Name________________________
How do paleobotanists use ancient pollen to find out about the Earth's climatic past?
This activity is based on actual pollen data collected from a lake in southwest Washington State. You will analyze sediment samples with other material mixed in to represent pollen grains and determine the type and amount of the "pollen" in the samples. From this information ,you will determine the type of vegetation and age of the samples and will present conclusions about the likely climate at the time the pollen was shed.
What You Need:
What You Do:
Observations and Questions:
Pollen Key
Code | Color and Shape | Plant Species | Climatic Characteristics |
---|---|---|---|
A | Western Hemlock | Principal dominant tree of many lowland, temperate sites. Requires very moist, temperate conditions for growth. | |
B | Douglas Fir | Prefers moderately cool to warm sites. Grows best under temperate, somewhat moist conditions. | |
C | grasses and sedges | These grasses and sedges are typically found in very cool alpine/subalpine meadow sites characterized by very cool summers, harsh winters, and short growing seasons. | |
D | Alder | Widespread throughout the Pacific Northwest, prefers abundant water and can grow in cool climates. | |
E | Grand Fir | Grows in cool climates, but not as cold tolerant as trees found at higher altitudes. | |
F | Engelmann Spruce | Found in cold, usually sub-alpine sites. | |
G | Western Cedar | Found only in temperate, very moist climates. | |
H | Lodgepole Pine | Found in areas of very cool climates typically growing on poor soils, often at high altitudes (above 3,500 feet) under the present climate. | |
I | mixed meadow species | This pollen is from a mixture of plants common to warm meadowlands. Typically, these species grow in areas of warm summer temperatures and summer drought. | |
J | Oak | Found in warm-temperate sites characterized by dry, warm summers. | |
K | Alpine Sagebrush | Woody, low-growing shrub that's found only at high-altitude, cold sites. |
Data Table
Sediment Layer | |||||
---|---|---|---|---|---|
Plant Species | 1 | 2 | 3 | 4 | 5 |
Western Hemlock | |||||
Douglas Fir | |||||
grasses and sedges | |||||
Alder | |||||
Grand Fir | |||||
Engelmann Spruce | |||||
Western Cedar | |||||
Lodgepole Pine | |||||
mixed meadow species | |||||
Oak | |||||
Alpine Sagebrush |