Wood growth patterns of Macrolobium acaciifolium (Benth.) Benth. (Fabaceae) in Amazonian black-water and white-water floodplain forests
Wood growth patterns of Macrolobium acaciifolium (Benth.) Benth. (Fabaceae) in Amazonian black-water and white-water floodplain forests
复制标题
Macrolobium acaciifolium (Benth.) Benth. 的木材生长模式。
DOI：
10.1007/s00442-005-0147-8
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发表时间：
2005
期刊：
影响因子：
2.7
通讯作者：
M. Worbes
中科院分区：
文献类型：
--
作者：
J. Schöngart;M. Piedade;F. Wittmann;W. Junk;M. Worbes
无叶大球藻Macrolobium acacciifolium(Bth.)本斯。豆科(Fabaceae)是一种优势豆科树种，生长在亚马逊低海拔的营养贫乏的黑水(IGAPó)和营养丰富的白水泛滥平原森林(Várzea)。作为一年一度的长期洪水的结果，该物种形成了不同的年轮，从而可以进行树种年代学分析。我们从亚马孙中部两种泛滥平原类型采集了20棵生长在相同海拔、洪水高度高达7米的大树的树芯，测定了树龄、木材密度(WD)、平均径向生长量(MRI)和单株树木的同步年轮格局，以建立每个研究地点的树轮年表。在IGAPó发现的最大树龄超过500年，而Várzea的树龄不超过200年。IGAPó组的MRI和WD显著低于Várzea组(MRI=1.5 2±0.38 mm/年−1，WD=0.39±0.0 5 g/cm−3)，而Várzea组(MRI=2.66±0.6 7 mm/年−1，WD=0.45±0.0 3 g/cm−3)。在这两个洪泛区森林中，我们制定了年轮年表，包括1857-2003年期间(n=7棵树)和1606-2003年期间(n=13棵树)。两个泛滥平原森林的年轮宽度与从1903年以来马瑙斯港每日记录的水位得出的陆相(植被期)的长度显著相关。在这两个年表中，我们发现厄尔尼诺事件期间木材生长增加，导致降水负异常和亚马逊河流量减少，从而导致陆地阶段的延长。在树状气候指标中，拉尼娜的气候信号并不明显。
Macrolobium acaciifolium (Benth.) Benth. (Fabaceae) is a dominant legume tree species occurring at low elevations of nutrient-poor black-water (igapó) and nutrient-rich white-water floodplain forests (várzea) of Amazonia. As a consequence of the annual long-term flooding this species forms distinct annual tree rings allowing dendrochronological analyses. From both floodplain types in Central Amazonia we sampled cores from 20 large canopy trees growing at identical elevations with a flood-height up to 7 m. We determined tree age, wood density (WD) and mean radial increment (MRI) and synchronized ring-width patterns of single trees to construct tree-ring chronologies for every study site. Maximum tree age found in the igapó was more than 500 years, contrary to the várzea with ages not older than 200 years. MRI and WD were significantly lower in the igapó (MRI=1.52±0.38 mm year−1, WD=0.39±0.05 g cm−3) than in the várzea (MRI=2.66±0.67 mm year−1, WD=0.45±0.03 g cm−3). In both floodplain forests we developed tree-ring chronologies comprising the period 1857–2003 (n=7 trees) in the várzea and 1606–2003 (n=13 trees) in the igapó. The ring-width in both floodplain forests was significantly correlated with the length of the terrestrial phase (vegetation period) derived from the daily recorded water level in the port of Manaus since 1903. In both chronologies we found increased wood growth during El Niño events causing negative precipitation anomalies and a lower water discharge in Amazonian rivers, which leads to an extension of the terrestrial phase. The climate signal of La Niña was not evident in the dendroclimatic proxies.