Understanding and saving the biocrust, Earth's living skin
The planet's protective layer is being destroyed
Many parts of Earth are covered and protected by a layer of organisms called a biocrust. The layer acts as a skin for the Earth, protecting landscapes and reducing long-term damage. But climate change and human activities are harming the biocrust, and the crucial layer takes a long time to restore. This could have problematic long-term implications for several ecosystems and even human structures.
What is the biocrust?
Biocrust, also called cryptobiotic soil, is a "community of tiny, dirt-dwelling organisms that form a distinct crust on the top of soil in arid landscapes," said Knowable Magazine. It covers approximately 12% of the Earth's surface and can play a vital role, especially in dry ecosystems, by preventing soil erosion and helping to retain water. Biocrust "often looks like a discolored patch of ground" and "upon closer inspection, the stain becomes a mosaic of small, dark lumps, dotted with tiny beds of moss and inconspicuous patches of lichen." Sometimes biocrust can be hard to identify as it can also appear as crusty soil.
Scientists recently discovered that biocrust can appear on manmade structures as well and not just as part of the natural ecosystem. One of the reason's for the Great Wall of China's longevity is its biocrust protection. "Compared with bare rammed earth, the cyanobacteria, moss and lichen biocrust-covered sections of the Great Wall exhibited reduced porosity, water-holding capacity, erodibility and salinity by up to 48%, while increasing compressive strength, penetration resistance, shear strength and aggregate stability by up to 321%," said CNN.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
Ecologically important, biocrust also takes a long time to be restored once destroyed. "When the biocrust is gone, it leaves behind a surface layer of exposed, loose dust that can feed dust storms," said Arizona State University News. "It can take decades for biocrust to grow back on its own and gain enough ground to suppress that dust once more." The current problem is that biocrust is being destroyed much faster than it once was.
Why is biocrust in danger?
Climate change and human activity are causing the destruction of biocrust. "Over the next 65 years, models suggest that climate change could slash 25% to 40% of biocrust cover," said Knowable Magazine. "The crusts are sensitive to higher temperatures and to fluctuations in precipitation — both extended dry spells and unusual increases in rainfall can harm them, depending on their location." Activities like farming and development also disrupt the biocrust. To combat this, scientists are trying to grow biocrust in the wild.
The two main complications in regrowing biocrust are determining where it grows best and where it can be transferred from effectively. If the biocrust is grown in a controlled environment, it still needs to be portable and eventually settle into the wild. Also, "biocrust is totipotent, which means just a small piece of it can eventually give rise to new crust," said Knowable Magazine. "Thus, one way of growing biocrusts in new areas is to crumble some up and sprinkle it on the landscape, similar to scattering seeds."
An existing biocrust community could be key in aiding regrowth. "We put [biocrust] out in these harsh environments, kind of alone, and say, 'Live, thrive,'" Sasha Reed, an ecologist at the United States Geological Survey, who is leading the research, said to the magazine. "We're not seeing it do that as much as we would hope."
However, one boon of microorganisms is their resilience. "Although they are still vulnerable to the impacts of climate change, these constantly evolving organisms are expected to deploy internal mechanisms to adapt to future extremes," said CNN.
Create an account with the same email registered to your subscription to unlock access.
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Devika Rao has worked as a staff writer at The Week since 2022, covering science, the environment, climate and business. She previously worked as a policy associate for a nonprofit organization advocating for environmental action from a business perspective.
-
7 cocktails for a comforting autumn
The Week Recommends Vodka, rum, brandy, mezcal: The gang's all here
By Scott Hocker, The Week US Published
-
Texas court allows execution in shaken baby syndrome case
Under the radar The state could be the first to carry out the death penalty for someone convicted due to the diagnosis, despite its controversial applicability
By Theara Coleman, The Week US Published
-
How do presidential elections affect the stock market?
The explainer If you are worried, take heart: Market changes in response to what is happening politically are likely to be short-term
By Becca Stanek, The Week US Published
-
Dozens dead in Vietnam after 'worst typhoon' in 30 years
At least 58 people are dead and hundreds are missing after Typhoon Yagi made landfall
By Rafi Schwartz, The Week US Published
-
5 of the most invasive plant species in the world
Under the Radar Invasive plants threaten biodiversity
By Devika Rao, The Week US Published
-
Scientists want to zap coastlines with electricity
Under the Radar Beaches are in for a shock
By Devika Rao, The Week US Published
-
The economic cost of the wildfire season
The Explainer Wildfires are exacting an 'eye-popping' financial toll for communities in fire-prone areas and beyond
By Abby Wilson Published
-
The Arctic is a ticking 'mercury bomb'
Under the Radar An icy prison break is on the way
By Devika Rao, The Week US Published
-
Bananas have been facing extinction. But maybe not for much longer.
under the radar Scientists may have a solution for a longstanding fungus problem
By Devika Rao, The Week US Published
-
Homeowners are getting burned by solar panel scammers
In Depth One-star reviews for solar companies have increased over 1,000% since 2018
By Justin Klawans, The Week US Published
-
China's winning battle against desertification
Under The Radar Beijing is using solar power to lead the fight as climate change intensifies the threat
By Chas Newkey-Burden, The Week UK Published