Table 6. Comparisons of altitude-related characteristics for the mean tree biological age and corresponding sample size in six typical periods.

Elevation/m	1204–1253/AD	1254–1303/AD	1435–1484/AD	1550–1599/AD	1684–1733/AD	1961–2010/AD
3551–3600	63/6	104/9	229/10	338/11	284/15	265/12
3601–3650	69/1	119/1	51/3	155/4	73/15	355/3
3651–3700	176/9	217/10	369/11	490/10	582/4	183/4
3701–3750	108/10	156/11	146/13	232/14	305/15	576/8
3751–3800	108/36	155/41	236/43	270/43	249/51	351/27
3801–3850	284/11	245/13	186/10	274/12	351/11	417/5
3851–3900	55/12	93/16	241/19	260/25	215/14	517/7
3901–3950	78/14	121/16	254/19	303/24	199/16	407/8
3951–4000	113/12	111/16	233/21	284/25	153/33	380/16
4001–4050	149/6	199/6	274/7	288/8	312/5	589/3
>4050	150/1	150/1	150/1	150/1	150/1