Reconstruction of disturbance history of a typical broad-leaved Pinus koraiensis forest and mechanisms of disturbance occurrence

doi:10.17521/cjpe.2015.0013

Abstract

Abstract: Aims

The primary broad-leaved Pinus koraiensis forests in China are almost completely lost due to human and natural disturbances in recent years. Hence, it is critical to quantify disturbance regimes in their typical distribution areas. The aims of this study were to: (1) develop the disturbance chronology in a typical broad-leaved P. koraiensis forest in Xiaoxing’an Mountain; (2) investigate the disturbance characteristics of forest gaps; and (3) explore the possible mechanisms of disturbances.

Methods

A total of 461 incremental cores in P. koraiensis and 145 cores in Abies nephrolepis were collected from 44 forest gaps in a 6 hm² permanent monitoring plot. Two disturbance chronologies were developed respectively for P. koraiensis and A. nephrolepis by detecting growth release with boundary-line release criteria. The significant disturbance period was identified by the multi-taper method (MTM) of spectral analysis. In addition, the disturbance mechanisms were evaluated by the superposed epoch analysis (SEA) between percentage growth changes in the two tree species and wind speed, extreme temperatures and sunspot numbers by using the EVENT program.

Important findings

The variations of percentage growth changes (GC) in P. koraiensis and A. nephrolepis at the edges of forest gap were similar to those in closed canopy. However, there are apparent differences in GC among different gaps; the forest gap disturbance and its impact varied greatly. The strong growth release in P. koraiensis occurred in the periods 1733-1738, 1748-1752, 1769-1771, 1798-1801, 1827-1833, 1841-1844, 1935-1939, and 1968-1973, with significant disturbance peaks in 1752, 1770, 1800, 1830, 1842, 1937, and 1970. The growth release in A. nephrolepis occurred in the periods 1889-1904, 1932-1938, 1947-1973, and 1986-2005, with significant disturbance peaks in 1894, 1934, 1951, 1968 and 1990. The disturbances occurred at intervals of 2.0 a, 3.5 a, 3.8 a, 7.3-7.9 a, and 9.1-18.2 a in P. koraiensis, and of 3.5-3.6 a, 7.5-48.8 a, and 65-85 a in A. nephrolepis. Wind was a major mode of disturbances for producing forest gaps and resulting in tree growth releases in the primary broad-leaved P. koraiensis forest in the Xiaoxing’an Mountain. In addition, extreme temperatures could also affect the regime of tree growth release in this region. Solar activity may be another important mechanism of forest gap disturbance and tree growth release in the primary broad-leaved P. koraiensis forest; it affects the forest gap dynamics by changing local wind speed, air temperature, precipitation, and other large-scale climate patterns in the Xiaoxing’an Mountain.

Key words: disturbance history, growth release, tree rings, the broad-leaved Pinus koraiensis forest, Xiaoxing’an Mountain

ZHU Liang-Jun,JIN Guang-Ze,WANG Xiao-Chun. Reconstruction of disturbance history of a typical broad-leaved Pinus koraiensis forest and mechanisms of disturbance occurrence[J]. Chin J Plan Ecolo, 2015, 39(2): 125-139.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2015.0013

https://www.plant-ecology.com/EN/Y2015/V39/I2/125

Figures/Tables 13

Fig. 1 Comparison of percentage growth changes between gap trees and non-gap trees for Abies nephrolepis (A, B) and Pinus koraiensis (C, D) and differences in percentage growth changes between trees in gap trees and non-gap trees.

Table 1 Statistics of characteristics in growth release in Pinus koraiensis and Abies nephrolepis

项目 Items	臭冷杉 Abies nephrolepis		红松 Pinus koraiensis
项目 Items	中等以上释放 Moderate and major releases	主要释放 Major releases	中等以上释放 Moderate and major releases	主要释放 Major releases
释放样芯所占比例(%) Percentage of cores with release (%)	93.8	67.6	89.4	51.0
单个样芯平均释放次数(平均值(最小值-最大值)) No. of release per core (mean (Min - Max) )	2.16 (0-6)	1.05 (0-4)	2.85 (0-9)	0.87 (0-7)
单个林窗平均释放次数(次) No. of release per gap	7.11	3.45	29.89	9.16
生长释放期的平均长度(年)(平均值(最小值-最大值)) Mean release length (a)(mean (Min - Max) )	6.54 (5-11)	6 (5-11)	5.87 (5-19)	5.57 (5-13)
初次释放平均年龄(年)(平均值(最小值-最大值)) Mean age of the first release (a) (mean (Min - Max))	32.14 (15-116)	41.21 (15-128)	41.97 (12-190)	60.59 (13-223)
平均间隔期(年)(平均值(最小值-最大值)) Mean interval of releases per core (a) (mean (Min - Max) )	16.56 (2-67)	18.02 (2-63)	27.78 (2-162)	31.85 (2-168)
每10 a生长释放比例(%) Percentage of release per 10 a (%)	17.23	8.79	11.61	3.13
每10 a干扰强度(%) Disturbance intensity per 10 a (%)	7.98	8.37	4.07	3.60
干扰间隔(年) Disturbance interval (a)	125	119	245	278

Fig. 2 Disturbance chronology of Pinus koraiensis in Xiaoxing’an Mountain. A, Number of trees with release changes over time. B, Percentage of trees with release changes over time.

Fig. 3 Disturbance chronology of Abies nephrolepis in Xiaoxing’an Mountain. A, number of trees with release changes over time. B, percentage of trees with release changes over time.

Fig. 4 Multi-taper method spectrums analysis for Pinus koraiensis (A) and Abies nephrolepis (B) disturbance chronologies. Values shown in the figure represent significant periods (p < 0.01).

Fig. 5 Correlation coefficients between percentage growth changes in Pinus koraiensis (black bar) and Abies nephrolepis (blank bar) and monthly mean wind speed (A) and maximum anomalous wind speed (B). The gray columns indicate significant correlations (p < 0.05). The letter P represents the previous year. For instance, “P8” represents the previous August.

Fig. 6 Superimposed events analysis between maximum anomalous wind speed and percentage growth changes in Pinus koraiensis (A) and Abies nephrolepis (B).

Fig. 7 Correlation coefficients between percentage growth changes in Pinus koraiensis (A) and Abies nephrolepis (B) and minimum anomalous air temperature and maximum anomalous air temperature. The gray columns indicate significant correlations (p < 0.05). The letter P represents the previous year. For instance, “P8” represents the previous August.

Fig. 8 Superimposed events analysis between extreme air temperatures and percentage growth changes in Pinus koraiensis (A) and Abies nephrolepis (B). The gray columns indicate significant correlations (p < 0.05).

Fig. 9 Photos of windthrow. A, Fraxinus mandschurica tree uprooted by the wind. B, Pinus koraiensis tree broken on trunk.

Fig. 10 Correlation coefficients between percentage growth changes in Pinus koraiensis and Abies nephrolepis and monthly sunspot number anomalous value. The gray color of columns indicate significant correlations (p < 0.05). The letter P in the horizontal axis represents the previous year. For instance, “P8” represents the previous August.

Fig. 11 Superimposed events analysis between sunspot eruption and percentage growth changes in Pinus koraiensis (A) and Abies nephrolepis (B). The gray columns indicate significant correlations (p < 0.05).

Table 2 Correlation coefficients between monthly sunspot values and monthly anomalous weather climate variables

月份 Month	平均最低气温 Minimum mean air temperature	平均最高气温 Maximum mean air temperature	极端最低气温 Extremely minimum air temperature	极端最高气温 Extremely maximum air temperature	平均风速 Mean wind speed	最大风速 Maximum wind speed
P7	0.22	-0.32	0.24	0.21	0.48	-0.01
P8	0.10	0.28	-0.07	0.25	0.39	0.56
P9	0.43	-0.27	0.41	-0.22	0.38	0.43
P10	0.22	0.03	0.13	-0.30	-0.09	-0.21
P11	0.49	0.22	0.60	-0.01	0.13	0.03
P12	0.32	0.39	0.51	0.25	0.32	0.35
1	0.34	0.38	0.51	0.16	-0.55	-0.41
2	0.50	0.50	0.39	0.11	-0.39	-0.15
3	0.31	0.42	0.39	0.21	0.06	-0.31
4	0.28	-0.02	0.45	-0.15	0.45	0.23
5	-0.31	-0.24	0.18	-0.21	-0.17	-0.39
6	-0.37	-0.47	-0.07	-0.36	0.07	-0.21
7	0.16	-0.40	0.18	0.11	0.32	-0.10
8	0.08	0.10	-0.24	0.03	0.37	0.40
9	0.53	-0.14	0.54	-0.19	0.02	0.14
10	0.18	-0.02	0.10	-0.49	0.00	-0.07

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