Litterfall dynamics of plant communities at different succession stages in Karst area of Puding, Guizhou Province of Southwest China

Litterfall is an important component of carbon budget and material cycling in terrestrial ecosystems. In this paper, an observation was conducted on the monthly dynamics of the biomass of litterfalls and their components (leaf, branch, and flower and fruit) from the plant communities at six succession stages (sparse-shrub tussock, thorny shrub, shrub, shrubtree transitional forest, secondary forest, and primary forest) in the Puding Karst area of central Guizhou Province from March 2011 to February 2012. At the six succession stages, the mean annual litterfall biomass was 789. 5, 3821. 8, 4315. 0, 4158. 8, 4201. 0, and 3950. 4 kg·hm^-2, respectively. With the forward succession of the communities, the litterfall biomass increased first, decreased gradually then, and tended to be stable lastly. The biomass of the litterfall components (leaf, branch, and flower and fruit) accounted for 59. 0% -77. 7%, 7. 9% -24. 0%, and 5. 4% - 24.0% of the total, respectively. With the forward succession, the biomass of leaf litterfall decreased while that of branch litterfall increased. The monthly variation pattern of the litterfall of sparse-shrub tussock, shrub, and primary forest was of unimodal type, while that of the other three succession communities was of bimodel. The leaf litterfall biomass showed a consistent monthly dynamic with the total litterfall.