Growing poplars for food security

4 August 2010, Rome - Around one million people in Siyang County, China, are now benefiting from the capacity of poplar forests to restore marginal flood plains and stabilize the banks of the Yellow, Huai and Yangtze rivers. Large swaths of planted poplar trees now protect fields once ravaged by floods, wind, sandstorms and soil erosion, giving boost to agricultural activities.

"Poplars are very fast-growing and amazingly resilient," said Jim Carle, Leader of the Forestry Management Team at FAO. "They can grow in many sorts of ways and can easily integrate with other land uses, making them ideal for supporting animal husbandry, agriculture, aquaculture, viticulture and horticulture."

Some of the services provided by these multi-purpose trees include furnishing material for shelter, shade and dwellings, protecting crops and supplying fodder for livestock, as well as offering viable sources of bio-energy. Poplar is one of the faster growing trees, with production cycles of 5 to 15 years, and has a wide range of end-uses. Increasingly poplars are grown for wood energy production.

By engaging Siyang farmers and smallholders in new income generating activities, the development of wood industries and resulting job creation has contributed to an improvement of the region's overall economic situation and an increase in the per capita income of both its urban and rural residents. 

Key to success

Siyang has long been pointed to as an example of the successful application of the international transfer of germplasm, scientific knowledge and technology. The history of Syiang's cooperative partnership in poplar cultivation dates back to the 1970s, when the county first imported 32 poplar clones from Italy, where centres of excellence in poplar research and development existed. This ongoing activity was facilitated by FAO's International Poplar Commission (IPC).

Covering more than 100,000 hectares of the county's land area, poplars are today Siyang's principal tree species, increasing its tree cover from seven to 47 percent over the last 30 years.

"Because of the scale [of the activity] and because of the fast-growing nature of poplars, it grew to become a very large rural development programme also supporting food security, livelihoods and other land-uses, pushing boundaries beyond what was originally planned," Carle added.

China is now the world's biggest poplar growing country, followed by France. The area of planted poplar forests and agroforestry (combining trees and crops or livestock) in China is about 8 million hectares, 30 times greater than the areas under poplar cultivation in France.

Support for agriculture

Poplar-based smallholder agroforestry has transformed the flood plains of Siyang County into a mosaic of green activity on the landscape. Faster leaf decomposition and biomass growth have created a much more fertile soil on once sandy land, which was not always suitable for cultivation.

"People can now diversify their activities," said Alberto Del Lungo, a Forestry Officer with FAO's International Poplar Commission. "Because of poplars' compatibility with many crops, farmers can now grow wheat and maize and an abundance of horticulture crops. Smallholder farmers, for example, also use the cut stems of poplar for cultivating mushrooms in their greenhouses." 

Wood as key industry

Poplars also provide wood, fibre and fuelwood for forest industries. Poplar wood is colourless, odourless and tasteless, making it highly suitable for fruit boxes, medical tools, chopsticks, flooring and furniture and manufacturing pulp and paper.

Siyang's wood processing industry today churns out nearly 100 types of products, including fibreboards, plywood, decorative veneer and furniture. At present there are more than 1 200 wood processing enterprises active in the region, employing around 50 000 workers. Siyang's wood processing capacity has recently surpassed 2 million cubic meters per year, with its products being exported to Europe, Africa and Southeast Asia.

Carbon sink

Poplar-based agroforestry is a profitable activity for another key reason. Carbon storage is a crucial environmental service provided by poplar trees and critically important for climate change mitigation.

Several studies have shown that agroforestry provides opportunities to create highly efficient carbon sinks. And the combination of poplar and wheat in particular is a good land-use option for increased carbon sequestration in farms, according to FAO.

"Great Green Wall" of China

Poplar cultivation has become popular in smallholder and agro-forestry plantings in other regions of China. "Cover the infertile mountain with trees, - turn the crawling desert into oases" — these rhyming phrases used by China's "green campaigners" refer to the Great Green Wall of poplar and willow forests, built to curb soil erosion and to reduce the intensity of sandstorms.

Smallholders who were producing little from the infertile cropland of the sandy Northwest region began to plant drought-resistant poplars and willows to provide shelter and shade from sandstorms. Later, once the advancing deserts were halted, smallholders started harvesting and selling lumber for a living, while keeping the sheltering greenbelts in place.

67-year-old Shi Guangyin — a farmer, who has fought with sandstorms since his childhood and, was awarded an "outstanding farmer" by FAO in 2002 — has played a lead role in this effort. In 1984, Shi joined with seven other rural families to found a company to combat advancing sands in his region by planting trees on 200 hectares of land. To date, his company has mobilized over $1.47 million to plant and reinforce 13 000 hectares of forests in Dingbian County, Shaanxi Province.

Important lesson to learn

"Poplar planting in China has been a tremendous success," said Carle. "China has become the key player in poplar cultivation and is now able to transfer knowledge and technology not only to other parts of China but also to other regions and territories, like Central Asia.

"The IPC plays an important role in improving farmers' livelihoods. It promotes the integration of poplar cultivation in agroforestry systems, by transferring science and technologies from developed to developing countries and by supporting policy-makers, strategic planners and investors in the implementation of poplar cultivation to contribute towards sustainable development and land-use".

In recognition of the role of poplars in rural development and to highlight the catalytic role played by FAO, the IPC and Italian cooperation, Siyang county created the world's only historic Poplar Museum. It was founded on the exact spot where the first two Italian clones were planted in Siyang. Building on the technology transfer facilitated by IPC members, specifically Italy, over the past 30 years, and investing further, China has become a world leader in poplar genomics and biotechnology to improve resistance to biotic agents, improve wood quality, increase productivity and contribution of poplars to rural development.