Dust storm in Beijing. (Wikimedia Commons)

WILLIAM RAU

China’s Loess Plateau experiment successfully restored depleted farmland in the less arid parts of the plateau. One precondition for success required an end to free-range grazing by goats, a major cause of soil erosion. The breakthrough came when a county executive banned grazing and in one summer his dull tan county turned into the beginnings of a verdant green grassland. The transformation led to the rapid spread of grazing bans to other counties. Introduction of improved breeds of sheep, goats and cattle, that were adapted to life in pens and that produced higher quality wool, milk and meat also supported the change.

Next, the government used bulldozers to widen farmer-built 5- to 10-foot terraces to 20- to 40-feet. Wider terraces allowed not only better rain capture, but a shift to machine harvesting which reduced harvesting time from typically three weeks to three days. With grasses and fruit trees planted on adjacent slopes and with absorbed water slowly released to the terraces below, grain production increased 60% in a few years. Project staff also encouraged diversification into high-value fruit and vegetable production for the Beijing market. Thus, over the 11 years of the project (1994-2005), farm income more than doubled.

By project’s end, ecological restoration encompassed an area larger than the State of Maryland. With once barren land now covered by crops, grasses, orchards and trees, 13,500 square miles of the plateau were turned into a green, carbon-absorbing sponge capable of feeding its inhabitants and generating lots of fruits and vegetables for urban markets. With upfront financial and technical assistance, large-scale ecological restoration of degraded farmland is eminently doable.

Unfortunately, the Loess Plateau experiment is the exception rather than the rule. A more common practice –– both in China and elsewhere –– is to convert degraded or marginal farmland into single-species, non-native tree plantations. That is, non-sustainable fake forests are replacing hundreds of years of bad husbandry. Called “green deserts” by Chinese ecologists, these plantation monocultures deprive native wildlife of food. As a result, varieties and numbers of birds and bees, two indicators of healthy biodiversity, are declining significantly. Commercial lumber interests may prove that we won’t need DDT to create a silent spring.

Planting the wrong trees in the wrong places is widespread. Ireland, for example, is also in the fake forest game. Once mostly covered by forest, Ireland today has only 1,300 native forest remnants covering 2% of the island.

One Irish reforestation plan? Fast-growing Sitka spruce monocultures, but without Alaska’s brown bears, sea lions and orca whales. This is how the Irish commercial interests plan to reforest a portion of their denuded island –– and make a buck selling lumber.

But, it’s hard to outdo China’s Three-North Shelterbelt Program, an effort to hold back expansion of the Gobi Desert and reduce “yellow dragon” sandstorms that can paralyze Beijing. Instead of planting locally adapted grasses, they chose deep-rooted aspen. The trees depleted surface water first, killing off the native grasses and then depleted deeper sources of water. In time, 85% of the trees also died off.

In the next column, we’ll turn to natural regeneration of native forests. They sequester 40 times more carbon than fake forests.

References

Cao, Shixiong et al. 2011. Excessive reliance on afforestation in China’s arid and semi-arid regions: Lessons in ecological restoration. Earth-Science Reviews; https://www.researchgate.net/publication/251557035_Excessive_reliance_on_afforestation_in_China’s_arid_and_semi-arid_regions_Lessons_in_ecological_restoration

Carroll, Rory. 2019 (Jul 7). The wrong kind of trees: Ireland’s afforestation meets resistance. Guardian; https://www.theguardian.com/world/2019/jul/07/

Conniff, Richard. 2016 (Sep 16). China Plants a Record Number of Trees—but Only One Kind. TakePart: http://www.takepart.com/article/2016/09/16/china-plants-record-number-trees-only-one-kind/

Holtz, Michael. 2017 (Jun 28). China spent $100 billion on reforestation. So why does it have ‘green deserts’? Christian Science Monitor; https://www.csmonitor.com/World/Asia-Pacific/2017/0628/China-spent-100-billion-on-reforestation.-So-why-does-it-have-green-deserts

Louma, Jon. 2012 (Jan 17). China’s Reforestation Programs: Big Success or Just an Illusion? Yale; https://e360.yale.edu/features/chinas_reforestation_programs_big_success_or_just_an_illusion