Table 2 Information of intra-annual density fluctuation (IADF) formation in increment coring trees. The ring width before (rw_b) and after (rw_a) IADF formation and their total (rw_t) were presented; Bst_IADF indicates the extra stem biomass when IADF formation; % increase means percent increase in stem biomass when IADF formation (%)

I02

24.7

1620

219

1839

0.225

13.6

I04

15.3

504

153

657

0.106

30.5

I05

15.6

532

242

773

0.276

33.1

I06

13.4

842

138

980

0.091

15.7

I07

10.8

1039

192

1231

0.102

18.6

I08

16.7

807

199

1006

0.248

14.9

I09

17.0

1094

219

1313

0.166

20.1

I10

15.5

837

177

1015

0.125

25.1

I11

14.1

1774

171

1945

0.097

11.3

I14

20.0

1135

154

1289

0.133

13.7

I15

16.5

785

114

899

0.084

14.6

I16

13.8

693

89

782

0.057

12.9

I18

16.9

2076

147

2222

0.112

7.2

I20

9.8

851

66

917

0.032

8.2

I21

14.2

1353

177

1530

0.117

13.2

I22

17.8

790

180

970

0.141

22.9

I23

16.0

1616

122

1738

0.088

7.6

I24

17.4

1088

237

1325

0.184

21.9

I25

5.3

557

72

629

0.022

13.0

I27

14.1

721

315

1036

0.205

43.9

I28

13.8

1239

119

1358

0.097

8.3

I30

17.2

1325

98

1423

0.075

7.4

I32

11.7

955

81

1036

0.046

8.5

I35

15.5

1296

138

1434

0.093

12.8

I36

7.5

783

127

910

0.050

16.4

I38

20.2

1518

84

1602

0.073

5.6

I39

22.9

1092

113

1205

0.104

10.9

I40

21.0

614

164

778

0.147

26.8

I44

16.2

785

180

965

0.131

23.0

I46

15.2

1417

233

1650

0.163

17.1

I48

15.7

808

234

1042

0.167

30.0

I49

20.6

1625

195

1820

0.173

12.1

Mean

15.7

1068

161

1229

0.123

16.9

SD

4.0

393

58

396

0.060

8.7