切根对亚热带4种林分土壤呼吸的影响

发布时间：2018-02-13 10:12

本文关键词： 土壤呼吸切根森林类型土壤温度土壤湿度 Q_(10)值　出处：《中南林业科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：在湖南省森林植物园对樟树林、马尾松林、枫香林及樟树-马尾松混交林4种森林类型采取了切根处理,对其土壤呼吸、土壤温度、湿度进行了为期la的定点观测,分析了在不同处理条件下土壤呼吸与环境因子的动态特征,研究结果将对揭示亚热带森林生态系统碳通量及其驱动机制提供基础数据。(1)自然条件下：4种森林类型土壤呼吸年动态呈单峰变化趋势,最大值出现在6月,最小值出现在1月；土壤呼吸的年均值表现为：樟树林(2.30±0.12μmolCO2m-2·s-1)樟树-马尾松混交林(2.03±0.15 μmolCO2m-2·s-1)枫香林(1.79±0.23 μmolCO2m-2·s-1)马尾松林(1.62±0.17 μmolCO2m-2·s-1)土壤呼吸年累积C排放量表现出：樟树林(31.92t·hm-2·a-1)樟树-马尾松混交林(28.16t·hm-2·a-1)枫香林(24.69 t·hm-2·a-1)马尾松林(22.47 t·hm-2·a-1)樟树林、樟树-马尾松混交林、枫香林、马尾松林4种森林类型土壤呼吸Q10值分别为：1.73、1.43、1.54、1.58；4森林类型土壤呼吸速率与5 cm土壤温度呈显著指数相关(P0.01),回归关系方程为R=aebt,其判定系数R2范围是0.768-0.928；与5 cm土壤湿度无明显相关性,线性回归方程：R=a1W+b1其判定系数R2均在0.124-0.209之间。(2)切根处理条件下：4种森林类型土壤呼吸年动态亦呈单峰变化趋势,最大值出现在6月,最小值出现在1月。土壤呼吸的年均值表现为：樟树林(1.90±0.16樟树-马尾松混交林(1.74±0.13枫香林(1.49±0.15马尾松林(1.36±0.11 μmolCO2m-2·s-1)土壤呼吸年累积C排放量表现出：樟树林(26.36 t-hm-2·a-1)樟树-马尾松混交林(24.13 t·hm-2·a-1)枫香林(20.81 t·hm-2·a-1)马尾松林(18.86 t·hm-2·a-1)。樟树林、樟树-马尾松混交林、枫香林、马尾松林4种森林类型土壤呼吸Q10值分别为：2.05、1.65、1.77、1.93；4森林类型土壤呼吸速率与5 cm土壤温度呈显著指数相关(P0.01),回归关系方程为：R=aebt,其判定系数R2范围是0.651-0.951；与5 cm土壤湿度无明显相关性,线性回归方程：R=aiW+bi其判定系数R2均在0.075-0.138之间。(3)切根处理均降低了4种森林类型土壤呼吸的速率,各月降幅为：樟树林(7.22%-48.53%)、樟树-马尾松混交林(4.55%-38.62%)、枫香林(6.41%-40.34%)、马尾松林(3.72%-54.51%),但并没有改变其季节变化趋势；切根处理降低了土壤呼吸年累积C排放量,樟树林、樟树-马尾松混交林、枫香林、马尾松林分别减低了17.41%、14.31%、15.71%和16.06%；切根条件下4种森林类型的Q10值均大于对照,增幅为：樟树林18.50%、樟树-马尾松混交林15.38%、枫香林14.94%、马尾松林22.15%；切根和对照条件下的土壤呼吸速率与土壤温度显著相关(P0.01),但在切根处理条件下,土壤呼吸速率与土壤温度的相关性混交林(0.651)降低,纯林(樟树林0.951、枫香林0.850、马尾松林0.894)升高；切根处理下土壤呼吸速率与土壤湿度相关性比自然条件下更低,切根和对照条件下土壤呼吸速率与土壤湿度的相关性均不显著(P0.05)。
[Abstract]:In Hunan Forest Botanical Garden, four forest types, camphor forest, Masson pine forest, maple incense forest and mixed forest of camphor and Pinus massoniana, were treated by root cutting, and their soil respiration, soil temperature and humidity were observed for a period of time. The dynamic characteristics of soil respiration and environmental factors under different treatment conditions were analyzed. The results will provide basic data for revealing carbon flux and its driving mechanism of subtropical forest ecosystem. The annual mean value of soil respiration is 2.30 卤0.12 渭 molCO2m-2 路s-1 for camphor tree and Masson pine mixed forest, 2.03 卤0.15 渭 molCO2m-2 路s-1 for maple incense forest, 1.79 卤0.23 渭 molCO2m-2 路s-1 for Pinus massoniana forest, and 1.62 卤0.17 渭 molCO2m-2 路s-1 for soil respiration. The annual cumulative C emissions of soil respiration are 31.92 t 路hm-2 路a-1 in camphor forest and 28.16t 路hm-2 路a-1 in Pinus massoniana mixed forest. Pinus massoniana forest was 22.47 t 路hm-2 路a-1). Mixed forest of camphor and Masson pine, maple forest, The Q10 values of soil respiration in four forest types of Pinus massoniana forest were respectively: 1. 73C. 1. 4N, 1. 54-1. 584.There was a significant exponential correlation between soil respiration rate and 5 cm soil temperature (P 0. 01). The regression equation was Rhizoma aebt.The determination coefficient R2 was within the range of 0. 768-0. 928, and had no significant correlation with soil moisture at 5 cm. Under the condition of root cutting treatment, the annual dynamics of soil respiration of the four forest types showed a single peak trend, and the maximum value appeared in June, and the coefficient R2 of the linear regression equation was between 0.124-0.209 and 0.124-0.209, respectively. The minimum value of soil respiration occurred in January. The annual mean value of soil respiration was 1.90 卤0.16 for camphor tree and Masson pine mixed forest, 1.74 卤0.13 for Maple pine forest, 1.49 卤0.15 for Pinus massoniana forest, 1.36 卤0.11 渭 molCO2m-2 路s-1 for soil respiration, and the annual cumulative C emission of soil respiration was 26.36 t-hm-2 路a-1 for camphor forest. Pine mixed forest (24.13 t 路hm-2 路a-1) Maple incense forest (20.81 t 路hm-2 路a-1), Pinus massoniana forest (18.86 t 路hm-2 路a-1). Mixed forest of camphor and Masson pine, maple forest, The Q10 values of soil respiration in four forest types of Pinus massoniana forest were: 1. 055, 1. 771. 93, respectively. There was a significant exponential correlation between soil respiration rate and 5 cm soil temperature (P 0. 01), and the regression equation was: 1. 0. 0. 01-0. 951, and the determination coefficient R2 was 0. 651-0. 951. There was no significant correlation between the soil respiration rate and 5 cm soil moisture. The root cutting treatments of the linear regression equation Rnaiwbi, whose determination coefficients R2 were between 0.075 and 0.138, all reduced the soil respiration rate of four forest types. The monthly decrease was 7.22 -48.53%, 4.55% -38.62%, 6.41-40.341g, 3.72-54.51g and 3.72-54.51m, respectively, and the root cutting treatment decreased the annual cumulative C emissions of soil respiration, camphor forest, camphor tree and Masson pine mixed forest, but did not change the seasonal variation trend; cutting root treatment reduced the annual cumulative C emissions of soil respiration, camphor tree forest, camphor tree forest and Pinus massoniana mixed forest, and the root cutting treatment decreased the annual cumulative C emissions of soil respiration, the camphor forest, the camphor tree and the Pinus massoniana mixed forest. In maple forest and Masson pine forest, 17.41% and 16.06% were decreased, Q10 values of four forest types were all higher than that of control. The increase was 18.50 in camphor forest, 15.38in mixed camphor and Masson pine forest, 14.94in maple forest, 22.15m in Pinus massoniana forest. Soil respiration rate was significantly correlated with soil temperature under root cutting and control, but under root cutting treatment, soil respiration rate was significantly correlated with soil temperature. The correlation between soil respiration rate and soil temperature was 0.651), while that of pure forest (camphor forest 0.951, maple forest 0.850, Masson pine forest 0.894) was increased, and the correlation between soil respiration rate and soil moisture was lower under root cutting than that in natural condition. There was no significant correlation between soil respiration rate and soil moisture under root-cutting and control conditions.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714

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