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Accurately describing the stem curve of precious tree species and estimating the quantity of various types of wood and their volume in the tropics can provide technical support for reasonable bucking. This study utilized Erythrophleum fordii, Castanopsis hystrix and Tectona grandis as study objects. Forty replicates of each species were used for a total of 120 individual trees. Their tape equations were constructed using simple tape equations, segmented taper equations and variable form taper equations. Statistical indicators were utilized to determine the best taper equation for the three types of precious tree species. A number of methods were compared and analyzed, including the index of correlation, the residual sum of squares, the mean prediction error, the variance of prediction errors and the root mean square error. Finally, a preliminary quantitative analysis was conducted to determine the trends of these three types of tree species. The result shows that the precision of the three predictions developed for each species is high, and, in particular, the segmented taper equations with optimized algorithms is the best. The tendency of the three species to vary was shown to be the highest for T. grandis in the range of 0.0 to 0.8 for its relative height, followed by E. fordii, while the variation of C. hystrix was the smallest. However, in the range of 0.8 to 1.0 relative height, the variation of Castanopsis hystrix was the largest, and the variation of both E. fordii and T. grandis were almost the same. Therefore, the segmented taper equations with optimization algorithms was recommended to fit the three types of tree species in the tropics. These types of equations can be used to estimate the stumpage and timber quantity and as a guide reasonable bucking for these three species.
Jun Jiang; Jie Li; Lifeng Pang; Angang Ming. A Comparative Evaluation of Three Stem Profile Equations for Three Precious Tree Species in Southern China. Forests 2020, 11, 669 .
AMA StyleJun Jiang, Jie Li, Lifeng Pang, Angang Ming. A Comparative Evaluation of Three Stem Profile Equations for Three Precious Tree Species in Southern China. Forests. 2020; 11 (6):669.
Chicago/Turabian StyleJun Jiang; Jie Li; Lifeng Pang; Angang Ming. 2020. "A Comparative Evaluation of Three Stem Profile Equations for Three Precious Tree Species in Southern China." Forests 11, no. 6: 669.
The Species-area relationship is one of the core issues in community ecology and an important basis for scale transformation of biodiversity. However, the effect of scale on this relationship, together with the selection of an optimal species-area model for different sampling methods, is still controversial. This study is based on the data from two sampling areas of 40 km2 in size, one in a Korean pine (Pinus koraiensis Sieb. et Zucc) broad-leaved mixed forest in Mt. Changbai and the other in Jiaohe, Jilin Province. The logarithmic, power, and logistic model were established on a scale of 10 km2, 20 km2, and 30 km2, respectively, using a nested sampling plot and random sampling plot. The goodness of the species-area model was tested by the Akaike information criterion (AIC). The results show that the sampling method affected the relationship between species and area, and the data were fitted better under random sampling compared with nested sampling. The construction of the relationship between species and area was closely related to the upper limit of the sampling area size. On a small scale (10 km2), the data were fitted best with the logarithmic and logistic model, whereas the logistic model was the best fit on a medium (20 km2) and large scale (30 km2). We evaluated the scale dependence of species-area relationship in two forests with nested and random sampling methods. We further showed that the logistic model based on the random sampling plot can explain most soundly the species-area relationship in Jiaohe and Mt. Changbai. More studies are needed in other regions to develop models to optimize sampling designs for different forest types under different density constraints at different spatial scales, and for a more accurate estimation of forest dynamics under long-term observations.
Beibei Chen; Jun Jiang; Xiuhai Zhao; Chen; Zhao. Species-Area Relationship and Its Scale-Dependent Effects in Natural Forests of North Eastern China. Forests 2019, 10, 422 .
AMA StyleBeibei Chen, Jun Jiang, Xiuhai Zhao, Chen, Zhao. Species-Area Relationship and Its Scale-Dependent Effects in Natural Forests of North Eastern China. Forests. 2019; 10 (5):422.
Chicago/Turabian StyleBeibei Chen; Jun Jiang; Xiuhai Zhao; Chen; Zhao. 2019. "Species-Area Relationship and Its Scale-Dependent Effects in Natural Forests of North Eastern China." Forests 10, no. 5: 422.
Facilitation can drive the successional dynamics and change the restoration trajectory of degraded forests. However, the relative importance of facilitation by tree species after variable retention harvesting is unclear. We used a field experiment to evaluate the effect of two facilitator species, Castanopsis fissa (C. fissa) and Manglietia glauca (M. glauca), managed with variable retention harvesting, on the development of two target species, Castanopsis hystrix (C. hystrix) and Erythrophloeum fordii (E. fordii), in a Masson pine (Pinus massoniana) monoculture. The following variables were measured for all of the four interplanted tree species: structural growth, regeneration, aboveground biomass accumulation, leaf area index, and soil conditions. The results indicate that the abundance, growth, and aboveground biomass were relatively greater in plots planted with C. fissa compared with M. glauca and that the target species performed best with 50% retention harvesting of C. fissa, with an improved establishment of both target species indicating a positive interaction. In addition, the regeneration, leaf area index and soil conditions differed between the two facilitators in the variable retention harvesting treatments because of the different intrinsic characteristic of the facilitators. In summary, our results imply that managers have considerable flexibility to employ various types of facilitation schemes coupled with different harvesting systems for successful short-term restoration within a monoculture.
Jun Jiang; Yuanchang Lu; Ling Wang; Xianzhao Liu; Daoxiong Cai; Hongyan Jia; Angang Ming; Beibei Chen. Facilitation by Tree Species in Variable Retention Harvesting for the Restoration of Monoculture Plantations in Southern China. Tropical Conservation Science 2019, 12, 1 .
AMA StyleJun Jiang, Yuanchang Lu, Ling Wang, Xianzhao Liu, Daoxiong Cai, Hongyan Jia, Angang Ming, Beibei Chen. Facilitation by Tree Species in Variable Retention Harvesting for the Restoration of Monoculture Plantations in Southern China. Tropical Conservation Science. 2019; 12 ():1.
Chicago/Turabian StyleJun Jiang; Yuanchang Lu; Ling Wang; Xianzhao Liu; Daoxiong Cai; Hongyan Jia; Angang Ming; Beibei Chen. 2019. "Facilitation by Tree Species in Variable Retention Harvesting for the Restoration of Monoculture Plantations in Southern China." Tropical Conservation Science 12, no. : 1.