Associations between forest vegetation and the fertility of soil organic horizons in northwestern Russia

Forest Ecosystems

Table 6 Characteristics of the fertility of soil organic horizons in pine, spruce and birch forests

Parameters	v-test			Mean in category			Standard deviation in category			Overall mean	Overall standard deviation	p-value
Parameters	pine (n = 66)	spruce (n = 37)	birch (n = 16)	pine (n = 66)	spruce (n = 37)	birch (n = 16)	pine (n = 66)	spruce (n = 37)	birch (n = 16)	Overall mean	Overall standard deviation	pine (n = 66)	spruce (n = 37)	birch (n = 16)
pH CaCl₂	−4.48	1.18	4.93	3.33	3.58	4.06	0.36	0.43	0.56	3.51	0.48	0	0.237	0
pH H₂O	−3.83	0.60	4.77	4.31	4.50	4.99	0.37	0.44	0.58	4.46	0.48	0	0.548	0
Total C (g∙kg^− 1)	3.22	−1.33	−2.88	409	369	325	72	89	119	385	89.22	0.001	0.183	0.004
Total N (g∙kg⁻¹)	−4.49	3.73	1.48	9.8	12.6	12.1	2.76	3.20	3.46	11.0	3.27	0	0	0.140
С/N	5	−3	−3	45	30	27	18	8	9	38	16	0	0	0.003
Exchangeable acidity^a	4.25	−2.00	−3.49	4.96	3.80	2.79	1.80	1.58	1.49	4.31	1.86	0	0.046	0
Exchangeable Ca^a	−4.96	2.74	3.52	10.6	15.0	17.5	3.98	5.49	7.3	12.9	5.66	0	0.006	0
Exchangeable Mg^a	−4.51	0.87	5.39	2.09	2.95	4.95	1.03	1.36	2.81	2.74	1.75	0	0.385	0
Exchangeable K^a	−1.72	0.77	1.46	2.39	2.58	2.76	0.78	0.71	0.90	2.50	0.78	0.085	0.439	0.145
Exchangeable Na^a	2.45	−1.01	−2.20	0.13	0.11	0.09	0.06	0.06	0.05	0.12	0.06	0.014	0.313	0.028
Exchangeable Al^a	3.13	−1.37	−2.70	1.35	0.88	0.41	1.24	0.66	0.33	1.08	1.05	0.002	0.171	0.007
Exchangeable Mn^a	−3.07	1.94	1.85	0.81	1.09	1.18	0.48	0.56	0.59	0.95	0.54	0.002	0.053	0.065
BS (%)	−5.21	2.69	3.94	74.0	83.0	89.4	11.0	9.0	6.4	78.9	11.4	0	0.007	0
Extractable P (mg∙kg^− 1)	−3.88	2.58	2.16	700	814	840	127	184	215	754	170	0	0.010	0.031