森林与环境学报2025，Vol.45Issue(3)：264-272,9.DOI:10.13324/j.cnki.jfcf.202412010
林龄和林分密度对杨树人工林有机碳储量的影响
Influences of stand ages and densities on organic carbon storage in poplar plantations
摘要
Abstract
The effects of stand ages and densities on organic carbon storage in the poplar plantations in Malanghu Forest Farm,Sihong County,Jiangsu Province were studied.The biomass and organ carbon content in 37 sample plots of poplar plantations with the stand age ranging from 5 to 21 years and densities between 200 and 451 plant·hm-2,as well as the organic carbon content and bulk density at different soil layers were investigated and analyzed.The prediction model of organic carbon storage in poplar plantations based on stand ages and densities was established by regression and machine learning model fitting and spatial feature analysis.The spatial distribution of organic carbon storage in poplar plantations in Malanghu Forest Farm was characterized.The results showed that the total biomass of poplar plantations with different stand ages and densities varied within the range of 5.25-193.82 t·hm-2,and the average total biomass of the investigated stands was 79.15 t·hm-2.The biomass of each stand component followed the order of trunk>branches>roots>leaves,and the trunk biomass was higher than that of other components(P<0.05).The carbon content of different biological components of poplar trees ranged from 42.31 g·kg-1 to 49.05 g·kg-1,showing a trend of trunk>branches>roots>leaves.The organic carbon content in soil gradually decreased with the deepening of soil layers,while the soil bulk density gradually increased.Both stand ages and densities affected the carbon storage of poplar stands and the total organic carbon storage in plantations,and the two factors had interactive effects(P<0.05).Stand ages affected organic carbon storage in the 0～60 cm soil(P<0.05),while stand densities had no significant effect on the organic carbon storage in soil(P>0.05).The machine learning models gradient boosting regression and random forest showed higher fitting degrees(R2>0.9)and lower prediction errors than the regression model when revealing the nonlinear relationship of stand ages and densities with organic carbon storage.The spatial distribution of the total organic carbon storage of poplar plantations in Malanghu Forest Farm was in a zonal pattern,with the total organic carbon storage ranging from 41.00 t·hm-2 to 964.76 t·hm-2.In summary,the GBR and RF models can effectively reveal the complex relationship of stand ages and densities and organic carbon storage in poplar plantations,providing a scientific basis for the management of regional poplar plantations for carbon sequestration.关键词
杨树/经营措施/林分生物量/土壤有机碳/回归模型/机器学习模型/空间分布Key words
poplar/management practice/stand biomass/soil organic carbon/regression model/machine learning model/spatial distribution分类
林学引用本文复制引用
郑思静,方杰,左思敏,刘钰,方升佐..林龄和林分密度对杨树人工林有机碳储量的影响[J].森林与环境学报,2025,45(3):264-272,9.基金项目
江苏省碳达峰碳中和科技创新专项"江苏省杨树人工林碳动态及减排增汇关键技术"(BK20220017). （BK20220017）
