Soil carbon storage and its determinants in the forests of Shaanxi Province, China

doi:10.17521/cjpe.2017.0102

Abstract

Abstract:

Aims The bank of soil carbon of forests plays an important role in the global carbon cycle. Our aim is to understand the characteristics of soil carbon storage and its determinants in the forests in Shaanxi Province.Methods The data of forest inventory in 2009 and resampling in 2011 were used to analyze the characteristics of soil carbon storage and its determinants in the forest soil in Shaanxi Province.Important findings The soil carbon storage in the forests in Shaanxi Province was 579.68 Tg. Soil carbon storage of Softwood and Hardwood forests were the highest among all forest types, accounting for 36.35% of the whole province forest soil carbon storage. The forest soil carbon storage was 4.15 times greater in the natural forest (467.17 Tg) than that in the plantations. The young and middle-aged forests were the main contributors to the total carbon storage across all age groups, accounting for about 57.30% of the total forest soil carbon storage. The average soil carbon density of forests in Shaanxi Province was 90.68 t∙hm^-2, in which the soil carbon density of Betula forests was the highest (141.74 t∙hm^-2). Soil carbon density of different forest types were gradually decreased with soil depth. In addition, it was highest in middle-aged forest. Soil carbon density was higher in the natural forest ecosystems than that in the plantations within the each age group, indicating natural forest ecosystems have higher capacity of carbon sequestration. Differences in the spatial patterns between carbon storage and density indicated that carbon storage was related to forest coverage. The soil carbon density and storage of forests in Yulin were the lowest across the province. This suggests that, in order to enhance the regional carbon sequestration capacity in this region, we need to appropriately strengthen artificial afforestation activities and manage them scientifically and rationally. The soil carbon density of forests in Shaanxi Province decreased with the increase of longitude, latitude, and annual temperature, but increased with the increase of altitude and annual rainfall. This study provides data basis for provincial estimation of forest soil carbon bank in China.

Key words: forest soils, carbon storage, carbon density, spatial distribution, influencing factors

Xi LI, Fang WANG, Yang CAO, Shou-Zhang PENG, Yun-Ming CHEN. Soil carbon storage and its determinants in the forests of Shaanxi Province, China[J]. Chin J Plan Ecolo, 2017, 41(9): 953-963.

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https://www.plant-ecology.com/EN/Y2017/V41/I9/953

Figures/Tables 9

References 40

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林型(代码) Forest type (Code)	主要树种 Dominant tree species	样点数 No. of plots
辽东栎林 Forest of Quercus wutaishanica (A)	辽东栎 Quercus wutaishanica	13
栓皮栎林 Forest of Quercus variabilis (B)	栓皮栎 Quercus variabilis	24
其他栎类林 Other quercus forests (C)	槲栎 Quercus aliena, 麻栎 Quercus acutissima	15
桦木林 Forest of Betula spp. (D)	白桦 Betula platyphylla, 红桦 Betula albosinensis	7
杨树林 Forest of Populus spp. (E)	毛白杨 Populus tomentosa, 山杨 Populus davidiana, 青杨 Populus tcathayana	13
刺槐林 Forest of Robinia pseudoacacia (F)	刺槐 Robinia pseudoacacia	12
油松林 Forest of Pinus tabuliformis (G)	油松 Pinus tabuliformis	12
其他松类林 Forest of other pines and conifer (H)	巴山松 Pinus henryi, 华山松 Pinus armandi, 马尾松 Pinus massoniana	9
其他针叶林 Forest of other conifer (I)	刺柏 Juniperus formosana, 侧柏 Platycladus orientalis	3
软阔与硬阔类林 Forest of softwood and hardwood (J)	椿树 Ailanthus altissima, 栾树 Koelreuteria paniculata, 板栗 Castanea mollissima, 木姜子 Litsea pungens	10
针阔混交林 Mixed coniferous and broad-leaf forest (K)	油松与辽东栎 Pinus tabulaeformis and Quercus wutaishanica, 油松与栓皮栎 Pinus tabuliformis and Quercus wutaishanica	3

林型(代码) Forest type (Code)	主要树种 Dominant tree species	样点数 No. of plots
辽东栎林 Forest of Quercus wutaishanica (A)	辽东栎 Quercus wutaishanica	13
栓皮栎林 Forest of Quercus variabilis (B)	栓皮栎 Quercus variabilis	24
其他栎类林 Other quercus forests (C)	槲栎 Quercus aliena, 麻栎 Quercus acutissima	15
桦木林 Forest of Betula spp. (D)	白桦 Betula platyphylla, 红桦 Betula albosinensis	7
杨树林 Forest of Populus spp. (E)	毛白杨 Populus tomentosa, 山杨 Populus davidiana, 青杨 Populus tcathayana	13
刺槐林 Forest of Robinia pseudoacacia (F)	刺槐 Robinia pseudoacacia	12
油松林 Forest of Pinus tabuliformis (G)	油松 Pinus tabuliformis	12
其他松类林 Forest of other pines and conifer (H)	巴山松 Pinus henryi, 华山松 Pinus armandi, 马尾松 Pinus massoniana	9
其他针叶林 Forest of other conifer (I)	刺柏 Juniperus formosana, 侧柏 Platycladus orientalis	3
软阔与硬阔类林 Forest of softwood and hardwood (J)	椿树 Ailanthus altissima, 栾树 Koelreuteria paniculata, 板栗 Castanea mollissima, 木姜子 Litsea pungens	10
针阔混交林 Mixed coniferous and broad-leaf forest (K)	油松与辽东栎 Pinus tabulaeformis and Quercus wutaishanica, 油松与栓皮栎 Pinus tabuliformis and Quercus wutaishanica	3

林型 Forest type	土壤碳密度 Carbon density in soil (t&#x02219;hm^-2)
林型 Forest type	I (0-10 cm)	II (10-20 cm)	III (20-30 cm)	IV (30-50 cm)	V (50-100 cm)	合计 Total
A	23.91 &#x000b1; 1.06^ab	14.13 &#x000b1; 0.65^bc	10.11 &#x000b1; 0.57^c	14.66 &#x000b1; 0.84^bc	24.20 &#x000b1; 2.17^b	87.01 &#x000b1; 3.81^bc
B	21.29 &#x000b1; 1.06^ab	14.02 &#x000b1; 0.66^bc	11.11 &#x000b1; 0.57^c	17.86 &#x000b1; 1.12^bc	33.81 &#x000b1; 2.11^ab	98.10 &#x000b1; 4.58^bc
C	18.76 &#x000b1; 0.86^ab	11.49 &#x000b1; 0.68^bc	7.99 &#x000b1; 0.52^c	11.61 &#x000b1; 0.90^bc	21.09 &#x000b1; 1.61^b	70.94 &#x000b1; 3.50^c
D	29.93 &#x000b1; 2.37^a	21.95 &#x000b1; 2.11^a	19.58 &#x000b1; 1.63^a	28.47 &#x000b1; 3.21^a	41.81 &#x000b1; 3.00^a	141.74 &#x000b1; 10.28^a
E	20.44 &#x000b1; 1.19^ab	13.06 &#x000b1; 0.91^bc	9.30 &#x000b1; 0.77^c	14.04 &#x000b1; 1.19^bc	31.27 &#x000b1; 2.96^ab	88.10 &#x000b1; 5.31^bc
F	14.86 &#x000b1; 1.41^b	7.87 &#x000b1; 0.88^c	6.34 &#x000b1; 0.73^c	9.51 &#x000b1; 0.92^c	19.67 &#x000b1; 1.74^b	58.26 &#x000b1; 5.16^c
G	19.01 &#x000b1; 0.97^ab	12.45 &#x000b1; 1.00^bc	9.44 &#x000b1; 0.61^c	13.06 &#x000b1; 0.86^bc	28.34 &#x000b1; 2.52^b	82.29 &#x000b1; 4.73^bc
H	21.70 &#x000b1; 1.44^ab	13.68 &#x000b1; 1.19^bc	9.91 &#x000b1; 0.97^c	15.24 &#x000b1; 2.45^bc	27.16 &#x000b1; 3.95^b	87.69 &#x000b1; 8.79^bc
I	20.47 &#x000b1; 1.57^ab	11.88 &#x000b1; 1.49^bc	7.66 &#x000b1; 1.05^c	12.70 &#x000b1; 2.58^bc	26.02 &#x000b1; 5.29^b	78.73 &#x000b1; 10.73^bc
J	23.41 &#x000b1; 2.44^ab	16.53 &#x000b1; 1.87^ab	12.99 &#x000b1; 1.50^b	19.54 &#x000b1; 2.64^b	34.98 &#x000b1; 3.96^ab	107.46 &#x000b1; 10.77^ab
K	30.63 &#x000b1; 4.63^a	13.63 &#x000b1; 1.36^bc	9.57 &#x000b1; 0.90^c	13.89 &#x000b1; 1.65^bc	23.64 &#x000b1; 3.08^b	91.36 &#x000b1; 9.35^bc

林型 Forest type	土壤碳密度 Carbon density in soil (t&#x02219;hm^-2)
林型 Forest type	I (0-10 cm)	II (10-20 cm)	III (20-30 cm)	IV (30-50 cm)	V (50-100 cm)	合计 Total
A	23.91 &#x000b1; 1.06^ab	14.13 &#x000b1; 0.65^bc	10.11 &#x000b1; 0.57^c	14.66 &#x000b1; 0.84^bc	24.20 &#x000b1; 2.17^b	87.01 &#x000b1; 3.81^bc
B	21.29 &#x000b1; 1.06^ab	14.02 &#x000b1; 0.66^bc	11.11 &#x000b1; 0.57^c	17.86 &#x000b1; 1.12^bc	33.81 &#x000b1; 2.11^ab	98.10 &#x000b1; 4.58^bc
C	18.76 &#x000b1; 0.86^ab	11.49 &#x000b1; 0.68^bc	7.99 &#x000b1; 0.52^c	11.61 &#x000b1; 0.90^bc	21.09 &#x000b1; 1.61^b	70.94 &#x000b1; 3.50^c
D	29.93 &#x000b1; 2.37^a	21.95 &#x000b1; 2.11^a	19.58 &#x000b1; 1.63^a	28.47 &#x000b1; 3.21^a	41.81 &#x000b1; 3.00^a	141.74 &#x000b1; 10.28^a
E	20.44 &#x000b1; 1.19^ab	13.06 &#x000b1; 0.91^bc	9.30 &#x000b1; 0.77^c	14.04 &#x000b1; 1.19^bc	31.27 &#x000b1; 2.96^ab	88.10 &#x000b1; 5.31^bc
F	14.86 &#x000b1; 1.41^b	7.87 &#x000b1; 0.88^c	6.34 &#x000b1; 0.73^c	9.51 &#x000b1; 0.92^c	19.67 &#x000b1; 1.74^b	58.26 &#x000b1; 5.16^c
G	19.01 &#x000b1; 0.97^ab	12.45 &#x000b1; 1.00^bc	9.44 &#x000b1; 0.61^c	13.06 &#x000b1; 0.86^bc	28.34 &#x000b1; 2.52^b	82.29 &#x000b1; 4.73^bc
H	21.70 &#x000b1; 1.44^ab	13.68 &#x000b1; 1.19^bc	9.91 &#x000b1; 0.97^c	15.24 &#x000b1; 2.45^bc	27.16 &#x000b1; 3.95^b	87.69 &#x000b1; 8.79^bc
I	20.47 &#x000b1; 1.57^ab	11.88 &#x000b1; 1.49^bc	7.66 &#x000b1; 1.05^c	12.70 &#x000b1; 2.58^bc	26.02 &#x000b1; 5.29^b	78.73 &#x000b1; 10.73^bc
J	23.41 &#x000b1; 2.44^ab	16.53 &#x000b1; 1.87^ab	12.99 &#x000b1; 1.50^b	19.54 &#x000b1; 2.64^b	34.98 &#x000b1; 3.96^ab	107.46 &#x000b1; 10.77^ab
K	30.63 &#x000b1; 4.63^a	13.63 &#x000b1; 1.36^bc	9.57 &#x000b1; 0.90^c	13.89 &#x000b1; 1.65^bc	23.64 &#x000b1; 3.08^b	91.36 &#x000b1; 9.35^bc