Forest Trees - Bioenergy Crop Plants - page 370

15.4 PoPlar BIoenerGy use and PotentIal WorldWIde

15.4.1 i introduction and B ackground
The use of poplars for bioenergy is not new (Anderson et al. 1983; Dickmann and Stuart 1983;
Dickmann 2006). In fact, there is archaeological and historical evidence that poplars have been
used for cooking and fuel throughout civilization. For example, archaeological evidence suggests
that indigenous people in North America including the Paleo-Indian, Hohokam and Ojibwe used
poplar for cooking and heating as well as many other uses as early as 3000 BC (Logan 2002). Over
a thousand years ago Euphrates poplars growing along the Tigris and Euphrates rivers, now in Iraq,
were used for charcoal and many other practical uses by the third Dynasty of Ur in Mesopotamia
(Gordon 2001). Moreover, the ancient Chinese before the Han Dynasty also used poplars for cook-
ing and heating at Youmulakekum in Western China from 700 to 200 BC; and during the Xian
period in China there is archaeological evidence that poplars were used for fuel and other practical
uses around 600 AD (Zhang J, personal communication).
Poplars have been used for fuel since antiquity throughout Europe, the Middle East, near East,
and Mediterranean in close association with agriculture (Zsuffa 1993). And, according to the diaries
of Lewis and Clark and David Thompson in the early 19 th century, the native cottonwood growing
along the rivers was used for cooking and fuel during the exploration and settlement of the western
United States and Canada (DeVoto 1953; Richardson et al. 2007).
Thus, it is well documented that poplar has been a source of bioenergy throughout early civiliza-
tion. However, as the world became industrialized, both industry and home owners became depen-
dent upon inexpensive fossil fuels for energy, and the use of wood for fuel declined. But, in the early
1970s when fossil fuels became more expensive and scarce, modern societies began to seek alterna-
tive sources of energy such as biomass (Rockwood et al. 2004). Over the years, the forest products
and pulp and paper industries have been the largest user of poplar biomass for energy in developed
industrialized countries; in fact, now they have largely become energy self-sufficient through their
use of biomass as a fuel (Konig and Skog 1987).
The aforementioned oil crisis and shortages in the 1970s sparked a worldwide emphasis on bio-
energy research and development from trees, especially poplar (Fege et al. 1979; Ranney et al.
1987). But, after only a few years when fossil fuels became more available and inexpensive again,
bioenergy research and development on poplars declined. Recent oil shortages and increased costs
of fossil fuels in the 21 st century have prompted yet another new wave of emphasis on alternative
fuels and bioenergy from poplar biomass.
Poplars have received worldwide attention for bioenergy use because of their high biomass
production rates and genetic improvement potential (Stettler et al. 1996; Davis 2008). We review
worldwide poplar biomass production rates and discuss the advantages and limitations of using
poplars for bioenergy, with emphasis on the current and potential future use of poplars for bioen-
ergy in developed countries. We fully realize that poplar is still an important source for fuel for
cooking and heating in many developing countries, and will likely remain so for years to come
(FAO 20 09).

15.4.2 p oplar B iomaSS p roduction

15.4.2.1 north america
The origin of the use of poplar plantations for biomass production in North America dates back
to the late 1800s and early 1900s when governmental agencies became concerned that the for-
ests of the northeastern United States and Canada were not sustainable because of overharvesting
(McKnight and Biesterfeldt 1968). This concern led to the establishment of the U.S. Forest Service
in 1905 and the Forest Survey in 1928 (LaBau et al. 2007). At the same time, Stout et al. (1927)
working at the New York Botanical Garden outlined opportunities for meeting the growing needs