Aboveground live tree carbon stock and change in forests of conterminous United States: influence of stand age

Table 2 Carbon accumulation rates (metric tons C/hectare/year, tC/ha/yr) by region and age class. Estimates are for aboveground live tree carbon. N = number of paired plots on which the estimate is based

Region	Age class	Average rate (tC/ha/yr)	N
Northeast	0–20	1.47	425
	21–40	1.16	897
	41–60	0.69	1823
	61–80	0.36	2782
	81–120	0.27	2083
	120+	0.07	136
	Overall	0.55
Northern Lake States	0–20	1.13	946
	21–40	0.82	1221
	41–60	0.26	2008
	61–80	0.14	2392
	81–120	0.16	1343
	120+	0.41	184
	Overall	0.40
South Central	0–20	2.41	2536
	21–40	0.52	1780
	41–60	0.37	2614
	61–80	0.11	1791
	81–120	0.04	433
	120+	1.33	7
	Overall	0.90
Southeast	0–20	2.03	2422
	21–40	0.29	1641
	41–60	0.49	1354
	61–80	0.45	1335
	81–120	0.77	763
	120+	0.57	61
	Overall	0.96
Central States	0–20	1.17	152
	21–40	0.97	490
	41–60	0.39	1058
	61–80	0.18	1025
	81–120	0.07	551
	120+	−0.49	47
	Overall	0.38
Great Plains	0–20	0.28	12
	21–40	0.69	81
	41–60	0.38	115
	61–80	−0.14	107
	81–120	−0.39	91
	121–160	−1.46	13
	161–300	0.17	4
	300+	–
	Overall	0.08
Rocky Mountain-North	0–20	0.54	421
	21–40	0.85	163
	41–60	0.78	192
	61–80	0.52	444
	81–120	−0.25	956
	121–160	−0.63	470
	161–300	−1.00	411
	300+	−0.80	19
	Overall	−0.70
Rocky Mountain-South	0–20	0.03	586
	21–40	0.02	229
	41–60	0.10	339
	61–80	0.03	776
	81–120	−0.19	2294
	121–160	−0.30	1578
	161–300	−0.28	1883
	300+	−0.14	112
	Overall	−0.18
Pacific Northwest - East	0–20	0.71	251
	21–40	1.09	239
	41–60	0.75	446
	61–80	0.44	890
	81–120	0.26	1167
	121–160	0.35	411
	161–300	0.28	406
	300+	0.42	42
	Overall	0.45
Pacific Northwest - West	0–20	3.06	516
	21–40	3.45	626
	41–60	0.33	355
	61–80	1.03	339
	81–120	1.63	449
	121–160	1.50	290
	161–300	0.64	555
	300+	0.38	205
	Overall	1.74
Pacific Southwest	0–20	1.32	94
	21–40	2.50	161
	41–60	1.17	268
	61–80	0.90	437
	81–120	0.45	650
	121–160	0.07	293
	161–300	−0.15	368
	300+	−0.64	73
	Overall	0.58

ISSN: 1750-0680