Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (7): 674-683.DOI: 10.3724/SP.J.1258.2013.00070

• Research Articles • Previous Articles     Next Articles

Effects of fertilization on Alnus formosana fine root morphological characteristics, biomass and issue content of C, N under A. formosana-Hemarthria compressa compound mode

MIAO Yu,CHEN Yue-Lin,LI Xian-Wei(),FAN Chuan,LIU Yun-Ke,YANG Zheng-Ju,ZHANG Jun,CAI Xin-Li   

  1. College of Forestry, Sichuan Agricultural University, Sichuan Provincal Key Laboratory of Forestry Ecological Engineering in Upper Reaches of Yangtze River, Ya’an, Sichuan 625014, China
  • Received:2013-01-28 Accepted:2013-04-26 Online:2013-07-01 Published:2013-07-05
  • Contact: LI Xian-Wei

Abstract:

Aims Our objectives were to: 1) examine fine root biomass, morphological characteristics and content of C and N of Alnus formosana in an A. formosana-Hemarthria compressa composite model in Danling, Sichuan Province, China, 2) examine the effects of fertilization on each order of fine roots, and 3) analyze the relationship between soil nutrients and fine root biomass, architecture and content of C and N.
Methods In September 2010, we established two subdistricts, eradicated weeds and planted H. compressa. We fertilized one subdistrict with N-P-K fertilizer in April, June, August and October and did not fertilize the other subdistrict. We excavated soil blocks of 20 cm × 20 cm × 10 cm (height) to sample intact fine root branches of at least the first branch orders. We dissected the intact root branches by orders and measured the diameter, specific root length, biomass, and C and N content of each order.
Important findings Fertilization reduced fine-root average diameter in soil surface and increased that in soil subsurface. In fine-root orders 1-5, specific root length increased as root order decreased. Fertilization significantly increased specific root length in fine-root orders 1-3 in soil surface and subsurface (p < 0.01). Fertilization reduced fine-root biomass in all soil layers and significantly reduced the ratio of fine-root biomass to total root biomass in orders 1-3 (p < 0.05), while fine root biomass increased in orders 4 and 5. The effect of fertilization on fine-root C content was not significant in all orders (p > 0.05). Soil surface total N content of fine roots of 1-5 orders was higher than that in subsurface. Fertilization significantly (p < 0.01) increased fine-root N content of order 1 fine roots in soil surface and orders 1 and 2 in the subsurface, but had no significant effects on orders 3-5 (p > 0.05).

Key words: Alnus formosana, biomass, fine root, Hemarthria compressa, morphology, total C, total N