ROOT SYSTEMS OF CHAPARRAL SHRUBS
ROOT SYSTEMS OF CHAPARRAL SHRUBS
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DOI：
10.1007/bf00345795
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发表时间：
1977-01-01
期刊：
影响因子：
2.7
通讯作者：
JOW, W
中科院分区：
文献类型：
--
作者：
KUMMEROW, J;KRAUSE, D;JOW, W
在美国加利福尼亚州圣地亚哥县(北纬32°54‘’；海拔900米)北向坡上的一片70平方米的茶树混交林中挖掘出查帕尔灌木的根系。灌木种类主要有束状腺口藻属、刺角葡萄属、格氏蜡梅属、簇毛胡杨属和羽扇豆属。灌木被用铁丝网固定在它们的位置上，它们下面的土壤被冲到大约60厘米深的地方，那里难以穿透的花岗岩阻碍了进一步的冲洗，根的生长受到了严重的限制。根系的间距和交织用比例尺绘图记录。根据根部的深度采集根部，将每个树种的直径分为不同的大小类别，并测量它们的干重。灌木的根主要局限在表层土壤中。簇毛偃麦草的根系主要集中在上层土壤中。束状腺口藻的根部比毛叶腺口藻的根部更浅。据推测，开挖现场的浅层土壤阻碍了不同根系的清晰深度分区。各灌木的平均干重根冠比为0.6，变化范围为0.8~0.4。根面积总是超过地上部面积，其对应的比例从刺参的6到松材的40。冠层下g干重/m2的细根密度显著高于非遮荫区。开阔地相应的45g干重/平方米仍然很高，足以使其他灌木难以建立。
Root systems of chaparral shrubs were excavated from a 70 m2 plot of a mixed chaparral stand located on a north facing slope in San Diego County California, USA (32.degree.54'' N; 900 m above sea level). The main shrub species present were Adenostoma fasciculatum, Arctostaphylos pungens, Ceanothus greggii, Erigonum fasciculatum and Haplopappus pinifolius. Shrubs were wired into their positions and the soil was washed out beneath them down to a depth of approximately 60 cm, where impenetrable granite impeded further washing and root growth was severely restricted. Spacing and interweaving of root systems were recorded by an in scale drawing. The roots were harvested in accordance to their depths, separated into diameter size classes for each species and their dry weights measured. Roots of shrubs were largely confined to the upper soil levels. The roots of E. fasciculatum were concentrated in the upper soil layer. Roots of Adenostoma fasciculatum tended to be more superficial than those from C. greggii. It is hypothesized that the shallow soil at the excavation site impeded a clear depth zonation of the different root systems. The average dry weight root:shoot ratio was 0.6, ranging for the individual shrubs from 0.8-0.4. The root area always exceeded the shoot area, with the corresponding ratios ranging from 6 for A. pungens to 40 for H. pinifolius. The fine root density of 64 g dry wt/m2 under the canopy was significantly higher than in the unshaded area. The corresponding value of 45 g dry wt/m2 for the open ground is still high enough to make the establishment of other shrubs difficult.