For years people have promoted bamboo as an eco-friendly material for everything from countertops to chopsticks. The fast-growing plant has been thought to store up carbon from the atmosphere as it grows, trapping the greenhouse gas.
But scientists had never actually measured bamboo’s storage ability. Now a study casts doubt on that process and even suggests that bamboo may be a carbon emitter. The researchers are quick to point out that their work was limited to only two plants grown over a short period of time, and that much more investigation is needed before bamboo’s green cred can be rejected or reaffirmed.
Bamboo is a fast-growing business, worth $27 billion in China alone, a figure that could rise to $48 billion by 2020. To better understand how the recent shift to cultivating and using more bamboo affects carbon dioxide levels in the atmosphere, scientists in India wrapped two bamboo plants tightly in plastic. One was six months old and the other was a year old. Next, they measured the gas exchange across the plants’ tissues for 24 hours.
Conventional wisdom suggests that the scientists would see carbon dioxide going into the plant and oxygen leaving, thanks to the equation of photosynthesis. But what they found surprised them, says study leader E.J. Zachariah, a researcher at the National Centre for Earth Science Studies in Thiruvananthapuram.
The plants actually appeared to release large amounts of carbon dioxide into the air, the team reported in February in the journal Plant Biology. These releases were higher when outside temperatures were warmer and in the younger plant. The gas may have come from incomplete photosynthesis as the plants grew quickly, through other processes inside the plants, or from the plants’ ability to draw the gas up out of the soil, says Zachariah, who notes more research is needed.From the day-long study period, the scientists extrapolated across the whole eight-year lifespan of the bamboo, estimating that the plants are net emitters of carbon dioxide during that time, not net sinks, as has been commonly assumed.
Source By Brian Clark Howard