亚热带退化红壤区湿地松和马尾松树干呼吸特征及其影响因素研究

发布时间：2018-02-16 22:14

本文关键词： 湿地松马尾松树干呼吸影响因素亚热带退化红壤区　出处：《南昌工程学院》2015年硕士论文　论文类型：学位论文

【摘要】：树干是森林生态系统最大的生物量储存体,也是长期而巨大的碳库。树木通过代谢呼吸向外界释放CO2,可以消耗自身光合固定碳量的50%以上。现有对树干呼吸的研究主要集中在温带森林和热带森林,对亚热带退化森林的报道尚不多见。采用全自动便携式光合仪(LC PRO-SD,英国ADC公司)与自制PVC呼吸环在江西省泰和县中国科学院千烟洲试验区对3个不同径级29年生湿地松(17.9~22.9cm、23.6~26.8cm、27.5~32.5cm)、马尾松(15.9~19.5cm、20.5~21.9cm、23.7~28.3cm)树干呼吸速率进行为期一年的观测,同时监测多个相关环境因子。探讨两树种树干呼吸速率的个体差异及季节变化,同时探讨树干呼吸对树干温度的响应情况,为正确评价南方亚热带退化红壤区湿地松、马尾松人工林对该地区生态系统碳收支的贡献,预测其在减缓全球变暖中的作用,以及构建森林碳循环机理模型提供基础数据和科学依据。结果如下:(1)湿地松树干呼吸日变化基本呈单峰型曲线,与树干温度日变化较为一致,树干呼吸对树干温度的响应都存在1~2小时的时滞现象,各月份树干呼吸一天当中峰值出现在16:00-17:00,均值出现的时间在11:00-14:00和22:00-2:00。树干呼吸与树干温度间存在良好的自然指数函数关系,树干温度可以解释树干呼吸日动态的16.6%~43.1%,且非生长季内树干呼吸对树干温度的变化更敏感。(2)在液流速率的上升期,生长季和非生长季各月树干呼吸与液流速率均无明显的相关关系(p0.05);在液流速率下降期,非生长季树干液流速率和树干呼吸存在显著的正相关关系(p0.05);在液流速率稳定期,对不同生长季树干呼吸速率与树干温度进行回归分析显示只有生长季7月份在该时段的回归模型优于日变化的回归模型。(3)湿地松和马尾松树干呼吸季节变化特征基本表现为单峰型模式,且季节变化差异显著。树干呼吸速率最高值均出现在7月份,最低值出现在1月份(马尾松)、2月份(湿地松)。湿地松不同阶级树干维持呼吸所占比例为41.4%~53.8%,马尾松为57.2%~67.8%,湿地松和马尾松都表现为大径级树干维持呼吸显著大于中、小径级。(4)湿地松中径级(23.6~26.8cm)树干呼吸对树干温度的敏感性显著高于大径级(27.5~32.5cm)(p0.05),大径级(27.5~32.5cm)高于小径级(17.9~22.9cm)(p0.05)。马尾松大(23.7~28.3cm)、中(20.5~21.9)径级树干呼吸对树干温度树干呼吸对树干温度的敏感性显著高于小径级(15.9~19.5cm)(p0.05),而大径级(23.7~28.3cm)和中径级(20.5~21.9cm)之间无显著差异(p0.05)。(5)湿地松及马尾松树干呼吸速率都表现为随着径级的增大而增大,树干呼吸与胸径间都呈极显著的线性相关关系(P0.01),表明胸径可以作为这2个树种树干呼吸预测和上推的一个简单而实用的指标。
[Abstract]:The trunk is the largest biomass store in the forest ecosystem, It is also a long-term and huge carbon pool. Trees release CO _ 2 to the outside world through metabolic respiration, which can consume more than 50% of their own photosynthetic fixed carbon. The existing researches on trunk respiration mainly focus on temperate and tropical forests. There are few reports of subtropical degraded forest. Using the automatic portable photosynthetic apparatus LC PRO-SD (ADC Company, UK) and self-made PVC breathing ring in the Qianyanzhou Experimental area of the Chinese Academy of Sciences of Taihe County, Jiangxi Province, the results of 29 years of different diameter grades were studied. The trunk respiration rate of Pinus elliottii was measured for one year. The trunk respiration rate of Pinus elliottii was 23.6 ~ 26.8cm ~ (2. 5) ~ 32.5 cm ~ (-1), and that of Pinus massoniana was 15.9 ~ (19. 5) cm ~ (20. 5) ~ 21. 9 cm ~ (2. 7) cm ~ (28. 3 cm). At the same time, several related environmental factors were monitored. The individual difference and seasonal variation of tree trunk respiration rate were discussed, and the response of trunk respiration to trunk temperature was also discussed in order to correctly evaluate Pinus elliottii (Pinus elliottii) in south subtropical degraded red soil area. The contribution of Pinus massoniana plantations to the carbon budget of ecosystems in the region and its role in mitigating global warming, The results are as follows: (1) the diurnal variation of trunk respiration of Pinus elliottii is basically a single-peak curve, which is consistent with the diurnal variation of trunk temperature. The response of trunk respiration to trunk temperature has a delay of 1 or 2 hours. The peak value of trunk respiration in each month is 16: 00-17: 00, and the mean time is 11: 00-14: 00 and 22: 00-2: 00. there is a good natural exponential function relationship between trunk respiration and trunk temperature. The trunk temperature can explain the increasing period of sap flow rate of 16.6% and 43.1%, and the trunk respiration is more sensitive to the change of trunk temperature in non-growing season. There was no significant correlation between trunk respiration and sap flow rate in growing season and non-growth season, there was a significant positive correlation between stem sap flow rate and trunk respiration in non-growth season during the period of decreasing sap flow rate, and there was a significant positive correlation between sap flow rate and sap flow rate at stable stage of sap flow rate. The regression analysis of trunk respiration rate and trunk temperature in different growing seasons showed that the regression model of tree trunk respiration rate in July was better than that of diurnal variation on July. The seasonal variation of tree trunk respiration of Pinus elliottii and Pinus massoniana was better than that of diurnal variation. Basic performance is single-peak mode, The highest respiration rate of trunk appeared in July. The lowest value appeared on January (Pinus massoniana, Pinus elliottii, Pinus elliottii, Pinus elliottii) and Pinus elliottii (Pinus elliottii) in February, the proportion of trunk maintenance respiration in different classes of Pinus elliottii was 41.4%, 53.8%, 57.2% and 67.8% of Pinus massoniana, respectively. The sensitivity of trunk respiration to trunk temperature was significantly higher than that of large diameter (27.5g / 32.5cm), large diameter (27.5cm), large diameter (27.5cm) (27.922.9cm), p0.055.The diameter of Pinus massoniana was 23.728.3 cm / cm ~ (3), and (20.521.9)) the effect of trunk respiration on trunk temperature was higher than that of small diameter grade (17.922. 9 cm ~ 0.05cm). The sensitivity of Pinus elliottii and Pinus massoniana were significantly higher than those of small diameter grade (15.9 ~ 19.5cm ~ (-1) cm), while there was no significant difference between large diameter class (23.728.3 cm) and middle diameter grade (20.5 ~ 21.9 cm). (P < 0.05) the trunk respiration rate of Pinus elliottii and Pinus massoniana increased with the increase of diameter grade. There was a significant linear correlation between trunk respiration and DBH, indicating that DBH could be used as a simple and practical index to predict and push up trunk respiration of these two tree species.
【学位授予单位】：南昌工程学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S791.246;S791.248

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