【作者】 张艳；

【导师】 姜培坤；

【作者基本信息】 浙江农林大学 ， 土壤学， 2011， 硕士

【摘要】 雷竹（Phyllostachys praecox f.prevelnalis）,是优良的笋用竹种。由于其具有产量高、成林快、出笋早、笋味鲜等特点,被大范围引种栽培。科研人员对雷竹栽培技术进行不断探索,总结出了以冬季地表增温覆盖和施肥为核心的雷竹集约经营技术。由于采用了冬季地表增温覆盖和多量施肥,实现了竹笋高产和反季生产,产生了很高的经济效益。然而,雷竹集约经营技术已对土壤有机碳含量和形态产生了深刻影响。为了揭示集约经营措施对土壤有机碳过程的影响,在浙江省雷竹主产区布置了定位试验,动态研究了雷竹覆盖物分解过程及其对土壤有机碳含量及结构的影响;研究了竹林土壤呼吸变化规律及其与环境因子的关系。通过研究,得出如下结果:1)雷竹覆盖物动态分解过程研究表明:1a时间竹叶和稻草分别分解了79.30%和67.54%,竹叶和稻草的碳含量分别下降了14.80%和15.32%,氮含量上升了15.77%和173.26%,C/N下降了26.36%和67.50%。竹叶和稻草中的烷基碳含量增加,烷氧碳含量下降,降幅分别为11.21%和13.29%,芳香碳含量下降,羰基碳含量总体增加,A/O-A值显著增加,而芳香度显著降低。2)覆盖措施下林地土壤有机碳变化过程研究表明:覆盖物分解进入土壤,使得土壤有机碳含量增加了22.15%,土壤CO2排放速率增加了3.29-7.65 umol·m^-2s^-1。覆盖物分解过程中,土壤有机碳中烷氧C成分迅速增加,而其芳香度降低,表明土壤C的稳定性下降。覆盖后提高了土壤呼吸速率,而春季提早揭去覆盖物能显著降低土壤呼吸速率。3)集约经营雷竹林土壤呼吸动态变化规律及其与环境因子关系研究表明:雷竹林地土壤总呼吸速率（RS）、土壤生物异养呼吸速率（RH）及根系自养呼吸速率（RA）的年平均值分别为5.42、2.24和2.89μmolCO2·m^-2·s^-1,土壤呼吸1a中在2月和7月出现了两个峰值,且变化幅度较大。雷竹林地土壤年释放CO2量为73.40 t·hm^-2·a^-1,其中林地异养呼吸和自养呼吸分别占总呼吸的45.67%和54.32%。RS、RH和RA均与土壤温度呈明显的指数关系,以土壤5 cm处温度为依据得到的温度系数（Q10值）分别为1.70、1.86和1.48,土壤总呼吸与5cm处土温、08时气温、WSOC（水溶性有机碳）含量和TOC（土壤总有机碳）含量呈显著正相关（P < 0.01）,而土壤含水量、08时大气相对湿度和WSON（水溶性有机碳）含量与土壤呼吸无显著相关性。更多还原

【Abstract】 Phyllostachys praecox is one of the best bamboo species used for edible bamboo shoot production. Due to its advantages of high production, rapid growth, early shoot period, and delicious taste, Phyllostachys praecox has been widely planted in the south of China. In the past several years, a method centered on heavy fertilization and use of organic mulch in the winter has gained popularity as a core technique for producing bamboo shoots early and with increased productivity. Consequently, the above intensive management would make great influence on the soil organic carbon content and forms. An experiment was conducted in typical phyllostachys praecox stands located in Lin’an, Zhejiang Province to investigate the chemical behaviour of various mulching materials including bamboo leaves and rice straw, and the impact of mulching on soil carbon （C） dynamics using solid state 13C-nuclear magnetic resonance （NMR） and to study the dynamic change of soil respiration and the relationship between soil respiration and environmental factors during 2009. The results obtained were summarized as follows:1)A field study was conducted to investigate the decomposition of various mulching materials including bamboo leaves and rice straw during 2009. The results showed that the bamboo leaves and rice straws were decomposited by 79.30% and 67.54%, respectively. The carbon content of bamboo leaves and rice straws decreased by 14.80% and 15.32%, nitrogen content increased by 15.77% and 173.26%, C / N decreased by 26.36% and 67.50% respectively. Alkyl C content increased but O-alkyl C content decreased by 11.21% and 13.29%, respectively in the decomposing mulching materials. Additionally, the aromatic C content decreased; A/O-A ratio was significantly increased, while the aromaticity was significantly reduced.2)A field study was conducted to investigate the impact of the mulching on soil carbon （C） dynamics during 2009. The results showed that with the treatment of mulching soil organic carbon content increased by 22.15% and the soil respiration rate increased by 5.47μmol·m^-2·s^-1. Alkyl C content increased but O-alkyl C content decreased in the decomposing mulching materials, whereas aromatic C content increased initially but decreased at later stage, indicating degradation of lignin. The residual materials had a significantly higher A/O-A ratio, but lower aromaticity than those in the original materials. Soil beneath the mulches rapidly built up organic C which was dominated by O-alkyl C with reduced aromaticity, indicating increased C lability. Mulching treatment enhanced soil respiration rate. An early removal of the mulching materials in spring significantly reduced soil respiration. It is recommended that mulching materials should be removed as early as practical to reduce CO2 emission associated with mulch treatment, which may help maintain soil organic matter stability for long term C sequestration.3)A experiment was conducted in typical phyllostachys praecox stands located in Lin’an, Zhejiang Province to study the dynamic change of soil respiration and the relationship between soil respiration and environmental factors. The results showed that the soil total respiration rate, heterotrophic respiration rate, and autotrophic respiration rate of phyllostachys praecox were 5.42, 2.24 and 2.89μmol·m^-2·s^-1 respectively. The annual dynamic pattern was represented with a double-peak curve and changed greatly.The amount of CO2 released from phyllostachys praecox was 73.40 t·hm^-2·a^-1, including 45.67% heterotrophic respiration and 54.32% autotrophic respiration. RS, RH and RA had strong exponential correlations with soil temperature, especially the temperature at 5 cm depth. The Q10 value at 5 cm depth was 1.70, 1.68 and 1.48 respectively. The relativity of soil temperature in 5 cm depth, atmospheric temperature at 8:00, WSOC, TOC and soil respiration is remarkable, while the relativity of soil water content, relative humidity at 8:00 , WSON and soil respiration is not remarkable.更多还原