Light and nutrient limitations for tree growth on young versus old soils in a Bornean tropical montane forest.
Light and nutrient limitations for tree growth on young versus old soils in a Bornean tropical montane forest.
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婆罗洲热带山地森林中年轻土壤与老土壤上树木生长的光照和养分限制。
DOI：
10.1007/s10265-020-01217-9
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发表时间：
2020
影响因子：
2.8
通讯作者：
Kitayama K.
中科院分区：
文献类型：
--
作者：
Aiba S.;Kitayama K.
在婆罗洲基纳巴卢山物种丰富的热带山地雨林中，我们研究了森林和树木对养分有效性随着土壤老化而减少的反应。比较了营养丰富的幼龄土和营养贫乏的老土上两块1公顷样地的群落组成、结构和乔木生长率。桃金娘科和壳斗科在两个样地中均占主导地位。随着土壤老化，樟科植物的优势度、茎密度、断面积和地上生物量下降，林下植被变得明亮。老土壤上的一些优势类群(罗汉果科和桃金娘属)在年轻土壤上几乎不存在；这归因于林下植被的光照限制。幼龄土壤林下乔木生长速率较低，老土壤上乔木生长速率较低。这说明幼龄土壤上林下乔木的生长受光照的限制，而老土壤上的冠层乔木的生长受养分的限制。在两个样地丰富的8种物种中，5种物种在老土壤上的优势度显著降低，其中4种物种的最大尺寸和生长速度也有所减小。其余三个物种在样地上表现出类似的优势，但生长速度没有下降，尽管它们在旧土壤上表现出最大尺寸的减小。这些分析表明，物种对土壤年龄梯度的反应是不同的。我们认为，物种对养分有效性降低和林下光照水平增加的不同反应解释了植物区系随土壤老化而更替的原因。
We examined forest and tree responses to decreasing nutrient availability with soil aging in a species-rich tropical montane rain forest on Mount Kinabalu, Borneo. Community composition and structure and tree growth rates were compared between two 1 ha plots on nutrient-rich young soil versus nutrient-deficient old soil. Myrtaceae and Fagaceae dominated both plots. With soil aging, the dominance of Lauraceae, stem density, basal area and aboveground biomass decreased, and the forest understory became brighter. Some dominant taxa on the old soil (Podocarpaceae and the genusTristaniopsisin Myrtaceae) were virtually absent on the young soil; this was attributed to light limitation in the understory. Growth rates of understory trees were lower on the young soil, whereas those of canopy trees were lower on the old soil. This suggested that the growth of understory trees was limited by light on the young soil, whereas that of canopy trees was limited by nutrients on the old soil. Of the eight species that were abundant in both plots, the dominance of five species was considerably lower on the old soil, four of which also exhibited decreased maximum sizes and lower growth rates. The remaining three species showed similar dominance across plots without a decline in growth rates, although they exhibited decreased maximum sizes on the old soil. These analyses demonstrated divergent responses of species to the soil-age gradient. We suggest that the differential responses of species to decreasing nutrient availability with a concomitant increase in understory light levels explain floristic turnover with soil aging.