eco-briefs

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MAKING IT RAIN 

Most Western states have tried “cloud seeding,” injecting clouds with silver iodide to produce precipitation, at some point. However, there’s never been any consensus in the scientific community about how well the process actually works.

In 2008, the Wyoming Weather Modification Pilot Project embarked on a $13 million endeavor to study snowfall created from cloud seeding over the course of six winters in southern Wyoming. The project recently released an initial 16-page summary report of their findings, which suggest that during ideal conditions, a seeded cloud can produce between 5 to 15 percent more precipitation, making it a viable way to supplement existing water supplies. They also found that the process has negligible environmental effects and almost no influence on precipitation in surrounding areas.

The project used ground-based seeding generators on the Wind River, Sierra Madre and Medicine Bow mountain ranges in Wyoming. Scientists studied orographic clouds that form over mountains. Working independently from the state and the cloud-seeding operator, National Center for Atmospheric Research scientists interpreted the data.

But not all scientists are convinced that cloud seeding is the answer to Western water woes. That 5 to 15 percent increase in rain only occurs in clouds that have “ideal” conditions, like temperature, moisture and wind speed.

A full report on the Wyoming Weather Modification Pilot Project is expected to publish in May 2015.

— Caitlin Rockett

COPING WITH CLIMATE CHANGE 

Researchers at Dartmouth College have found that a Rocky Mountain mustard plant alters its physical appearance and flowering time in response to changing environmental conditions. The findings, which were published in the journal Global Change Biology, suggest that some species can quickly change shape to cope with climate change without having to migrate or evolve.

The “shape-shifting” phenomenon is known scientifically as phenotypic plasticity — a process by which an organism can look different without changing its genetic code.

“Because climate change affects some environmental factors like precipitation and temperature but not others like day length, phenotypic plasticity could allow some species to persist in a habitat despite changing conditions and provide more time for them to evolve and migrate,” co-author Zachariah Gezon, a PhD student in Ecology and Evolutionary Biology at Dartmouth, said in a press release about the study.

Researchers are still unclear on whether physical shape shifting will reduce the probability of extinction under climate change. While phenotypic plasticity could give some species more time to evolve or migrate, it could also cause some species to physically change in ways that reduce their biological fitness and hinder their ability to adapt to climate change.

— Caitlin Rockett