| 摘要 |
[Objectives] The paper was to study the fine root distribution
characteristics of Populus cathayana plantations at different ages in
alpine sandy land. [Methods] With 5, 10, 15, 20, and 25 years old P.
cathayana plantation in the eastern margin of Gonghe Basin, Qinghai
Province as the research objects, fine roots were collected by root core
drilling method, and the differences of fine root biomass, root length
density, average diameter and root tip number at the soil depths of
0-20, 20-40, 40-60, 60-80 and 80-100 cm were analyzed. [Results] The
total biomass density of P. cathayana plantation was mainly distributed
in the soil layer of 0-60 cm, accounting for 76% of the entire soil
layer, and its value increased with the increase in forest age. With the
increase in different forest ages, the root length density, average
diameter and root tip number of living fine roots in the soil layer of
0-60 cm accounted for 74%-81% of the entire soil layer, and the
proportions in the soil layers of 60-80 and 80-100 cm were 9%-11%. The
biomass density, root length density, average diameter and root tip
number of living and dead fine roots of P. cathayana plantation
increased with the increase of forest age. The root length density,
average diameter and root tip number of P. cathayana fine roots showed a
linear function change trend with the growth of forest age, which could
be described by the linear function equation y=ax+b(a>0). The
analysis results showed that the root length density, average diameter
and root tip number of P. cathayana were significantly correlated with
the total biomass density of fine roots, and the root length density and
average diameter had an extremely positive correlation with the total
biomass density. [Conclusions] In the future, P. cathayana plantation
should be properly tended to promote the development of fine roots and
maximize its ecological benefits. |
