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Root biomass and productivity in dominant plantation populations in the mountainous area in western Sichuan |
| LIU Xingliang1, MA Qinyan2, YANG Dongsheng3, SHI Zuoming4, LIU Shirong4, SU Yiming, 5, YANG Yupo5, ZHOU Shiqiang6 |
| 1.College of Environment and Resources, Beijing Forestry University, Beijing 100083, China; Sichuan Academy of Forestry, Chengdu 610081, China; 2.College of Environment and Resources, Beijing Forestry University, Beijing 100083, China; 3.Sichuan Forestry Department, Chengdu 610082, China; 4.Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China; 5.Sichuan Academy of Forestry, Chengdu 610081, China; 6.China WWF Research and Conservation Centre for the Giant Panda, Wenchuan 623005, China; |
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Abstract This study investigated root biomass and productivity in dominant populations in western Sichuan, China. A total of 4 plots (Picea balfouriana plantation for 22 age in Maerkang, 9 trees, mean DBH of population for 10.4 cm and height for 10.5 m; Larix maxteriana plantation for 22 age in Wolong, 9 trees, mean DBH of population for 17.0 cm and height for 13.8 m; Abies fabri plantation for 35 age in Ebian, 18 trees, mean DBH of population for 14.1 cm and height for 11.9 m; Larix kaempferi plantation for 23 age in Miyaluo, 8 trees, mean DBH of population for 17.4 cm and height for 14.5 m; a 20 m?25 m plot located on each of the 4 types in western Sichuan, China) were randomly selected and excavated to a depth of 60 cm for each of the 4 plantation types. To estimate the root biomass of an individual tree using D2H, an exponential model was selected with the highest coefficient ranging from 0.94 to 0.99. The total root biomass per hm2 varied among plantation population types following the order: L. kaempferi (37.832 t/hm2) > A. fabri (24.907 t/hm2) > L. maxteriana (18.320 t/hm2) > P. balfouriana (15.982 t/hm2). The biomass fractions of a given root size class compared to the total root biomass differed among plantation population types. For all 4 studied plantation types, the majority of the roots were distributed in the top 40 cm of soil, e.g., 97.88% for P. balfouriana population, 96.78% for L. maxteriana, 95.65% for A. fabri, and 99.72 for L. kaempferi population. The root biomass fractions distributed in the top 20 cm of soil were 77.13% for P. balfouriana, 77.13% for L. maxteriana, 65.02% for A. fabri and 80.66% for L. kaempferi, respectively. The root allocation in the 0 20, 20 40, and 40 60 cm soil layers gave ratios of 34:12:1 for P. balfouriana, 24:6:1 for L. maxteriana, 15:7:1 for A. fabri, and 64:4:1 for L. kaempferi populations. The root biomass density of dominant plantation population was 10.782 t/(hm2•m) for P. balfouriana, 8.230 t/(hm2•m) for L. maxteriana, 24.546 t/(hm2•m) for A. fabri, and 13.211 t/(hm2•m) for L. kaempferi population, respectively. The root biomass productivity was found to be 0.57 t/(hm2•year) for P. balfouriana, 0.83 t/(hm2•year) for L. maxteriana, 0.71 t/(hm2•year) for A. fabri and 1.64 t/(hm2•year) for L. kaempferi population, respectively.
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Issue Date: 05 December 2006
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