Interestingly, plot MNND changed very little for these diverse plots and the low diversity polycultures are centered on MNND change of zero (Fig. 3b).
Dybzinski et al. [15] further tested the diversity effect on plant productivity by investigating the fertility of soil beneath plots of varied levels of diversity and found that more diverse plots can support increased productivity via greater nutrient retention and inputs.
In a paper published in the 6 June issue of Nature, they show that in more diverse plots, fewer invaders sprout, and those that do sprout end up smaller than in less diverse plots.
They then went out into the field and counted the trees and shrubs growing on 20 of both the most diverse and least diverse plots.
The most diverse plots produced 238percentt more bioenergy yield than the average plot containing a single species, says team leader David Tilman.
Genotypically diverse plots had greater floral abundance, suggesting that positive genotype interactions occur in mixture plots.
Genotypically diverse plots included 7 replicates of each of the 3, 6, and 12 genotype mixtures (21 total).
Despite the short time scale, the most diverse plots lost an average of 16.25 species, while monocultures gained an average of 7.06 species.
One potential explanation for greater floral abundance plots is increased productivity in genotypically diverse plots compared to monocultures, which has been previously shown in the S. altissima system [23].
In this model, only flower visitor abundance was related to taxonomic richness (Flower visitor abundance: F 1,63) = 78.06, p<0.0001; Genotypic Diversity: F 1,63) = 0.14, p = 0.71), indicating the higher taxonomic richness of floral visitors observed in genotypically diverse plots was a result of more abundant floral visitors, and not a direct effect of genotypic diversity.
