Seasons and Living Things

Introduction: Let's explore the connection between seasons and living things!

Hello! Let’s learn all about "Seasons and Living Things," a topic you'll be studying in your 4th-grade science class. Around us, we have the four seasons: spring, summer, autumn, and winter. As the seasons change, the temperature changes too. Interestingly, this causes the appearance and behavior of plants and animals to change drastically.
Let’s solve questions like, "Why do insects disappear in winter?" and "Why do cherry blossoms bloom in spring?" as we peek into the resilient ways living things survive!
You might feel like there’s a lot to memorize at first, but don't worry. Just think about the nature around you and try to relax as you read through these notes.

1. Spring: The season when life awakens

As the winter chill eases and the temperature rises, living things all start to become active at once.

Plants in spring

Spring is the season of "beginnings."

• Cherry blossoms: The flowers bloom first, and then the leaves appear.
• Sprouting: Plants that were holding on through the winter begin to sprout.
• Sowing seeds: This is the perfect time to plant seeds for things like luffas and sunflowers.

Animals in spring

• Waking from hibernation: Frogs, snakes, and other creatures emerge from the ground.
• Birth of insects: Cabbage white butterflies emerge from their chrysalises, and larvae hatch from eggs.

【Key Point】
The keyword for spring is "rising temperature." Getting warmer is the signal for living things to "wake up!"

2. Summer: The season of rapid growth

This is the season when the temperature is at its highest all year. Bathed in plenty of sunlight, living things become at their most powerful.

Plants in summer

• Luffas and sunflowers: Their stems get thicker and they grow tall very quickly. The number of leaves increases, and the leaves themselves grow larger.
• Flowers and fruit: They bloom with many flowers and begin to produce fruit.

Animals in summer

• Insect activity: Cicadas sing, and rhinoceros beetles and stag beetles move around energetically.
• Foraging: This is the time when living things are most active in searching for food.

【Did you know?】
Luffa leaves spread out wide in the summer so they can soak up as much sunlight as possible to make energy for growing!

【Common Misconception】
People often think, "The hotter it is, the happier plants are," but if there isn't enough rain or the temperature gets too high, plants can wilt and sag. They’re just like us humans!

3. Autumn: The season of preparing for winter

The temperature gradually drops, and the days get shorter. Living things begin to prepare to survive the harsh winter ahead.

Plants in autumn

• Autumn colors: The leaves of cherry and maple trees turn red or yellow.
• Falling leaves: Trees shed their leaves to avoid wasting water.
• Seeds and fruit: To pass life on to the next generation, plants produce plenty of seeds and fruit (this is also when luffas dry out and turn brown, producing seeds).

Animals in autumn

• Preparing for winter: Mantises lay eggs, and bears eat plenty of food to store up fat.
• Migratory birds: Swallows and other birds begin their journey to warmer southern countries.

【Key Point Summary】
Autumn is the season of "preparation to sustain life." Producing seeds and laying eggs is essential.

4. Winter: The season of waiting and enduring

The temperature drops significantly, and it becomes hard to see signs of living things. But they haven't died!

Plants in winter

• Winter buds: At the tips of tree branches, there are "winter buds"—tiny buds wrapped in hard shells. Inside, the flowers and leaves that will bloom in spring are waiting for their turn.
• Under the withered grass: Even if the parts above the ground have withered, many plants have roots that remain alive underground.

Animals in winter

• Hibernation: Frogs, snakes, and bears stay still and sleep to conserve energy.
• Eggs and pupae: Many insects spend the winter in the form of eggs or pupae, enduring the cold.

【Analogy】
Living things in winter are like a "battery that is charging." They may look like they aren't doing anything from the outside, but they are storing up power to move at 100% when spring arrives.

5. Summary of the Year: The relationship between temperature and living things

Have you noticed a pattern after looking at all of this? The year for living things is always linked to "changes in temperature."

【Summary Diagram】
Spring: Temperature rises = Start of activity!
Summer: Temperature is high = Rapid growth!
Autumn: Temperature drops = Preparing for winter!
Winter: Temperature is low = Waiting and enduring.

【Final Advice for Studying】
On science tests, you will often see questions that ask you to compare how a plant looks in different seasons, such as, "What does this plant look like in the summer?" or "How does it spend the winter?"
Try looking closely at the pictures in your textbook and practicing spotting the differences by asking, "What about the color of the leaves?" or "What about the size?"
The best way to learn is to actually go outside and observe one living thing in the current season!