Aboveground biomass and seasonal patterns of aboveground net primary productivity in five bamboo species in northern Laos
Aboveground biomass and seasonal patterns of aboveground net primary productivity in five bamboo species in northern Laos
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DOI：
10.1093/jpe/rtz056
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发表时间：
2020-04
影响因子：
2.7
通讯作者：
Singkone Xayalath;I. Hirota;S. Tomita;M. Nakagawa
中科院分区：
文献类型：
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作者：
Singkone Xayalath;I. Hirota;S. Tomita;M. Nakagawa
竹林的生物量和净初级生产力（NPP）是评价竹林固碳潜力的重要指标。然而，在东亚和印度以外的地区，很少收集到对减缓气候变化至关重要的相关数据。NPP及其组成部分的季节模式的信息将使量化的影响竹林碳平衡的因素。在这项研究中，我们量化的地上生物量（AGB）和地上净第一性生产力的五个主要竹种在老挝北方每月收集的数据超过12个月的时间。在10个2 m × 2 m的样地（1种单轴类竹种：大竹）和30丛（4种丛生类竹种：圆竹、细穗竹、膜竹和巨竹）中，所有活秆均被采集。编号并测量胸高。我们为每个物种设置了10到20个凋落物收集器来收集凋落物。每月进行一次死亡和补充秆的普查以及枯枝落叶收集，持续12个月。AGB在I. sinica（59.87 Mg ha-1），C. virgatum（11.54 Mg ha−1），大多低于竹子的合理全球范围（32-256 Mg ha−1）。多个竹种的同域分布在研究地点可能抑制了AGB的五个研究物种中的四个。地上NPP估计值在3.43和14.25 Mg ha−1 yr−1之间; D.膜壳菌（8.20 Mg ha-1 yr-1）和I. sinica（14.25 Mg ha−1 yr−1）与全球温带万年青林（8.78 Mg ha−1 yr−1）和热带潮湿林（10.56 Mg ha−1 yr−1）的平均估计值相当。高秆补充率（15.20-23.39% yr-1）是地上NPP估计的主要贡献者。地上NPP的季节格局在很大程度上受新秆物候的影响。在四个合轴竹种，新秆开始出现后，持续降雨，主要是在7月和8月。而单轴型种I.温度呈上升趋势，主要集中在3、4月份。因此，我们的研究结果表明，竹子在老挝北方具有相当大的固碳潜力，但这种潜力可能会受到气候变化的影响。
Accurate estimates of bamboo biomass and net primary productivity (NPP) are required to evaluate the carbon sequestration potential of bamboo forests. However, relevant data that are important for climate change mitigation, have rarely been collected in regions outside of East Asia and India. Information on seasonal patterns of NPP and its components will enable the quantification of factors that influence the carbon balance in bamboo forests. In this study, we quantified the aboveground biomass (AGB) and aboveground NPP of five major bamboo species in northern Laos using monthly data collected over a 12-month period. All live culms in 10, 2 m × 2 m plots (for one monopodial bamboo species: Indosasa sinica) and 30 clumps per species (for four sympodial bamboo species: Bambusa tulda, Cephalostachyum virgatum, Dendrocalamus membranaceus and Gigantochloa sp.) were numbered and measured at breast height. We set 10 or 20 litter traps per species to collect litterfall. Censuses of dead and recruited culms and litterfall collection were performed once per month for 12 months. The AGB was highest in I. sinica (59.87 Mg ha−1) and lowest in C. virgatum (11.54 Mg ha−1), and was mostly below the plausible global range for bamboos (32–256 Mg ha−1). The sympatric distribution of multiple bamboo species at the study sites may have suppressed the AGB in four of the five studied species. The aboveground NPP estimates were between 3.43 and 14.25 Mg ha−1 yr−1; those for D. membranaceus (8.20 Mg ha−1 yr−1) and I. sinica (14.25 Mg ha−1 yr−1) were comparable to mean global estimates for temperate evergreen forests (8.78 Mg ha−1 yr−1) and tropical moist forests (10.56 Mg ha−1 yr−1). High culm recruitment rates (15.20–23.39% yr−1) were major contributors to aboveground NPP estimates. Seasonal patterns of aboveground NPP were largely influenced by the phenology of the new culms. In the four sympodial bamboo species, new culms began to emerge following the onset of persistent rainfall, mainly in July and August. However, the sprouting of new culms in the monopodial species I. sinica followed a trend of increasing temperatures, mainly in March and April. Thus, our results indicate that bamboos have considerable potential for sequestering carbon in northern Laos, but that this potential may be affected by climate change.