Brief Review of Competition Experiments

p lanting of mixtures of species is often preferredto monocultures due to a desire for greater bio-diversity or an appearance more similar to nat-ural plant communities. Potentially, mixtures could be more productive than monocultures if the differ-ent species utilize different resources or if 1 species improves the productivity of the other, typically by fixing nitrogen (Assman 1970; Kelty 1992). However, productivity of different mixtures will vary, regardless whether the “products ” are crops, timber, biomass, wildlife habitat, or aesthetics. When mixtures are planted, it is desirable to deter-mine how species composition determines growth and survival of individual plants, as well as overall produc-tivity per unit area. Below, I describe some novel sys-tematic designs after providing the context of tradi-tional competition and mixture experiments