| Litter decomposition is an essential part in material circulation and energy transportationin forest ecosystem. The decomposition and its rate play important role in soil carbon storage,mineralization of organic nutrients, concentration of inorganic nutrients and carbon balance.Forest soil carbon pool keep40%of the total global soil carbon pool, global annual returned bylitter decomposition to soil organic carbon pool is about50Gt. Litter decomposition (includingof the root litter) contributed70%of total annual carbon flux with about68Pg C a-1(Pg=1015g). According to some research, litter mass accumulation inhanced the release of soilcarbon. The quantity of litter with increased by30%, the concentration of CO2in atmosphereincreased by150ppm, and carbon on soil decreased0.6t C·ha-1·yr-1.Moso bamboo(Phyllostachys pubescens) plantations are one of the most important foresttypes in China, which had a lot of advantages with wide adaptability and fast growth. We usenylon bag method to explor our study with leaf-litter decomposition dynamic, carbon loss andnutrient return for moso bamboo forest with different litter mass accumulation. To provide animportant basic knowledge for the biogeochemical cycle of bamboo forest ecosystem,particularly the cycling of global carbon, substrate quality, decomposition rate, microbialcomponents, and nutrient return to surface soil(0-10cm) of moso bamboo with different littermass accumulation were investigated.Our study area located in Miaoshanwu nature reserve, Fuyang, Zhejiang province betweenthe period of March,2012to March2013. Based on the survey, we concluded that:(1) The sequence of remaining mass of leaf-litter with different mass accumulation in unitarea after365days’ decomposition from the most to the least was in the following order:30g(49.64%)>60g(46.71%)>90g(43.61%), implying that leaf-litter with more massaccumulation decomposed faster in the unit area. And the differences between different massaccumulation were not significant. The decomposition mode in three treatments was similar. The litter decomposition rate constant was0.13,0.15and0.17in T30, T60andT90,respectively.(2) Litter decomposition rate was positively correlated with nitrogen content and negativequadratic function with phosphorus content. C/N ration, C/P ratio and N/P ratio showeddifferent correlationship with litter decomposition. C/N ration was negatively correlated withlitter decomposition. Litter decomposition rate was positively correlated with N/P ratio andnegative quadratic function with C/P ratio.(3) Nutrient release differed from element to element in various sites: K, Mg, Fe, Cu, Zncontent show a rather high increase, Ca show reduced tendency. And the differences betweendifferent mass accumulation were significant in Zn content (P<0.05).(4) Bacteria played a most important role in the decomposition process, and quantity ofbacteria were significant or very significan correlated with remaining mass. In addition,microbial components had seasonal differences. The total microbial number and the number offungi and bacteria reached the peak value in100days’(July) decomposition, however thenumber of aetinomyces reached the peak value in235days’(November). In the decompositontime of300days, total microbial number, bacteria number, fungi number and aetinomycesnumber reached the valley value.(5) Our results showed that, more litter mass accumulation in unit area enhanced thedecomposition of leaf-litter and it’s harmful to the stability of soil carbon in some period (about0-235d). Then, the influence of different litter mass accumulation to decomposition decreasedfollowing the next stages.(6) WSOC and LFOM were significantly related to TOC and C/N ratio on surfacesoil(0-10cm). Among them, LFOM were very significantly related to C/N ratio. |
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