Nutrient dynamics and lignocellulose degradation in decomposing Quercus serrata leaf litter ERIC F. SALAMANCA,* NOBUHIRO KANEKO,   SHIGEO KATAGIRI    AND YASUHIDE NAGAYAMA Faculty of Life and Environmental Sciences, University of Shimane, 690 Matsue City, Japan The litter mass loss, concentration and mass of some major nutrient elements, degradation of lignin and cellulose in decomposing Quercus serrata Murray leaf litter were monitored for 3 years using the litterbag method. The mobility of elements during the course of the study was in the order of: K > P > C > Mg > Ca > N. Three patterns of nutrient dynamics were observed: (i) concentration in- creased while mass decreased (N, Mg and Ca); (ii) concentration and nutrient mass decreased (K and C); and (iii) both concentration and mass had ¯uctuated (P). The C to element ratio tended to increase as the element was released, and decreased as the element was retained. Nitrogen mobility in relation to carbon was characterized by three phases: (i) initial release; (ii) accumulation and (iii) ®nal release. The decay rate (k) calculated from 0±6 months period was overestimated for an average annual rate while those of 0±36 months ®t the negative single exponential model (Adj. r 2  0.99) better than shorter periods. For lignin, the concentration had increased then decreased but tended to stabilize after 1 year while the lignin mass had continuously decreased throughout the study period. During the ®rst 9 months, both the concentrations and mass of cellulose had ¯uctuated but declined thereafter. The amounts of N had initially increased but declined after 1 year; P had ¯uctuated while K, Ca, Mg and C had decreased throughout the study. N and C/N ratio exerted strong in¯uence on mass loss during the ®rst 24 months but the in¯uence of lignin emerged after 24 months. Key words: cellulose; decomposition; lignin; nutrient dynamics; Quercus. INTRODUCTION In forest ecosystems, decay of leaf litter is in¯u- enced by the interactions of physicochemical characteristics of the resource material (referred to as resource quality), environmental conditions and decomposing organisms (Swift et al. 1979). The residence time for fallen leaves to lose its mass and consequently release the nutrients em- bedded in the litter varies depending on litter type and decay environment. Some tree species take several months to lose half of their leaf litter mass (Ishii et al. 1977), while other species require several years (Ando 1970; Lousier & Parkinson 1976). The labile fractions are lost at the early stage while the recalcitrant components such as lignin are decomposed slowly and usually regulate the decay process at the later stage (McClaugherty & Berg 1987). Lignin impedes the overall de- composition of litter because lignin and lignin- like compounds often form resistant shield around the holocellulosic compounds (Berg et al. 1984). Likewise, by-products of lignin degrada- tion form stable nitrogenous compounds, thereby making them less available to decomposer organisms (Stevenson 1982). Few studies have been conducted for more than 1 year on decomposition of Japanese oaks (Quercus species) (Kawahara 1975; Kawahara 1985; Takeda et al. 1987). Mass loss and nutrient *Present address: College of Agriculture and For- estry, Don Mariano Marcos Memorial State Univer- sity, 2515 Bacnotan, La Union, Philippines.   Present address: Department of Soil Zoology, In- stitute of Environmental Science and Technology, Yokohama National University, Tokiwadai 79-7, Hodogaya, 240-8501, Yokohama, Japan    Author to whom requests for offprints should be addressed. Received 25 August 1997. Accepted 3 March 1998. Ecological Research (1998) 13, 199±210