LANDSLIDE DISTURBANCE AND FOREST REGENERATION IN THE UPPER LUQUILLO MOUNTAINS OF PUERTO-RICO
LANDSLIDE DISTURBANCE AND FOREST REGENERATION IN THE UPPER LUQUILLO MOUNTAINS OF PUERTO-RICO
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DOI：
10.2307/2260901
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发表时间：
1990-09-01
影响因子：
5.5
通讯作者：
GUARIGUATA, MR
中科院分区：
文献类型：
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作者：
GUARIGUATA, MR
在海拔530 ~ 850 m的44 km ~ 2带内，研究了滑坡干扰的自然状态和滑坡后演替的主要趋势。（亚热带低山地潮湿森林，意为霍尔德里奇）位于波多黎各[西印度群岛]的卢基略山脉。对1936年至1988年的航空照片和实地调查的研究显示，有46次山体滑坡。40%的滑坡的地图面积（实际面积的水平投影）在200至400平方米之间。 > 1800 m2的滑坡占样本的不到10%，但占扰动总地图面积的40%左右。滑坡的发生具有时空异质性。平均而言，滑坡干扰的最小值为0.3%和0.08%的森林地图面积每世纪的斜坡上的侵入岩和火山岩，分别。在8宗发生少于1年的山泥倾泻中，下层泥土（包括有机泥土、破碎的植物部分及被连根拔起的树木）的有机碳及营养物浓度，一般较上层泥土（通常由暴露的风化岩床及矿物泥土组成）为高。需光树种的可萌发埋藏种子仅分布在下层（22粒m-2），约为相邻成熟林平均埋藏种子密度的5%。对20个滑坡的52年时间序列进行的植被分析表明，在较低的地带，再生一直比较活跃。物种组成占主导地位的滑坡高达38岁的光需求，快速增长的先锋树。上层区域的植被重建似乎被大量的光需求蕨类植物所阻碍。断面积和植物区系组成开始类似于300-600平方米，52岁的滑坡干扰前的条件。
The natural landslide disturbance regime and the major trends in post-landslide succession were studied within a 44-km2 belt between 530 and 850 m a.s.l. (subtropical lower montane wet forest, sensu Holdridge) in the Luquillo Mountains of Puerto Rico [West Indies]. Examination of aerial photographs from 1936 to 1988, and field surveys, revealed forty-six landslides. Forty per cent of the landslides had map areas (the horizontal projection of their actual areas) between 200 and 400 m2. Landslides > 1800 m2 comprised less than 10% of the sample, but accounted for about 40% of the total map area disturbed. Landslide occurrence is spatially and temporally heterogeneous. On average, landslides disturb a minimum of 0.3% and 0.08% of the forest map area per century on slopes underlain by intrusive and volcaniclastic rocks, respectively. On eight landslides less than one year old, the soil in the lower zone (which included deposits of organic soil, broken plant parts and uprooted trees) generally had a higher concentration of organic carbon and nutrients than that in the upper zone (usually consisting of exposed weathered bedrock and mineral soil). Germinable buried seeds of light-demanding species were found only in the lower zone (22 seeds m-2), about 5% of the average buried seed density found in adjacent mature forest. Vegetation analyses on a fifty-two-year chronosequence of twenty landslides showed that regrowth was consistently more vigorous in the lower zone. Species composition is dominated on landslides up to thirty-eight years old by light-demanding, fast-growing pioneer trees. Revegetation of the upper zone seemed to be retarded by extensive mats of light-demanding ferns. Basal area and floristic composition start to resemble pre-disturbance conditions on 300-600-m2, fifty-two-year-old landslides.