多代连栽人工林碳贮量的变化

通过收集多代连栽桉树、落叶松和杉木人工林生长和土壤方面的数据,分析了不同代数间林分生物量和土壤有机碳贮量的变化,并定量或定性分析了混交、施肥等地力维护措施对林分生物量和土壤有机碳贮量的影响.随着连栽代数的增加,生物量和土壤有机碳贮量均呈现明显的下降,2代杉木人工林生物量和土壤有机碳贮量分别比1代下降24%和10%,3代分别比2代下降39%和15%.地力维护措施可在很大程度上防治连栽人工林生物量和土壤有机碳贮量的下降,2代杉阔混交林生物量和土壤有机碳贮量分别比2代纯林提高69%和19%;2代桉树与相思属树种的混交林生物量比2代桉树纯林增加29%;施肥可使2代杉木人工林生物量提高22%.轮作和林下植被培育也能提高林分生物量,但对土壤有机碳贮量的影响尚需进一步研究.

Carbon Stock Changes of Successive Rotations of Plantations

Growth and soil property data over successive rotations of Larix sp.and Cunninghamia lanceolata(Lamb.) Hook.plantations were collected and archived from published literatures.The stock changes of biomass,soil organic carbon and the impact of fertility maintaining on carbon stocks were estimated and analyzed based on the dataset.Results showed that with the increase of the successive rotations stand biomass and soil organic carbon stock decreased apparently.The biomass and soil organic carbon stock reduced by 24% and 10% from the first to the second rotation of Cunninghamia lanceolata plantations,respectively,and by 39% and 15% respectively from the second to the third rotation.But fertility maintaining measures can prevent the growth decline and soil degradation in the successive rotation of plantation.The biomass and soil organic carbon stock of the second rotation of Cunninghamia lanceolata and broad-leaved trees mixed plantations were 69% and 19% higher than that of the pure Cunninghamia lanceolata plantation respectively.Mixed Eucalyptus sp.and Acacia sp.in the second rotation can increase the biomass by 29% compared to the Eucalyptus sp.pure stand.Fertilization on the second rotation of Cunninghamia lanceolata resulted in 22% increase in biomass.