 > 0:02:52Let's try to understand how much energy is released
0:02:52 > 0:02:55when we burn different types of wood,
0:02:55 > 0:02:57and here's where a bit of algebra comes in handy.
0:02:57 > 0:03:02So, Y. Y is the amount of energy that's contained in the wood
0:03:02 > 0:03:05that can be released when we burn it.
0:03:05 > 0:03:09X is the mass of the wood, the amount of it that we've got.
0:03:13 > 0:03:18But it all depends on the different amounts of moisture in it.
0:03:19 > 0:03:23It's a simple equation. When you double the amount of wood,
0:03:23 > 0:03:27or biomass, X, you get twice as much energy, Y, out.
0:03:28 > 0:03:31The tree - we'll select the tree for various reasons,
0:03:31 > 0:03:34whether it's not suitable for fencing or timber,
0:03:34 > 0:03:36can be used for biomass.
0:03:36 > 0:03:39We will fell it, we will section it up into the proper lengths
0:03:39 > 0:03:43for collecting it in the woods, and then we'll stack it
0:03:43 > 0:03:47in the woods so it starts to lose moisture, and when it gets down
0:03:47 > 0:03:51to around about 40% moisture then we'll come along with a big machine
0:03:51 > 0:03:56and extract it to the roadside or to the place that will chip it.
0:04:12 > 0:04:13Look at this!
0:04:13 > 0:04:17All of that huge amount of wood from the forest has been turned
0:04:17 > 0:04:22into a vast mountain of sawdust. Julian, hi, there.
0:04:22 > 0:04:26- Hello, Stefan.- What's happened, why does it now look like this?
0:04:26 > 0:04:29It looks like this because what we've done is we have chipped it
0:04:29 > 0:04:33into wood chip and it's important that it's not sawdust.
0:04:33 > 0:04:35It's all to do with how our boilers work.
0:04:35 > 0:04:38And what we're trying to do is turn it into something that flows,
0:04:38 > 0:04:41and can be moved in a consistent way
0:04:41 > 0:04:43to get a consistent amount of energy from it.
0:04:43 > 0:04:45What you're doing is you're increasing the surface area
0:04:45 > 0:04:48of the chip in order for the air to get at it
0:04:48 > 0:04:51and therefore for it to be able to burn effectively.
0:04:51 > 0:04:55How do you work out the moisture level of the wood?
0:04:55 > 0:04:57We can, in the field, use moisture meters,
0:04:57 > 0:05:00which are sort of electronic gadgets really,
0:05:00 > 0:05:02but here at the yard in the farm,
0:05:02 > 0:05:06we can use something as simple as a domestic microwave.
0:05:07 > 0:05:11I don't recommend people do it at home, but you take a certain amount.
0:05:11 > 0:05:13Let's say 100 grams. You put it in the microwave,
0:05:13 > 0:05:17heat it up, for a period, take it out, reweigh it.
0:05:17 > 0:05:20Heat it up again, take it out, reweigh it.
0:05:20 > 0:05:23Once the weight no longer changes, you've got a final weight,
0:05:23 > 0:05:24and you subtract that weight
0:05:24 > 0:05:29from your original weight and you have your percentage in effect.
0:05:29 > 0:05:31The final weight of 73 grams
0:05:31 > 0:05:35is subtracted from the initial weight of 100 grams,
0:05:35 > 0:05:39to give the moisture content. In this case, 27%.
0:05:39 > 0:05:43The energy Y is proportional to the mass X of the wood fuel.
0:05:43 > 0:05:46The gradient function M depends on the moisture.
0:05:46 > 0:05:48The lower the moisture, the steeper the gradient
0:05:48 > 0:05:51and the more energy you can get from the wood.
0:05:52 > 0:05:55So in terms of getting energy out of this stuff,
0:05:55 > 0:05:57what are the other aspects of the equation?
0:05:57 > 0:05:59Clearly you've got to cut the wood down,
0:05:59 > 0:06:01so there's energy in terms of the chainsaws used,
0:06:01 > 0:06:04there's energy in terms of the vehicles that are used
0:06:04 > 0:06:06to actually get it out of the woods,
0:06:06 > 0:06:09to transport it from the woodlands to our yards.
0:06:09 > 0:06:11And clearly also in the chipper,
0:06:11 > 0:06:13and then being transported from here,
0:06:13 > 0:06:16being loaded then transported from here to the customer site.
0:06:16 > 0:06:18- Is that a big part of it?- Indeed.
0:06:18 > 0:06:21We try to deliver within a 15-mile radius,
0:06:21 > 0:06:23maximum of 30-mile radius, and that gives you
0:06:23 > 0:06:25a sense of the distance it travels.
0:06:25 > 0:06:29Compare that to oil, which has often come halfway round the world
0:06:29 > 0:06:33from Saudi Arabia or somewhere like that, and this is a local product
0:06:33 > 0:06:37produced by local people, it's a local energy resource.
0:06:37 > 0:06:40And this is where the fire is.
0:06:45 > 0:06:47Wow, that's terrifyingly hot.
0:06:47 > 0:06:51And it's amazing to finally see all of the energy that was stored
0:06:51 > 0:06:53in the forest finally being released.
0:07:01 > 0:07:06But this massive biomass boiler doesn't heat some factory.
0:07:06 > 0:07:08It heats this place. It's a school,
0:07:08 > 0:07:11and I'm going to find some experts who can tell me all about it.
0:07:14 > 0:07:18- Hi, Eco-Team, how are you doing? - ALL: Hi!
0:07:18 > 0:07:20Tell me about this biomass boiler, it's just so cool.
0:07:20 > 0:07:23How much wood chip does it use every hour?
0:07:23 > 0:07:27Well, to work it out we took the measurements of each container.
0:07:27 > 0:07:31This container is six days' worth of wood chip to heat the school.
0:07:31 > 0:07:33The students use the measurements to calculate
0:07:33 > 0:07:34how much they need per hour,
0:07:34 > 0:07:36so they can compare it with other fuels.
0:07:36 > 0:07:39That's 2 metres 35.
0:07:40 > 0:07:43So the amount of wood chips that go through that to heat
0:07:43 > 0:07:48the whole school for one hour is 0.247 cubic metres?
0:07:48 > 0:07:50- Yeah.- OK, well, that's fantastic,
0:07:50 > 0:07:53so now we know how much wood chip the boiler uses.
0:07:53 > 0:07:57The big question is, really, how does that compare to other fuels?
0:07:57 > 0:08:00So, Natalie, you know about this, don't you?
0:08:00 > 0:08:03Well, with the oil it's 3.4 times more energy
0:08:03 > 0:08:06for every kilogram than biomass.
0:08:06 > 0:08:10- Wow, that's a big difference, isn't it?- Yes.- So oil,
0:08:10 > 0:08:16- 3.4 times more energy. Per kilo that is, isn't it?- Yeah.
0:08:18 > 0:08:21So it's a big difference, isn't it? So this, this is heating oil.
0:08:21 > 0:08:26That gives you 3.4 times more energy per kilo.
0:08:26 > 0:08:28- Mm-hmm. - That's a big difference. OK.
0:08:28 > 0:08:30But what I want to know is how does it compare?
0:08:30 > 0:08:32So let's get some gas on here.
0:08:33 > 0:08:36How does wood chip compare to gas?
0:08:36 > 0:08:41Gas, you get three times more energy per kilogram.
0:08:41 > 0:08:42OK, so a little bit different
0:08:42 > 0:08:45but still a big difference compared to it, isn't it?
0:08:45 > 0:08:50Three times more energy per kilo.
0:08:50 > 0:08:53So there's a huge difference in the energy per kilo,
0:08:53 > 0:08:56but what about the cost, is there any difference?
0:08:56 > 0:09:00Um, biomass is about 10% more expensive than gas.
0:09:00 > 0:09:04- Oh, wow. So there is a significant difference, isn't there?- Mm-hmm.
0:09:07 > 0:09:10So this is really interesting. There's a huge amount less energy
0:09:10 > 0:09:15per kilo, and it's more expensive, so why would you go for wood chip?
0:09:15 > 0:09:17Because it's not burning any fossil fuels.
0:09:17 > 0:09:21Whereas trees can be regrown, we can't get the fossil fuels back
0:09:21 > 0:09:23and in 30 years they might run out.
0:09:23 > 0:09:25- Yeah.- So overall it's better for the environment.
0:09:25 > 0:09:28Biomass should stay at quite a steady price
0:09:28 > 0:09:31whereas things like oil should increase more
0:09:31 > 0:09:34because there's less of them.
0:09:35 > 0:09:39It's amazing to use maths to unravel the secret behind wood
0:09:39 > 0:09:44as a biomass fuel, and I wondered if this could be inspiring for you.
0:09:44 > 0:09:47Maybe you could change the way that your school uses energy using maths.
0:09:54 > 0:09:56VIOLIN MUSIC PLAYS
0:10:08 > 0:10:13Hiya, I'm Stef and this is glorious Dorset farmland,
0:10:13 > 0:10:17which produces some of the finest food in the world.
0:10:20 > 0:10:22The trouble is food production
0:10:22 > 0:10:27uses a vast amount of energy, water and land.
0:10:27 > 0:10:31And with the world population increasing so fast,
0:10:31 > 0:10:33land is becoming a huge issue.
0:10:37 > 0:10:40But the earth isn't growing in size, so we need to use land
0:10:40 > 0:10:44in the best way possible to feed as many people as we can.
0:10:44 > 0:10:47Now, I'm going to tackle this problem using maths,
0:10:47 > 0:10:51but this isn't any old maths - this is Ecomaths.
0:10:52 > 0:10:53ICE CRUNCHES
0:10:55 > 0:10:57The best thing to start with is protein, cos it's essential
0:10:57 > 0:11:02to our diet, and we get most of our protein from meat.
0:11:02 > 0:11:04But there are other ways to produce protein.
0:11:04 > 0:11:08Ways that might chill your soul.
0:11:08 > 0:11:12Welcome to the weird and wonderful world of the gastropod.
0:11:16 > 0:11:18Meet Sidney.
0:11:19 > 0:11:23'I'm here to find out whether gastropods, or snails to you and me,
0:11:23 > 0:11:28'could be the future of the burger and save the planet along the way.'
0:11:28 > 0:11:31Easy, now!
0:11:31 > 0:11:35Let's go to meet the man who uses clever Ecomaths to produce
0:11:35 > 0:11:38a large amount of snails on a very small amount of land.
0:11:38 > 0:11:40These are the breeding snails.
0:11:40 > 0:11:43They are enormous! They're terrifying!
0:11:43 > 0:11:47The bigger the snail that we use for breeding,
0:11:47 > 0:11:49the bigger the egg we get from it.
0:11:49 > 0:11:51Snails lay eggs?
0:11:51 > 0:11:58- Yep! About 100 eggs in a batch.- Wow.
0:11:58 > 0:12:05And with our system we ask them to lay eggs every five weeks.
0:12:05 > 0:12:09Now, these have actually hatched and they're small baby snails
0:12:09 > 0:12:11and they are absolutely tiny.
0:12:11 > 0:12:12These are so sweet,
0:12:12 > 0:12:16- you can see they've got those little tiny antennae!- Yeah.
0:12:16 > 0:12:20- OK, so that's the first stage of being a baby snail.- Yeah.
0:12:20 > 0:12:23- So can we have a look at the fatties?- Yeah, sure.
0:12:23 > 0:12:25- So I've got the feed here.- Yeah.
0:12:25 > 0:12:28- That's all they need? - That, for one day, yeah.
0:12:28 > 0:12:31That's enough... That's 100 snails? That is tiny,
0:12:31 > 0:12:33when you think about the amount of food you feed to livestock,
0:12:33 > 0:12:38I think it's an amazing use of resources.
0:12:39 > 0:12:43- This is a batch which is now ready for the market.- Wow!
0:12:43 > 0:12:48How many snails do you produce every week to send off to the restaurants?
0:12:48 > 0:12:50Around about 6,000 each week.
0:12:50 > 0:12:536,000 snails? That's a huge amount, isn't it?
0:12:53 > 0:12:55Not really, if you think it's only...
0:12:55 > 0:13:00The average amount of snails in a dish on a menu is six.
0:13:00 > 0:13:02That's only 1,000 dishes.
0:13:02 > 0:13:06Mmm, it's not bad. And how much does each snail weigh?
0:13:06 > 0:13:09They weigh between 12 and 15 grams.
0:13:09 > 0:13:12The big question is how much land do you use
0:13:12 > 0:13:15to produce these 6,000 snails?
0:13:15 > 0:13:19The boxes take up around about 400 square feet,
0:13:19 > 0:13:22which is about 37 square metres.
0:13:22 > 0:13:25So snails are a very efficient use of space?
0:13:25 > 0:13:29- I'd say very efficient, yeah.- Cos they just stack up higher and higher
0:13:29 > 0:13:32rather than spreading out over big fields.
0:13:32 > 0:13:35Well, if you take seven boxes stacked high,
0:13:35 > 0:13:37you've got 700 snails there.
0:13:37 > 0:13:40And then if you go up to 10, that's 1,000 in each stack.
0:13:40 > 0:13:42But there's one last thing I need.
0:13:42 > 0:13:45How much protein is there in your snails?
0:13:45 > 0:13:50There's no fat at all, and there's about 90% protein.
0:13:50 > 0:13:5390% protein, brilliant. That's all I need to know,
0:13:53 > 0:13:56- I've got all of my facts and figures.- Good.
0:13:56 > 0:13:58- There's your blanched snails ready to cook.- Fantastic.
0:13:58 > 0:14:01And there's the live ones. Take care.
0:14:01 > 0:14:05- Ha-ha! You're a star.- Thanks a lot. - Thank you very much.- Take care.
0:14:05 > 0:14:07So how does that compare with figures of land use
0:14:07 > 0:14:10to produce more traditional lamb or beef?
0:14:13 > 0:14:16I know some young people who know all about the Ecomaths
0:14:16 > 0:14:17behind lamb production.
0:14:20 > 0:14:23This working farm is part of Oathall Community College
0:14:23 > 0:14:25and today they're weighing the lambs.
0:14:25 > 0:14:2717.
0:14:33 > 0:14:35It's 43 kilograms.
0:14:40 > 0:14:44We return to the classroom to look at the maths.
0:14:44 > 0:14:47We calculated the mean of their growth weight, of their growth.
0:14:47 > 0:14:50- Is that in kilograms? - Yeah, that's in kilograms.
0:14:50 > 0:14:55And their breed, so Suffolk, Pedigree Suffolk, Texel, just a few.
0:14:55 > 0:14:58So can you choose certain animals because they're fast-growing
0:14:58 > 0:14:59and other ones for taste?
0:14:59 > 0:15:02Why would you choose a different breed, why do you think?
0:15:02 > 0:15:06It all kind of depends on how well they grow
0:15:06 > 0:15:10and what breed will produce the best meat. You want it to taste nice
0:15:10 > 0:15:13but you also want to make money out of it and make a profit.
0:15:15 > 0:15:17- So, Sam and Freya, can I squeeze in here?- Yes.
0:15:17 > 0:15:20Tell me what you've been up to here.
0:15:20 > 0:15:26Well, we've been working out the amount of land used by lambs.
0:15:26 > 0:15:29So literally the amount of space you require to produce
0:15:29 > 0:15:30- a kilo of lamb?- Yes.
0:15:30 > 0:15:33We produce about two lambs each week.
0:15:33 > 0:15:38Each lamb, the bit that we use is about 22.5 kilograms.
0:15:38 > 0:15:42Ten lambs needs 4,048 square metres.
0:15:42 > 0:15:45As the farm produces two lambs each week,
0:15:45 > 0:15:47we have to divide that by five.
0:15:49 > 0:15:52We then take the 809 and divide it
0:15:52 > 0:15:58by the amount of protein produced, and that gives us 25.7.
0:15:58 > 0:16:01That is brilliant, because you've used maths to come up with
0:16:01 > 0:16:06something really useful. We now know it takes 25.7 square metres of land
0:16:06 > 0:16:10to produce one kilo of lamb protein.
0:16:10 > 0:16:14That's pretty good, but I've got a challenge for you.
0:16:14 > 0:16:18Can you use the same maths to work out something about this fella here?
0:16:19 > 0:16:22This is Sidney the snail. Can you work out for me
0:16:22 > 0:16:27how much land you need to produce a kilo of snail protein? OK.
0:16:27 > 0:16:30- That sound like a good challenge? - Yeah.- Freya, put your hand out.
0:16:30 > 0:16:32Get to work!
0:16:35 > 0:16:37I left them with the data I collected at the snail farm
0:16:37 > 0:16:41in Dorset, and a few friends I brought with me.
0:16:42 > 0:16:45While these guys are finding out how much protein there is
0:16:45 > 0:16:49in these fellas, I thought it might be a good idea to cook them some.
0:16:49 > 0:16:53And this is how you go about it. First of all, get about 100 snails,
0:16:53 > 0:16:56and boil them up in lots and lots of water,
0:16:56 > 0:17:00then chuck them in a pan with lots and lots of garlicky butter,
0:17:00 > 0:17:03and that way, frankly, anything should taste good.
0:17:03 > 0:17:06To make it fair in the lamb v snail comparison, they took 12 grams
0:17:06 > 0:17:09as the average weight per snail without the shell,
0:17:09 > 0:17:13just as they took 50% to be the useable meat per lamb.
0:17:13 > 0:17:17They also adjusted for the different protein content for the dry meat -
0:17:17 > 0:17:2070% for lamb and 90% for snail.
0:17:20 > 0:17:23Their final figures for land use for kilogram per week
0:17:23 > 0:17:25were really surprising.
0:17:25 > 0:17:270.57.
0:17:27 > 0:17:32So that's 0.57 square metres to produce a kilo of snail protein,
0:17:32 > 0:17:36compared to 25.7 square metres for a kilo of lamb protein.
0:17:36 > 0:17:39So now that we understand the amount of land needed for snails and
0:17:39 > 0:17:44the amount needed for lamb, how do you relate the two figures together?
0:17:44 > 0:17:49We took the two numbers and we came up with a ratio of 1 to 45.
0:17:49 > 0:17:53Brilliant. So you need 45 times the amount of land to produce
0:17:53 > 0:17:56a kilo of protein from lamb than you do from snail.
0:17:58 > 0:18:02So this is a little bit of snails on toast.
0:18:03 > 0:18:05So, first time for a gastropod?
0:18:07 > 0:18:10- Mmmm.- Mm.- They're not bad, are they?
0:18:10 > 0:18:13Do you think that there's something important
0:18:13 > 0:18:17about foods like this that take a lot less land to produce?
0:18:17 > 0:18:19Although lamb does take up more land,
0:18:19 > 0:18:23it's usually land that's unable for humans to use,
0:18:23 > 0:18:26like they're grown on hills.
0:18:26 > 0:18:33I think they are a lot better... way to preserve land,
0:18:33 > 0:18:36but, to be honest, I'd still rather eat lamb!
0:18:36 > 0:18:38STEFAN LAUGHS
0:18:39 > 0:18:44Now, snails might not be your cup of tea but when you use maths
0:18:44 > 0:18:46to take a close look at different types of food
0:18:46 > 0:18:48and look at the energy and land and water
0:18:48 > 0:18:51that goes into the production, you can make some choices
0:18:51 > 0:18:54that could really change the world.
0:19:13 > 0:19:17Everywhere you look, the planet is teeming with life.
0:19:17 > 0:19:19It's called biodiversity and it's simply
0:19:19 > 0:19:24the huge variety of living things that make up the natural world.
0:19:28 > 0:19:30But that variety is getting less and less.
0:19:30 > 0:19:34Who knows what that will mean for the good old human being.
0:19:35 > 0:19:38Time is running out but there are solutions,
0:19:38 > 0:19:40and we need maths to find them -
0:19:40 > 0:19:44but not just any old maths. This is what I call Ecomaths.
0:19:46 > 0:19:49But you don't have to go to the ends of the earth to find living things
0:19:49 > 0:19:52that are under threat, and one of the main culprits
0:19:52 > 0:19:55is this - insecticide.
0:19:55 > 0:20:00It's used by farmers and gardeners across the world to kill pests.
0:20:00 > 0:20:03So, what's the problem?
0:20:03 > 0:20:06That's the problem - harmful to the environment.
0:20:06 > 0:20:08So, what's going on?
0:20:08 > 0:20:11I'm here at Swansea University to find out.
0:20:11 > 0:20:15So, Tariq, explain to me about pesticides.
0:20:15 > 0:20:20OK, Stef. Pesticides are chemicals which control organisms
0:20:20 > 0:20:23which are undesirable organisms. They could be weeds...
0:20:23 > 0:20:27Most of us think of pesticides as controlling insects
0:20:27 > 0:20:31which are pests to crops, but they could also be diseases of crops.
0:20:31 > 0:20:32So what are you doing here?
0:20:32 > 0:20:36We're trying to develop alternatives to conventional chemical pesticides.
0:20:36 > 0:20:41We're trying to exploit natural organisms which occur in the soil
0:20:41 > 0:20:45and in our environment, so we're trying to develop these organisms
0:20:45 > 0:20:49as alternatives to the chemical pesticides.
0:20:49 > 0:20:53'This is where they keep all the pests. Let's take a look.'
0:20:53 > 0:20:57Here, for example, we have weevils. There's a whole range of weevils.
0:20:57 > 0:21:01These can actually devastate a whole range of forest trees.
0:21:01 > 0:21:05They have powerful mouth parts and they chew away and remove bark,
0:21:05 > 0:21:08particularly young saplings. It can be starved and stunted
0:21:08 > 0:21:11and it can actually topple over, and basically, it's killed.
0:21:11 > 0:21:15At the university, they're developing naturally occurring fungi
0:21:15 > 0:21:18that have evolved to attack and kill specific bugs.
0:21:18 > 0:21:21One such fungus, called Metarhizium,
0:21:21 > 0:21:26is proving to be a potent biological alternative to harmful chemicals.
0:21:26 > 0:21:29So you're developing alternatives to pesticides.
0:21:29 > 0:21:33How do you go about proving whether they work or not?
0:21:33 > 0:21:37You have to compare our fungus - this is the agent we're developing -
0:21:37 > 0:21:39with the chemical pesticide.
0:21:39 > 0:21:43It has to show that it's just as good in killing the pest.
0:21:43 > 0:21:46One of the most important things is mathematics,
0:21:46 > 0:21:49because you have to prove to a lot of people
0:21:49 > 0:21:51that this thing is working.
0:21:52 > 0:21:55So, Minshad, what are you preparing here?
0:21:55 > 0:21:58This is the fungus, and I'm going to prepare a test.
0:21:58 > 0:22:01It's called an LC50, Lethal Concentration,
0:22:01 > 0:22:03to kill 50% of the insects.
0:22:03 > 0:22:04'Minshad is doing a vital test
0:22:04 > 0:22:08'to see how effective the fungus is at killing pests.
0:22:08 > 0:22:10'These aren't actually the target pests.
0:22:10 > 0:22:12'They're little larvae called Galleria.
0:22:12 > 0:22:16'They're usually chosen to make sure it's a fair test.'
0:22:16 > 0:22:19- Can I pick this up?- Yeah. They are quite friendly,
0:22:19 > 0:22:22- and this is used as a model host, worldwide.- Quite friendly!
0:22:23 > 0:22:27First Minshad takes the fungus, here in this Petri dish,
0:22:27 > 0:22:30and makes up a concentrated solution.
0:22:30 > 0:22:33'The preparation has to be done in sterile conditions.'
0:22:34 > 0:22:38He needs to know how many spores there are per millilitre.
0:22:38 > 0:22:41Believe it or not, he counts them.
0:22:41 > 0:22:44He takes a tiny drop and looks down the microscope.
0:22:47 > 0:22:50He counts the spores in the larger square.
0:22:51 > 0:22:53Then another square.
0:22:55 > 0:23:00He does this five times and takes an average, in this case 40.
0:23:00 > 0:23:05As there are 25 squares, this means that there are 25 times 40 spores -
0:23:05 > 0:23:08or 1,000 - in the sample.
0:23:08 > 0:23:10'Since he knows the volume of the sample,
0:23:10 > 0:23:12'he can calculate the concentration.
0:23:12 > 0:23:15'It's 10 to the 8 spores per millimetre.'
0:23:15 > 0:23:17So the final concentration will be
0:23:17 > 0:23:20one times ten to the power of eight conidia per millilitre.
0:23:22 > 0:23:25So, from this I'm going to make a dilution.
0:23:25 > 0:23:28Now he prepares what's called a serial dilution.
0:23:28 > 0:23:32He takes one millilitre of the concentrated solution
0:23:32 > 0:23:35and adds it to nine millilitres of the wetting agent
0:23:35 > 0:23:36in the second tube.
0:23:39 > 0:23:44This makes the second tube ten times less concentrated.
0:23:45 > 0:23:49Minshad repeats the process from one tube to the next.
0:23:51 > 0:23:53You can see from the labels on the tubes
0:23:53 > 0:23:57that the serial dilution gives you lower and lower concentrations,
0:23:57 > 0:23:59each ten times less.
0:23:59 > 0:24:02The last tube is the control with no spores.
0:24:02 > 0:24:06In the LC50 test, they want to know which of these concentrations
0:24:06 > 0:24:08will kill 50% of the bugs.
0:24:11 > 0:24:17The fungus works by piercing the outer casing and infecting the bug.
0:24:17 > 0:24:19The fungus grows and develops spores,
0:24:19 > 0:24:22so that it can spread to other bugs.
0:24:22 > 0:24:24Because the fungus is naturally occurring,
0:24:24 > 0:24:28birds and other creatures that feed on these bugs are unharmed,
0:24:28 > 0:24:33even if they do fancy a nibble at something distinctly unappetising.
0:24:35 > 0:24:38And here are the bugs in the LC50 test.
0:24:38 > 0:24:42It's day eight, so let's see what's happened.
0:24:42 > 0:24:44This looks pretty gruesome.
0:24:44 > 0:24:46What's going on here?
0:24:46 > 0:24:51This is the LC50 test, where I'm testing the different concentration.
0:24:51 > 0:24:57He counts how many have died and fills in the table for day eight.
0:24:57 > 0:25:01The LC50 test results are that between ten to the six
0:25:01 > 0:25:06and ten to the seven spores are needed to kill 50% of the bugs.
0:25:06 > 0:25:11A computer program allows Minshad to calculate the exact concentration.
0:25:13 > 0:25:18Now, it takes 2.3 million spores to kill half of the insects -
0:25:18 > 0:25:20that's a vast amount of spores.
0:25:20 > 0:25:23Well, it just looks a vast amount of spores,
0:25:23 > 0:25:28but in natural conditions you can find the same number anywhere.
0:25:28 > 0:25:30So where are we going?
0:25:30 > 0:25:33'But where do you collect the fungi? Deepest Africa?
0:25:33 > 0:25:36'The Amazon rainforest? No.
0:25:36 > 0:25:39'This parkland is part of the university campus,
0:25:39 > 0:25:43'and lurking in the soil could be a new fungus strain.'
0:25:43 > 0:25:46This is an untreated area,
0:25:46 > 0:25:50and we're hoping to find a bio-control agent.
0:25:50 > 0:25:52So we're looking to find some fungi?
0:25:52 > 0:25:54Yes, we're looking to find fungi.
0:25:54 > 0:25:59'Earthworms are a sign of the rich biodiversity of untreated soil.
0:25:59 > 0:26:01'That's why Minshad chooses this location
0:26:01 > 0:26:03'to search for promising new fungi
0:26:03 > 0:26:06'for the development of biological pesticides.'
0:26:06 > 0:26:09It's only because of the huge biodiversity of the planet
0:26:09 > 0:26:12that we can find something as amazing as a fungus
0:26:12 > 0:26:14that can help us combat pests.
0:26:14 > 0:26:17But you have to do the maths to prove that it works.
0:26:17 > 0:26:21I'm off somewhere else where they're keeping an eye on the environment.
0:26:23 > 0:26:25Birds are often the earliest indication
0:26:25 > 0:26:29of changes to our environment and their impact on biodiversity.
0:26:29 > 0:26:32These students at Dorothy Stringer High School in Brighton
0:26:32 > 0:26:35are carrying out a bird walk and counting the species
0:26:35 > 0:26:37in the school grounds.
0:26:37 > 0:26:40Can you guys count how many gulls there are
0:26:40 > 0:26:43on the top of the main block over there?
0:26:43 > 0:26:47ALL: One, two, three, four, five.
0:26:47 > 0:26:50- Brilliant. Make a note.- Are you going to mark them on your sheets?
0:26:50 > 0:26:53STUDENTS CHATTER
0:26:55 > 0:26:58Right, we're now coming to the woodland environment,
0:26:58 > 0:26:59so now I want you to...
0:26:59 > 0:27:02You've got your lists - look up in the trees
0:27:02 > 0:27:04and we'll try to see how many we can identify.
0:27:04 > 0:27:08Most important is that you count the number of each species that you see.
0:27:08 > 0:27:11Each winter for four years, the students have been recording
0:27:11 > 0:27:14the birds, and building a valuable database,
0:27:14 > 0:27:17that contributes to a nationwide survey.
0:27:17 > 0:27:19What have you discovered over the years?
0:27:19 > 0:27:23We've got some data here from the main birds
0:27:23 > 0:27:25that actually are in this area.
0:27:25 > 0:27:28Are there any big changes that you've seen?
0:27:28 > 0:27:32The blackbird - it's gone from, in 2009, seven,
0:27:32 > 0:27:34to 0.5.
0:27:34 > 0:27:37- That's quite surprising. - Yeah, that's quite a big change.
0:27:37 > 0:27:40There's always a constant with the black-headed gulls
0:27:40 > 0:27:46and the heron gulls. They've always been a big species here,
0:27:46 > 0:27:49but the jackdaws have kind of gone down, but the problem is,
0:27:49 > 0:27:53as the recording isn't always at the same time of year...
0:27:53 > 0:27:56- And that'll have a big effect on the numbers.- Yeah.
0:27:56 > 0:27:59And this is averaged over quite a few different visits to the woods,
0:27:59 > 0:28:00- isn't it?- Yes.- Yes.
0:28:00 > 0:28:02Over the course of the whole of the year.
0:28:02 > 0:28:04I think every class...
0:28:04 > 0:28:07- Pretty much every person would have gone through.- Yes.
0:28:07 > 0:28:11- A lot of people.- There's quite a lot of data, then, being averaged out
0:28:11 > 0:28:14- and condensed.- It should be pretty reliable if it's that many.
0:28:14 > 0:28:17'They're not just collecting data - they're also
0:28:17 > 0:28:19'investing in future biodiversity by planting trees
0:28:19 > 0:28:21'to attract butterflies.'
0:28:21 > 0:28:25- So what are we going to do here? - We'll plant some saplings.- Yeah.
0:28:25 > 0:28:27- So, you've got to make a T shape.- Yep.
0:28:27 > 0:28:32- The bottom bit of the T.- Yep.- And then make that the top bit of the T.
0:28:34 > 0:28:37'Come springtime, they'll be back,
0:28:37 > 0:28:41'analysing the results of their efforts using Ecomaths.'
0:28:51 > 0:28:54Subtitles by Red Bee Media Ltd