The secret of the winter flowers

It’s January 1st and the floor of the wood is covered with fresh new leaves, growing in dense patches. The first flowers are starting to open. Within a week, the air is scented with a sweet fragrance. This is the winter heliotrope, which is just as much at home in Nowhere as it is in its native North Africa.

The winter heliotrope was probably brought to Britain by Victorian gardeners.

 

We have a large Victorian estate called Tyntesfield down the road, so originally it could easily have come from there. The plant has a big secret: its flowers are just for show!

The winter heliotrope is unusual because it has separate male and female plants. As far as we know, the Victorian gardeners only imported male plants into Britain, because they liked the showy flowers and its rich scent. So, although the flowers make good pollen, there are no female flowers available to receive it. These plants cannot make seeds.

How do the plants reproduce, if they  cannot make seeds?

What is its big secret?

 

 

 

 

Below the soil the plant has a special underground stem, called a rhizome. During the year the rhizome stores food ready for the wintertime. Then, early in the new year, it grows new leaves and flowers.

During the summer the rhizomes grow so large, that they eventually break off and become new plants. This is a different way of reproducing, called vegetative reproduction. The plants are all clones, they have the same genetic information, which means that they all flower at more or less the same time.

So good is the winter heliotrope at growing in this way, that the plant is seen by some gardeners as an uwanted pest. It seems to grow well in Nowhere Wood, where it grows undisturbed.

1. What do you think are the advantages of being able to reproduce vegetatively, without making seeds?

2. Are there any disadvantages to having plants that all have the same genetic information. Is variation needed for the survival of plants?

Goodbye, for now

By late October, the last of the visitors are leaving Nowhere Wood. House martins are birds that build nests in the eaves of the surrounding houses. They fly by swooping up and down in the summer skies, feeding on flying insects.

 

Then, suddenly, as the season changes, they leave. But where do they go?

Amazingly, for such confident, visible, birds, they have been able to keep this a secret from us. And, even today, we really do not know for sure. We think they fly to Africa, over the Sahara Desert, to countries like Cameroon, Congo and the Ivory Coast. That’s a journey of over 5 000 km.

There they spend the winter, feeding and resting, before making the return journey in early Spring, arriving back to Nowhere Wood by April.

 

If all goes well, they return to the wood, and even to the same nests. It is a dangerous adventure and not all make it back. The birds can be eaten by birds of prey, or trapped by hunters.

Above all, the declining number of insects is killing the house martins. Loss of habitats, use of pesticides and climate change are all linked to human activity, so indirectly, we are to blame. So, perhaps, in the future, it will not be goodbye for now, but goodbye forever.

  1. How does the use of pesticides across Europe and Africa affect the survival of house martins?
  2. How could we conserve our populations of house martin?

Fruits of the autumn

Safety in numbers

cluster fliesThese animals look like cars parked in the autumn sunshine. They look harmless enough, but they have some gruesome secrets.

What are they and what are they doing? They are called cluster flies, and they are warming their bodies in the sun, before flying to feed on the fruits of the wood.

They are having adventures in time and space in Nowhere Wood.  Life in the wood is dangerous and the animals are busy being alive: feeding, drinking and staying warm.

The animals certainly look like flies: with one pair of wings, a large head and huge compound eyes. Look closer and you might see their mouthparts, sucking water from the surface of the leaf.

cluster flies
cluster flies on leaf in Nowhere Wood, October 2021

The flies have lived their whole lives in Nowhere Wood. Their mothers laid their eggs in the soil last autumn. In the Spring, the eggs hatched to release larvae into the soil that burrowed into the bodies of earthworms.

They spent the early summer feeding on the worms before pupating. The adults emerged in the early summer, killing their earthworm hosts.

 

 

The flies are in a hurry to breed before it goes colder, later in the month. They are becoming mature enough to produce the next generation of flies.

Then the cycle of ‘being and becoming’ will begin again.

There is safety in numbers. The main predator of these flies is a type of wasp. There are twenty pairs of eyes looking out for danger and when one senses the wasps, they all fly away.

Life is so uncertain in Nowhere Wood. As well as wasps, the air contains the spores of dangerous fungi, that can infect and grow inside the adults,  eating them up from the inside! In spite of the dangers, enough cluster flies survive to breed to be present in the wood next year.

Life is an uncertain adventure for the cluster flies, the earthworms, the wasps and the fungi. Everything is connected in Nowhere Wood.

  1. Suggest why cluster flies need to warm their bodies in the morning, before they can fly.
  2. Suggest why there is safety in numbers.

Goodbye, for now

Time travellers to Nowhere (3)

We are in Nowhere Wood, about 300 million years ago, staring at a forest of tree ferns, watching them make oxygen. Over the years, these tree ferns have made so much oxygen that its concentration in the air has risen to about 35%, (compare that with the 21% found in the 21st century).

There is so much oxygen that the lightning strikes produce frequent explosions in the air, causing forest fires. Nowhere Wood is a dangerous place to be, sometimes.

 

 

The animals are using the oxygen to grown large: some millipedes are 1.5 metres in length and 0.5 metres wide. Some dragonflies have 70 cm wingspans.

 

 

 With all of this food available, there are opportunities for new  carnivorous lizards to appear, including Hylonomus. This is one of the first creatures to have a new  eggs with membranes inside, a characteristic later shown by all birds.

 

 Also the flesh-eating Anthracosaurs first appeared at this time. These are the direct ancestors of the dinosaurs, that appeared millions of years later.

In Nowhere Wood, everything is connected together, in space and in time.

 

So many adventures in space and time, so much opportunity for the evolution of new forms. All of which depends on the formation of sandstone in Nowhere Wood.

  1. Imagine what it was like to live in Nowhere Wood 300 million years ago. What would be the same and what would be different.
  2. How do you think the world will change in the future?

Safety in numbers

Time travellers to Nowhere (2)

We are not alone in Nowhere Wood, about 300 million years ago. We are deep in a forest of tree ferns, towering above us, fifteen metres high. The damp air has a sweet and woody fragrance, heavy with spores, heavy with promise.

 

The plants are silently photosynthesising, growing ever taller and adding oxygen to the air. Year after year, generation after generation.

 

The wood in the tree stems is a new invention of evolution: no other plants have wood and fungi have yet to discover a way to eat it. This means that when the trees die and fall into the swampy wet soil, they do not decay, but stayed for thousands of years, gradually becoming compressed together to form deposits of coal.

The tree ferns took carbon dioxide from the air and locked it away as wood and coal. They took so much and the amount of carbon dioxide in the air fell so much, that the  climate cooled, lead to the destruction of the tropical forests.

Today, humans have found the coal and burned it, putting the hidden carbon dioxide back into the air, re-warming the planet. No we face a global warming, not a global cooling. Perhaps, one day, Nowhere Wood will be destroyed for a second time.

  1. Think about how interconnected the rocks, the trees, the atmosphere and the climate are. How does a change to one thing affect everything else?
  2. Ferns are the first group of plants to develop proper roots. Think about why it would be an advantage for the early tree ferns to grow into sandstone.

Back then, the tree ferns grew through sandstone much as the smaller ferns in Nowhere Wood do today. Read more about this in another story: Climbing the walls.

Time travellers to Nowhere (3)

Time travellers to Nowhere (1)

Imagine you had a time machine, where and when would you go? Come with me back to Nowhere Wood, about 300 million years ago. That is long before humans, mammals or even dinosaurs existed, but frogs laid their eggs in pools, much as they do today. Today it is hot, humid and very quiet: with no birdsong or animal noise, apart from the distant croaking of frogs. Tomorrow, there will be a raging tropical storm and the mountain will be pounded by its violence.

Nowhere Wood is located just above the equator, and we are looking up at the aftermath of a series of global catastrophes, which has taken hundreds of million years to happen. Two continents collided and sent shockwaves through the land, pushing upwards to form the mountains that we can see ahead of us. We are in a valley, downstream from a range of tall mountain peaks.

The mountain rock is soft and is easily weathered by the stormy wind and rain. Cascades of small, eroded particles surge down the mountain slopes, transported in the muddy river waters.

Mountains become tiny grains of sand settling at the bottom of the smaller streams running through Nowhere Wood. Layers upon layers of sediment are depositing in the streams, blocking the channels. Over time, the increasing weight of sand squeezes the water out, cementing the grains together to form sandstone. These are the cliffs we can see today at the far end of Nowhere Wood. It is called Pennant sandstone and was quarried to make roof tiles for the people of the town.

 

  1. It is easy to think of living organisms having uncertain adventures through time and space. But the same is true of rocks, although on a much larger time scale. Find out where the matter that makes up planet Earth originally came from.
  2. Think about what has happened to the sandstone in Nowhere Wood since it was formed.

Time travellers to Nowhere (2)

Early risers!

Every year, the snowdrop is the first plant to flower in Nowhere Wood. It is a symbol of the birth of Spring, bringing good cheer and hope at the end of a long winter. This is one reason why people plant snowdrops in their gardens.

Snowdrops are tougher than they look: they can grow through ice and snow. Their leaves have hardened edges that act as snowploughs and their cells contain a snowdrop antifreeze that stops ice crystals forming. The real secret of the snowdrop’s success is found below the ground, in the frozen soil. There, in the darkness, is a bulb, full of food made in last Spring’s photosynthesis. Like a battery, it is an energy store, so that the plant can start to grow in the weak winter sunshine.

This means that the plant can make leaves to grow in the warming Sun. The leaves make food to store in its bulbs ready for next year. Snowdrops do all of this before the leaves of the big trees open to steal the light, so that the floor of the wood becomes shaded. By then, the work of the snowdrop is over and it can wait for the next winter.

1. How have people helped the snowdrop to survive for so many years?

2. What advantages do snowdrops have by storing their food in underground bulbs. Can you think of any possible disadvantages?

Snowdrops have many more secrets that help them in their adventures in time and in space. We may tell more stories about snowdrops in the coming days! Come back to read them.

Time travellers to Nowhere (1)

The singing trees

ice freezes the pondWinter has come to Nowhere Wood and ice has formed around the fallen trees in the pond. Everything shivers and wood is silent again. Squirrels search for food in the frozen mud, but everything else is waiting, biding its time.

 

 

 

Silent, except for an ancient overgrown hedge formed from a row of old trees, bound together into a thicket by generations of bramble stems. These trees are singing, for this is the home of the tree sparrows. The trees are just outside the wood, next to a path much used by dogs taking their owners for a daily walk.

 

 

 

The tree sparrows are warm, protected from the icy wind by the layers of dead branches that surround them. Impenetrable, they are hidden amongst the branches, out of harm’s way. In this forgotten place, they thrive and they sing.

 

Well not quite forgotten. In the garden of a house, less than 10 metres from the singing trees, is a garden with a bird feeder, filled daily by its residents. The sparrows dart from the hedge to the feeder and then back again, hour after hour, making sure they do not go hungry.

 

Small acts of kindness can make a big difference to the birds in Nowhere Wood. These ancient hedges are important, too, as wildlife corridors, joining ancient woodlands together, giving animals a chance to move safely across the landscape.

  1. Why are the ancient hedges such a good place for the tree sparrows to live?
  2. Why are bird feeders so important in the winter months?

A year in the life of a sugar factory

The leaves of plants are everywhere in Nowhere Wood, helping to keep the wood alive. Leaves are organs: collections of living tissues and cells, having adventures in time and space. This is the story of a year in the life of an oak leaf.

Leaves are factories for making sugar from sunlight, water and carbon dioxide from the air. No human factory can do this, which is why we, and all other organisms, are so dependent on plants. Leaves are the producers of food.

In is late November and the cells that will divide to make the new leaf are protected safely inside the scales of the bud. Early in March, when the days warm and get longer, stem cells within the bud start to divide many times, producing all of the cells of the new leaf. To start with, the cells are very small and all look the same.

Soon, the cells take up water and get much larger. They escape the protection of the bud and the new leaf emerges. The new cells no longer look the same: they are on different journeys of development, becoming all of the different cells and tissues that make up the leaf.

 

The leaf is a factory for making sugar. Like any factory, it has a source of energy and transport systems to get the raw materials into the factory.  It also moves the manufactured sugar out to the places in the plant where it is needed. The heart of the factory is the production line where sugar is made. These are called chloroplasts and the leaf has millions of them, all making sugar whenever the sun shines. The Spring and Summer are sugar making seasons.

Gradually, in the autumn, when the days get cooler and shorter, the sugar factories are shut down and abandoned. The chloroplasts lie in ruins as everything useful is recycled back into the branches of the tree. All that remain are the frameworks of cell walls, turning brown as they dry in the autumn air.

 

Finally, the oak tree makes a special layer of cells that separates the old leaf from the stem, and the leaf is ready to fall when the wind blows strongly. The fallen leaves are not wasted, becoming energy stores for the organisms that feed on them. Next year’s buds are forming and wait for spring and the production of new leaves.

If leaves are factories form making sugar, then trees are factories for making leaves.

Everything has its own season in Nowhere Wood.

  1. Think about how the leaf is a factory for making sugar. Where does its energy store come from? How do the raw materials get to the production line?
  2. The production of leaves is sustainable in Nowhere Wood. What do you think this sentence means?

Subterranean superheroes

Life is a relay race

This story continues the adventures of the ferns in Nowhere Wood. The first part of the story is Climbing the walls.

The genome of the fern contains essential information that the fern needs to grow and  make new cells. At different times the fern produces spores, sperm and eggs and the two forms of the plant. The genome contains information on the growth of each of these stages.

The information in the genome is the same in every cell of the fern because an identical copy of the genome is found inside the nuclei of all the cells of this fern at every stage of its life.

The genome is found in the nucleus of each cell.

The genome is divided between a number of chromosomes. The diagram shows the genome of the Adder’s tongue fern. It has about 1440 chromosomes. This is the largest number of chromosomes of any organism in the world!

Fern genomes are larger than the genomes of other organisms, because they contain the information the fern needs to grow spores, sperms and eggs as well as the two forms of plant.

The genome contains the secrets of how to be a fern and how to move forward in the adventure. This information has been copied and passed on to each generation of ferns, ever since the first ferns evolved about 390 million years ago.

 

 

Life is like a relay race: genetic information is passed on from one generation to the next in the genomes of sperms, eggs and other gametes.

These ferns are having risky and uncertain adventures in time as well as space. If the secret information is not passed on correctly, then the species may become extinct. History shows us that most species that have ever lived on Earth are now extinct.

    1. Why do you think it is essential that the genetic information from parents to offspring is copied accurately?
    2. Why do you think the fern genome is so large, compared with other types of plant?

All change!