Potential biodiversity response to intercropping herbaceous biomass crops on forest lands

Abstract

Intensive forestry presents opportunities for intercropping herbaceous biomass species between crop tree rows for producing cellulosic feedstocks. Switchgrass (Panicum virgatum) and other native prairie grasses are being evaluated as potential biofuel crops. It is unclear how intercropping within intensively managed forests will affect biodiversity compared with similar forests under traditional timber management. However, research with grasses in row crop agriculture suggests some basic principles. Effects will likely vary with habitat needs of individual species and communities. Additionally, intercropping regimes favoring mixed native warm-season grasses over switchgrass only, spring harvests over fall, and rotational harvests producing mosaics of grass heights would likely benefit biodiversity. A critical knowledge gap is how potential edge effects of growing crop trees may influence habitat quality of intercropped stands. Although biomass intercropping may increase diversity by adding predominantly grass components to intensively managed forest landscapes, predictions about biodiversity response are not possible until more research is done. © 2012 by the Society of American Foresters.