林龄对木荷人工林材种结构及碳储量的影响OA

Stand age is a key factor affecting the timber structure and carbon storage of plantations.This study explored the evo-lutionary rules of timber structure and variation characteristics of carbon storage in Schima superba plantations at different stand ages in Pushang State-owned Forest Farm of Fujian Province,aiming to provide a reference for the management mode of S.superba plantations that balances timber production and ecological service functions.Sample plots of S.superba plan-tations aged 10,15,27 and 64 years were established in Pushang State-owned Forest Farm,Shunchang County,Fujian Province.The variation characteristics of timber structure and carbon storage as well as their synergistic trade-off mecha-nisms across stand ages were systematically analyzed.The results showed that individual tree volume and stand volume of S.superba increased significantly with the rise of stand age.The proportion of medium and large-diameter timber in 64-year-old stands was obviously higher than that in other age groups.The yield rate of large-diameter timber rose sharply in 15-27-year-old plantations,indicating this period was a critical turning point for the optimization of timber structure.The carbon storage of various arbor components(stem,branch,leaf,root and bark)in young S.superba plantations was sig-nificantly lower than that in older stands.The annual increment of arbor carbon storage(10.76t·hm-2)and soil carbon storage(5.92t·hm-2)both peaked in 10-15-year-old plantations.The total carbon storage of the four age groups was 125.17,209.29,261.09 and 306.58 t·hm-2,respectively.Both stand carbon storage and soil carbon storage increased with stand age,while the growth rate gradually slowed down in the later stage,and stand carbon storage gradually became dominant.The optimization of timber structure and carbon sequestration potential of S.superba plantations presented dis-tinct stage-specific characteristics with the change of stand age,and there was a significant synergistic relationship between the two indicators.The 10-15-year-old stage delivered a prominent short-term carbon sequestration effect.The 15-27-year-old stage yielded the maximum output of medium and small-diameter timber in a short period.The 64-year-old stands achieved the highest large-diameter timber yield and the strongest carbon sequestration capacity.