TABLE 1.

Mean values of water chemistry and vegetation variables within pH classes in 1998–1999 and 2018 and paired t test results

	High pH		p	Intermediate pH		p	Low pH		p	Extr. low pH		p
	1998	2018		1998	2018		1998	2018		1998	2018
pH	5.80	5.75		4.82	4.90		4.39	4.57		4.17	4.40	***
DOC (mg/L)	20.1	18.7		42.2	33.7		43.3	36.4	*	50.5	41.5	*
Al (mgl/L)	0.083	0.040		0.093	0.084		0.173	0.136		0.252	0.175	**
Ca (mg/L)	2.98	3.57		1.65	1.92		1.31	1.59		1.29	1.63	*
Fe (mg/L)	0.311	0.078		0.430	0.468		0.677	0.415	*	0.818	0.464	**
Mg (mg/L)	1.51	1.53		0.72	0.70		0.52	0.41		0.43	0.35	*
Mn (mg/L)	0.009	0.005		0.006	0.009		0.009	0.011		0.015	0.009	**
Na (mg/L)	2.70	2.45		1.50	1.23		1.37	0.97	**	1.15	0.96	*
Si (mg/L)	4.70	3.44		2.81	2.56		4.01	2.97	*	3.11	3.14
n		10			9			11			18
Sphagnum moss cover %	32	51	**	67	64		77	88		90	96
Non‐sphagnaceous moss cover %	53	31	***	16	16		7	1	*	5	2
Vascular plant cover %	26	35	**	25	29		19	18		21	21
Species richness (S)	11.6	15.8	***	11.8	13.2	**	9.6	11.7	***	10.1	11.5	***
Shannon diversity index (H)	1.34	1.58	**	1.31	1.29		1.33	1.35		1.25	1.33
Number of Sphagnum species	1.2	1.6	**	2.5	2.5		3.2	4.0	*	3.6	3.8
Number of non‐sphagnaceous moss species	2.9	3.1		1.3	1.3		0.5	0.5		0.4	0.4
Number of vascular plant species	7.2	10.2	***	7.6	8.8	**	5.4	6.6	**	5.9	6.9	***
n		53			52			45			53

^* p < .05.

^** p < .01.

^*** p < .001.