Affiliations: College of Life Science & Biotechnology, Shanghai
Jiaotong University, Shanghai 200030, China | Institute of Applied Ecology, Chinese Academy of
Sciences, Shenyang 110016, China | Normal College, Shenyang University, Shenyang 110016,
China
Abstract: Picea mongolica W. D. Xu. is an endemic species in China. The spruce
forest is only found in semi-arid habitat in Inner Mongolia Autonomous Region
of China. Based on the simulative defoliation experiment, it was proved that
Picea mongolica seedlings had the compensatory and overcompensatory effects
under the certain defoliation rate. The results of variance analysis on growth
indexes showed that in PM I (natural regeneration seedlings under Picea
mongolica forest), the differences of H_1 (height in June
23) and H_2 (height in September 3) were extremely
significant, and the difference of D(diameter at the breast height) were not
significant. In PM II (artificial regeneration seedlings under Betula
platyphylla Suk. forest), the difference of H_1 was
significant, the difference of H_2 was not significant, and
the difference of D was extremely significant. The regression equations were
established and the compensatory and overcompensatory points were obtained. In
PM I, the compensatory points of H_1,
H_2, and D were 0.7628, 0.7436, 0.5725, and the
overcompensatory points were 0.6056, 0.5802 and 0.2909 respectively. In PM II,
the compensatory points of H_1, H_2, and
D are 0.5012, 0.3421, 0.2488, and the overcompensatory points are 0.4137,
0.2633 and 0.0747 respectively. These results suggested that the induction of
compensatory growth mechanisms in spruce seedlings required a threshold level
of defoliation, and the insects in Picea mongolica forest could be controlled
in a certain degree.
Keywords: Picea mongolica W. D. Xu, compensate, overcompensate, growth, defoliation rate
