Fall in rice strains typifies China's biodiversity gap
[BEIJING] The number of China's rice varieties has dramatically decreased, raising fears about the country's food security and biodiversity.
China had 46,000 rice varieties in the 1950s, but this plummeted to just 1,000 in 2006, according to a Chinese study published in BioScience this month (November).
The research used a variety of environmental indicators — such as forest coverage and water quality — to examine China's progress since parties to the Convention on Biological Diversity agreed in 2002 to significantly reduce biodiversity loss by 2010.
It found that despite making progress with its forest resources, China needs a more integrated biodiversity strategy.
"A significant reduction of biodiversity loss — or even a halt of it — can be achieved only if biodiversity conservation is mainstreamed into national and sectoral strategies and action plans. The next decade is a critical period for China," the authors wrote.
According to the study, China's grasslands have declined by 15,000 square kilometres per year over the past 30 years, and previous research found than 90 per cent of China's grasslands are degraded.
But there is some good news. Water quality in marine ecosystems has improved by more than four per cent per year from 2001 to 2007. The area of China's forests has increased from 13 per cent to 18 per cent in 2003, and forest growing stock — the volume of trees in an area that have more than a certain diameter at chest height — has increased by over 40 per cent.
"Biodiversity is increasing in China's forests," the study said.
Earlier this month, the State Forest Administration of China published its plan to adapt to climate change, proposing that China's forest coverage should increase to 20 per cent by 2010.
Bao-Rong Lu, a professor at China's Fudan University, told SciDev.Net: "The huge decrease [in rice yields] is a result of the extensive cultivation of a few genetically improved modern varieties that are high-yielding and pest-resistant."
"In addition, the farming style of monoculture — with only a few dominant varieties covering a huge area — will lead to a vulnerable agro-ecosystem."
Lu said that genebanks and nurseries could boost conservation but have their limitations, such as seeds not being able to adapt to environments after being frozen for long periods of time.
"The role of agriculture extension workers and scientists as active partners of farmers is also very important in the conservation of rice genetic diversity," added Lu.
BioScience 59, 843 (2009)