Abstract
Appropriate estimation of the effects of species interactions on
ecosystem function is essential for understanding biodiversity effects
and supporting development of environmental policies. Species undergo
changes in competitive environment from monocultures to mixtures; highly
productive species are generally more competitive and increase their
performance and less productive species reduce their performance in
mixtures, resulting in net increases of ecosystem function. This
positive biodiversity effect, largely due to species differences in
monoculture yield, does not involve complementary interactions (niche
differentiation or facilitation) and therefore should not be included in
biodiversity effect estimation. To reduce impacts of the ‘sampling
effect’ and overestimation of biodiversity effects by additive
biodiversity partitioning, we present a method to adjust species
expected performance based on their monoculture performance and
proportion in mixtures. Our method offers more appropriate estimations
and interpretations of biodiversity effects for biodiversity
experiments.