冀北辽河源典型森林类型土壤呼吸研究

发布时间：2018-03-11 18:16

本文选题：土壤总呼吸　切入点：凋落物呼吸　出处：《北京林业大学》2015年硕士论文　论文类型：学位论文

【摘要】：以冀北辽河源大窝铺林场为实验地,在2013年和2014年生长季选取典型森林类型：不同演替阶段的油松天然次生林—油松中龄林(HF)、油松近熟林(NF)、油松成熟林(MF)、油松过熟林(OF),落叶松人工林(LP)、以及白桦-辽东栎-山杨混交天然次生林(MBF)为研究对象,应用Li-8100土壤碳通量测量系统,定期测定土壤呼吸速率及其温湿度等环境因子,得出以下结论：1.土壤总呼吸及其组分呼吸呈现明显的月际变化。各样地土壤总呼吸及其组分呼吸从测定月份开始升高,在6-8月达到峰值。大部分林分的根系呼吸在8、9月份达到最大值；大部分林分的凋落物呼吸、矿质土壤呼吸在生长旺盛期速率(6-8月)较高。在土壤温度较低时,土壤温度对土壤呼吸及其组分呼吸起主导作用；在生长旺盛期,土壤温湿度共同对土壤呼吸起主导作用,但较高的土壤温度会抑制矿质土壤呼吸。2.各组分呼吸比例因年份而异。各林分两年矿质土壤呼吸贡献比例最大,2013年平均值为59.37%,2014年为66.14%；其次为凋落物呼吸,2013年平均值为26.63%,但2014年凋落物呼吸降低至与根系呼吸比例近似相等,分别为16.58%、16.62%；根系呼吸贡献比例在2013年平均值为14.00%。3.温湿度对不同林分土壤呼吸的差异的影响不同。土壤组分呼吸可能对环境因子响应引起的变化近似相同,因此两年间土壤各组分呼吸大小顺序基本一致。土壤温度对不同林分的土壤呼吸起到主导作用,但土壤湿度对土壤总呼吸速率及凋落物呼吸速率也起到一部分的促进作用；对不同年份而言,引起土壤呼吸速率差异的原因可能是土壤温度以及大气湿度。4.土壤呼吸与温度均呈显著指数相关。土壤温湿度的解释能力最强。土壤温湿度可以解释土壤总呼吸变化的53.4%-86.4%,凋落物呼吸变化的71.0%-89.7%,根系呼吸变化的42.5%～65.6%,矿质土壤呼吸变化的74.1%-92.3%。对土壤总呼吸及各组分呼吸的Q10值进行比较：凋落物呼吸土壤总呼吸矿质土壤呼吸根系呼吸：土壤呼吸对大气温度的敏感性小于土壤温度。
[Abstract]:Taking the Dawopu Forest Farm of the Liaohe River in the north of Hebei as the experimental site, In 2013 and 2014, typical forest types were selected: natural secondary forest of Pinus tabulaeformis at different succession stages, middle age forest of Pinus tabulaeformis, NFN of Pinus tabulaeformis, mature forest of Pinus tabulaeformis, overmature forest of Pinus tabulaeformis, LPU, LPU of Larix olgensis plantation, and Bai Hua-. The natural secondary forest (MBF) of Quercus variabilis and Populus davidiana was used as the research object. The soil respiration rate and environmental factors such as temperature and humidity were measured by Li-8100 soil carbon flux measurement system. The following conclusions can be drawn: 1. Soil total respiration and component respiration show significant intermonthly changes. The total and component respiration of soil in various plots increases from the measured month. The root respiration of most stands reached its maximum value in August and September, and the litter respiration and mineral soil respiration rate of most stands were higher in the period of vigorous growth. When the soil temperature was low, the root respiration of most stands reached the peak in June and August, and the root respiration of most stands reached the maximum in August and August. Soil temperature plays a leading role in soil respiration and component respiration, and soil temperature and humidity play a leading role in soil respiration during the growing period. However, higher soil temperature can inhibit mineral soil respiration. The respiration ratio of each component varies from year to year. The contribution ratio of mineral soil respiration in each stand for two years is the largest, with an average value of 59.37 in 2013 and 66.14 in 2014, followed by litter respiration, averaging 2013. In 2014, the respiration of litter decreased to about the same as that of root respiration. The ratio of root respiration contribution in 2013 was 14.00.3.The effect of temperature and humidity on the difference of soil respiration in different stands was different. The changes of soil component respiration may be similar to those caused by environmental factors. Soil temperature played a leading role in soil respiration of different stands, but soil moisture also played a part in promoting soil total respiration rate and litter respiration rate. For different years, The difference of soil respiration rate may be caused by soil temperature and atmospheric humidity .4.There is a significant exponential correlation between soil respiration and temperature. The interpretation of soil temperature and humidity is the strongest. Soil temperature and humidity can explain soil total respiration. 53.4% -86.4%, 71.0-89.7% of litter respiration, 42.5% 65.6% of root respiration changes, 74.1 -92.33.3% of mineral soil respiration changes. The Q10 values of total soil respiration and component respiration were compared: litter respiration soil total respiration mineral soil respiration root respiration root exhalation: litter respiration total respiration mineral soil respiration root respiration. Suction: the sensitivity of soil respiration to atmospheric temperature is less than that of soil temperature.
【学位授予单位】：北京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S714

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