【作者】 杨爽；

【导师】 江洪；

【作者基本信息】 浙江农林大学 ， 生态学， 2012， 硕士

【摘要】 毛竹为我国分布最广、面积最大、经济价值最高的竹种之一，具有生长快、周期短、产量高、用途广、效益大等诸多优点。本文利用涡度相关方法，采用开路式通量观测系统，同时辅以常规气象观测系统，对2010年12月至2011年11月安吉毛竹林生态系统与大气间二氧化碳交换及其环境因子进行了观测和研究，估算了一年中毛竹林的净碳吸收能力，为了解我国毛竹林生态系统的固碳能力及其影响因子提供了重要的基础数据。研究结果表明：毛竹林CO₂通量月平均日变化表现出明显的季节差异性，在11²月份、5⁶月份白天CO₂通量峰值在-0.303^-0.495mg·m^-2·s^-1之间；在3⁴月份、7¹0月份白天CO₂通量峰值在-0.521^-0.596mg·m^-2·s^-1之间。CO₂通量日累积通量在-14.9¹1.2mg·m^-2·d^-1之间，平均值为-3.7±3.49mg·m^-2·d^-1，一年中有315天日累积通量为负值，占总天数的86.3%。2010年12月到2011年11月间各月生态系统呼吸（Reco）变化范围为63.4⁹2.1gC·m^-2·mon^-1,，平均77.7±10.4gC·m^-2·mon^-1，最小值出现在1月份，最大值出现在7月份，2010年12月到2011年11月间各月总生态系统碳交换量（GEE）变化范围为-90.9636^-191.481gC·m^-2·mon^-1，平均值-132.962±30.021gC·m^-2·mon^-1。逐月CO-12净生态系统交换NEE为-24.9^-99.3gC·m^-2·mon，平均值为-55.2±23.4gC·m^-2·mon^-1，表现为双峰型，在3月份和7月份分别出现了峰值。毛竹林逐月CO₂净生态系统交换NEE在12个月中均表现为碳汇。光合有效辐射PAR是毛竹林生态系统NEE的重要驱动因子，NEE主要受到PAR的控制，白天NEE与PAR密切相关，利用Michaelis-Menten模型进行拟合，得到相关系数R2在0.333⁰.606之间，随着光合有效辐射的增强，毛竹林的NEE也相应的增加，将一年分为前半年2010年12月至2011年5月和后半年2011年6月至2011年11月分别和PAR拟合曲线后发现，前半年的光能利用效率α和最大光合速率Nes都低于后半年的拟合值。对于夜间NEE，采用温度-水分连乘形式耦合呼吸模型进行拟合，比单独利用一个因子进行拟合提高了拟合率。月尺度上，GEE与气温、空气饱和差具有较强的相关性，相关系数R2分别为0.756、0.593，且随着气温升高，GEE绝对值增大，当空气饱和差小于8hPa时，GEE绝对值随饱和水汽压差的增加而增大，当空气饱和差超过8hPa时，GEE绝对值随饱和水汽压差的继续增加而减小。月尺度上NEE随气温和空气饱和差的变化趋势与GEE一致。月尺度上RE与气温呈现线性相关，相关系数R2为0.882，RE与空气饱和差、土壤含水量呈现二次曲线关系，R2分别为0.555和0.472。毛竹叶面积指数与GEE、NEE、RE均表现出较好的相关性。毛竹林生态系统2010年12月至2011年11月的NEE、RE、GEE总量分别为、-6.02tC·ha^-1·a^-1、9.32tC·ha^-1·a^-1、-15.95tC·ha^-1·a^-1。更多还原

【Abstract】 With its remarkable advantages of rapid growth, high yield, wide application and goodeconomic returns, Phyllostachys edulis has been one of the most extensively distributed baboo inChina,especially in South China. In this paper，open path eddy covariance system and automatedobserving systems of gradient weather were used to determine the characteristics of CO₂flux and itsresponse mechanism to environmental factors in a ecosystem of Phyllostachys edulis stands in Anjifrom December2010to November2011. At the same time，the carbon absorption capacity of systemwas estimated. The study contributed to the research of carbon cycle of Phyllostachys edulis and theunderstanding of carbon sink of forests in China especially the bamboo forest.The results showed that:1.CO₂flux had obvious diurnal and yearly variations. First of all，the average diurnal variationwas basically the same in each month and the value of CO₂flux was negative in the daytime as well aspositive in other times. The variability of CO₂flux was large,which showed that the maximum ofnegative value was about-0.303to-0.495mg·m^-2·s^-1from November to June except March andApril,about-0.521to-0.596mg·m^-2·s^-1in the other months. Secondly，diurnal cumulative value of CO₂flux floated between^-14.9to11.2mg·m^-2·d^-1, mean as-3.7±3.49g mg·m^-2·d^-1, diurnal cumulative valueof CO₂flux was negative at most of days in the year, The days about86.3%of a year were negativewith diurnal cumulative value of CO₂flux.2.The seasonal variation of GEE was basically consistent with NEE. The monthly NEE wereall negative,and the maximum is July(-99.3gC·m^-2·mon^-1)while the minimum is January(-24.9gC·m^-2·mon^-1).Differently，the monthly RE varied as a“single peak”curve in the year and came tominimum in February (63.3671gC·m^-2·mon^-1)whereas reached its maximum in July(92.15gC·m^-2·mon^-1).3.CO₂flux was mainly affected by photosynthetic active radiation（PAR）in the daytime andfitted the Michaelis-Menten model well.With the increase of PAR，the carbon sink was increased,Usedthe NEE in the daytime fitted the Michaelis-Menten model month by month,we got the correlationcoefficient between0.333and0.606. The response of CO₂flux to PAR was different at differentseasons,the second half year of2011got higher αand Nes than first half year. At nighttime，therespiration of ecosystem had correlation with soil temperature and soil water content（SWC）.Night-timeCO₂flux showed an exponential relationship with soil temperature and SWC at5cm depth， amix-model with temperature and water is better fitted than model with only water or temperature. In themonth scale，the respiration of ecosystem was related to SWC as a quadratic parabola opening upward.4.NEE，RE and GEE were effected by air temperature、VPD and SWC obviously on month scale.On month scale，GEE has strong relationship with temperature and VPD, RE with air temperatureshowed significant linear correlation while NEE and air temperature related as a quadratic curve. The total amount of NEE, RE, GEE were respecti vely-6.02t C-m^-2a^-1，9.32t C-m^-2a^-1，-15.95t C-m^-2a^-1.更多还原