Sample size determines diversity and structure of soil eukaryotic communities

Abstract

Sample size is important in microbial ecology as it is a fundamental unit for studying diversity and community composition of soil microbes in a given environment. The effect of sample size on the community structure of soil bacteria and fungi is well known but it was not tested on other soil fauna. We investigated how diversity and community structure of soil eukaryotes vary by different sample sizes using MiSeq amplicon sequencing. Microbial diversity increased with increasing sample size without reaching the asymptote even at the largest sample size of 10g. Community variation between replicates of a sample size became smaller with increasing sample size but variation pattern differed by taxa. With the acceleration of sequencing technologies, direct DNA extraction method becomes more common compared to traditional methods in ecology of soil fauna. Sample size should be appropriately used depending on the research goal and target taxa.