Login

GPC Members Login
If you have any problems or have forgotten your login please contact [email protected]


Incomplete drought recovery may be the new normal

The amount of time it takes for an ecosystem to recover from a drought is an important measure of a drought's severity. During the 20th century, the total area of land affected by drought increased, and longer recovery times became more common, according to new research published by Nature by a group of scientists including Carnegie's Anna Michalak and Yuanyuan Fang.

Scientists predict that more-severe droughts will occur with greater frequency in the 21st century, so understanding how ecosystems return to normal again will be crucial to preparing for the future. However, the factors that influence drought recovery have been largely unknown until now.

"Research has usually focused on the amount of rain and other precipitation that ends the deficit of water that causes a drought, but assessments of drought-recovery need to account for the restoration of normal plant function," explained Michalak.

The team -- including three other alumni of Carnegie Global Ecology research groups William Anderegg (University of Utah), Adam Wolf (Arable Labs Inc.), and Deborah Huntzinger (Northern Arizona University) -- used measures of photosynthetic activity to assess drought recovery. Quantifying how long it took for plant productivity to return to normal gave the researchers a better understanding of the longevity of a drought's effects.

"If another drought arrives before trees and other plants have recovered from the last one, the ecosystem can reach a 'tipping point' where the plants' ability to function normally is permanently affected," Fang said.

The conditions most-strongly contributing to drought recovery time were precipitation and temperature, they found. Unsurprisingly, better conditions shortened recovery. Temperature extremes, both hot and cold, lengthened it.

Recovery took the longest in the tropics, particularly the Amazon and Indonesia, and in the far north, especially Alaska and the far east of Russia.

Other factors influencing drought recovery included pre-drought photosynthetic activity, carbon dioxide concentrations, and biodiversity.

The team found that drought impacts increased over the 20th century. Given anticipated 21st century changes in temperature and projected increases in drought frequency and severity due to climate change, their findings suggest that recovery times will be slower in the future. A chronic state of incomplete drought recovery may be the new normal for the remainder of the 21st century and the risk of reaching "tipping points" that result in widespread tree deaths may be greater going forward, they say.

Read the paper: Global patterns of drought recovery.

Article source: Carnegie Institution for Science.

Image credit: William and Leander Anderegg

News

New 'Buck' naked barley: Food, feed, brew

Researchers at Oregon State University (OSU) are giving an ancient grain a new life: this barley is naked, but not in an indecent way.


Clean and green: A moss that removes lead (Pb) from water

Researchers at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan have demonstrated that that moss can be a green alternative for decontaminating polluted water and soil. Published in PLOS One, the study shows that in particular, the moss Funaria hygrometrica tolerates and absorbs an impressive amount of lead (Pb) from water.


New study shows producers where and how to grow cellulosic biofuel crops

According to a recent ruling by the United States Environmental Protection Agency, 288 million gallons of cellulosic biofuel must be blended into the U.S. gasoline supply in 2018. Although this figure is down slightly from last year, the industry is still growing at a modest pace. However, until now, producers have had to rely on incomplete information and unrealistic, small-scale studies in guiding their decisions about which feedstocks to grow, and where. A new multi-institution report provides practical agronomic data for five cellulosic feedstocks, which could improve adoption and increase production across the country.