J Plant Ecol ›› 2015, Vol. 8 ›› Issue (3): 284-290 .DOI: 10.1093/jpe/rtu013

• Research Articles • Previous Articles     Next Articles

Interactive effects of understory removal and fertilization on soil respiration in subtropical Eucalyptus plantations

Songze Wan1,2, Chenlu Zhang3, Yuanqi Chen1,2, Jie Zhao4, Xiaolin Zhu1,2, Jianping Wu5, Lixia Zhou1, Yongbiao Lin1, Zhanfeng Liu1 and Shenglei Fu1,*   

  1. 1 Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Science, Xingke Road No. 723, Tianhe District, Guangzhou 510650, China; 2 Graduate University of the Chinese Academy of Sciences, Yuquan Road No.19, Shijingshan District, Beijing 100049, China; 3 Key laboratory of Plant Stress Biology, College of Life Science, Henan University, Minglun Street, Jinming Road, Kaifeng City, Henan 475004, China; 4 Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Yuandaer Road No.644, Furong District, Changsha 410125, China; 5 Institute of Ecology & Environmental Science, Nanchang Institute of Technology, Tianxiang Road NO.289, Gaoxin District, Nanchang 330099, China
  • Received:2014-02-25 Accepted:2014-07-18 Published:2015-05-20
  • Contact: Fu, Shenglei

Interactive effects of understory removal and fertilization on soil respiration in subtropical Eucalyptus plantations

Abstract: Aims It has been well recognized that understory vegetation plays an important role in driving forest ecosystem processes and functioning. In subtropical plantation forests, understory removal and fertilization have been widely applied; however, our understanding on how understory removal affects soil respiration and how the process is regulated by fertilization is limited. Here, we conducted an understory removal experiment combined with fertilization to evaluate the effects of the two forest management practices and their interactions on soil respiration in subtropical forest in southern China.
Methods The study was conducted in a split-plot design with fertilization as the whole-plot factor, understory removal as the subplot factor and block as the random factor in subtropical Eucalyptus plantations. In total, there were four treatments: control with unfertilized and intact understory (CK), understory removal but without fertilization (UR), with fertilization but without understory removal (FT) and with fertilization + understory removal (FT + UR). Eucalyptus above- and belowground biomass increment, fine root biomass, soil temperature, soil moisture and soil respiration were measured in the present study. Understory respiration (R U) was quantified in different ways: R u = R CK ? R UR or R u = R FT ? R (FT + UR); fertilization increased soil respiration (R FI) was also quantified in different ways: R FI = R FT ? R CK or R FI = R (FT + UR) ? R UR .
Important findings Over a 2-year experiment, our data indicate that understory removal significantly decreased soil respiration, while fertilization increased soil respiration. Understory removal decreased soil respiration by 28.8% under fertilization, but only 15.2% without fertilization. Fertilization significantly increased soil respiration by 23.6% with the presence of understory vegetation, and only increased by 3.7% when understory was removed, indicating that fertilization increased soil respiration mainly by increasing the contribution of the understory. Our study advances our understanding of the interactive effects of understory management and fertilization on soil respiration in subtropical plantations.

Key words: understory removal, fertilization, interactive effects, soil respiration, subtropical plantation

摘要:
Aims It has been well recognized that understory vegetation plays an important role in driving forest ecosystem processes and functioning. In subtropical plantation forests, understory removal and fertilization have been widely applied; however, our understanding on how understory removal affects soil respiration and how the process is regulated by fertilization is limited. Here, we conducted an understory removal experiment combined with fertilization to evaluate the effects of the two forest management practices and their interactions on soil respiration in subtropical forest in southern China.
Methods The study was conducted in a split-plot design with fertilization as the whole-plot factor, understory removal as the subplot factor and block as the random factor in subtropical Eucalyptus plantations. In total, there were four treatments: control with unfertilized and intact understory (CK), understory removal but without fertilization (UR), with fertilization but without understory removal (FT) and with fertilization + understory removal (FT + UR). Eucalyptus above- and belowground biomass increment, fine root biomass, soil temperature, soil moisture and soil respiration were measured in the present study. Understory respiration (R U) was quantified in different ways: R u = R CK ? R UR or R u = R FT ? R (FT + UR); fertilization increased soil respiration (R FI) was also quantified in different ways: R FI = R FT ? R CK or R FI = R (FT + UR) ? R UR .
Important findings Over a 2-year experiment, our data indicate that understory removal significantly decreased soil respiration, while fertilization increased soil respiration. Understory removal decreased soil respiration by 28.8% under fertilization, but only 15.2% without fertilization. Fertilization significantly increased soil respiration by 23.6% with the presence of understory vegetation, and only increased by 3.7% when understory was removed, indicating that fertilization increased soil respiration mainly by increasing the contribution of the understory. Our study advances our understanding of the interactive effects of understory management and fertilization on soil respiration in subtropical plantations.