CLONAL GROWTH OF FARGESIA NITIDA UNDER DIFFERENT CANOPY CONDITIONS IN A SUBALPINE DARK CONIFEROUS FOREST IN WOLONG NATURE RESERVE, CHINA

Abstract

Aims Fargesia nitida, one of the Giant Panda's main food sources, is adapted to varied canopy conditions through changes in morphology and/or biomass allocation. We hypothesized that changes in clonal regeneration may be another way for this plant to be adapted to different canopy conditions. Methods From August to September 2005, we measured the number, size and rhizome size of new shoots and the age and size of the parent ramet in four canopy conditions: forest understory (FU), moderate gap (MG), large gap (LG) and forest edge wilderness (FEW) in an Abies faxoniana forest in Wolong Nature Reserve in the western Sichuan, China. The data were analyzed by One-Way ANOVA, independent-sample t-test and regression. Important findings The density of surviving new shoots was lower in the FU than that in the other three canopy conditions. With decreasing canopy cover (i.e., from FU to MG to LG), the number of surviving new shoots per genet increased. At the ramet level, the mean height, basal diameter, and biomass of surviving new shoots and parent ramet were significantly different (p0.01) and increased as canopy cover decreased. In the different canopy conditions, the number of new shoots cloned by two-year-old primary parent ramets was the largest, but mean ages of parent ramets were not significantly different. There were no significant differences in average number and basal diameter of surviving new shoots reproduced by primary parent ramets with different ages in the same environment. In each canopy condition, the basal diameter of primary and secondary parent ramets were both positively correlated with basal diameter of surviving new shoots, but the effect of the primary parent ramets on surviving new shoots was stronger than that of the secondary parent ramets. The rhizome diameter of new shoots was positively correlated with the basal diameter of new shoots and primary parent ramet, but the rhizome length of surviving new shoots was not significantly correlated with basal diameter of the primary parent ramet. These results indicated that the clonal growth features exhibited significant differences strongly correlated with canopy conditions.