Table 2 Forested land area, volume, converted stem C, and estimated total C with different WDs for all forests for eight inventory periods from 1973 to 2013 in China. Estimated total C is based on AB biomass, Estimated forest contains primarily timber forests and do not contain economic, bamboo, under storey, and shrub forests

1st

1973–1976

101.68

7.78

76.1

0.451 (average)

1.7

3.0

58.3%

29.5

3.5–4.4

0.429 (average, − 5%)

1.7

2.9

28.1

0.474 (average, + 5%)

1.8

3.1

30.8

0.700 (upper limit)

2.7

4.4

43.4

2nd

1977–1981

95.62

7.98

83.4

0.465 (average)

1.9

3.2

57.7%

33.6

3.6–4.7

0.442 (average, −5%)

1.8

3.1

32.1

0.488 (average, + 5%)

1.9

3.4

35.1

0.700 (upper limit)

2.8

4.6

48.1

3rd

1984–1988

102.19

8.09

79.2

0.470 (average)

1.9

3.3

57.4%

32.4

3.2–5.0

0.447 (average, −5%)

1.8

3.2

31.0

0.494 (average, + 5%)

2.0

3.5

33.9

0.700 (upper limit)

2.8

4.7

46.0

4th

1989–1993

108.64

9.09

83.6

0.469 (average)

2.1

3.6

58.6%

33.5

3.8–9.1

0.446 (average, −5%)

2.0

3.5

32.0

0.493 (average, + 5%)

2.2

3.8

35.0

0.700 (upper limit)

3.2

5.2

47.5

5th

1994–1998

129.20

10.09

78.0

0.478 (average)

2.4

4.1

58.4%

31.9

4.6–5.7

0.454 (average, −5%)

2.3

3.9

30.5

0.502 (average, + 5%)

2.5

4.3

33.3

0.700 (upper limit)

3.5

5.8

44.6

6th

1999–2003

142.79

12.10

84.7

0.473 (average)

2.9

4.9

58.9%

34.0

5.2–7.7

0.450 (average, −5%)

2.7

4.6

32.5

0.497 (average, + 5%)

3.0

5.1

35.5

0.700 (upper limit)

4.2

6.8

47.9

7th

2004–2008

155.59

13.36

85.9

0.468 (average)

3.1

5.3

58.9%

34.1

5.8–6.7

0.444 (average, −5%)

3.0

5.1

32.6

0.491 (average, + 5%)

3.3

5.5

35.6

0.700 (upper limit)

4.7

7.6

48.5

8th

2009–2013

164.60

14.78

89.7

0.469 (average)

3.5

5.9

59.2%

35.5

6.2–8.4

0.446 (average, −5%)

3.3

5.6

34.0

0.493 (average, + 5%)

3.6

6.1

37.1

0.700 (upper limit)

5.2

8.3

50.5

220.61^d

23.00^d

104.3

0.469 (?)

5.4

9.1

59.2% (?)

41.3

–

–

1.5

–

–

–

–

3.0

–

–

–

–

12.6

–

–