Fig. 2. Vegetation treatment effects on cumulative total P (TP) load and mean annual runoff volumes 2004 through 2005, Madison, WI. Mean runoff volumes were significantly different (P < 0.05) on 20 Feb. and 28 Feb. 2004 and 7, 16, and 19 Mar. 2005. Asterisks indicate significant treatment differences (P = 0.05) in mean TP load on specified dates. Soil freezing (5 cm) occurred on 12 Dec. 2003 and 14 Dec. 2004. Soil thawing took place on 24 Mar. 2004 and 28 Mar. 2005.