Table 1 A mixed linear model for the effects of the forest layers and tree species on the pH values and C/N/P contents. Post hoc multiple comparisons for the variability of pH values and C/N/P contents (C carbon, N nitrogen, P phosphorous, DOC dissolved organic carbon, DN dissolved nitrogen, DP dissolved phosphorous) in litter (L), fermentative (F) and humus (H) layers of the subalpine forests in China. (mean ± SD)

Spruce Picea asperata

L

6.6 ± 0.4^bA

38.2 ± 10.9^aB

61.4 ± 10.4^aD

236.4 ± 36.7^aB

417.2 ± 24.3^aC

10.4 ± 1.2^aB

2.5 ± 0.8^aB

F

7.1 ± 0.3^abA

15.5 ± 8.6^bA

49.4 ± 7.5^abD

82.8 ± 23.5^bBC

219.0 ± 34.7^bC

8.5 ± 1.4^bC

2.2 ± 0.7^aC

H

7.3 ± 0.4^aA

9.7 ± 5.2^bA

22.8 ± 11.8^bB

42.2 ± 18.2^cA

137.1 ± 94.1^bB

7.0 ± 0.6^bB

2.0 ± 0.4^aB

Fir Abies faxoniana

L

6.1 ± 0.2^aB

39.7 ± 9.9^aB

105.4 ± 13.6^aB

203.8 ± 19.8^aB

400.4 ± 41.4^aC

12.0 ± 1.5^abB

4.9 ± 0.2^aA

F

6.1 ± 0.4^aB

25.0 ± 14.9^bA

74.8 ± 20.1^bC

68.4 ± 16.2^bC

288.5 ± 75.1^bC

13.9 ± 1.0^aAB

1.7 ± 0.3^bC

H

6.1 ± 0.6^aB

13.8 ± 3.3^bA

44.0 ± 8.9^cA

31.8 ± 5.9^cA

221.7 ± 28.2^bA

11.0 ± 2.3^bA

5.0 ± 0.6^aA

Birch Betula platyphylla

L

4.7 ± 0.2^bC

57.7 ± 6.1^aA

174.2 ± 10.5^bA

454.8 ± 38.9^aA

573.7 ± 34.6^aA

13.9 ± 1.5^abA

2.5 ± 0.4^aB

F

5.4 ± 0.3^aC

22.8 ± 6.4^bA

202.2 ± 20.4^aA

243.8 ± 41.2^bA

485.4 ± 86.7^aA

16.4 ± 2.6^aA

3.3 ± 0.9^aB

H

5.0 ± 0.4^abC

12.1 ± 1.3^cA

54.8 ± 21.7^cA

33.0 ± 19.2^cA

288.2 ± 85.2^bA

12.6 ± 3.2^bA

2.5 ± 0.5^aB

Rhododendron Rhododendron lapponicum

L

5.1 ± 0.4^aC

52.2 ± 11.8^aA

84.4 ± 11.1^bC

200.0 ± 35.3^aB

495.6 ± 60.8^aB

8.5 ± 1.3^bC

5.6 ± 0.9^aA

F

5.2 ± 0.5^aC

15.7 ± 2.8^bA

101.6 ± 12.9^aB

125.8 ± 64.1^bB

367.5 ± 58.0^bB

12.8 ± 2.2^aB

6.2 ± 0.8^aA

H

4.9 ± 0.6^aC

10.5 ± 1.6^bA

54.8 ± 12.4^cA

35.8 ± 7.3^cA

213.5 ± 72.9^cA

9.4 ± 2.4^bAB

2.3 ± 0.7^bB

Species effect

F (P) df = 3

74.70**

4.44**

37.38**

17.04**

20.78**

20.78**

11.00**

Layer effect

F (P) df = 2

3.31*

57.11**

37.44**

56.82**

76.43**

5.80**

2.84*