...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Forest Ecology and Management >Allometric equations for estimating tree aboveground biomass in evergreen broadleaf forests of Viet Nam
【24h】

Allometric equations for estimating tree aboveground biomass in evergreen broadleaf forests of Viet Nam

机译：越南常绿阔叶林乔木地上生物量的测度方程

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

For mitigating climate change through carbon sequestration and for reporting, Viet Nam needs to develop biomass equations at a national scale. These equations need to be accurate and provide quantifiable uncertainty. Using data from 968 trees across five ecoregions of Viet Nam, we developed a set of models to estimate tree aboveground biomass (AGB) in evergreen broadleaf forests (EBLF) at the national level. Diameter at breast height (DBH), tree height (H), wood density (WD), and combination of these three tree characteristics were used as covariates of the biomass models. Effect of ecoregion, wood density, plant family on AGB were examined. Best models were selected based on AIC, Adjusted R-2, and visual interpretation of model diagnostics. Cross-validation statistics of percent bias, root mean square percentage error (RMSPE), and mean absolute percent error (MAPE) were computed by randomly splitting data 200 times into model development (80%) and validation (20%) datasets and averaging over the 200 realizations. Effects models were used, the best results were obtained by using a combined variable ((DBHHWD)-H-2 (kg) = (DBH (cm)/100)(2) x H (m) x WD (g/cm(3)) x 1000) model AGB = a x ((DBHHWD)-H-2)(b). Including a categorical WD variable as a random effect reduced AIC, percent bias, RMSPE, MAPE of models AGB = a x DBHb and AGB = a x ((DBHH)-H-2)(b); ecoregion as a random effect reduced the AIC of models AGB = DBHb x WD, AGB = a x ((DBHH)-H-2)(b), and AGB = a x ((DBHHWD)-H-2)(b). For models that did not include WD variable, including plant family as a random effect reduced AIC, RMSE, and MAPE; recommendations are provided for models with specific parameters for main families and without WD if this variable is not available. The overall best model for estimating AGB was the equation form AGB = a x ((DBHHWD)-H-2)(b) with ecoregion as a random effect. (C) 2016 Elsevier B.V. All rights reserved.
机译：为了通过固碳来缓解气候变化并进行报告，越南需要在全国范围内建立生物量方程。这些方程式必须准确，并提供可量化的不确定性。我们使用了来自越南五个生态区的968棵树木的数据，开发了一组模型来估算国家一级常绿阔叶林（EBLF）中树木的地上生物量（AGB）。胸高（DBH）的直径，树高（H），木材密度（WD）以及这三种树特征的组合用作生物量模型的协变量。研究了生态区，木材密度，植物科对AGB的影响。根据AIC，Adjusted R-2和模型诊断的直观解释选择了最佳模型。偏差百分比，均方根误差百分比（RMSPE）和平均绝对误差百分比（MAPE）的交叉验证统计数据是通过将数据随机分为200次分成模型开发（80％）和验证（20％）数据集并在200个实现。使用效果模型，通过使用组合变量（（DBHHWD）-H-2（kg）=（DBH（cm）/ 100）（2）x H（m）x WD（g / cm（ 3））x 1000）模型AGB = ax（（DBHHWD）-H-2）（b）。包括分类WD变量作为随机效应，可以降低模型AGB = a x DBHb和AGB = a x（（（DBHH）-H-2）（b））的AIC，偏差百分比，RMSPE，MAPE;生态区作为随机效应会降低模型AGB = DBHb x WD，AGB = a x（（（DBHH）-H-2）（b）和AGB = a x（（DBHHWD）-H-2）（b）的AIC。对于不包含WD变量的模型，包括作为随机效应的植物家族，会降低AIC，RMSE和MAPE;如果此变量不可用，则为具有主要系列特定参数且不带WD的模型提供建议。估计AGB的总体最佳模型是AGB = a x（（DBHHWD）-H-2）（b）的等式，其中生态区域为随机效应。 （C）2016 Elsevier B.V.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号