Maximum size-density relationships for mixed-hardwood forest stands in New England

Maximum size-density relationships were investigated for two mixed-hardwood ecological types (sugar maple-ash and beech-red maple) in New England. Plots meeting type criteria and undergoing self-thinning were selected for each habitat. Using reduced major axis regression, no differences were found between the two ecological types. Pure species plots (the species basal area greater than 70 percent of the total plot basal area) were identified for six major hardwood species, and corresponding size-density relationships were developed. Results showed that shade tolerant and intermediate species had similar intercept and slope coefficients for the maximum size-density line. No differences were found between each species and habitat types; however, shade intolerant species had smaller intercept and slope coefficients than others. The two ecological types were combined, and one maximum size-density relationship was constructed for mixed-hardwood stands.