Dynamic characteristics of litterfall and N:P ecological stoichiometry in Liquidamba formosana plantation in Hunan, China
Litterfall production and this substrate quality is of importance for understanding nutrient cycling, forest growth and interactions with environmental variables in forest ecosystems. Litterfall production, component, seasonal variation and its N:P ecological stoichiometry were intensively studied during the period of 2009-2011 in one typical fast growth forest, Liquidamba formosana Hance plantation in Hunan province China.
There was no significant differences of literfall production between different years during the period of 2009-2011, ranging from 4935.7 ± 609.7 kg·ha-1 to 5085.9 ± 657.6 kg·ha-1. The leaf was main component for litterfall, accounting for 57.32%. Components of litter biomass of L. formosana plantation showed significant dynamic characteristics of the season, only between leaf and branch biomass had the significant correlation (P<0.01), the remaining components had no significant correlation.
Litter N, P content in L. formosana plantation showed different seasonal dynamic characteristics, and between N and P element was a significant positive correlation (P<0.05).. Components of litter N:P ratios were greater than 25, and P content was low generally, it is showed that litter had higher N and lignin content, it was low about the decomposition rate, which is mainly restricted by low P content.
The result of CCA of Canoco analysis on the N, P content and ratio of N:P in each component of litter fall and soil showed that N, P, N:P ratio and pH value of soil was closely related with N, P and N: P ratio of litter components, while pH value of soil was greatly influenced by N:P in branch and flower, and N, P and N: P in fragment. Between N in soil and N in fragment and leaf, between P in soil and P in fragment and leaf, and between N:P in soil and N:P in fragment and leaf were significantly negative correlated, while litter N:P ratios was positive correlated with the soil pH value. The results reported here may indicate that increased soil pH value could increase N:P ratio in branch and leaf of litterfall, and then improve the decomposition rate of litterfall.