Submitted to: Ecological Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2008
Publication Date: 12/20/2009
Citation: Adler, P.R., Sanderson, M.A., Weimer, P.J., Vogel, K.P. 2009. Plant species composition and biofuel yields of conservation grasslands. Ecological Applications. 19(8):2202-2209. Interpretive Summary: Conservation lands have been considered an essential component in the production of biomass for biofuel production, however, little is known about the kinds of plants on conservation lands and how the composition of plants species may affect the amount of biomass produced and its quality for use as a biofuel. A survey of conservation grasslands in the Northeastern US was conducted. This study found that the quantity of mineral elements in biomass varied greatly between sites and this affects its use for production of energy from combustion. Biomass and biofuel yield increased as switchgrass, big bluestem, and indian grass increased because of both greater biomass yields and increased quality of biomass for production of ethanol. The average biomass over all sites and years sampled was about 3 tons per acre. Both the quantity of biomass produced and its quality as a biofuel were affected by the composition of plants on conservation lands in the Northeastern US.
Technical Abstract: Conservation Reserve Program (CRP) grasslands are a critical component for reaching the billion annual tons of biomass feedstock production goal. Few studies have determined the capacity of CRP land for biomass production or biofuel quality. The objective of this study was to assess the potential of CRP land in the Northeastern US as a resource for biofuel feedstock, measuring the impact of plant composition and site on the biofuel yield and quality. To assemble a database for the resource assessment of warm season grasslands in the Northeastern USA we determined plant species composition at multiple scales using the modified Whittaker plot technique, measured various soil properties, and quantified biomass yield and quality on CRP, WHIP, mine reclamation, and other grasslands. A total of 34 sites were sampled in New York, Pennsylvania, New Jersey, Maryland, and Virginia during late August through early October in 2002 and 2003. Plant species composition did not impact biofuel quality as measured by the concentration and composition of elements in aboveground biomass, which is important to thermal conversion of biomass. The affect of plant species composition on biofuel quality may have been masked by a larger effect of specific site factors such as soil. However, plant composition did affect the concentration of lignin, cellulose, and hemicellulose, which affect the potential ethanol yield from the biomass on CRP land. Ethanol yields decreased as plant species richness increased and increased as the cover of C4 grasses increased. This impact of plant species composition on potential ethanol yield is important to consider when describing ethanol production from diverse grasslands.