Decomposition Rate Of The Litter Of Artifical Forest Of Liquidambar Formosana And Its Effects Of Soil Nutrient

Liquidambar formosana is a fast-growing deciduous broad-leaved species in China's subtropical regions, adaptable and a fine timber species. Study decomposition rate of the litter of artifical forest of L. formosana and its effects of soil nutrient is helpful for providing the level of silviculture and generalizing the planting of L. formosana, there is important denotation it could promote sustainable development management of L. formosana forest.The results showed that monthly dynamics of the litter storey were unevenly distributed and the order of total quantity of the litter with the seasons was winter >autumn>spring> summer. The range of the monthly litter amount was 112.700～615.787 kg·hm-2. Both sample plots were located in south slope, which had a good condition of water and heat and a stable community structure. Biomass of L. formosana litter, which was typical of its kind, were 2665.700kg·hm-2 and 1095.086kg·hm-2 in undecomposition layer and decomposition layer. The order of the content of macro-element in litter was N> Ca> K> Mg> P. The regularity of monthly dynamics of the content of nutrient in litter was indistinct but showed some tendency. The content of N, P element reached the peak in May-July, and the highest value were 16.040 g·kg-1 and 0.474 g·kg-1. The range of the content of organic cabon was 4.275～5.32 g·kg-1. The content of K element in litter at low level in rainy spring were due to leaching and ion-exchange, and the highest value was 5.291 g·kg-1 in November. The content of Ca and Mg element reached their peak at 14.956g·kg-1 and 3.152g·kg-1 respectively in January. The order of the content of micro-element in litter with the higher content and Wider range was Mn> Fe> Zn> Pb> Cu> Ni> Co> Cd. The content of Mn element was much higher than other micro-element.Modifing the exponential attenuation model Xt=Xoe-kt proposed by Olsen in 1963, the exponential regression of residue rate of decomposition of the litter of artifical forest of L. formosana were concluded to y=1.0033e-0.0017t. The half-life and turn-around time of the litter decomposition were 409.800d and 1764.100d with the formula.In the process of litter decomposition, the release of N element was mainly through the decomposition and mineralization of organic matter with slower migration. The content of N element increased gradually in the early stage of the decomposition process, followed by the rapid decline in the latter part of the process and the stable and slight increase at last. N element mainly occurred in organic matter, and was subjected to microbiological deterioration before release. In the decomposition process, organic carbon in litter gradually released into the soil, which was good for improving content of organic matter in soil. The lowest content of organic carbon was 3.659 g·kg-1. The changes of content of P and N element had a similar regularity. K element had faster decomposition rate at the beginning, and then the change of content of this element was relatively stable at lower level. Therefore, a large number of elements returned to woodland after leaf litter had returned to the ground. The change of content of Ca, Mg element contrasted with the transfer of N, P element.There were widely different release rates of all kinds of micro-element in the course of litter decomposition. The order of the content of micro-element in litter with the higher content was Mn> Fe> Zn> Pb> Cu> Ni> Co> Cd. The content of Mn element was much higher than other micro-element.In the process of litter decomposition, soil were acidic, pH values ranged between 4.0 and 4.5. Soil organic matter and N element had essentially the same change tendency, which correlated positively(r= 0.901, p= 0.014). The content of P element was not high in soil, and change was not obvious. It was very different from the pattern of variability of content of N element. The range of the content of P element that originate from soil parent material and some decomposed and mineralized organic matter was 0.455-0.667 g·kg-1. The range of the content of K element was 0.966～4.778 g·kg-1. The change ranges of Ca, Mg element was relatively small. The order of the content of micro-element in soil was Fe> Mn> Zn> Pb> Ni> Cu> Co> Cd. The content of Fe element was much higher than other micro-element, up to 5580.797 g·kg-1The content of macro-element in the soil of artifical forest of L. formosana began to increase in March and till May showed their own various regularity. There was no significant correlation between the changes of content of macro-element in the soil A layer and the changes of content of macro-element in litter. The changes of content of micro-element in the soil contrasted with the changes of content of micro-element in litter. The content of micro-element in litter was low when the content of micro-element in the soil was high, and vice versa. This illustrates that the content of micro-element in the soil was easily affected by litter decomposition. There was vigorous life activity of plant in summer, and root system absorb more of micro-element. So the content of micro-element in the soil decreased in summer.The innovative points of this study were the changes of decomposition rate of the litter of artifical forest of L. formosana are systematically studied, and provide basic data in management of L. formosana forest; the effects of decomposition of the litter of artifical forest of L.. formosana on soil nutrient were systematically investigated, and study, compare and summarize the data.