Warmer Winter Ground Temperatures Trigger Rapid Growth of Dahurian Larch in the Permafrost Forests of Northeast China

2019 ◽  
Vol 124 (5) ◽  
pp. 1088-1097 ◽  
Author(s):  
Xianliang Zhang ◽  
Xueping Bai ◽  
Meiting Hou ◽  
Zhenju Chen ◽  
Rubén D. Manzanedo
Keyword(s):  
Rapid Growth ◽  
Northeast China ◽  
Dahurian Larch ◽  
Winter Ground ◽  
Ground Temperatures

scholarly journals The Effect of Crown Dimensions on Stem Profile for Dahurian Larch, Korean Spruce, and Manchurian Fir in Northeast China

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 398
Author(s):  
Amna Hussain ◽  
Muhammad Khurram Shahzad ◽  
Lichun Jiang
Keyword(s):  
Northeast China ◽  
Least Squares Method ◽  
Model Fitting ◽  
Nonlinear Least Squares ◽  
Dahurian Larch ◽  
Fit Statistics ◽  
Crown Length ◽  
Crown Shape ◽  
Natural Stands ◽  
Crown Dimensions

Crown architecture has long been evaluated for its impact on taper modeling. However, most of the research has focused on a limited number of crown dimensions. This study examined the effect of adding several crown dimensions in improving the diameter and volume estimates of Dahurian larch, Korean spruce, and Manchurian fir in northeast China. The crown dimensions included crown length, crown ratio, crown width, height to live crown base, diameter at the crown base, and crown shape. A well-known taper model of Clark et al. (1991) was fitted to the data of 276 trees from natural stands. To adjust the inherent autocorrelation in the data, we added a third-order continuous-time error structure in the model fit. Model fitting was carried out with the NLMIXED procedure (Non-linear Mixed Procedure), followed by the MODEL procedure of SAS using the generalized nonlinear least-squares method. Fit statistics and graphical assessments were used to evaluate the original and modified models. Above 98% of the total variance of d was explained by the models for all species. The addition of crown variables showed slight improvements for root mean square error (RMSE) values in the analyzed species. The RMSE plots indicated that the models with crown variables slightly improved the diameter and volume predictions for the species but only for the upper stem (>50%–90%). The study demonstrated that crown dimensions influence the stem taper, but the original model of Clark et al. (1991) reasonably realized that effect.

Responses of soil chemical and biological properties to nitrogen addition in a Dahurian larch plantation in Northeast China

2010 ◽  
Vol 333 (1-2) ◽  
pp. 81-92 ◽  
Author(s):  
Ya-Lin Hu ◽  
De-Hui Zeng ◽  
Yun-Xia Liu ◽  
Yu-Lan Zhang ◽  
Zhen-Hua Chen ◽  
...  
Keyword(s):  
Northeast China ◽  
Nitrogen Addition ◽  
Biological Properties ◽  
Dahurian Larch ◽  
Larch Plantation

Soil moisture, ground temperatures, and deformation of a high-speed railway embankment in Northeast China

2017 ◽  
Vol 133 ◽  
pp. 7-14 ◽  
Author(s):  
Fujun Niu ◽  
Anyuan Li ◽  
Jing Luo ◽  
Zhanju Lin ◽  
Guoan Yin ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Northeast China ◽  
High Speed ◽  
High Speed Railway ◽  
Ground Temperatures

Increased sensitivity of Dahurian larch radial growth to summer temperature with the rapid warming in Northeast China

Trees ◽  
2016 ◽  
Vol 30 (5) ◽  
pp. 1799-1806 ◽  
Author(s):  
Xianliang Zhang ◽  
Xueping Bai ◽  
Yongxing Chang ◽  
Zhenju Chen
Keyword(s):  
Northeast China ◽  
Radial Growth ◽  
Summer Temperature ◽  
Dahurian Larch ◽  
Increased Sensitivity

scholarly journals A Newly Built Model of an Additive Stem Taper System with Total Disaggregation Model Structure for Dahurian Larch in Northeast China

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1302
Author(s):  
Yanli Xu ◽  
Lichun Jiang ◽  
Muhammad Khurram Shahzad
Keyword(s):  
Northeast China ◽  
Additive Model ◽  
Stem Bark ◽  
Forest Growth ◽  
Growth And Yield ◽  
Dahurian Larch ◽  
Bark Thickness ◽  
Stem Taper ◽  
The Difference ◽  
Model Structures

Stem taper function is an important concept in forest growth and yield modeling, and forest management. However, the additivity of the function and the inherent correlations between stem components (diameter outside bark—dob, diameter inside bark—dib, and double-bark thickness—dbt) are seldom considered. In this paper, a total disaggregation model (TDM) structure was developed based on the well-known Kozak (2004) model to ensure the additivity of the stem components. The reconstructed model was fitted with the data of 1281 felled Dahurian larch trees from three regions of Daxing’anling Mountains in Northeast China. The results from TDM were compared with other additive model structures including adjustment in proportion (AP), non-additive taper models (NAM), and three logical structures of NSUR (AMO, SMI, SMB). The results showed that the difference was significant among the three regions. The performance of TDM was slightly better than those of other model structures. Therefore, TDM was considered as another optimal additive system to estimate stem, bark thickness, and volume predicting for Dahurian larch in Northeast China besides NSUR, a method widely used in calculating additive volume or biomass throughout the world. We believe this work is cutting-edge, and that this methodology can be applied to other tree species.

Sign in / Sign up

Export Citation Format

Share Document