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.

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

Larry Venable, an ecologist at the University of Arizona (UA) in Tucson, has been studying something called "bet-hedging" in plants. Bet-hedging is an adaptation seeds make to help them survive when conditions in the environment aren't good. The seeds delay their germination until the conditions are better. 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.

Researchers measure carbon and nitrogen in the plants' leaves to learn how well the different 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.

Last modified May 12, 2010 by Becca Hatheway.

You might also be interested in:

Cool It! Game

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

Effects of Climate Change Today

Have you ever taken your temperature to see if you are getting sick? Scientists have been taking the Earth's temperature and have found that it is getting warmer. During the past 100 years, the Earth's...more

Rain

Raindrops form when tiny water droplets collide together in clouds to form bigger ones. When they get too heavy, rain falls out of the clouds. Rain is more than 5mm in diameter. The types of clouds that...more

Nitrogen

There is more nitrogen gas in the air than any other kind of gas. About four out of five of the molecules in Earth's atmosphere is nitrogen gas! A molecule of nitrogen gas is made up of two nitrogen atoms....more

Photosynthesis

There are many different kinds of plants. Some have big leaves. Some have small leaves. Some even have flowers. All plants make their own food. When sunlight hits the leaves of a plant, photosynthesis...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. Adam Kent, a geologist at Oregon State University, says this...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. The mantle is made up of many different reservoirs that have different chemical compositions. Scientists...more

It’s Not Your Fault – A Typical Fault, Geologically Speaking, That Is

Some faults look strong and like they wouldn’t cause an earthquake. But it turns out that they can slip and slide like weak faults causing earthquakes. Scientists have been looking at one of these faults...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