Litter fall and Decomposition

LITTER FALL AND DECOMPOSITION

Litterfall and litter decomposition represent a major contribution to the nutrient and carbon inputs in forest ecosystem. We measured litterfall quantity and nutrient dynamics in decomposing litter for two years at the Kwangnung Long-Term Ecological Research (LTER) site in Korea. 

Litterfall was collected in circular littertraps (collecting area : 0.25m²) and mass loss rates and nutrient release in decomposing litter were estimated using the litterbag technique employing 30cm nylon bags with 1.5mm mesh size. Total annual litterfall was 5,627kg/ha/yr and leaf litter account for 61% of the litterfall. 

The leaf litter quantity was highest in Quercus serrata, followed by Carpinus laxiflora and C. cordata, etc., which are dominant tree species in the site. Mass loss rates from decomposing litter were more rapid in C. laxiflora and C. cordata than in Q. serrata litter. About 77% and 84% of C. laxiflora and C. cordata litter disappeared, while about 48% in the Q. serrata litter lost for two year. Lower mass loss rates of Q. serrata litter may be attributed to the difference of substrate quality such as lower nutrient concentrations compared with the other litter types. 

Nutrient concentrations (N, P, Mg) of three litter types except for potassium (K) increased compared with initial nutrient concentrations of litter over the study period. The results suggest that litter mass loss and nutrient dynamic processes among tree species vary considerably on same site condition.

Introduction

Litterfall inputs and litter decomposition represent a large and dynamic portion of the nutrient cycling in forest ecosystem. In addition, the turnover of litter is a major pathway of the nutrient and carbon inputs to forest soils. Significant amounts of organic matter and nutrients in the soils can be transferred during litter decomposition processes.

Natural hardwood stands in the temperate forest zone of Korea are mixed with various kinds of deciduous tree species. Although several studies have reported litterfall inputs and litter decomposition in hardwood forest ecosystem in Korea, little is known about the direction and rates of change associated with mixed-hardwood forest ecosystem. 

The objectives of this study were to measure litterfall and nutrient quantity; 2) to examine decomposition rates in Quercus serrata, Carpinus laxiflora and C. cordata litter; 3) to determine patterns of nutrient release from decomposing litters at the LTER site of Kwangnung, a mixed-hardwood forest ecosystem in Korea.