Chin J Plant Ecol ›› 2012, Vol. 36 ›› Issue (9): 965-972.DOI: 10.3724/SP.J.1258.2012.00965

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Response of fine root biomass to changes in spatial heterogeneity of soil moisture and nitrogen in Larix principis-rupprechtii forest

YANG Xiu-Yun, HAN You-Zhi*(), WU Xiao-Gang   

  1. Forestry College of Shanxi Agricultural University, Taigu, Shanxi 030801, China
  • Received:2011-11-18 Accepted:2012-05-16 Online:2012-11-18 Published:2012-09-06
  • Contact: HAN You-Zhi

Abstract:

Aims Fine root biomass is known to respond to spatial heterogeneity in the distribution of soil characteristics. Cutting disturbance created changes of soil physical and chemical factors, but how the changes affect fine root biomass and turnover processes remain unclear. Our objective was to analyze the relationships of spatial heterogeneity of the fine root biomass with changes of soil moisture and nitrogen by cutting disturbance in Larix principis- rupprechtii forest.
Methods This study was conducted in L. principis-rupprechtii forest of Pangquangou National Natural Reserve, located in Guandi Mountain, Shanxi Province, China. Two plots (32 m × 32 m) were placed. Plot A was a disturbed stand, but plot B was undisturbed. Each soil core (30 cm depth) was separated into 3 sections, 0-10, 10-20 and 20-30 cm. The live fine roots were classified into two categories (≤ 1 and 1-2 mm). The partial correlation and the multi-regression coefficients of the semivariance between fine root biomass and soil moisture, nitrogen and pH were analyzed based on theory and methodology of spatial pattern analysis in geostatistics.
Important findings Spatial variability of fine root biomass and spatial heterogeneity of soil nitrogen and soil moisture were positively correlated, with the latter being significantly stronger than the former. After cutting disturbance, the correlation became more significant. The correlation between spatial variability of fine root biomass and spatial heterogeneity of soil ammonium (NH4 +) and pH was unclear in disturbed and undisturbed stands. Multiple regressions of soil factors against biomass of fine root were statistically significant. However, spatial distribution of biomass of fine roots was largely affected by soil moisture and total nitrogen and nitrate nitrogen after cutting disturbance.

Key words: cutting disturbance, fine root biomass, Larix principis-rupprechtii forest, soil nitrogen, soil water content