不同生物炭对湿地松各组分生物量和碳储量的影响

Impacts of Biochars on Biomass and Carbon Storage in Different Organs of Pinus elliottii

通过将不同生物质原料(木屑和鸡粪)放置在低温(400°C)无氧条件下进行裂解,形成不同生物炭,研究了不同生物炭对湿地松不同组分(树叶、树皮、树枝和树干)生物量、碳密度、碳储量以及碳素年净固定量的影响。试验结果表明:以木屑和鸡粪为原料制备而成的两种生物炭p H和养分含量等性质差异显著;生物质裂解后,木屑p H由8.25降到木屑炭的7.46,而鸡粪炭p H为10.48,高于鸡粪的9.35;同时,C、N、P和K元素在两种生物炭中均出现富集,鸡粪生物炭N、P和K含量显著高于木屑生物炭,但两种生物炭速效P和速效K占总P、总K的比例与原料相比均出现显著降低。经过一年试验,鸡粪生物炭还田处理显著提高湿地松各个组分生物量,其中湿地松地上部分生物量增量是对照的4.92倍,而木屑炭处理对湿地松各个组分生物量影响不显著;木屑炭和鸡粪炭处理改变湿地松生物量增量在树叶和树皮中的分配比例,但对湿地松各个组分的碳密度影响不显著;鸡粪炭处理能显著提高湿地松各个组分碳素年净固定量,该处理湿地松地上部分碳素年净固定量(99.64 g/棵)分别是木屑炭处理(19.85 g/棵)和对照处理(25.77 g/棵)的5.02倍和3.87倍。由此可见,鸡粪炭可以作为提高林木土壤肥力的改良剂。

Artificial forest plays an important role in the buildup of forest carbon sink. However, successive rotations of fast-growing species cause soil degradation, which lead to the apparent decline of the tree growing rate. This paper aims to investigate the effects of sawdust biochar and chicken manure biochar on biomass, carbon concentration and carbon storage in different organs of Pinus Elliottii. The results showed that feedstock decided the biochar properties. After pyrolysis, the p H of sawdust biochar（7.46） was lower than the sawdust p H of 8.25, while the p H of chicken manure biochar（10.48） was higher than the p H of chicken manure（9.35）. The elements of C, N, P and K were enriched during sawdust and chicken manure biochar pyrolysis. And contents of N, P and K in chicken manure biochar were significantly higher than those in sawdust bicochar. The percentages of available P and K in total P and K were reduced after feedstocks were converted to biochars. After one year experiment, chicken manure biochar significantly increased biomass in different organs of Pinus elliottii. The increment of tree aboveground biomass in the chicken manure biochar treatment was 4.92 times of that in the control, while sawdust biochar had no significant effect on tree growth. And chicken manure biochar and sawdust biochar had significant effects on the distribution of increased biomass in leaf and bark of Pinus Elliottii. No significant differences on carbon concentration in different organs of Pinus Elliottii were found in both biochars treatments. Annual net carbon fixations（ANCF） in different organs were significantly increased in the treatment of chicken manure biochar. And ANCF of tree aboveground in the treatment was 5.02 times of that in sawdust biochar treatment and 3.87 times of that in the control, respectively. Thus, chicken manure biochar could be used as an amendment to increase productivity of artificial forest. However, the effects of different biochars on the properties of soils need further research.