Organic Carbon Storage and Its Distribution in Forest Litters among Forest Communities in Dongguan,South China

In this study,forest litter organic carbon storage and density among forest communities were estimated based on a forest survey in Dongguan,south China.Filed sampling was carried out based on a 2 km×2 km grid system overlaid on the topographic map of the forest land in Dongguan.The results showed that the litter of natural forests contained significantly more organic carbon than that of artificial forests,which was assessed by One-way ANOVA using STATISTICA 8.0;and the litter organic carbon density among the 10 types of forests classified by their dominant trees were significantly different with each other.The order of the litter carbon density from large to small is:Pinus elliottii broad leaf forest Acacia magium Pinus massoniana and Cunninghamia lanceolata Schima superba Eucalyptus exserta Cunninghamia lanceolata broad leaf forest Pinus massoniana and broad leaf forest Litchi chinensis and Dimocarpus longan Bambusa textilis.In addition,coniferous forest litter contained 59% of carbon per unit mass,more than that of broadleaved forests.The second largest litter carbon content per unit mass existed in the forests dominated by Acacia magium and Schima superba.Litter organic carbon storage was also influenced by forest management regimes.Closing the mountain for forest rehabilitation led to higher level of litter organic carbon density.There was no significant influence among different slopes and different aspects.However,different positions on slopes were found to have significant influence on the litter organic carbon density.The highest level of litter organic carbon density was found on the ridge of the hill.The total litter organic carbon pool was estimated as 0.23±0.008 Mt,and the average litter organic carbon density was 4.25±0.15 t/hm2.The dynamics of litter organic carbon are closely related to the soil organic carbon pool.Therefore,appropriate measures should be taken to prevent the ecosystem from the decrease of litters by human activities,which will be useful for increasing the carbon pools of the study area.