1 of 13

CLIMATE CHANGE AND MICHIGAN FORESTS

Climate and Plant Growth

Lesson 6

2 of 13

What is the difference between

weather & climate?

3 of 13

Weather is the state of the atmosphere at a particular time and place.

Climate is the average weather patterns of a region over a long period of time.

What is the difference between

weather & climate?

4 of 13

How does climate determine

where and when plants grow?

5 of 13

Photosynthesis requires specific precipitation and temperature conditions.
Photosynthesis is the process by which plants build new cells and grow.

How does climate determine

where and when plants grow?

First, remember that temperature and precipitation are the two major components of climate. Plants grow best in the right temperature and with the right amount of precipitation. This is because photosynthesis requires specific precipitation and temperature to occur.

[Worksheet Q2: precipitation and temperature]

OPTIONAL REVIEW:

Precipitation - Plants need water to grow because photosynthesis requires water. Up to a point, the more water plants get, the more they can grow. If water is too scarce, plants cannot make food from sunlight and grow. Water also gives plants their shape. Lack of water causes plants to wilt. Too much precipitation can also be harmful to plants. This promotes disease and prevents trees from absorbing nutrients from the soil.
Temperature - Warmer temperatures make photosynthesis occur faster. Generally, as temperature increases plants grow faster. However, extreme temperatures (hot and cold) can damage plant tissues.

OPTIONAL

Indirect Effects – Temperature affects the amount of water plants access. Low temperatures freeze water in the ground and plants cannot access it. High temperatures evaporate water, making it scarce. In this way, temperature indirectly impacts plant growth by impacting water availability. This is called an “indirect effect.”

6 of 13

What is a “growing season”?

7 of 13

The time of year in which the climate allows plant growth to occur.

What is a “growing season”?

8 of 13

How do plants survive such different climates?

How do plants survive different climates? Accept student answers. Over time, plants adapt to live in a specific geographic range. Adaptations are structures or functions that help a plant or animal survive in their environment.

Plants can only survive where their adaptations match the environmental conditions.

Example 1 – Cacti are adapted to live in deserts. This means they have the right structures to allow them to survive there. Deserts are very dry. When it rains, cacti store the scare water in their thick fleshy bodies which also have a waxy exterior that keeps water in. Instead of leaves, which lose a lot of water to evaporation, cacti have spines which don’t. The spines also protect cacti from herbivores seeking moisture.

Example 2 – White spruce trees are adapted to live in northern coniferous forests. They survive cold winters by dropping leaves and going dormant. However, a white spruce tree wouldn’t survive in a desert environment.

9 of 13

What is a biome?

10 of 13

What is a climograph?

Average

This is a climograph, short for climate graph. A climograph shows average annual temperature and precipitation data for a specific geographic location. What variable is shown on the x-axis? (Answer: time in months) What about the y-axis? (Answer: Precipitation in inches + temperature in degrees Fahrenheit). This graph is a little complex because there are is a y-axis on both sides. On this climograph, precipitation data is the green bars and temperature data is the red line.

What geographic location do you think this climograph represents? Let’s think about the information provided. The temperature data shows pretty cold winters (about 20 degrees on average) and warm summers (about 75 degrees on average). Precipitation is pretty steady throughout the year. Where could this data be from? Accept student answers. This climograph shows the climate in Detroit, Michigan! Based on this climograph, when do you think plants grow best (the growing season) in lower Michigan? Accept student answers. The growing season for lower Michigan is typically April through September, when average temperatures are above freezing (freezing is 32 degrees Fahrenheit.

[Worksheet Q4: average annual temperature and precipitation data for a specific geographic location]

[Worksheet Q5: Detroit, MI]

OPTIONAL DISCUSSION QUESTIONS:

How can we use this climograph to estimate total annual (yearly) precipitation for Detroit, MI? (Answer: sum all the months’ precipitation)
What is the driest month in Detroit? (Answer: February)
During what months is the average temperature below freezing? (Answer: January, February, March and October, November, December)

11 of 13

CLIMOGRAPHS AND BIOMES ACTIVITY

A

B

C

D

E

Climograph	Biome
A	?
B	?
C	?
D	?
E	?

12 of 13

CLIMOGRAPHS AND BIOMES ACTIVITY

A

B

C

D

E

Climograph	Biome
A	?
B	?
C	?
D	?
E	?

Reproduce the table above on your chalkboard or dry erase board and fill in the correct answers as you go.

Let’s review your answers as a class. Which climographs were you sure about? Which were confusing? Accept student answers. Ask students to use the Biome Description Cards to back up the correct answers. Answers: A = Desert (Las Vegas, NV); B = Tropical rainforest (Hilo, HI); C = Northern coniferous forest (Sault St. Marie, MI); D = Tundra (Fairbanks, AK); E = Temperate deciduous forest (Detroit, MI)

Are the growing seasons in each biome different? Why or why not? What factor, precipitation or temperature, limits the growing seasons in each biome?

A) Desert: In deserts precipitation limits the growing season. Since rainfall is variable in the desert, the growing season is also variable. Plants can grow year-round when there is enough water. When water is scarce, plants stop or reduce their growth. After a rainstorm desert plants take advantage of the excess water and grow rapidly. This is why you may have noticed a desert looks a greener for a few days after a rain storm.

B) Tropical rainforest: In a tropical rainforest, neither temperature nor precipitation limit the growing season. Temperature doesn’t change a lot throughout the year. Precipitation is also high throughout the year, with only a slight decrease during the summer months. Therefore, rainforest plants grow year-round. In this case, other factors may limit plant growth (for instance nutrients in the soil).

C) Northern coniferous forest: In this biome, the growing season is limited by temperature. Remember from earlier today that very cold temperatures prevent plant growth in several ways. Photosynthesis needs heat to occur, and plants can’t acquire frozen water.

D) Tundra: In the tundra, the growing season is limited by temperature. The tundra climograph shows that temperature is below freezing. Plants in the tundra are specially adapted to surviving extremely cold temperatures.

E) Temperate deciduous forests: The growing season of temperate deciduous forests is limited by temperature for the reasons we have already discussed (see Northern coniferous forest answer).

13 of 13

How does climate change impact these biomes?