Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (6): 1277-1284.DOI: 10.3773/j.issn.1005-264x.2008.06.008

• Original article • Previous Articles     Next Articles

EFFECTS OF HORIZONTAL DISTANCE ON FINE ROOT BIOMASS AND SEASONAL DYNAMICS IN LARIX PRINCIPIS-RUPPRECHTIIPLANTATION

YANG Xiu-Yun, HAN You-Zhi(), ZHANG Yun-Xiang   

  1. College of Forestry, Shanxi Agricultural University, Taigu, Shanxi 030801, China
  • Received:2008-01-03 Accepted:2008-06-05 Online:2008-11-30 Published:2008-11-30
  • Contact: HAN You-Zhi

Abstract:

Aims Root systems are important in carbon and nutrient cycling in forest ecosystem. There is much research on vertical distribution and seasonal dynamics of fine root biomass; however, horizontal distribution and seasonal dynamics at different horizontal distances remain poorly understood. Our objectives are to determine how fine root biomass and seasonal dynamics of fine root biomass change with horizontal distance.

Methods The study was conducted in a 28-year-old Larix principis-Rupprechtii plantation in Guandi Mountain (110°30′ E, 37°28′ N) in Shanxi Province, China. Soil cores (30.0 cm depth, 7.0 cm diameter) were taken in May, July, September and October,2004, at different horizontal distances (100, 50 and 20 cm) from the stem. Soil cores were separated into 3 sections, 0-10, 11-20 and 21-30 cm. Fine roots (≤2 mm) were separated into live and dead, and live fine roots were classified into two categories, ≤1 and 1-2 mm. Roots were dried at 80oC to constant mass for weighing.

Important findings The biomass of fine roots was 244.20, 209.45 and 221.03 g·m-2at 100, 50 and 20 cm, respectively, and differences were not statistically significant (p>0.05). Total fine root biomass changed from 169.67 to 263.09 g·m-2. Differences were larger at 0-10 cm depth than at 11-20 and 21-30 cm. Seasonal dynamics of fine root biomass changed significantly in the 0-10 cm layer (p<0.05), and it changed more at the 100 and 20 cm distances rather than at 50 cm. Horizontal differences in fine roots likely resulted from tree crowns causing heterogeneous illumination, soil water, temperature and nutrients. The study indicates that combined and integrated horizontal distribution factors should be considered in research on spatial distribution and seasonal dynamics of fine roots.

Key words: fine root biomass, plantation, horizontal distribution, seasonal dynamics