Results/Conclusions Four major patterns emerged: 1. Both field and common garden studies showed that individual tree genotypes supported different communities. 2. We found significant broad-sense heritability for community composition (H2C = 0.66), species richness (H2C = 0.31), abundance (H2C = 0.36), and stability (H2C = 0.32). 3. As a possible mechanism for our stability findings, we found that the abundance of a common insect herbivore and arthropod species richness of individual tree genotypes were both significantly correlated with increased community stability. 4. Broad-sense heritability of community composition was highly repeatable and over three consecutive years ranged from H2C = 0.63 to 0.68. These findings demonstrate that the genetics of a foundation tree species can structure a diverse community of arthropods. Our findings of significant community heritability, repeatability, and stability represent an important advance in understanding the genetic components of community structure, which have evolutionary and conservation implications.