Note: Data are the means ± SEs shown with significant differences among sites as assessed using Tukey’s HSD test (P < 0.05). Values followed by the same letter were not significantly different among sites. Values with an asterisk (*) were significantly different among the two growth stages at the same site. Results are presented for both early growing season (denoted as EGS, n = 5) and late growing season (denoted as LGS, n = 5).