Shop Windows to the Universe

Our Glaciers: Then and Now activity kit helps you see the changes taking place in glaciers around the world. See all our activity kits and classroom activities.
Eriophyllum lanosum, one of the desert winter annuals that Larry Venable, an ecologist at the University of Arizona in Tucson, and his collaborators monitored for 26 years. The photo was taken in March 2008.
Click on image for full size
Image Courtesy of Jonathon Horst

Even in the Desert, Plants Feel the Heat of Global Warming

Scientists who study plants in the Sonoran Desert are worried about global warming.

While desert winters have become warmer and drier over the years, climate changes have pushed the arrival of winter rains later in the winter season, forcing some winter annual plants to come out when temperatures are colder.

In 1982, Larry Venable, an ecologist at the University of Arizona (UA) in Tucson, began an investigation on "bet-hedging" in plants. Bet-hedging is an adaptation seeds make that allows them to remain dormant for a period of time if conditions in the environment make germination and survival less likely. This delay can be caused by lack of rainfall, lack of nutrients, temperatures that are too hot or too cold, or any other condition that would affect the survival of a seed. Bet-hedging allows a plant to improve chances of survival.

The later arrival of Sonoran desert winter rains pushes the germination of the winter annuals later into the year and has affected the types of winter annuals that do well there. Researchers measure carbon and nitrogen in the plants' leaves to learn how well the various species grow at winter's lower temperatures. The amount of carbon in a plant's leaves tells scientists how well a plant has adapted to water storage in cold weather. Higher amounts of nitrogen can mean that the plant is better at gathering light in cold weather and is better able to photosynthesize.

If plants are better at photosynthesis, they are more able to use energy from sunlight and convert it into food, which improves the plant's chances for survival. They also found that plants that are better at storing water do better in colder environments.

If the later arrival of winter rains continues, the germination of the winter annuals will continue to occur later in the year, and the plant community will continuously change and favor plants that do well in colder environments.

Last modified May 12, 2010 by Becca Hatheway.

Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Effects of Climate Change Today

Over 100 years ago, people worldwide began burning more coal and oil for homes, factories, and transportation. Burning these fossil fuels releases carbon dioxide and other greenhouse gases into the atmosphere....more

Rain

Rain is precipitation that falls to the Earth in drops of 5mm or more in diameter according to the US National Weather Service. Virga is rain that evaporates before reaching the ground. Raindrops form...more

Nitrogen

There is more nitrogen gas in the air than any other kind of gas. About 4/5ths of Earth's atmosphere is nitrogen gas! A molecule of nitrogen gas is made up of two nitrogen atoms. There are other molecules...more

Photosynthesis

Photosynthesis is the name of the process by which autotrophs (self-feeders) convert water, carbon dioxide, and solar energy into sugars and oxygen. It is a complex chemical process by which plants and...more

Triggers of Volcanic Eruptions in Oregon's Mount Hood Investigated

Scientists have learned that Mount Hood, Oregon's tallest mountain, has erupted in the past due to the mixing of two different types of magma. "The data will help give us a better road map to what a future...more

Oldest Earth Mantle Reservoir Discovered

The Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core, and makes up about 84 percent of the Earth's volume. The mantle is made up of many distinct portions or...more

Its Not Your Fault A Typical Fault, Geologically Speaking, That Is

Some geologic faults that appear strong and stable, slip and slide like weak faults, causing earthquakes. Scientists have been looking at one of these faults in a new way to figure out why. In theory,...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA