Earthworm Biomass vs. soil pH by Cover Type

Ave. Earthworm Biomass vs. Ave. Soil pH by Forest Cover Type at White Memorial in 2014.

The strength of relationship was explored between soil pH and introduced earthworm biomass by forest cover type.  As previously posted, the overall relationship is significantly positively correlated. All of the relationships by cover types were positive and contributed to the overall association. The strongest relationships was observed in the mixed conifer and mixed hardwoods.  The lack of significant differences within each forest cover was likely due to small sample sizes.  Although the strength of the relationship between soil pH and earthworm biomass was not significant, northern hardwood forests had greater earthworm biomass and soil pH.  Northern hardwood tree species leaf litter increases the O-horizon pH significantly and this could favor introduced earthworms.