True or false, grass is better at storing carbon than trees.
Hmm… trees store more carbon per plant than grass does, but a tree takes up a lot of space. You can get a lot more grass stems in a given area than you can trees, so the question goes to an area of trees or grass. So, forests or prairies, which one pulls in more carbon and locks it down forever?
When a plant dies, it’s carbon is released to the environment. The advantage of trees is they can live for centuries, packing more carbon dioxide into their ever-expanding trunks and constantly regenerating leaves and needles adding carbon to the forest floor. One of the big reasons we protect our forests is to keep all the carbon they hold from being released.
There’s a problem with trees, though. Their carbon is stored mostly above ground in their trunks, limbs and leaves. When they die, all that carbon returns to the atmosphere. Which isn’t a problem in a stable climate, but with our forests becoming increasingly threatened by wildfire, the status of a forest area as a carbon sink or carbon source depends on how much of it has been on fire lately.
Grass, on the other hand, stores its carbon underground. If you’re used to thinking of grass as a lawn, you might not realize that the larger part of a grass plant is underground, in its roots. So, when a prairie fire hits, some carbon is released, but most of it remains in the soil.
We can see how a prairie becomes a forest in the process of regeneration a forest undergoes after it has burned off. The vegetation returns in stages.
Wildflowers are the first to arrive… because nature is heavenly and wildflowers are the best choice to quickly restore beauty and hope! ☺️
In more scientific terms, these “ephemeral” or “pioneer” plants, commonly known as “weeds,” the seeds of which are always blowing around, take root in the char-coaled earth of a devastated forest. Their roots draw nutrients out of the soil, and when they die, for they are short-lived, these nutrients are deposited on the ground.
The seeds and fruit of these species feed the insects, rodents and birds who return after the fire. These critters draw in larger animals, and they all go merrily along eating and spreading nutrients until a good topsoil is reestablished.
Grass is the next to take root. It grows tall, providing shade and shelter for other plants and animals, allowing them to flourish, creating a rich tapestry of vegetation in support of a diverse wildlife population.
Among the new vegetation, where water is plentiful enough to support trees, low, scrubby ones are the first to thrive, ones that grow well in full sun. They shade out the grass, making room for bigger trees to grow and develop a forest ecosystem.
Land that is too dry for trees remains as grasslands. Land where forests have burned off due to drought may return to the grass stage, or degrade further and succumb to soil erosion, tipping the land toward desertification.
With most of the grasslands’ carbon tucked safely underground, other than erosion, about the only way to get it out is to dig it up. Tragically, our grasslands are under attack by a nasty, quickly spreading parasite doing just that.
Known in the scientific community as homo sapiens, this bug tears into the earth using gigantic, diesel-fueled claws, ripping up centuries-old root beds and replacing them with shallow-rooted vegetable plants, which the parasite returns later to snatch out of the ground at the peak of the growing cycle.
The destruction has been catastrophic:
“More than 70 percent of America’s prairies have been destroyed. In the Great Plains, 10 million acres of grasslands were lost between 2016 and 2020, and another 1.8 million acres were lost in 2020 alone—plowed primarily for row crop agriculture.” –World Wildlife Fund
Overgrazing, too. That’ll mess up a grassland. Overgrazing happens when a grassland is taxed with meeting the demands of some remote economic system rather than the requirements of its own health and productivity. Overgrazing destroys biodiversity and biomass while spreading invasive species, which leads to soil erosion and desertification.
And climate change. As the homo sapien population grows, increasingly imposing its food production demands on grasslands, climate change is quickly drying them out. Decreased rainfall interspersed with torrential gully-washers erode and wash away the topsoil, threatening irretrievable loss of these precious lands.
Photos by Lee R. DeHaan, Rich Martello, US Fish and Wildlife Service‘s Rick Bohn, Gannon Castle, Greg Kramos, Eric Cole, Ryan Hagerty, K. Theule, Jason Leung and Sabine Krafczyk, seif eddine kharrachi, Spencer DeMera, Evan Wise
