A green roof is a beautiful idea for cities. They feel good, look good, they clean the air and reduce temperatures inside in the summer, increase them in the winter. They are good for the birds and the bees. But green roofs are cut off from the great web of information and possibilities found in soil attached to the earth. Scientists have a new idea: Mycorrhizal fungi.

In the US green roofs are typically planted with non-native plants in sterile soils, and their effectiveness declines over time. A Dartmouth-led research team set out to determine if managing green roof soil microbes could boost healthy urban soil development, a methodology that could be applied to support climate resilience in cities.

The team created an experimental green roof in Chicago to test how enhancing soil with native prairie microbes would change the soil microbial community over time. They were particularly interested in tracking the presence of beneficial mycorrhizal fungi.

Mycorrhizal fungi are well-known to live in roots and support plants in a symbiotic underground relationship, delivering nutrients and water to them in exchange for plant sugars. Mycorrhizal fungi could be particularly helpful to plants in green roofs that have to endure high temperatures, intense sun, and periodic flooding.

The researchers added soil rich with native mycorrhizal fungi obtained from a local restored prairie, referred to as “inoculum,” to the experimental green roof’s soil. They planted inoculated and untreated soil with native prairie plants and green roof succulents. Over two years, the team tracked changes in the mycorrhizal fungal community of the green roof. They also compared the green roof fungal species identified to those present in the inoculum and in the air.

Their findings demonstrate that active management of green roof mycorrhizal fungi accelerates soil development faster than if mycorrhizal fungal communities are left to passively reestablish on their own. Green roofs treated with mycorrhizal fungi foster a more diverse soil community that is more likely to support long-term green roof sustainability, according to the results published in New Phytologist.

“In this urban rooftop setting, we saw more diversity in the fungal communities of the inoculated soil,” said lead author Paul Metzler, soil ecology lab manager in the Department of Environmental Studies at Dartmouth. “The long-term and consistent effects of the inoculum were quite surprising, as it’s not necessarily something you would expect when working with such small microorganisms.”

Using a molecular technique called “DNA metabarcoding,” which enables the identification of multiple organisms in one sample, the researchers could identify fungi present in the green roof soils as well as potential sources of these fungi. Many fungi came from the inoculum while other species got there through some other vector such as wind.

The co-authors state that their study was different than most of its kind, as few studies track mycorrhizal community shifts over time post-inoculation and even fewer attempt to track the sources of species pools. The team also had a number of species in their green roof that likely arrived via unmeasured vectors such birds, insects, or even rats.

Still, the most diverse fungal communities were those that had been treated with the inoculum, illustrating how mycorrhizal fungi could be used to improve soil health in green roofs. The results suggest that active management of soil microbial communities is effective and worth the effort and resources in cities.

“Green roofs have a shelf life and they’re not always the self-sustaining ecosystems that we think they are,” says senior author Bala Chaudhary, an associate professor of environmental studies at Dartmouth. “They can be beneficial to urban areas but tend to lose their efficacy over time.”

While green roofs are marketed as “set it and forget it,” the co-authors explain that ecological thought should be incorporated into their design, construction, and maintenance to maximize the benefits and role that green roofs play in the climate resilience of urban areas.

“Our cities could be a window into the future,” says Chaudhary. “They are experiencing the impacts of climate change—warming temperatures and increased drought and flooding—in an intensified way, which make them a great microcosm to study some of these impacts below ground.”

The post Adding Mycorrhizal fungi to green roofs appeared first on Green Prophet.

The study, conducted by Aylin Dogen of Mersin University, involved 177 homes, with particular focus on kitchen and bathroom appliances and fixtures. Researchers collected almost 900 samples using cotton swabs moistened with physiological saline from dishwashers, refrigerators, washing machines, bathroom walls, tubs and showers.

The Turkish study discovered traces of mold everywhere, but dishwashers proved the favored real estate for black yeast-like fungi with 62% of the appliances testing positive. The moist, warm and highly alkaline interior of the appliance provide a perfect habitat for harmful germs to thrive.

Published in the journal Medical Mycology, the study found  Exophiala (black yeast) in most of the tested dishwashers, followed by Rhodotorula (red yeast) and Candida parapsilosis (white yeast).

The study said that Exophiala species are known to cause systemic disease in people and can colonize in the lungs of patients with cystic fibrosis.

Separately, the World Health Organization warned that “exposure to mycotoxins can produce both acute and chronic toxicities ranging from death to deleterious effects on the central nervous, cardiovascular and pulmonary systems.” Mycotoxins are troublesome byproducts of mold.

Fungi can break down manufactured materials and buildings, as seen in Green Prophet’s report on a Sharjah apartment eaten by mold.  It can also become a significant pathogen in pets.

We’ve harnessed fungi for food products, for fermenting alcohol and soy sauce, for producing antibiotics, and, more recently, extracted specific fungi enzymes for use as biological pesticides to control weeds and insects. Some fruiting structures (the mushroom-like blooms) of fungi species are consumed recreationally or in traditional spiritual ceremonies, due to the hallucinogenic affects of their psychotropic compounds.

Amazingly versatile, but unleashed, they can wreak havoc on human health.  Look around your own home.  See anything suspect? Check out this excellent guide (link here) from the US Environmental Protection Agency.

Try some of their DIY tips, or call in your building manager or a mold specialist.  And consider a return to hand-washing your dishes.

Image of a dishwasher interior from Shutterstock

The post Consider Hand Washing Your Dishes as Turks Find Toxins in Kitchens appeared first on Green Prophet.

Sounds like a 1950’s horror flick, but it’s been no Hollywood experience for this family-of-five in the United Arab Emirates of Sharjah. They’ve been living in a hotel since September 4 when they returned from vacation to discover the havoc wreaked by mold in their Al Majaz apartment. Incidents like this are increasingly common in hot and humid Gulf states, causing stress, expense, disruption to homelife and litigation. But the real damage is to our health.  

Illnesses caused by mold exposure are a growing problem that few people, including most physicians, are aware of.  Prolonged exposure to high spore concentration can cause serious chronic illness and a syndrome called Mixed Mold Toxicosis. I read this while eating a salad, slathered in blue cheese dressing. I don’t know much about mold.

The father of this family told Gulf News,“When I opened the apartment door I was shell-shocked. Everything was covered in black mold. I’m a pharmacist and know the health risk mold poses, especially to kids. I asked them to stay back while I stepped inside to inspect the extent of the damage. It was far worse than I’d imagined. We immediately decided to move to a nearby hotel.”

“Everything is destroyed. My TV, sofa, bedroom sets, washing machine and all our clothes,” he said. The mold was likely caused by a poorly executed paint job. A second coat was applied before the first had properly dried and the moisture trapped on the walls and ceilings created a perfect environment for fungus to colonize. The 20-story apartment building is just four years old.

Mold is a fungus that thrives in warm, humid conditions, making most Middle Eastern nations especially susceptable to outbreaks, which is why moisture control and ventilation are critically important.  Once established in a building, it spreads quickly. Washing machines are a common haven for spore growth, as are poorly ventilated bathrooms and air conditioning systems. Mold loves gypsum wallboard and fibrous ceiling tiles: add moisture and it spreads across the surface’s cellulose face.

Molds are categorized by their ability to grow at a certain water activity requirements.  The organism creates tiny spores to reproduce just as plants produce seeds. Once airborne, spores are difficult to filter out. That black mold around the shower curtain can blow to the ceiling, from the ceiling to the carpet, then onto your bed, and into your body.  It’s incidious and fast, and some molds produce toxins.

The World Health Organization recently published a report on mycotoxins, or toxic mold. It warned that “exposure to mycotoxins can produce both acute and chronic toxicities ranging from death to deleterious effects on the central nervous, cardiovascular and pulmonary systems.”

You’ve heard about “sick building syndrome” (SBS) where people suffer a range of symptoms related to a certain building, often their workplace, with no specific identifiable cause. This poorly understood phenomenon grabs frequent headlines (test Google to find examples in your neck of the woods).  Workers in modern buildings with inoperable windows and mechanical heating and air conditioning are most at risk, and mold is a major culprit.

SBS symptoms include:

• headaches, dizziness
• nausea
• aches, pains
• fatigue
• poor concentration
• shortness of breath, chest tightness
• eye, skin, throat irritation
• irritated, blocked or running nose

What to do if you spot mold?  Do not Google this one, it’s too risky to depend on bogus guidance.  If you can see mold on the outside of a surface, it’s likely on the backside too.  Don’t discount the invisible spores in the ether, either.

Instead, take a peek at this (PDF) excellent guide from the US Environmental Protection Agency.  Try some of their DIY tips, or call in your building manager or a mold specialist.

The best tip is prevention.  Keep your spaces sparkling clean.  Read the labels on the paint can. Open windows on drier days and let the spaces breathe. And hang up your wet towels.

Image of moldy wall by Shutterstock

The post Fungus Forces Family From Sharjah Home appeared first on Green Prophet.