Effects of differences in aboveground dead organic matter types on the stand‐scale necromass and CO2 efflux estimates in a subtropical forest in Okinawa Island, Japan
Effects of differences in aboveground dead organic matter types on the stand‐scale necromass and CO2 efflux estimates in a subtropical forest in Okinawa Island, Japan
复制标题
日本冲绳岛亚热带森林地上死亡有机物类型差异对林分规模坏死物和二氧化碳流出量估计的影响
DOI：
10.1111/1440-1703.12317
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发表时间：
2022
影响因子：
2
通讯作者：
Matsumoto Kazuho
中科院分区：
文献类型：
--
作者：
Abe Hayato;Katayama Ayumi;Taniguchi Shingo;Takashima Atsushi;Kume Tomonori;Matsumoto Kazuho
死有机质（DOM）包括凋落叶、细木质残体（FWD;直径<3 cm）、下落的粗木质残体（CWDlog）和站立或悬浮的粗木质残体（CWDsnag），对森林碳循环有贡献;然而，很少有研究考虑DOM类型的差异对林分尺度的死物质和CO2排放量（Rstand）碳储量估计的影响。以日本冲绳亚热带森林为研究对象，研究了DOM类型对森林总死生物量、总Rstand的影响，以及总死生物量和总Rstand的估算误差。CWDsnag占总坏死量（1499.7 g C m−2）的比例最高（54%），其次是CWDlog（24%），FWD（11%）和落叶（11%）。凋落叶占总Rstand（340.6 g C m− 2 year −1）的比例最高（37%），其次是CWDsnag（25%），CWDlog（20%）和FWD（17%）。枯落物的变异系数为173%，比凋落叶和FWD的变异系数（72%~ 73%）高2倍。CWD的潜在误差分别占总坏死块和Rstand估计误差的99%和79%。对于本研究区域中估计误差<10%的CWDsnag和CWDlognecromass估计值，分别需要≥ 28，750 m2和≥2058- 42，875 m2的采样面积。我们的结果表明，CWD对该森林地上DOM的林分尺度碳储量和排放量有很大贡献，导致林分尺度估计的主要误差来源。
Dead organic matter (DOM), which consists of leaf litter, fine woody debris (FWD; <3 cm diameter), downed coarse woody debris (CWDlog), and standing or suspended coarse woody debris (CWDsnag), contributes to forest carbon cycling; however, few studies have considered effects of differences in DOM types on the stand‐scale estimates of carbon stocks of necromass and CO2efflux (Rstand). This study investigated characteristics of necromass andRstandin a subtropical forest in Okinawa Island, Japan, to quantify the effect of DOM type on total necromass, totalRstand, and estimate error of total necromass andRstand. The CWDsnagaccounted for the highest proportion (54%) of total necromass (1499.7 g C m−2), followed by CWDlog(24%), FWD (11%), and leaf litter (11%). Leaf litter accounted for the highest proportion (37%) of totalRstand(340.6 g C m−2year−1), followed by CWDsnag(25%), CWDlog(20%), and FWD (17%). The CWDsnagwas distributed locally with 173% coefficient of variation for necromass, which was twofold higher than those of leaf litter and FWD (72%–73%). The potential error in CWD accounted for 99% and 79% estimate error for total necromass andRstand, respectively. For the estimates of CWDsnagand CWDlognecromass with the estimates error of <10% in this study area, sampling areas of ≥28,750 m2and ≥2058–42,875 m2, respectively, were required. Our results showed that CWD considerably contributed to stand‐scale carbon stocks and efflux among aboveground DOM in this forest, resulting in a major source of errors in the stand‐scale estimates.