Table 5.

Results of Bonferroni-corrected pairwise comparisons among ecoregions and provinces for levels of TN, TP, and CHLA conducted after finding significant group effects via ANOVA. Different letters of the alphabet within a column and across either marine-coast provinces or inland ecoregions are used to show significantly different levels for that analyte (p ≤ 0.05). To aid in seeing patterns, rows are ordered from generally high to low nutrient levels (see Table 2 for actual values).

Site group	TN	TP	CHLA
Marine-coast provinces
Louisianian	A	A	A
N. Atlantic	A	AB	A
Pacific	B	AB	B
S. Atlantic	B	B	B
Inland ecoregions
TPL (temperate plains)	A	A	A
SPL (southern plains)	AB	A	A
NPL (northern plains	AB	AB	AB
UMW (upper midwest)	AB	BC	A
CPL (coastal plains)	B	B	A
XER (xeric)	BC	BC	AB
SAP (S. Appalachian)	C	BC	AB
WMT (western mountains)	C	BC	B
NAP (N. Appalachians)	C	C	B