Root development across a chronosequence in a Japanese cedar (Cryptomeria japonica D.!Don) plantation
Root development across a chronosequence in a Japanese cedar (Cryptomeria japonica D.!Don) plantation
复制标题
DOI：
10.1007/s10310-006-0256-1
复制
发表时间：
2007-04-01
影响因子：
1.5
通讯作者：
Tokuchi, Naoko
中科院分区：
文献类型：
--
作者：
Fujimaki, Reiji;Tateno, Ryunosuke;Tokuchi, Naoko
研究了日本中部奈良县杉木（Cryptomeria japonica D. Don）人工林细根和小根的生物量、垂直分布和比根长（SRL）。在4、15、30、41和88年不同树龄的5个人工林中，从深度达50厘米的土壤块中收集根系。15年林分细根生物量在林冠关闭前达到最大值（639 g m(-2)）， 30年林分细根生物量下降（422 g m(-2)），之后保持稳定。除30年林分外，随着林龄的增加，深层细根生物量增加，且细根累积生物量达到90%的深度与平均茎粗呈良好的异速生长关系。各林分的根长密度（单位土壤体积根长）和SRL均随土壤深度的增加而减小，表明植物主要从浅层土壤中获取水分和养分。林龄为4年的林分，林龄与林分的关系尚不清楚。表层土壤SRL随根长密度的增加而降低，表明细根系发育过程中的分支与密度相关，而与年龄无关。
We investigated the biomass, vertical distribution, and specific root length (SRL) of fine and small roots in a chronosequence of Japanese cedar (Cryptomeria japonica D. Don) plantations in Nara Prefecture, central Japan. Roots were collected from soil blocks up to 50 cm in depth in five plantations of differing age: 4, 15, 30, 41, and 88 years old. Fine-root biomass reached a maximum (639 g m(-2)) in the 15-year-old stand before canopy closure, decreased in the 30-year-old stand (422 g m(-2)), and thereafter was stable. Except in the 30-year-old stand, fine-root biomass increased in deeper soil layers as stand age increased, and the depth at which the cumulative biomass of fine roots reached 90% exhibited a good allometric relationship with mean stem diameter. Both root-length density (root length per unit soil volume) and SRL decreased with soil depth in all stands, indicating that plants mainly acquire water and nutrients from shallow soils. The highest SRL was observed in the 4-year-old stand, but the relationship between SRL and stand age was unclear in older stands. The SRL in surface soils seemed to decrease with increases in root-length density, suggesting that branching of the fine-root system during development is related to density-dependent processes rather than age.