MonticelloLive

A pair of University of Arkansas at Monticello forest resources scientists made presentations examining the impact and viability of biofuel production in the Lower Mississippi Valley at the Conference on the Ecological Dimensions of Biofuels March 10 in Washington, D.C. The conference was sponsored by the Ecological Society of America.
            Dr. Philip A. Tappe, professor and associate dean of the UAM School of Forest Resources, and Dr. Hal Liechty, professor of forestry, made presentations based on research into the effects of biofuel production on ecosystems.
            Tappe’s research, conducted with UAM faculty members Dr. Matthew Pelkki, Dr. Robert Ficklin, and Liechty, examines the impact of the collection of post-logging forest residues, known as slash, and turning the material into cellulosic biomass for biofuel production.
            According to Tappe, cellulosic ethanol, made largely from logging waste, has the potential to replace 30 percent of U.S. petroleum use. “Pine plantations produce the majority of harvested forest volume in the U.S. South,” says Tappe, “ and are projected to increase 53 percent in area by 2050. Projections estimate that two-thirds of the national softwood harvest will occur on plantations that cover 20 percent of the U.S. forest base. Clearly, pine plantations have an important role in producing biofuel feedstocks.”
            There are drawbacks, Tappe says. Whole-tree chipping, which includes the removal of all above-stump biomass, may have detrimental impacts on site productivity and ecosystems. “Forest harvesting can reduce the base saturation of soils and this intensifies with the amount of biomass removed,” Tappe explains. “Whole-tree harvesting can also reduce cycling of soil carbon, which modify soil properties and reduce future productivity.”
            Tappe says the quantity, size, distribution and decay status of woody debris in forests influences plant and animal community composition and diversity, but also as the potential to negatively impact several species groups.
            Written with Michael A. Blazier, Tappe, and Pelkki, Liechty’s research examines the suitability of the Lower Mississippi Alluvial Valley for large-scale biofuel feedstock production. Liechty says the Lower Mississippi Valley’s high rainfall, long growing season, central location, and well-developed agriculture infrastructure make the region well suited for biofuel production.
            But not without tradeoffs.
            According to Liechty, production of common biofuel feedstocks such as corn and soybeans require significant inputs of fertilizer, pesticides and water for irrigation while doing little for water quality protection, wildlife habitat, or carbon sequestration.
            According to Liechty, a better method for biofuel feedstock production may involve reforestation of marginal agricultural lands in an area once dominated by forests and turning these agroforests into flexible and innovative cropping systems and ecosystems. “Agroforest systems composed of varying mixtures of feedstock species, such as cottonwood trees and switchgrass, have the potential to provide a suite of ecological services along with the high cellulosic biomass production to meet a variety of management objectives, social constraints, and soil and site conditions,” said Liechty.
            The potential of agroforest systems to increase biofuel production capacity could also have the added benefit of improving economies of faltering rural communities and enhance environmental conditions, such as soil, water, and wildlife habitat quality.