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生态学杂志 ›› 2020, Vol. 39 ›› Issue (11): 3576-3587.doi: DOI: 10.13292/j.1000-4890.202011.037

• 研究报告 • 上一篇    下一篇

改变凋落物输入对不同林龄油松林土壤呼吸的影响

韩尚君1,韩海荣1,2*,程小琴1,董玲玲1,蔡锰柯1,商添雄1   

  1. 1北京林业大学生态与自然保护学院, 北京 100083;2七老图山定位研究站, 内蒙古赤峰 024000)
  • 出版日期:2020-11-11 发布日期:2021-05-10

Effects of alterations in litter inputs on soil respiration of Pinus tabuliformis forests at different ages.

HAN Shang-jun1, HAN Hai-rong1,2*, CHENG Xiao-qin1, DONG Ling-ling1, CAI Meng-ke1, SHANG Tian-xiong1   

  1. (1School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China; 2Qilaotu Mountain Positioning Research Station, Inner Mongolia, Chifeng 024000, Inner Mongolia, China).
  • Online:2020-11-11 Published:2021-05-10

摘要: 为了解不同林龄油松林凋落物输入与土壤呼吸的关系以及不同呼吸组分的贡献,本研究以辽河源地区3种不同林龄(中龄林、近熟林、成熟林)的油松天然林为对象,利用LI-8100土壤碳通量测量系统对4种不同凋落物输入(加倍地上部分凋落物(DL)、去除地上部分凋落物(NL)、地上部分凋落物和根系去除(NI)以及对照(CK))处理生长季的土壤呼吸速率进行连续观测。结果表明:改变凋落物输入对中龄林的土壤温湿度均产生显著影响。NL处理显著增加了中龄林和成熟林土壤温度,显著降低了中龄林和近熟林的土壤湿度,但改变凋落物输入对近熟林土壤温度和成熟林土壤湿度没有显著影响。DL处理显著提高土壤呼吸速率,NL处理显著降低土壤呼吸速率,DL处理土壤呼吸增加的幅度大于NL处理土壤呼吸降低的幅度。中龄林和近熟林不同呼吸组分对总呼吸的贡献表现为:矿质土壤呼吸>凋落物呼吸>根系呼吸,而成熟林根系呼吸贡献大于凋落物呼吸。随林龄的增加,矿质土壤呼吸贡献逐渐降低,而根系呼吸贡献逐渐增加,两种呼吸组分贡献在中龄林和成熟林间有显著差异。去除凋落物显著改变不同林龄土壤温湿度中主要限制因子并提高主要限制因子对土壤呼吸的影响,加倍凋落物处理土壤呼吸主要受土壤温度的影响,温度和湿度共同解释了不同林龄油松林土壤呼吸季节变化的60.2%~77.5%,不同处理土壤呼吸速率与细根生物量呈显著正相关。不同林龄油松林土壤呼吸对凋落物输入改变的响应特征存在差异。在预测未来气候变化对土壤呼吸影响时,应考虑凋落物输入改变对土壤呼吸的影响。

关键词: 油松林, 凋落物输入, 林龄, 土壤呼吸

Abstract: To explore the relationship between litter inputs and soil respiration in different aged forests, we carried out a leaf litterfall manipulation experiment in Pinus tabuliformis forests inLiaohe River, Northern China. We examined the sensitivity of soil CO2 emissions to alteration in litter inputs. There were nine experimental plots with three stand ages (middle-aged, nearly mature, and mature stands). Treatments included adding (by doubling) of aboveground litter (DL) (including leaf, twig, bark), removing all aboveground litter (NL), removing aboveground litter and root (NI), and control (CK). Soil respiration was measured with a  LI-8100 infrared gas analysis. The results showed that alterations in litter inputs significantly affected soil temperature and moisture in middle-aged stand. Soil temperature was significantly increased in NL treatment in middle-aged and mature stands, whereas soil moisture was significantly-reduced in NL treatment in middle-aged and nearly mature stands. Alterations in litter inputs did not affect soil temperature in nearly mature stand and soil moisture in mature stand.  Soil respiration rate was significantly increased in DL treatment, whereas soil respiration rate was significantly decreased in NL treatment. The magnitude of increment in soil respiration in DL treatment was greater than that of the decline in NL treatments. The relative contributions of different soil respiration components to total soil respiration following the order mineral soil respiration > litter respiration > root respiration in middle aged and nearly mature stands, and following the order of mineral soil respiration > root respiration > litter respiration in mature forest. The contribution of mineral soil respiration decreased with increasing stand age, but an opposite pattern for the contribution of root respiration. Mineral soil respiration and root respiration were significantly differentbetween middleaged stand and mature stand. Litter removal had significant effects on soil microclimate, which affected soil respiration. Soil respiration in DL treatments was mainly affected by soil temperature. The combined effects of soil temperature and moisture explained 60.2%-77.5% of the variation of soil respiration in different aged P.tabuliformis forests. Soil respiration under different treatments had a significant positive correlation with fine root biomass. The responses of soil respiration to the alteration in litter inputs depended on stand age. Our findings indicate that  alterations of litter inputs should be considered in predicting soil respiration under climate changes.

Key words: Pinus tabuliformisforest, litter input, forest age, soil respiration.