http://ecology.okstate.edu/Libra L. I. B. R. A. Laboratory for Innovative Biodiversity Research and Analysis Hay meadows: Biofuels for Biodiversity?
Maize (corn) as a biofuel Do the energetics balance?
Switchgrass has advantages over maize • Locally adapted • High genetic variation • High water use efficiency • High nitrogen use efficiency • Perennial • Low erosion
However, introducing a new monoculture may be a mistake. • Problems with monocultures: • Disease • Unstable production • Costly (energetics as well as money) • No nitrogen-fixing legumes • Nature abhors a monoculture • Plowing means enhanced soil respiration, hence this is not a good solution for global warming
Switchgrass as the ‘next crop’ • A California biotech company Ceres is genetically modifying switchgrass with genes from Arabidopsis to maximize yield. • “You could turn Oklahoma into an OPEC member by converting all its farmland to switch grass”, said Richard W. Hamilton, the Ceres chief executive. • NY Times, 8 September 2006 • Productivity is measured in yield – not the most energetically relevant measure. • Wild switchgrass is everywhere in much of North America. Keeping transgenes from crossing with native switchgrass will prove impossible.
Abandonment of grasslands Vast acreages of hay meadows in the southern Great Plains are being abandoned, resulting in degraded systems of low value.
Eastern red cedar (Juniperus virginiana) is the main species invading unmanaged grasslands Cedar pollen causes severe allergy problems
Cedars also: • Alter hydrology • Reduce diversity • Increase erosion • Reduce grassland bird populations (including threatened species) (however, cedars have uses – and there are genuine old-growth cedar stands in Oklahoma)
Mowing is a frequently used management tool to enhance biodiversity worldwide Laeletu wooded meadow, Estonia In many cases, the cuttings are considered waste. Why not use them?
Mowing experiment, western Payne County Established 1996
Mowing frequency Control Single 35 Double Triple 30 25 20 Mean species richness 15 10 5 1997 1998 1999 2004 2005 Year of Sampling
Will hay meadows, with complex species mixtures, work as biofuels? Probably, using gasification techniques.
Biofuels may make control of exotic species such as Johnsongrass or sericea cost-effective.
Multi-use systems are possible: biofuels are potentially compatible with livestock, honey, wildlife (game and nongame), conservation, windfarms
Numerous areas are subject to Nitrogen pollution Why not take advantage of this, and harvest the enhanced productivity?
Productivity of haymeadows • Yield / acre: probably lower than other proposed biofuels such as switchgrass • Yield / cost, Yield / water, yield / Nitrogen: probably higher than other proposed biofuels • Benefits / cost: definitely much higher than other proposed biofuels
Other Environmental and Social Concerns with biofuels: • Competes with food production • Clearing of Amazon or other pristine areas • Encouraging invasive species • Transportation of fuels These are minimal issues with native hay meadows
Basic and theoretical ecology can benefit from interest in grasslands as biofuels. Note that geology, hydrology, physics and chemistry have all experienced major advances because of energy.
Conclusions: an equation A need to decrease dependence of fossil fuels for environmental and geopolitical stability +abandoned grasslands leading to environmental, health, and public safety problems+serious concerns about biofuel crops =Let us use our grasslands as a source of biofuels, for a sustainable economy and environment