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Trees Are Growing Bigger | Earth Wise

November 3, 2022 By EarthWise Leave a Comment

The alarming rate of carbon dioxide flowing into the atmosphere is having a real and actually positive effect on plant life. Higher concentrations of carbon dioxide make plants more productive because photosynthesis makes use of the sun’s energy to synthesize sugar out of carbon dioxide and water. Plants make use of the sugar both as a source of energy and as the basic building block for growth. When carbon dioxide levels go up, plants can take it up faster, supercharging the rate of photosynthesis.

In a new study published in the journal Nature Communications, scientists at Ohio State University found that trees are feasting on decades of carbon dioxide emissions and are growing bigger as a result.

The researchers tracked wood volume in 10 different tree groups from 1997 to 2017 and found that all of them except aspens and birches grew larger. Over that time period, carbon dioxide levels climbed from 363 parts per million to 405 parts per million. According to the study, each 1% increase in lifetime CO₂ exposure for trees has led to more than a 1% increase in wood volume.

In the big picture, the news isn’t so positive. The global warming caused by increasing carbon dioxide levels increasingly threatens the forests of the world. It has led to worsening droughts, insect infestations, and wildfires. So overall, increasing levels of carbon dioxide are by no means a good thing for the world’s trees. However, since trees are growing bigger more quickly, it means that planting them is an increasingly cost-effective method for fighting climate change because the same number of trees can sequester more carbon.

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As Carbon Dioxide Grows More Abundant, Trees Are Growing Bigger, Study Finds

Photo, posted September 12, 2015, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rewilding The American West | Earth Wise

September 14, 2022 By EarthWise Leave a Comment

Oregon State University scientists have proposed a series of management changes for western federal lands aimed at re-establishing ecosystems there. Their proposal would result in more gray wolves and beavers in nearly 200,000 square miles of federal lands in 11 states.

In each of those states, the researchers identified areas containing prime wolf habitat. Gray wolves were hunted to near extinction in the West but have been gradually reintroduced in some areas starting in the 1990s. Wolf restoration offers significant ecological benefits by helping to naturally control the population of grazing animals such as elk. This in turn facilitates the regrowth of vegetation species such as aspen, which ultimately supports diverse plant and animal communities.

Beaver populations, which used to be robust across the West, declined roughly 90% after settler colonialism and are now nonexistent in many areas. By felling trees and shrubs and constructing dams, beavers enrich fish habitat, increase water and settlement retention, maintain water flows during droughts, and increase carbon sequestration.

According to the researchers, the biggest threat to these western lands is livestock grazing, which has degraded ecosystems to a great extent. They recommend the removal of grazing on about 30% of the federal lands being used for that purpose and instead would have rewilding efforts go on.

The American West is going through a period of converging crises including extended drought and water scarcity, extreme heat waves, massive fires, and loss of biodiversity. Rewilding is a way to reestablish long-standing ecosystems.

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More wolves, beavers needed as part of improving western United States habitats, scientists say

Photo, posted October 1, 2020, courtesy of Tina DaPuglet via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.