EVALUATION OF REGION AND SUBREGION-BASED TOTAL VOLUME EQUATIONS FOR DAHURIAN LARCH IN NORTHEAST CHINA

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.

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Growth variations of Dahurian larch plantations across northeast China: Understanding the effects of temperature and precipitation

Journal of Environmental Management ◽

10.1016/j.jenvman.2021.112739 ◽

2021 ◽

Vol 292 ◽

pp. 112739

Author(s):

Bingrui Jia ◽

Hongru Sun ◽

Herman Henry Shugart ◽

Zhenzhu Xu ◽

Peng Zhang ◽

...

Keyword(s):

Northeast China ◽

Dahurian Larch ◽

Temperature And Precipitation ◽

Effects Of Temperature ◽

Dahurian Larch Plantations

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Altitudinal disparity in growth of Dahurian larch (Larix gmelinii Rupr.) in response to recent climate change in northeast China

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.03.232 ◽

2019 ◽

Vol 670 ◽

pp. 466-477 ◽

Cited By ~ 5

Author(s):

Xueping Bai ◽

Xianliang Zhang ◽

Junxia Li ◽

Xiaoyu Duan ◽

Yuting Jin ◽

...

Keyword(s):

Climate Change ◽

Northeast China ◽

Larix Gmelinii ◽

Dahurian Larch ◽

Recent Climate Change ◽

Recent Climate

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A model form for stem taper and volume estimates of Asian white birch (Betula platyphylla): a major commercial tree species of Northeast China

Canadian Journal of Forest Research ◽

10.1139/cjfr-2019-0088 ◽

2019 ◽

pp. 274-286 ◽

Cited By ~ 3

Author(s):

Muhammad Khurram Shahzad ◽

Amna Hussain ◽

Lichun Jiang

Keyword(s):

Northeast China ◽

Individual Species ◽

Betula Platyphylla ◽

White Birch ◽

Box Plots ◽

Stem Taper ◽

Overall Evaluation ◽

Betula Platyphylla Suk ◽

Volume Estimates ◽

Volume Equations

Stem taper functions are valuable tools for the study of stem profile and predict volume estimates. Such functions have long been analyzed for different birch species in the world. However, Asian white birch (Betula platyphylla Suk.) has not yet been investigated as an individual species in China or abroad. This study presents stem taper and volume equations for B. platyphylla in Northeast China. Eight commonly used taper functions were fit to the data of 615 destructively sampled trees from two regions of Northeast China. A second-order continuous autoregressive error structure was incorporated to address the autocorrelation in the data and to achieve the valid parameter estimation. The condition number was used to detect the multicollinearity in the models. The taper functions were compared in terms of overall evaluation statistics and by examining the box plots of diameter and volume residuals against relative heights and diameter classes. The equations of A. Kozak (2004, For. Chron. 80(4): 507–515; model 2), Z. Fang et al. (2000, For. Sci. 46(1): 1–12), and H. Bi (2000, For. Sci. 46(3): 397–409) were the leading models for diameter and volume estimates. Overall, the equation of Z. Fang et al. (2000, For. Sci. 46(1): 1–12) exhibited the best results for estimating diameter and total and merchantable volumes in terms of statistical performance and lower multicollinearity.

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

Plant and Soil ◽

10.1007/s11104-010-0321-6 ◽

2010 ◽

Vol 333 (1-2) ◽

pp. 81-92 ◽

Cited By ~ 35

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

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

Trees ◽

10.1007/s00468-016-1413-6 ◽

2016 ◽

Vol 30 (5) ◽

pp. 1799-1806 ◽

Cited By ~ 16

Author(s):

Xianliang Zhang ◽

Xueping Bai ◽

Yongxing Chang ◽

Zhenju Chen

Keyword(s):

Northeast China ◽

Radial Growth ◽

Summer Temperature ◽

Dahurian Larch ◽

Increased Sensitivity

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

Forests ◽

10.3390/f12101302 ◽

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.

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