桂东南柳杉人工林生物量回归模型应用研究

【目的】估算和比较分析桂东南地区3种密度柳杉人工林的林分总生物量和林分径阶生物量，为南亚热带地区柳杉人工林生物量及碳汇估算提供技术支撑。【方法】用线性和非线性生物量模型分别对来自3种密度柳杉人工林的19个单株和各器官的生物量进行方程拟合，选择最优拟合方程进行3种密度林分生物量的估算和分析。【结果】对单株和各器官的生物量估算，模型W=a＊Db＊Hc要略优于其他4种模型；模型的应用结果表明，低、中、高3种密度柳杉人工林林分的总生物量分别为201．30、182．46和171．03t／hm^2，表现出林分总生物量随密度增加而降低的趋势；不同密度的柳杉人工林的径阶生物量分配格局不同，低密度和中密度的柳杉人工林的径阶生物量主要集中在15．0cm径阶以上，分别占85．36％和75．25％，而高密度林分的生物量主要集中在11．0—14．9cm径阶，占41．52％。【结论】对单株和各器官的生物量估算，非线性模型要略优于线性模型，南亚热带柳杉人工林的保留密度过大反而不利于其林分生物量的积蓄。

Biomass regression model of the Cryptomeria fortunei plantation in southeast subtropical region of Guangxi

[Objective]The total stand biomass and diameter class biomass of three Cryptomeria fornnei plantations with different density were estimated and analyzed comparatively in order to provide technical support for estimating biomass and carbon sink of Cryptomeria [ortunei plantation in southeast subtropical regions. [Method]The biomass of 19 individual trees and their organs from Cryptomeria fortunei plantations with different density were sampled and fitted by the linear model or non-linear model, and finally estimated and compared by the best fitting equation. [Result]Regarding biomass estimation of individual plant and organs, model W=a＊D b＊Hc outshined the other four models. The application re- sults from the models showed that the estimated total stand biomass of low density, medium density and high density plan- tation was 201.30,182.46 and 171.03 t/ha, respectively, which indicated that biomass dropped with the increase of densi- ty. Diameter class biomass of three Cryptomeria forunei plantations with different density varied with one another. Diameter class biomass of low and medium densities was mainly scattered in 15.0 cm and above, which accounted for 85.36% and 75.25%, respectively, while diameter class biomass of high density was centered on 11.0-14.9 cm occupying 41.52%. [Conclusion]Concerning calculating the biomass of different plant and organ, non-linear model beats linear model. Over dense CryptomeHa fortunei plantation in southern subtropical region hinders the accumulation of stand biomass.