Forestry College, Shenyang Agricultural University, Shenyang, China.
Center for Biological Disaster Prevention and Control, National Forestry and Grassland Administration, Shenyang, China.
PeerJ. 2024 Aug 6;12:e17820. doi: 10.7717/peerj.17820. eCollection 2024.
Plantation forests enhance carbon storage in terrestrial ecosystems in China. (Lamb.) Carrière (Lamb.) ( Henry) is the main species for afforestation in the eastern Liaoning Province. Therefore, it is important to understand the correlation between the site class and carbon sink potential of plantations in Liaoning Province for afforestation and carbon sink in this area. The model was fitted using three classical theoretical growth equations: the Richards model, the Korf model, and the Hossfeld model. This study used the forest resource inventory data for management in Liaoning Province in 2011 to build six dynamic height-age models for a plantation in Dandong City regardless of base-age. The optimal model derived by the generalized algebraic difference approach (GADA) method was compared with the model derived by the algebraic difference approach (ADA) method. The superiority of GADA was demonstrated by comparison. The Levenberg-Marquardt algorithm was used to fit the model. The statistical and biological characteristics were considered synthetically when comparing the models. The best model was screened out by statistical analysis and graphic analysis. The results show that the differential height-age model derived from Richards equation can well explain the growth process of in Dandong City, Liaoning Province under different conditions. The site index model based on Richards equation and derived by GADA was used to calculate the site class of a plantation in Dandong City. The net primary productivity (NPP) value from the past ten years was extracted from the MOD17A3HGF data set. Spearman correlation analysis and Kendall correlation analysis were used to show that there is a significant positive correlation between NPP value and site class of plantation in Dandong City. Among them, the highest growth occurred in 2016; NPP increased by about 3.914 gC/m/year for every two increases in height-age grade; the lowest increase in NPP was in 2014; NPP increased by about 2.113 gC/m/year for every two increases in height-age grade; and for every two increases in height-age grade in the recent ten years, the average NPP value increased by about 2.731 gC/m/year.
人工林增强了中国陆地生态系统的碳储存。（Lamb.）Carrière（Lamb.）（Henry）是辽宁省东部造林的主要树种。因此，了解辽宁省造林的林分地位与碳汇潜力之间的相关性对于该地区的造林和碳汇具有重要意义。该模型采用了三个经典的理论生长方程：Richards 模型、Korf 模型和 Hossfeld 模型进行拟合。本研究利用辽宁省 2011 年森林资源清查数据，建立了 6 个不考虑基龄的丹东市人工林动态高度-年龄模型。通过广义代数差分法（GADA）和代数差分法（ADA）分别对模型进行了比较。通过比较证明了 GADA 方法的优越性。采用 Levenberg-Marquardt 算法对模型进行拟合。综合考虑了模型的统计和生物学特征。通过统计分析和图形分析筛选出最佳模型。结果表明，Richards 方程推导的差分高度-年龄模型能够很好地解释辽宁丹东市不同条件下的生长过程。基于 Richards 方程并通过 GADA 推导的地位指数模型用于计算丹东市人工林的地位指数。从 MOD17A3HGF 数据集提取过去十年的净初级生产力（NPP）值。采用 Spearman 相关分析和 Kendall 相关分析，结果表明，NPP 值与丹东市人工林地位指数呈显著正相关。其中，2016 年生长量最大；高度-年龄等级每增加两级，NPP 值增加约 3.914 gC/m/年；2014 年 NPP 值增加量最小，高度-年龄等级每增加两级，NPP 值增加约 2.113 gC/m/年；近十年高度-年龄等级每增加两级，NPP 值平均增加约 2.731 gC/m/年。
