| 摘 要：In revegetated desert areas, roots are critical for plant growth and community
stability. A field study was conducted to investigate the distribution and dynamics
of roots in a revegetated stand of Artemisia ordosica Kracsh. in the Tengger Desert
during the growing seasons of 2004 and 2005. Seven trenches 1.2m wide and 1.0m
deep were excavated around stems to determine the coarse root length and weight.
Soil cores, spaced from the stem at an interval of 0.2, 0.4, 0.6, 0.8, and 1.0 m, were
designed to take fine root samples, and minirhizotrons were buried at intervals of
0.2, 0.5, and 1.0m away from the stem to measure the fine root number and length.
The results showed that the root systems of A. ordosica is distributed vertically in
the uppermost soil profile, especially for coarse roots, which were concentrated in
the 0.2-m soil profile. The horizontal distribution of A. ordosica coarse roots was
limited to a range of 0.6m and 0.4m away from the trunk for root length and weight,
respectively. Fine roots were distributed uniformly in comparison with coarse roots.
The total root biomass and fine root biomass were 0.42 and 0.26 kgm2, which
accounted for about 80% and 50% of the total biomass, respectively. The growth
and distribution of fine roots were mainly related to soil water content. Peak values
in both soil water content and fine root length were observed twice, in 2004 and 2005.
The peak value of soil water content was observed 1 month prior to that of fine root
length density. The fine roots were abundant 1 month later, when the volumetric soil
water content reached 2.75%. |
研究报告目录
Distribution and Seasonal Dynamics of Roots in a Revegetated Stand of Artemisia ordosica Kracsh. in the Tengger Desert (North China)