*3.1. Soil Properties*

There were differences in general soil characteristics between road types and the control sites (Table 1). Significantly more alkaline pH was recorded from new roadsides compared to other sites; total organic carbon was highest in the oldest roadside soils and EC was lowest in the control soil. There was no significant difference in Pc or ECEC between the roadside soil sites, i.e., new, medium and old roads.

**Table 1.** Soil characteristics for roadside soils in western Melbourne, Australia, on Newer Volcanic parent material; values are mean ± standard error (n = 3). Soils were collected from new (N = 1.5–5 years), medium (M = 5–10 years) and old (O ≥ 15 years) roads. Numbers in a column with the same letter are not significantly different (*p* > 0.05).


Pc = soil particle concentration determined using Equation (3); EC = electrical conductivity, TOC = total organic carbon, ECEC = effective cation exchange capacity. Values are means (*n* = 3), ± standard error, a, b, c, denotes the significance between the sites at *p* < 0.05.
