Culm dynamics and dry matter production of bamboos in the Wolong and Tangjiahe giant panda reserves, Sichuan, China.

Bamboos dominate the understorey of montane and subalpine forests in C Sichuan, where they are the sole food source for giant pandas Ailuropoda melanoleuca. Above-ground biomass averaged 23.7 t ha^-1 for Fargesia spathacea, 9.3 t ha^-1 for F. scabrida and 7.4 ha^-1 for Sinarundinaria fangiana. Average annual net production of F. spathacea and S. fangiana was 3.6 t ha^-1 and 1.5 t ha^-1, respectively. Insects, giant pandas, rodents and other predators killed 46% of all F. spathacea shoots and 45% of all F. scabrida shoots. Giant pandas selected large shoots and insects small ones of both F. spathacea and F. scabrida, favouring development of stands composed of intermediate sized culms. Average annual culm recruitment for F. scabrida, S. fangiana and F. spathacea were 8.5%, 9.1%, and 10.6%, respectively. Average annual mortality rates for F. scabrida, S. fungiana and F. spathacea were 8.5%, 9.1%, and 10.6%, respectively. Sinarundinaria fangiana flowered and died in 1983. Culm selection by pandas in remaining live patches is expected to change to use in proportion to availability. Pandas will shift their diet to F. spathacea if remaining patches of S. fangiana flower and die. The most effective means preventing food shortages for pandas during periods of bamboo flowering is by preserving the existing mosaic of bamboo species. -from Authors