Growth dynamics and tree form quality of mixed Betula alnoides-Castanopsis hystrix plantation

doi:10.12302/j.issn.1000-2006.202009009

JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 2022, Vol. 46 ›› Issue (1): 97-105.doi: 10.12302/j.issn.1000-2006.202009009

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Growth dynamics and tree form quality of mixed Betula alnoides-Castanopsis hystrix plantation

TANG Jixin¹^,²(), ZHU Xueping¹, JIA Hongyan¹^,^*(), ZENG Ji¹, GUO Wenfu¹, HUANG Dewei¹

1. Experimental Center of Tropical Forestry, Chinese Academy of Forestry, Pingxiang 532600, China
2. Guangxi Youyiguan Forest Ecosystem Research Station, Pingxiang 532600, China

Received:2020-09-03 Accepted:2020-11-04 Online:2022-01-30 Published:2022-02-09
Contact: JIA Hongyan E-mail:tangjixin999@126.com;rlzxjhy@126.com

Abstract

Abstract:

【Objective】 This study explored the growth dynamics and tree form quality of a mixed Betula alnoides-Castanopsis hystrix plantation with row cluster and the same age. This was carried out to provide management reference for large-diameter timber cultivation of the mixed plantation.【Method】 An 11-year-old mixed plantation was adopted as the research object. Nine and ten sample trees of species B. alnoides and C. hystrix, respectively,were selected for stem analysis. The growth dynamics, diameter class accumulation composition, stem form, crown height ratio and stem branching ratio of different tree species in the plantation were analyzed. 【Result】 The rapid stage of diameter at breast height (DBH) growth (annual growth amount >1.0 cm, the same below) of average and dominant trees of B. alnoides occurred in the 3rd to 7th and 3rd to 9th years,respectively.The DBH rapid-growth period of the average trees of C. hystrix occurred in the 4th to 8th year, and the DBH of dominant trees of C. hystrix occurred from the 3rd year; in the 11th year, this was still on going. Tree height rapid-growth period of average and dominant trees of B. alnoides occurred during the 1st to 7th and 1st to 8th years.The rapid-growth period of tree height of average trees of C. hystrix mainly occurred in the 3rd to 7th year, while for the dominant trees of this species occurred in the 1st to 7th year. For B. alnoides, the rapid-growth periods of a single volume of average and dominant trees commenced in the 6th and 5th year, respectively;in the 11th year, this was still on going. For C. hystrix, in the first 11 years of afforestation, the growth of the single volume of average trees was still in the slow stage. From the 4th year, the total growth of DBH, tree height, and single volume of average trees for B. alnoides were significantly higher than the total growth of the average trees of C. hystrix (P<0.05). The total growth of the DBH, tree height, and single volume of the dominant trees for B. alnoides were significantly higher than the counterparts for C. hystrix from the 5th, 8th, and 5th years, respectively (P<0.05). The binary volume model (V=a×10^-4×D^b×H^c) demonstrated a good fitting and prediction effect on the single volume for B. alnoides and C. hystrix. For both species, the distribution of diametral class accumulation was approximately normal. In the 11-year-old mixed plantation, the ratio of excellent stem form of B. alnoides and C. hystrix was 67.71% and 97.31%, respectively, and stem branching ratio of both species was <6.0%. 【Conclusion】 During the middle and young stages, B. alnoides occurred in upper layer of the mixed plantation.In the mixed plantation, it was conducive to decent stem form quality and tree viability of B. alnoides and C. hystrix. The fast-growth period of DBH, tree height of the dominant trees of the two species were larger than the growth of average trees.

Key words: Betula alnoides, Castanopsis hystrix, mixed plantation, growth dynamics, tree form quality

CLC Number:

S757

TANG Jixin, ZHU Xueping, JIA Hongyan, ZENG Ji, GUO Wenfu, HUANG Dewei. Growth dynamics and tree form quality of mixed Betula alnoides-Castanopsis hystrix plantation[J]. JOURNAL OF NANJING FORESTRY UNIVERSITY, 2022, 46(1): 97-105.

Figures/Tables 9

Fig.1

Table 1

Fig.2

Table 2

Student’s t test and growth performance of different tree species of the mixed plantation"

林龄/a forest age	树种 tree species	林分密度/ (株·hm^-2) stand density	平均木胸径/cm mean DBH		平均木树高/m mean height		平均木单株材积/ ×10^-2 m³ mean individual volume		优势木胸径/cm mean DBH of dominant tree		优势木树高/m tree height of dominant tree		优势木单株材积/ ×10^-2 m³ mean individual volume of dominant tree
林龄/a forest age	树种 tree species	林分密度/ (株·hm^-2) stand density	总生长量 total growth	连年生长量 annul increment	总生长量 total growth	连年生长量 annul increment	总生长量 total growth	连年生长量 annul increment	总生长量 total growth	连年生长量 annul increment	总生长量 total growth	连年生长量 annul increment	总生长量 total growth	连年生长量 annul increment
1	A	950	0	0	1.06±0.33	1.06±0.33	0	0	0	0	1.30±0.00	1.30±0.00	0±0.01	0±0.01
1	B	950	0	0	0.81±0.27	0.81±0.27	0	0	0	0	1.18±0.27	1.18±0.27	0	0
2	A	678	0.12±0.13	0.12±0.13	2.46±1.15	1.40±0.86	0±0.01	0±0.01	0.78±0.61	0.78±0.61	3.60±0.00	2.30±0.00	0.02±0.02	0.01±0.02
2	B	873	0.06±0.13	0.06±0.13	1.76±1.03	0.96±0.75	0	0	0.48±0.37	0.48±0.37	3.14±1.03	1.96±0.76	0±0.01	0±0.01
3	A	678	1.48±1.09	1.36±0.98	4.80±1.10	2.34±1.18	0.06±0.06	0.06±0.06	3.23±1.23	2.45±0.66^*	6.10±1.00	2.50±1.00	0.24±0.17	0.22±0.15
3	B	873	0.50±0.32	0.44±0.21	4.60±1.00	2.84±0.95		0	1.76±0.88	1.28±0.55^*	5.20±0.89	2.06±0.13	0.08±0.07	0.08±0.06
4	A	678	4.36±1.65^*	2.88±0.99^*	8.40±1.10^*	3.60±0.89	0.47±0.25^*	0.41±0.21^*	6.00±2.05	2.78±0.83	9.60±1.63	3.50±1.00	0.86±0.56	0.63±0.38
4	B	873	2.04±0.65^*	1.54±0.46^*	6.80±1.10^*	2.20±1.10	0.12±0.06^*	0.03±0.01^*	4.08±0.96	2.32±0.30	8.40±1.10	3.20±1.10	0.46±0.22	0.37±0.16
5	A	678	6.96±2.15^**	2.60±0.74^*	12.20±0.89^**	3.80±0.45^**	1.41±0.85^*	0.94±0.64^*	9.83±2.25^*	3.83±0.66^**	12.85±0.96	3.25±0.96	2.89±1.18^*	2.03±0.70^**
5	B	873	3.48±0.31^**	1.44±0.61^*	8.80±1.30^**	2.00±0.71^**	0.38±0.12^*	0.08±0.02^*	5.88±1.08^*	1.80±0.19^**	11.20±1.67	2.80±1.10	1.21±0.45^*	0.75±0.25^**
6	A	678	9.14±1.74^**	2.18±0.69^*	15.20±0.89^**	3.00±1.41^*	3.08±1.50^*	1.67±0.69^**	12.92±2.25^**	3.10±0.12^**	15.10±1.00	2.25±1.26	6.66±1.94^**	3.78±0.78^**
6	B	873	4.68±0.52^**	1.20±0.46^*	10.20±0.89^**	1.40±0.55^*	0.84±0.27^*	0.14±0.04^**	7.80±1.15^**	1.92±0.23^**	13.60±1.41	2.40±0.89	2.72±1.00^**	1.51±0.57^**
7	A	678	10.88±1.06^**	1.74±0.88	16.66±0.93^**	1.46±0.78	5.50±1.25^**	2.42±0.51^**	15.48±2.29^**	2.55±0.41^*	18.10±1.92	3.00±1.15	13.19±3.24^**	6.52±1.44^**
7	B	873	5.84±0.40^**	1.16±0.21	11.30±0.98^**	1.10±0.55	1.44±0.36^**	0.21±0.05^**	9.70±1.25^**	1.90±0.28^*	15.36±2.00	1.76±0.72	4.66±1.53^**	1.94±0.60^**
8	A	678	11.82±0.96^**	0.94±0.50	17.10±0.96^**	0.44±0.09	7.66±1.19^**	2.16±0.42^**	16.65±2.45^**	1.18±0.31^**	20.35±1.50^*	2.25±0.50^**	17.72±4.31^**	4.53±1.29^*
8	B	873	6.92±0.52^**	1.08±0.26	11.98±0.93^**	0.68±0.30	2.23±0.50^**	0.28±0.06^**	11.46±1.16^**	1.76±0.13^**	16.20±2.20^*	0.84±0.38^**	7.16±2.00^**	2.50±0.59^*
9	A	678	12.46±0.90^**	0.64±0.21	17.52±1.02^**	0.42±0.11	9.50±1.17^**	1.84±0.41^**	17.85±2.47^**	1.20±0.37	21.15±183*	0.80±0.40	22.86±5.10^**	5.14±0.95^*
9	B	873	7.78±0.47^**	0.86±0.19	12.60±0.92^**	0.62±0.24	3.09±0.56^**	0.34±0.06^**	13.10±1.40^**	1.64±0.62	16.64±2.04^*	0.44±0.21	10.41±2.87^**	3.26±1.06^*
10	A	226	12.90±0.87^**	0.44±0.11^**	18.04±0.80^**	0.52±0.33	11.20±1.09^**	1.70±0.29^**	18.83±2.61^*	0.98±0.39^**	21.68±2.11*	0.53±0.38	28.76±6.86^**	5.90±1.93
10	B	291	8.72±0.30^**	0.94±0.27^**	13.10±0.90^**	0.50±0.20	4.11±0.57^**	0.41±0.06^**	15.14±1.31*	2.04±0.31^**	17.18±1.85^*	0.54±0.25	14.71±3.50^**	4.30±0.68
11	A	226	13.40±0.81^**	0.50±0.27	18.52±0.66^**	0.52±0.33	12.56±1.19^**	1.36±0.46^*	19.88±2.31^*	1.05±0.30	22.23±2.38^*	0.55±0.34	33.87±7.58^**	5.12±1.30^*
11	B	291	9.44±0.51^**	0.72±0.18	13.60±0.98^**	0.50±0.21	4.89±0.58^**	0.45±0.05^*	16.40±1.13^*	1.26±0.34	17.70±1.70^*	0.52±0.26	17.92±3.49^**	3.21±0.45^*

Table 2

Fig.3

Table 3

Fig.4

Table 4

Table 5

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径阶/cm diameter	径阶株数百分比/% percent of tree number in the diameter class
径阶/cm diameter	A	B	A	B	A	B	A	B
≤4	0.33	0.51	—	—	—	—	—	—
6	3.45	13.90	—	—	—	—	—	—
8	10.51	22.96	—	—	—	—	—	—
10	14.12	26.15	—	5	—	10.42	—	13.60
12	15.60	19.01	—	—	—	—	—	—
14	18.72	10.71	4	—	14.05	—	18.68	—
16	19.54	4.08	1	—	16.10	—	17.90	—
18	11.66	1.91	—	4	—	17.24	—	17.80
20	4.43	0.51	2	1	19.75	19.90	22.60	18.30
22	1.15	0.13	—	—	—	—	—	—
≥24	0.49	0.13	2	—	24.10	—	21.85	—
合计total	100	100	9	10	—	—	—	—

树种 tree species	模型 model	样本数 sample number	参数parameter			模型评价指标evaluated index of model
树种 tree species	模型 model	样本数 sample number	a	b	c	R²	σ(RMD)/%	σ(RRMSE)/%
西南桦 B. alnoides	(4)	9	0.528 1±0.149 0	1.999 0±0.067 6	0.865 4±0.100 8	0.997 0	-0.07	3.10
红椎 C. hystrix	(4)	10	1.061 4±0.417 8	2.151 9±0.147 6	0.453 7±0.190 0	0.993 2	0.33	5.17

树种 tree species	不同干形等级占比/% percentage of diffrent grade of stem form				不同冠高比等级占比/% percentage of diffrent grade of crown height ratio				分杈率/% bifurcation percentage
树种 tree species	优 best grade	良 second grade	中 third grade	差 last grade	优 best grade	良 second grade	中 third grade	差 last grade	分杈率/% bifurcation percentage
西南桦 B. alnoides	30.21	37.50	29.17	3.13	36.46	58.33	5.21	0.00	5.10
红椎 C. hystrix	82.96	14.35	2.69	0.00	0.90	4.04	69.96	25.11	0.51

树种 tree species	占比/% percentage
树种 tree species	A级 grade A	B级 grade B	C级 grade C	D级 grade D	E级 grade E
西南桦 B. alnoides	7.89	47.04	38.49	4.61	1.97
红椎 C. hystrix	10.46	52.68	36.48	0.38	0

Growth dynamics and tree form quality of mixed Betula alnoides-Castanopsis hystrix plantation

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