首页 > 分享 > 四川省甘孜藏族自治州高寒矮灌丛生物量分配及其碳密度的估算

四川省甘孜藏族自治州高寒矮灌丛生物量分配及其碳密度的估算

花匠小妙招
2025-09-03 16:15

摘要：

灌丛面积增加引起的碳储量增加被认为是我国陆地生态系统碳储量增加的主要原因, 是陆地生态系统碳汇研究中一个最不确定的因素。为了揭示高寒矮灌丛生物量在不同器官、不同层片的分配规律和估算高寒矮灌丛生物量碳密度, 该文对青藏高原东缘海拔3500-4650 m的14个灌丛群落进行了研究。结果表明: 1)研究区域灌木层平均生物量为(5.38 ± 3.30) Mg·hm-2; 不同灌丛类型灌木层生物量存在显著差异, 亚高山落叶阔叶灌丛灌木层平均生物量为(7.28 ± 4.96) Mg·hm-2, 亚高山革叶灌丛灌木层平均生物量为(4.32 ± 1.36) Mg·hm-2; 个体形态和群落结构指标与亚高山灌丛单位面积生物量存在显著相关关系, 但这种相关关系是建立在多个群落结构因子基础上的, 单个群落结构因子不足以解释生物量的变化规律; 不同灌丛类型的生物量分配规律存在显著差异, 表现为高寒生境条件下亚高山灌丛将更多的光合产物分配到植物的根部。2)灌丛群落平均总生物量为(6.41 ± 3.86) Mg·hm-2, 灌木层生物量占群落总生物量的(83.18 ± 8.14)%; 灌木层生物量与草本层生物量、凋落物层生物量、灌丛群落总生物量之间均存在显著相关性(p < 0.05), 灌木层各器官生物量与群落总生物量之间也存在极显著的相关性(p < 0.01), 故可以建立生物量模型。3)采用生物量转换因子法从14个调查群落获得的该区域灌丛平均生物量碳密度为(3.20 ± 1.93) Mg·hm-2。

关键词: 高寒灌丛, 生物量, 碳密度, 青藏高原

Abstract:

Aims Shrub recovery is identified as a major cause of an increase in carbon stocks in terrestrial ecosystems in China, and yet there is a great uncertainty in the contribution of shrubs to the carbon sink. Our objectives were to determine the biomass allocation pattern and carbon density in alpine shrubs.
Methods We conducted investigations in 14 shrub communities in eastern Qinghai-Xizang Plateau, at 3500 m above sea level. Plant samples were collected from each plot and measured for biomass in leaves, branches and stems, and roots in laboratory; the data were used to analyze the biomass allocation and carbon density.
Important findings The mean biomass was (5.38 ± 3.30) Mg·hm-2 in the shrub layer. There were significant differences in biomass between different shrub types, with the mean of (7.28 ± 4.96) Mg·hm-2 for the broadleaved deciduous shrubs and (4.32 ± 1.36) Mg·hm-2 for the leathery-leaved shrubs. The indicators of individual feature and community structure were significantly correlated with biomass per unit land area. However, these relationships were developed based on multiple community structure factors; any single factor alone was insufficient to explain the patterns of biomass variations. The patterns of biomass allocation differed significantly between different shrub types. In this study, there was more allocation of photosynthetic products to roots. The mean total community biomass was (6.41 ± 3.86) Mg·hm-2 and the shrub layer accounted for (83.18 ± 8.14)% of the total community biomass. There were significant correlations (p < 0.05) between shrub layer biomass and herb layer biomass, between shrub layer biomass and litter layer biomass, and between shrub layer biomass and the total community biomass. The biomass of various organs were also significantly correlated (p < 0.01) with the total community biomass. The mean biomass carbon density of the shrubs was estimated at (3.20 ± 1.93) Mg·hm-2 across the 14 communities by using biomass conversion factor method.

Key words: alpine shrubs, biomass, carbon density, Qinghai-Xizang Plateau