CHANGSHA, June 9 (Xinhua) -- In the city of Yuanjiang, central China's Hunan Province, local people are treating guests to their treasure -- tasty, nutritious and high-yield fungal edibles grown on reed residue, which have now become a local cash cow and environment savior.

These mushrooms have created an inspiring transition of the city, known as the "hometown of reeds."

For years, paper-making mills across China have been envious of their peers based around Dongting Lake, China's second-largest freshwater lake, for their inexhaustible reeds growing like wild grass in the wetlands.

As an alternative to timber, cost-efficient reeds provide perfect raw material for high-quality pulp and help curb deforestation at the same time.

However, with time, this enviable "natural endowment" turned out to be an ecological threat with production capacity upgraded at an unimaginable ecological cost -- the discharge of millions of gallons of toxic waste every year.

Papermaking had been a mainstay of the local economy until provincial authorities ordered a shutdown in 2018 of all paper and pulp mills around the lake by the end of 2019. This was amid an unprecedented nationwide ecological campaign.

It was a blessing for the lake, yet a disaster for workers, who found themselves laid off all of a sudden. Despite a government pledge to solve the problem of unemployment, few people wanted a brand-new job.

It was also "a fall from grace" for the reeds, of which 90 percent were abandoned ashore as they gradually lost their value. Worse still, rotten reed remnants were causing water eutrophication and impacting the lake biotope.

Who would be willing to clear away this ecological burden without getting paid? Local authorities had been racking their brains for years trying to explore an eco-friendly and economical way to utilize the reeds.

The silver lining came when Shi Yuelong, a local living and working in the reed fields for more than 30 years, came across a vast group of "little umbrellas," which looked like edible fungi, growing from rotten reeds on one rainy day.

"It was like a surprise encounter with a gem," Shi, now general manager of the mushroom-cultivating Hunan Guangya Company, recalled with excitement.

Without hesitation, he collected five or six types of these wild mushrooms and sent them to fungal biological institutes for identification and nutrient analysis.

"We've identified from these reed mushrooms three edible varieties for commercialization," said Wu Zhengkun, vice director of the Edible Fungi Research Institute at Hunan Agricultural University, pointing one-by-one at a white-colored spring mushroom, a mayonnaise-colored one and a bulbous fungus.

"These high-quality mushrooms are worthy of promotion, given the abundant reed resources here," Wu added.

Starting from 2017, Shi called upon several fungal biologists to experiment with domestication and cultivation of wild reed mushrooms, which proved much easier said than done in the early years with no precedents to follow.

The real breakthrough came in 2019 with a successful small-scale trial cultivation of the three domesticated mushroom varieties from a soil matrix containing reed residue.

"The average output of mushroom cultivation is 10 times that of reeds, so later on we began with large-scale promotion," Shi said, adding that this is an awesome way to utilize reed resources and avoid pollution since 0.067 hectares of mushrooms consume up to 20 tonnes of reeds.

To monitor in real-time the temperature, humidity, carbon dioxide concentration and other parameters inside, a reed mushroom greenhouse is also equipped with a display screen. With wireless connections, conditions can either be controlled remotely with mobile phones or automatically to create an optimal growth environment.

"With the multifunctional greenhouse, we can guarantee a stable and unaffected growth of the reed mushrooms for three seasons each year and a dramatically increased output per unit area," Wu said.

Reeds, once disfavored, have now come back as an enviable resource.

To further support this promising industry, the city has set up a special office in March this year and are employing an increasingly large number of local farmers, who no longer have to migrate for jobs.

Now with scaled production, local reed mushrooms are expanding in output and influence, with an estimated annual capacity of over 100,000 tonnes by 2022.

Looking ahead, Shi has a vision -- to build an organic fertilizer plant, utilizing the reed residue left over from mushroom cultivation.

"This is how we push toward green recycling and comprehensive transformation of the reed industry," he said. Enditem