Influence of Long-Term Thinning on the Biomass Carbon and Soil Respiration in a Larch (Larix gmelinii) Forest in Northeastern China
Table 1
Long-term thinning effects on the growth and biomass C accumulation of species found in larch plantations. Values in parentheses are standard deviations.
Parameters
Treatment
Arbor layer
Shrubs and saplings
Total
Larix gmelinii
Betula platyphylla
Fraxinus mandshurica
Arbor total
Diameter (cm)
Thinned
21.7 (4.7)b
19.2 (2.4)a
18.1 (9.2)a
—
1.34 (1.57)a
—
Unthinned
18.0 (5.3)a
21.8 (3.8)a
14.2 (6.7)a
—
2.12 (2.06)a
—
Density (No·hm−2)*
Thinned
950 (45)a
38 (15)a
63 (16)a
1050 (40)a
10500 (550)a
—
Unthinned
1063 (67)b
100 (18)b
100 (24)b
1263 (60)b
7700 (450)b
—
Mean height (m)
Thinned
18.5 (1.9)a
17.5 (3.4)a
16.6 (6.5)a
—
1.68 (1.22)a
—
Unthinned
17.8 (2.0)a
18.1 (4.3)a
13.8 (6.8)a
—
2.08 (1.46)a
—
Biomass (Mg·ha−1)
Thinned
216.0 (12.1)a
7.1 (3.1)b
5.0 (1.3)b
231.1 (13.2)a
1.52 (0.73)a
232.6
Unthinned
156.4 (13.1)b
15.1 (4.2)a
12.9 (3.2)a
191.2 (15.1)b
2.51 (0.63)a
193.7
Biomass C (g C m−2)
Thinned
10800 (605)a
355 (155)a
250 (38)b
11555 (660)a
76 (36)a
11630
Unthinned
7820 (655)b
756 (210)b
646 (160)a
9560 (755)b
126 (31)a
9686
Difference (g C m−2)
Thinned-Unthinned
2980
−400
−396
1994
−50
1944
Annual C change (g C m−2 yr−1)#
114.6
−15.4
−15.2
76.7
−1.9
74.8
Tree density for arbor layer species was calculated for trees of DBH > 10 cm, while for shrubs and saplings it was calculated for plants of basal diameter > 0.4 cm. #The annual C change is the difference between thinned and unthinned divided by the total thinning duration (26 years).