title: Comment on "Carbon-negative biofuels from low-input high-diversity grassland biomass".
abstract: Tilman et al. (Reports, 8 December 2006, p. 1598) argued that low-input high-diversity grasslands can provide a substantial proportion of global energy needs. We contend that their conclusions are not substantiated by their experimental protocol. The authors understated the management inputs required to establish prairies, extrapolated globally from site-specific results, and presented potentially misleading energy accounting.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, St. Paul, MN 55108, USA. michael.russelle@ars.usda.org
authors.forename: Michael P
authors.initials: MP
authors.lastname: Russelle
authors.forename: R Vance
authors.initials: RV
authors.lastname: Morey
authors.forename: John M
authors.initials: JM
authors.lastname: Baker
authors.forename: Paul M
authors.initials: PM
authors.lastname: Porter
authors.forename: Hans-Joachim G
authors.initials: HJ
authors.lastname: Jung
mesh_terms: D000383:Agriculture; D018533:Biomass; D002244:Carbon / Q000032:analysis; D002980:Climate; D017753:Ecosystem; D004736:Energy-Generating Resources; D007887:Fabaceae / Q000254:growth & development / Q000378:metabolism; D063245:Plant Development; D010944:Plants / Q000378:metabolism; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism; D012987:Soil
chemical_list: D012987:Soil; D002244:Carbon