Litterfall dynamics in an overcrowded mangrove Kandelia obovata (S., L.) Yong stand over five years
Litterfall dynamics in an overcrowded mangrove Kandelia obovata (S., L.) Yong stand over five years
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DOI：
10.1016/j.ecss.2011.11.012
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发表时间：
2012-02
影响因子：
2.8
通讯作者：
Sahadev Sharma;A. R. Hoque;Kangkuso Analuddin;A. Hagihara
中科院分区：
文献类型：
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作者：
Sahadev Sharma;A. R. Hoque;Kangkuso Analuddin;A. Hagihara
由于有机物对碎屑成分的支持，需要对进入边缘湿地地区的有机物通量进行量化。在东亚分布区最北端的红树林（Kandeliaobovata）进行了为期5年的研究，结果表明，叶凋落物和托叶凋落物具有明显的月变化规律，最大值出现在7月，最小值出现在2月。在这个地区，红树林经历了独特的季节性气候，其特点是低温和频繁的台风。繁殖体凋落量在4月和5月最大，而在夏季没有繁殖体凋落。Kendall的一致性系数表明，凋落物的月趋势在不同年份之间没有显著差异（分支，p < 0.05;其他成分，p < 0.001）。自相关系数分析表明，除分支凋落量与台风发生有关外，其他凋落量均表现出1年周期。月分支凋落量随月最大风速的增加呈指数增加。月平均温度、月平均最大风速、月平均日长和月平均太阳辐射对凋落物总量的影响达0.1%显著水平，月平均湿度对凋落物总量的影响达5%显著水平。年平均总落叶量范围为891.1至1162.0 g m-2 yr-1，其中树叶落叶量占49.3- 67.9%。台风期间分支凋落物的高产量是造成年凋落物总量较高的原因。托叶凋落物（新叶冲洗的指标）减少，增加花/果和繁殖体凋落物和平均每年每棵树的落叶量减少，随着密度的增加图之间。年落叶量与密度无关，平均叶龄为12.04 ± 0.04个月。
Organic matter fluxes into marginal wetland areas require to be quantified given their support for the detrital components. Following their study for 5 years in a mangrove (Kandelia obovata) stand near the northernmost limit of the species’ distribution in East Asia, leaf and stipule litterfalls exhibited a clear monthly pattern, with maximum values in July and minimum values in February. In this region, mangroves experience a distinct seasonal climate characterised by low temperatures and frequent typhoons. Propagule litterfall was largest in April and May, whereas no propagule litterfall occurred in summer. Kendall’s coefficient of concordance revealed that the monthly trends of litterfall did not significantly differ among years (branch, p < 0.05; other components, p < 0.001). Autocorrelation coefficient analysis demonstrated that all litterfall components exhibited a 1-year cycle, except for branch litterfall, which instead depended on typhoon occurrence. Monthly branch litterfall increased exponentially with increasing monthly maximum wind speed. The monthly total litterfall was significantly affected by mean monthly temperature, mean monthly maximum wind speed, monthly day length and mean monthly solar radiation at a 0.1% significant level, and mean monthly humidity at a 5% significant level. Mean annual total litterfall ranged from 891.1 to 1162.0 g m−2yr−1, of which leaf litterfall constituted 49.3–67.9%. Higher annual total litterfall was caused by high production of branch litterfall during typhoons. Stipule litterfall (an indicator of new-leaf flush) decreased with increasing levels of flower/fruit and propagule litterfalls and mean annual leaf litterfall per tree decreased with increasing tree density among plots. Annual leaf litterfall per plot was almost constant regardless of tree density and mean leaf longevity was estimated to be 12.04 ± 0.04 month.