Biomes part 1 – the hot, the wet and the cold

We’ve looked at ecosystems before and are now turning our eyes to biomes. Biomes are often confused with ecosystems but they shouldn’t be. Hundreds or thousands of ecosystems can exist within one biome; the species within it have adapted especially for that biome’s conditions.

These conditions are caused often by factors which aren’t brought about by animals and plants, such as soil, geology and climate.

Here are three of the major biomes:

 

Desert – most notable in Africa, Asia and Central America. Water is the source of all life and so in a very dry environment like a desert, life is scarce. Those species which do survive need very special adaptations. Scorpions, for example, have a very tough outer coating to prevent their bodies from drying. Cacti are capable of storing huge masses of water to keep them alive through long dry stretches.

Ocean – the ocean is home to many creatures who couldn’t survive elsewhere – certainly not in the Sahara or halfway up Everest! Oceans can be warm or cold and their different levels are home to various creatures: turtles near the light, warm surface, and glowing angler fish in the deepest, darkest depths.

Tundra – the greatest threat in the tundra is the low temperatures. Plants such as moss, heath and lichen grow closely together and can perform photosynthesis even when cold. Animals such as musk oxen and polar bears have long, thick coats in order to keep warm. Like the scorpion in its very different environment, these animals have adapted outer “coats” which protect their bodies from the extreme climate.

In our next post, we’ll look at the other biomes of grasslands, mountains and forests!

Hibernation

Hibernation is part of the annual cycle for many animals in winter. Cold weather is difficult to survive in for some creatures, especially when it kills off the plants and animals they feed on. A hibernating creature goes into a deep sleep. Its temperature drops and its heartbeat and breathing slow down. This enables it to use up less energy, which is very important when there’s less food available. Different animals hibernate in different ways:

Hedgehogs – during summer, a hedgehog will eat lots to build up its fat stores in time for hibernation. This lasts from October/November to March/April. During this period their activity is so minimal that they can survive for months on this fat.

Polar bears – only pregnant polar bears hibernate. The other females and males remain active in the harsh conditions of the Arctic winter. Like the hedgehog, the hibernating polar bear will feed heavily in the late summer so that they can live off fat reserves. But unlike the hedgehog, she does not enter a sleep-like state. She has to remain awake for pregnancy, birth and in order to nurse her cubs. Look at this video of polar bear cubs emerging in the spring.

Garter snakes – unlike the hedgehog and the polar bear, garter snakes in Canada hibernate in large groups. Rather than remaining warm by building up fat, they gather together in their hundreds or even thousands – not a site for anyone afraid of snakes! When the snow melts in the spring, the garter snakes emerge in their droves to bask in the sun.

Compost heaps

People are trying harder to find ways of reusing their rubbish as they are concerned about manmade climate change and use of the world’s resources. The majority of us send our glass, paper and plastic to be recycled – we even reuse ice-cream tubs and glass bottles as containers around the home. But what about leftover food that we can’t eat? Is there a use for that?

Many people throw their scrap food onto a compost heap in the garden – be it apple cores, potato peeling or burnt toast! Compost heaps are a great way of reducing the rubbish a household chucks out while improving your garden at the same time.

But what can make rotten fruit and veg good for a garden? It’s simple – bacteria. They break down rotten plants and vegetables. You can watch this process happen as the food scraps appear to fall apart, turn brown and most importantly get hotter. In fact, even a small compost heap or food bin can get very hot – sometimes around 40-60 degrees Celsius. If you hold your hand over a compost heap, you can feel the temperature. This increase in temperature happens as the bacteria break down the old scraps and they create carbon dioxide and heat. This isn’t so different to us humans when we’re exercising!

When it gets hot, microorganisms take over. Insects, slugs and worms also join in, eating the food and excreting the finished compost.

After a few months, once the compost has cooled and all the food has broken down, it should be ready to put into the soil. This introduces nutrients into the earth which are much needed by plants. The microscopic organisms also help to bring air into the soil. This makes for a very healthy crop of veg – whose peelings and leaves can be thrown into the heap next year!

Rock pooling

We’ve just got back from a holiday in Polzeath, Cornwall, where we had the pleasure of revisiting an old childhood pastime – rock pooling!

Rock pools are truly fascinating finds. They exist in the intertidal zone which means they’re above the sea when the tide’s in and below when the tide’s out. This unique position means that they are natural aquariums which change every day.

We spotted crabs, mussels and hundreds of limpets in the ones we looked at because they were quite shallow. Although rock pools look very picturesque, they are tough places to survive in. Creatures and plants have to cope with frequent changes in temperature, levels of salt and levels of oxygen – affecting how they eat and breathe. This means there are many animals who can’t survive these conditions.

The rock pools closer to the sea spend more time underwater and are therefore easier to live in for more vulnerable creatures. This means that the closer you get to the sea, the more diverse the animals and plants. Depending on where you are, you might find sea urchins, sea cucumbers, snails and whelks!

Next time you’re down at the beach, take a look at the rock pools near you and see what exciting creatures you find!

Perseids – August showers

August 10th to 13th are the dates all budding astronomers should put in their diaries. Coming up are the Perseids, a brilliant meteor shower visible before dawn.

They’re named the Perseids because of their proximity to Perseus (the Greek hero best known for slaying the terrifying snake-haired Medusa). This is an easy constellation to spot once you have found Andromeda and Auriga as he’s in between those two, both of whom have very distinctive patterns. The picture below and any night sky map should show you what it looks like.

Though they’re often called shooting stars and look like stars, meteors aren’t stars. They’re caused by debris in the sky, such as the leftovers of a comet, reaching the earth’s atmosphere. When they enter at very high speeds, the matter burns up, causing the “starry” bright light.

Radiant of the Perseid meteors (BBC images)

As in this picture, meteors appear to spread out from a single point (the radiant), which is inside Perseus. But this is an optical illusion. Imagine standing in the middle of a dozen very long, parallel train tracks. When the trains appear in the far distance, they’ll all seem to be at the same point. But as they approach (just as the meteors approach Earth), they appear to spread out. Really they are still running parallel.

We can predict when a meteor shower comes because we know when the Earth will pass through the remnants of a comet. There are many to see throughout the year, and we’ve got them all down in our diaries!

The Perseids continue for much of early to mid August but their peak time is before dawn on August 10th to 13th. Let us know if you get any good photos!

Strawberry fields forever (as long as the slugs stay away)

Wimbledon approaches, and with it the season of strawberries! We’ve planted ours out and have begun to enjoy the first of the crop. We’re hoping the real flush will coincide with another Andy Murray victory in a few weeks!

Because we’re so used to buying fruit and veg from the supermarket, it’s easy to forget they’re as much part of the food chain as any other plant or animal in nature. Just as foxes and snakes compete with each other for rabbits to prey on, different animals fight for strawberries. For us strawberry growers, that competition comes in the form of slugs! People have found new ways to fight these rivals – using salt, raised beds, and pesticides (pest killers).

Strawberries pollinate in a similar way to other plants and trees, with the help of the wind or an insect. Once the petals drop away, the fertilised flower swells into fruit. Around early June they begin to ripen into red strawberries. Each fruit is studded with seeds. After fruit has passed through an animal’s body the seeds return to the earth and start to grow.

An excellent, fruit-packed dessert – perfect for eating during tennis – is Eton Mess. Follow this very simple recipe of crushed-up meringues, strawberries and cream – though at Storm, we also like to throw in ice cream, mint and raspberries to make it extra refreshing!

Offa’s Dyke: a springtime expedition

In a break from the usual science posts, we thought we’d give you the highs and lows of our recent Offa’s Dyke trek.

The first two days took us from Knighton to Kington and onto Hay-on-Wye, a lovely town with around 50 bookshops! By far, the toughest slog was the trek over Hatteral Ridge on the third day. This entailed walking through a cloud of hail for ten miles or so. We were very cold and very wet and would strongly advise against it if weather conditions are adverse. The path is pitted with black bogs and began to resemble something from Middle Earth!

 

 

The Dead Marshes: not a million miles off

We emerged soaked in the village of Pandy. Making a beeline for Wales’ oldest pub, The Skirrid, we pulled our chairs as closely as possible to the open fire while eating as much as possible.

The next day was much milder and brought us into Monmouth, another nice town with great cafes and pubs. Our knees and feet shattered, we collapsed in the corner of one coffee shop for about two hours.

Arriving triumphant at the end of the gruesome Hatteral Ridge

The final walk to Chepstow was by far the nicest stretch of the whole trip. Weaving in and out of Gloucestershire and Monmouthshire, we passed along river and through woodland. The walk along the Wye Valley offered great views, looking down the river and either side up the vale. This is a great walk even for a day trip and we highly recommend it!

Tintern Abbey is well worth the small diversion – a stunning ruin, though we mostly admired it from a beer garden while nursing out feet. I strongly recommend this hike for anyone keen on long hikes but would advise warmer weather than early April!

Why do flowers bloom in spring?

Spring has sprung! It might not feel too warm but outdoors it’s starting to look a lot more spring-like. Flowers have bloomed and buds are appearing on the trees. But what is it about spring that makes the plant world come to life?

Leaves breathe in air, take in sunlight and use water from the roots to make food for the plant. But this process also requires energy. In this instance, it is light energy provided by the sun. Therefore, the more sunlight there is, the more food the plant is able to produce. The more food it has, the more the plant grows. Because the days get longer in spring, the plant is exposed to more sunlight in these months. This means the plant grows more quickly than in winter when it is darker.

The springtime increase in temperature also causes an increase in growth. Like all biological activity, plant growth speeds up with heat, provided it does not become too hot. The rise in temperature at this time of year means that plants grow more quickly and seeds germinate. Now bring on some warmer weather!

At the root of the matter

In the depths of winter, with all the colourful parts of the plants hidden away, here at Storm we’re getting to know roots much better.

Roots are the underground part of a plant. Though you can’t see them, they play one of the most important roles. While the leaves bring sunlight and carbon dioxide into the plant, roots draw water and nutrients from the soil in order to feed the plant.

Most larger plants, like trees, often start with a large root, which then spread out into smaller roots. By spreading out, they are able to gain as much goodness as possible from the earth. The root also allows the plant to anchor itself in the ground, useful for when bad weather and animals shake it. If you’ve ever seen a tree felled in a storm, you’ll know how impressive the root system can be.

Above: Tree roots visible after the Great Storm of 1987

Roots such as carrots, parsnips and turnips can often be used as food for humans and animals. These types of plant have a single, large root, which is called a tap root. Traditionally, in climates such as the UK, root vegetables are a staple diet for winter. This is because the root hoards much of the plant’s food and water here. By keeping its food source underground it is better protected against predators and cold weather. So when your tomatoes, lettuce and berries disappear with the mid-autumn snap, the hardier underground root vegetables are doing just fine.

This makes them the perfect winter veg. A firm favourite at Storm is Jamie’s winter stew, using onions, carrots, parsnips and any other root veg you can get your hands on.

To learn more about how roots fit into the rest of the plant, keep an eye out for our app Naming Parts of Plants and Animals – out later this month!

Hitchhiking, back-scratching and other inter-species favours

It’s not always such a savage world out there. Different species don’t only interact on a predator-and-prey level. Two species can provide a mutually useful service for each other (also called symbiosis). There are many examples of this:

• Sea anemones hitchhike on the backs of hermit crabs, enabling them to travel further and eat the crab’s leftover food. But the crab also gains something too. Having these tentacled creatures on their backs fend off octopuses and other predators who might otherwise eat the hermit crab. Watch this guy moving his anemone friend from an old shell to a new.
  
• African oxpeckers eat ticks off the backs of zebras and elephants. This enables the birds to eat but also does the bigger animals the service of removing parasites off their backs.
• The classic example of symbiosis is often easily forgotten: simple insect pollination. The bees uses the flower’s pollen to make honey, while spreading the pollen further, enabling the plant to reproduce.

If your pupils are interested in learning more about different species, our brand new app Sorting for Early Science can introduce them to the foundation science vocabulary to get them started!