scholarly journals Developing growth models for tree plantations using inadequate data – a case for Korean pine in Northeast China

Silva Fennica ◽  
2019 ◽  
Vol 53 (4) ◽  
Author(s):  
Xingji Jin ◽  
Timo Pukkala ◽  
Fengri Li ◽  
Lihu Dong
Keyword(s):  
Northeast China ◽  
Growth Models ◽  
Pinus Koraiensis ◽  
Tree Plantations ◽  
Korean Pine

Pinus koraiensis

scholarly journals Height-diameter relationship for Pinus koraiensis in Mengjiagang Forest Farm of Northeast China using nonlinear regressions and artificial neural network models

2019 ◽  
Vol 65 (No. 4) ◽  
pp. 134-143 ◽  
Author(s):  
Tuan Nguyen Thanh ◽  
Tai Dinh Tien ◽  
Hai Long Shen
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Northeast China ◽  
Tree Height ◽  
Pinus Koraiensis ◽  
Accurate Estimation ◽  
Korean Pine ◽  
Ann Models ◽  
Artificial Neural ◽  
Forest Farm

Korean pine (Pinus koraiensis Sieb. et Zucc.) is one of the highly commercial woody species in Northeast China. In this study, six nonlinear equations and artificial neural network (ANN) models were employed to model and validate height-diameter (H-DBH) relationship in three different stand densities of one Korean pine plantation. Data were collected in 12 plots in a 43-year-old even-aged stand of P. koraiensis in Mengjiagang Forest Farm, China. The data were randomly split into two datasets for model development (9 plots) and for model validation (3 plots). All candidate models showed a good perfomance in explaining H-DBH relationship with error estimation of tree height ranging from 0.61 to 1.52 m. Especially, ANN models could reduce the root mean square error (RMSE) by the highest 40%, compared with Power function for the density level of 600 trees. In general, our results showed that ANN models were superior to other six nonlinear models. The H-DBH relationship appeared to differ between stand density levels, thus it is necessary to establish H-DBH models for specific stand densities to provide more accurate estimation of tree height.

scholarly journals Height Growth of Korean Pine Seedlings Planted under Strip-Cut Larch Plantations in Northeast China

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Toshiaki Owari ◽  
Shinichi Tatsumi ◽  
Liangzhi Ning ◽  
Mingfang Yin
Keyword(s):  
Northeast China ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Height Growth ◽  
Pinus Koraiensis ◽  
Stand Age ◽  
Seedling Height ◽  
Korean Pine ◽  
Open Site ◽  
Pine Seedlings

To develop two-storied forest management of larch plantations in Northeast China, this study examined the height growth of Korean pine (Pinus koraiensisSieb. et Zucc.) seedlings planted under strip-cut larch canopies. We measured the height growth of the underplanted seedlings 4 years after planting. The larch canopies were of varying stand age (12, 17, and 37 years) and strip-cut width (4.5, 6.0, and 7.5 m). We measured the seedling height growth in an open site (i.e., a site with no canopy). Underplanted seedlings had a smaller height growth (12.1–20.1 cm year−1) than the seedlings planted in the open site (23.7 cm year−1). The seedlings underplanted in the wider strip-cuts tended to have greater height growth than the seedlings underplanted in the narrowest strip-cuts. A generalized linear mixed model analysis predicted the greatest seedling height growth in the open site. A 36–47% reduction in annual height growth was predicted for the narrowest strip-cuts (4.5 m) versus the open site, while a 13–36% reduction in annual height growth was predicted for the wider strip-cuts (6.0–7.5 m) versus the open site. To maintain adequate height growth, forest managers are recommended to create wider strip-cuts (i.e., ≥6.0 m) for the purpose of underplanting Korean pine seedlings in larch plantations.

Use of direct seeding and seedling planting to restore Korean pine (Pinus koraiensis Sieb. Et Zucc.) in secondary forests of Northeast China

2021 ◽  
Vol 493 ◽  
pp. 119243
Author(s):  
Jing Wang ◽  
G. Geoff Wang ◽  
Ting Zhang ◽  
Junfeng Yuan ◽  
Lizhong Yu ◽  
...  
Keyword(s):  
Northeast China ◽  
Direct Seeding ◽  
Pinus Koraiensis ◽  
Secondary Forests ◽  
Korean Pine

scholarly journals Biomass Functions and Carbon Content Variabilities of Natural and Planted Pinus koraiensis in Northeast China

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 201
Author(s):  
Faris Rafi Almay Widagdo ◽  
Lihu Dong ◽  
Fengri Li
Keyword(s):  
Carbon Content ◽  
Northeast China ◽  
Model Systems ◽  
Pinus Koraiensis ◽  
Korean Pine ◽  
Dummy Variable ◽  
Shoot Ratio ◽  
Population Average ◽  
Root To Shoot Ratio ◽  
Biomass Functions

The population of natural Korean pine (Pinus koraiensis) in northeast China has sharply declined due to massive utilization for its high-quality timber, while this is vice versa for Korean pine plantations after various intensive afforestation schemes applied by China’s central authority. Hence, more comprehensive models are needed to appropriately understand the allometric relationship variations between the two origins. In this study, we destructively sampled Pinus koraiensis from several natural and plantation sites in northeast China to investigate the origin’s effect on biomass equations. Nonlinear seemingly unrelated regression with weighted functions was used to present the additivity property and homogenize the model residuals in our two newly developed origin-free (population average) and origin-based (dummy variable) biomass functions. Variations in biomass allocations, carbon content, and root-to-shoot ratio between the samples obtained from plantations and natural stands were also investigated. The results showed that (1) involving the origin’s effect in dummy variable models brought significant improvement in model performances compared to the population average models; (2) incorporating tree total height (H) as an additional predictor to diameter at breast height (D) consistently increase the models’ accuracy compared to using D only as of the sole predictors for both model systems; (3) stems accounted for the highest partitioning proportions and foliage had the highest carbon content among all biomass components; (4) the root-to-shoot ratio ranged from 0.18–0.35, with plantations (0.28 ± 0.04) had slightly higher average value (±SD) compared to natural forests (0.25 ± 0.03). Our origin-based models can deliver more accurate individual tree biomass estimations for Pinus koraiensis, particularly for the National Forest Inventory of China.

Effects of Korean Pine Basal Area in Mixed Broadleaved–Korean Pine Forest Stands on Its Natural Regeneration in Northeast China

2020 ◽  
Author(s):  
Xiaowen Ge ◽  
Jiaojun Zhu ◽  
Deliang Lu ◽  
Chunyu Zhu ◽  
Pingzhen Gao ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Northeast China ◽  
Forest Restoration ◽  
Basal Area ◽  
Age And Growth ◽  
Pinus Koraiensis ◽  
Growth Stages ◽  
Stem Density ◽  
Korean Pine ◽  
Korean Pine Forest

Abstract Understanding the natural regeneration of Korean pine (Pinus koraiensis Sieb. et Zucc.) in mixed broadleaved–Korean pine (MBK) forests is crucial for MBK forest conservation and secondary deciduous broadleaved forest restoration. We hypothesized the ratio of Korean pine basal area (RKp) in MBK stands affected its natural regeneration. Regeneration censuses, including the height, root collar diameter, age, and growth stages (younger seedling, older seedling, smaller sapling, and taller sapling) of Korean pine, were conducted in northeast China. Results indicated the stem density and age composition of younger seedlings were positively correlated with RKp, whereas those of the saplings were negatively correlated with RKp. In the stands with lower RKp (<80% in Lesser Khingan Mountains [LKM]; <40% in Lushuihe Forestry Bureau [LFB]), individuals in all growth stages regenerated well with an age span of 65 yr. However, the regeneration of taller saplings was severely inhibited with increasing RKp (LKM: RKp ≥ 80%; LFB: RKp ≥ 40%). In summary, RKp significantly affected the natural regeneration of Korean pine in MBK forests. The basal-area thresholds limiting regeneration were found to be 80% in LKM stands and 40% in LFB stands. These basal-area thresholds provided evidence of why the zonal climax was MBK forests rather than pure Korean pine forests.

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