Chin J Plan Ecolo ›› 2007, Vol. 31 ›› Issue (1): 102-109.doi: 10.17521/cjpe.2007.0013

• Research Articles • Previous Articles     Next Articles

ESTIMATING FINE_ROOT LONGEVITY OF FRAXINUS MANDSHURICAAND LARIX GMELINII USING MINI-RHIZOTRONS

YU Shui_Qiang; WANG Zheng_Quan*; SHI Jian_Wei; QUAN Xian_Kui; MEI Li; SUN Yue ; JIA Shu_Xia; YU Li_Zhong   

  1. School of Forestry, Northeast Forestry University, Harbin 150040, China
  • Online:2007-01-30 Published:2007-01-30
  • Contact: WANG Zheng_Quan

Abstract:

Aims Fine-roots (≤2 mm diameter) are important in controlling energy and matter exchange between tree and soil. Fine-root longevity is a critical determinant of fine-root turnover and therefore carbon allocation and nutrients returned to the soil. However, little is known about variation in fine-root longevity in relation to spatial and temporal heterogeneity in availability of soil resources (such as temperature, moisture and nitrogen). How does availability of soil resources affect fine root longevity? Do different tree species, soil depths and root cohorts have different fine-root longevity in the same forest site? To answer these questions it is important to understand the fate of fine roots in s oil with heterogeneous resource availability. The objectives of this study were to: 1) compare fine-root longevity between ash (Fraxinus mandshurica) and larch (Larix gmelinii) in the same site, 2) define patterns of fine-root longevity in different soil depths and elucidate the effect of availability of soil resources on fine-root longevity and 3) analyze seasonal changes of fine-root longevity for both species.
Methods Mini-rhizotrons (root observation tubes) were used to estimate fine-root longevity. We established three 20 m×30 m plots in an ash and larch plantation, and installed six clear PVC (polyvinyl chloride) mini-rhizotron tubes (90 cm long × 5.5 cm inside diameter) in each plot in October 2003. From 16 April to 30 October in 2004, video images were collected from the mini-rhizotron tubes at approximately two-week intervals and analyzed with an image analysis system (RooTracker software). We compared differences in longevity between tree species , soil depths and seasonal root cohorts using cumulative survival rate and median root longevity (MRL) of fine roots by Kaplan-Meier methods in survival analysis. 
Important findings Cumulative survival rate of fine roots decreased gradually with time. Survivorship curves showed that cumulative survival rate of fine roots in ash was significantly higher than that in larch (p<0.001);MRL was 111±7 d in ash and 77±4 d in larch. Higher fine root mortality was found in 0-20 cm soil, as MRL was 62±11 d for larch and 111±6 d for ash, contrasting with 95 ±11 d for larch and 124±20 d for ash in deep soil. This study also indicated longer life spans of fine roots produced in summer (82±6 d for larch) than spring (47 ±13 d). Similar seasonal pattern was found for ash. Fine-root longevity was different between tree species due to different root genetics, physiology and architecture. High soil temperature and high N content can decrease fine root longevity. In summer, photosynthates are allocated to roots and fine roots grow rapidly and have increased longevity. Our results suggested that fine-root longevity is correlated with genetics of the species, physiological status and soil resource availability.

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[2] Wu Jian-feng. Lichen Ptant in Langskan Area Nantong[J]. Chin Bull Bot, 1993, 10(01): 62 .
[3] . [J]. Chin Bull Bot, 1998, 15(专辑): 35 -38 .
[4] . [J]. Chin Bull Bot, 2000, 17(05): 478 .
[5] WANG Zheng-Feng ZHANG Jun-Li LI Ming-Guang WANG Bo-Sun HE Xing-Jin PENG Shao-Lin. Advances of Plant Molecular Ecology (Ⅰ)—— Genetic Structure and Hybridization[J]. Chin Bull Bot, 2001, 18(06): 635 -642 .
[6] Zhao Yu-hua. Effect of the Plant Cold-resister on Overcoming Rice Seedling Decay in Low Temperature Stress in our County[J]. Chin Bull Bot, 1994, 11(特辑): 97 -99 .
[7] Danlong Jing, Jiang Ma, Bo Zhang, Yiyang Han, Zhixiong Liu, Faju Chen. Expression Analysis of MwAG in Different Organs and Developmental Stages of Magnolia wufengensis[J]. Chin Bull Bot, 2013, 48(2): 145 -150 .
[8] Li Xiang-gan. The Population Characteristics and determination of Biomass in the Quercus acutissima Forest Community on Mount Lao[J]. Chin J Plan Ecolo, 1987, 11(1): 21 -31 .
[9] MIAO Bao-He, LI Xiang-Dong, LIU Bo, HE Qi-Ping, ZHU Tao, LIU Xing-Tan, ZHU Qi-Yu, QIAO Guang-Fa, FAN Ting-An, CHEN Cheng-Jun, DONG Qing-Yu, YU Song-Lie. EFFECT OF WAVING-CANOPY CULTURAL TYPE ON ACTIVE OXYGEN AND MEMBRANE LIPID METABOLISM PEROXIDATION OF HIGH OIL SOYBEAN LEAVES[J]. Chin J Plan Ecolo, 2008, 32(3): 673 -680 .
[10] REN Jian-Yi, LIN Yue, YUE Ming. SEED GERMINATION CHARACTERISTICS OF BETULA ALBO-SINENSIS AT MOUNTAIN TAIBAI, CHINA[J]. Chin J Plan Ecolo, 2008, 32(4): 883 -890 .