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Plants & Climate Change

Plant Response to Natural Climate Change

By studying the plant pollen found in sediments deposited in lakes and bogs, scientists have mapped the distribution (location and relative population) of plant species in North America as climate has warmed from the end of the most recent Ice Age.

In the movie below, spruce trees, which thrive in cooler climates, advance northward as the ice sheets (light blue) and the region of favorable growing conditions retreat poleward. The trees are not moving on their own, rather the scattering of their seeds allow new trees to grow in areas that best suite the spruce. The trees growing in unfavorable climate conditions die.

This is one of the concerns of human-induced climate change: Will climate conditions move too quickly for plants to keep up by seed redistribution? If this happens, entire populations of plant species would be lost.

Spruce tree pollen distribution for past 21,000 years

 Color Key

Light Blue
Light Gray
0-5% of plants in area are spruce trees
Light Green
5-20% of plants are spruce
Medium Green
20-40% spruce
Dark Green
40-100% spruce
Areas with No Data

To view the redistribution of more than 50 species of plants over the past 21,000 years, visit Pollen Viewer. Data and imagery provided by Williams, J.W., B.N. Shuman, T. Webb III, P.J. Bartlein, P.L. Leduc, 2004, Late Quaternary vegetation dynamics in North America: scaling from taxa to biomes, Ecological Monographs, 74:309-334.

Guided activities using these maps and the software, AnalyzingDigitalImages, are being developed so vegetation change within regions may be calculated for each millennia. (Under Development)