【作者】 姜丽芬；

【导师】 石福臣；

【作者基本信息】 东北林业大学 ， 植物学， 2003， 博士

【摘要】 本文采用传统技术与现代手段相结合的方法对两个不同林龄兴安落叶松人工林光合特性及呼吸作用进行研究，结果表明： 5月份两个林分和7月份31年生落叶松光合作用日变化呈双峰曲线；6月份、8月份两个林分及7月份17年生落叶松光合作用日变化均呈单峰曲线。落叶松光合速率的日平均值31年生基本都大于17年生。气孔导度的日变化与光合速率成正比，胞间CO₂浓度的日变化与光合速率成反比。 最大净光合速率的平均值两个林分都是落叶松最高；31年生林分落叶松及主要阔叶树的最大净光合速率的平均值都大于17年生。光饱和点两个林分都是落叶松最高；光补偿点也是落叶松最高。31年生落叶松及阔叶树的饱和点的平均值都高于17年生；光补偿点基本都低于17年生。31年生林分树种的表观最大量子效率的平均值大于17年生。 31年生落叶松各月份日光合同化量基本都大于17年生，31年生和17年生落叶松单位土地面积年光合同化总量分别为817.41和438.20gCm^-2。 31年生林分落叶松及阔叶树叶绿素含量的平均值都高于17年生；阔叶树种的总叶绿素含量高于落叶松。31年生林分阔叶树SPAD的平均值高于17年生；叶绿素含量与SPAD值有很好的相关关系。 两个林分都是落叶松叶总碳含量最高，31年生林分树种叶的碳含量基本都高于17年生；31年生林分树种叶氮含量均高于17年生。 31年生林分土壤呼吸速率高于17年生；17年生林分根系呼吸速率明显高于31年生；根系呼吸在土壤呼吸中所占的比率也是17年生高于31年生。土壤呼吸、根系呼吸与根生物量呈很好的线性相关，根系呼吸与根生物量的相关系数大于土壤呼吸与根生物量的相关系数。土壤呼吸和根系呼吸与土壤温度呈很好的指数相关。温度较高时，含水量的增加能促进土壤和根系呼吸。土壤呼吸的Q₁₀值较高，反映了根系呼吸的重要性；根系呼吸的Q₁₀值都高于土壤呼吸的Q₁₀值；31年生林分土壤和根系呼吸Q₁₀值都比17年生的略高。两个林分土壤呼吸速率都随土壤深度的加深急剧下降，到30cm处土壤呼吸主要是微生物的呼吸。31年生和17年生林分土壤年呼吸总量分别为382.41和315.53gCm^-2、根系年呼吸总量分别为72.06和185.35gCm^-2。 17年生林分树二「呼吸速率高于31年生;树干呼吸与树于温度呈很好的指数相关;31年生和17年生林分树干呼吸的Q，o值分别为1.96和3.44;空气相对湿度很高时能大大促进树千的呼吸;31年生和17年生林分一单位土地面积上树干的年呼吸总量分别为185.41和59.30 9 C mZ。 17年生林分树种叶呼吸速率基本都高于31年生。31年生林分落时一松呼吸速率几乎是所测定的树种中最低的，而17年生林分落计卜松呼吸速率较高。31年生和17年生落叶松单位土地面积上叶的年呼吸总量分别为1 69.67和146.94 gC;:一二。 各月份31年生林分凋落物量一般都高于17年生;31年生林分年凋落物的碳素产量几乎是17年生的两倍;凋落物的碳素生产在不同组分中的分配两个林分差异不大;凋落物碳素生产以叶为主要成分;随林龄增加，针叶所占比例减小，阔叶比例增加。 31年生和17年生林分土壤年净碳交换量分别为8.33和1 06.969 cm一2、 31年生和17年生落叶松人工林的群落碳平衡分别为390.27和46.619c爪Za一’，生态系统的碳平衡分别为7991和一83.56 9 cm一，a一‘。31年生落什}-松人工林生态系统是碳汇;17年生却是碳的源，这主要是土壤呼吸的结果。因此应加强对现有幼龄林的抚育和管理，随着幼林的发育，落叶松人工林的碳汇功能会进一步加强。更多还原

【Abstract】 By using the combination of traditional and modern experimental methods, photosynthesis and respiration of two larch plantations of different age was studied and the results showed as follows.Diurnal changes pf photosynthesis of Larix gmelinii of two larch plantations in May and larch plantation of 31 years old in July are double peak curves; and diurnal change pf photosynthesis of Larix gmelinii of two larch plantations in June and in August and larch plantation of 17 years old in July are single peak curves. Mean values of diurnal photosynthetic rate of Larix gmelinii of larch plantation of 31 years old are greater than those of 17 years old. Diurnal changes of stomatal conductivity are positively correlated with photosynthetic rate while diurnal changes of intercellular CO2 concentration are negatively correlated with photosynthetic rate.Mean values of maximum net photosynthetic rate of Larix gmelinii are the highest. Mean values of maximum net photosynthetic rate of Larix gmelinii and main broad-leaved trees of 31 year-old plantation are greater than those of 17 year-old plantation. The light saturation point Larix gmelinii is the highest in both larch plantations and so is the light compensation point. Mean values of light saturation point of Larix gmelinii and main broad-leaved trees of 31 year-old plantation are higher than those of 17 year-old. Mean values of light compensation point of Larix gmelinii and main broad-leaved trees of 31 year-old plantation are lower than those of 17 year-old. Mean values of apparent maximum quantum efficiency of trees in 31 year-old plantation are greater than those of 17 year-old plantation.Diurnal assimilation amount of Larix gmelinii of 31 year-old plantation in different months are almost greater than that of 17 year-old plantation. Annual assimilation amount of Larix gmelinii of 31 year-old plantation and 17 year-old plantation on unit land is 817.41 and 438.20 g C m-2 respectively.Mean values of chlorophyll content of Larix gmelinii and main broad-leaved trees of 31 year-old plantation are higher than those of 17 year-old plantation. Total chlorophyll content of main broad-leaved trees are higher than that of Larix gmelinii. SPAD values of main broad-leaved trees of 31 year-old plantation are higher than those of 17 year-old plantation. There is good correlation between chlorophyll content and SPAD values.Total carbon content of leaves of Larix gmelinii is the highest in both plantations. Total carbon content of leaves of 31 year-old plantation are almost higher than that of 17 year-old plantation. Total nitrogen content of leaves of 31 year-old plantation are all higher than that of 17 year-old plantation.Soil respiration rate of 31 year-old plantation is higher than that of 17 year-old plantation. However, both root respiration rate and percentage of root respiration to soil respiration of 17 year-old plantation are higher than those of 31 year-old plantation. There is good linear correlation between soil and root respiration and root biomass. Correlation coefficient of root respiration and root biomass is greater than that of soil respiration and root biomass. There is good exponential correlation between soil and root respiration and soil temperature. When soil temperature are higher, increase of soil moisture can promote root and soil respiration. Q10 values for soil respiration are high, indicating the significance of root respiration. Q10 values for root respirationare higher than those for soil respiration. Q10 values of both root and soil respiration of 31 year-old plantation are a little higher than those of 17 year-old plantation. Soil respiration rate of both plantations declines sharply with increase of soil depth. At 30cm deep, microbial respiration is main soil respiration. Annual soil respiration of 31 year-old plantation and 17 year-old plantation are 382.41 and 315.53 g C m-2 respectively and annual root respiration of 31 year-old plantation and 17 year-old plantation are 72.06 and 185.35 g C m-2 respectively.Stem respiration ra更多还原