The Contribution of Intraspecific Trait Variability to Plant Community Assembly Patterns on the Niche-neutral Continuum

Many trait-based plant investigations have neglected the intraspecific trait variations. A lot of ecologists consider that this is unreasonable, because intraspecific variation significantly affects various ecological dynamics. However, it is not feasible to record the traits of each plant individually at every community site. Therefore, the aim of this study was to determine in which circumstances it is most important to account for intraspecific trait variations. We conducted analyses using a trait-based niche–neutral continuum model integrating interand intraspecific variance. Then we tested the model through three popular community pattern indexes generated from four kinds of community assembly processes. The results showed that it was more important to consider intraspecific variations in plant communities with large niche overlaps. In such cases, including intraspecific variation increases the number of species and strongly affects the community’s abundance structure. In contrast, when there is strong niche differentiation, the contribution of plant intraspecific variation could be neglected. In addition, the species richness and rank–abundance curve were insensitive to the magnitude of intraspecific variation, but plant trait distribution increased exponentially when intraspecific variation was included. Our results will be useful when designing field studies, to determine which data are most informative for various community types.