白刺属植物灌丛沙包生物量分布及预测

Biomass allocation and prediction in Nitraria nabkhas

灌丛沙包广泛分布于西北干旱区,本研究以干旱区常见的白刺属(Nitraria)植物灌丛沙包为研究对象,通过样地收集和文献数据整理,获取45个唐古特白刺(Nitraria tangutorum)和21个泡泡刺(Nitraria sphaerocarpa)灌丛沙包形态及生物量数据,构建白刺属植物灌丛沙包生物量预测模型。结果表明:灌丛沙包植物总生物量每增加1 kg,沙包上部、沙包内部、沙包下部的生物量及枝叶生物量、根生物量分别增加0.31、0.57、0.12、0.44和0.56 kg。植株高度变化能够解释各组件生物量及总生物量变化的76%~88%。沙包长度变化能够解释各组件生物量及总生物量变化的76%~92%。植株高度和沙包长度联合能够解释各组件生物量及总生物量变化的89%~94%。随灌丛沙包高度的增加,沙包上部生物量占比呈现减少,沙包内生物量占比明显增加,沙包下部生物量占比没有明显的变化趋势。另外,随沙包高度增加,沙包内部根系的迅速增加是白刺属植物根生物量占比呈增加的主要原因。白刺属植物灌丛沙包各组件生物量和总生物量之间存在极显著相关关系(P<0.01),这种关系可用于相互间的预测,进而可以为野外跟踪监测提供理论参考依据。

Shrub nabkhas(sand dunes)are widely distributed in the arid region of northwest China.Using the common Nitraria shrub nabkha in the arid region as the research object,this study obtained the morphological and biomass data of 45 Nitraria tangutorum and 21 Nitraria sphaerocarpa shrub nabkhas through sample plot collection and literature data collection and established a biomass prediction model for Nitraria shrub nabkhas.It was found that the biomass of the surface,inner,and lower parts of the nabkha and that of the branch and leaf,and root increased by 0.31,0.57,0.12,0.44,and0.56 kg,respectively,as the total biomass increased by 1 kg.The change in plant height could explain 76%~88%of the total biomass and that of each component of the nabkha.The change in nabkha length could explain 76%~92%variation in the total biomass and that of each component of the nabkha.The combination of plant height and nabkha length could account for 89%~94%of variation in the total biomass and that of each component of the nabkha.With an increase in nabkha height,the proportion of plant biomass above the sand dune decreased and that inside the nabkha increased,however,there was no significant change under the sand dune.In addition,the proportional increase in root biomass was attributed to the increase in roots inside the sand dune.There were significant correlations between each part of the biomass and the total biomass of Nitraria(P<0.01).This relationship can be used to predict each component using the other,thus achieving a field-tracking monitor.