Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (8): 785-796.DOI: 10.17521/cjpe.2015.0075

• Orginal Article • Previous Articles     Next Articles

Effects of forest gap size on litter recalcitrant components of two tree species in Pinus massoniana plantations

ZHANG Yan1, ZHANG Dan-Ju1, ZHANG Jian1,2,*(), YANG Wan-Qin1, DENG Chang-Chun1, LI Jian-Ping1, LI Xun1, TANG Shi-Shan1, ZHANG Ming-Jin1   

  1. 1Institute of Ecology & Forestry, College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
    and 2Key Laboratory of Forestry Ecological Engineering in Sichuan, Ya’an, Sichuan 625014, China
  • Received:2015-01-29 Accepted:2015-05-29 Online:2015-08-01 Published:2015-08-17
  • Contact: Jian ZHANG
  • About author:

    # Co-first authors

Abstract:

Aims The objective of the study was to evaluate the dynamics of recalcitrant components during foliar litter decomposition at different forest gap size in Pinus massoniana plantation in the low hilly land, Sichuan basin. Methods The experiment was set up by thinning P. massoniana plantation to establish seven different gap sizes (G1: 100 m2, G2: 225 m2, G3: 400 m2, G4: 625 m2, G5: 900 m2, G6: 1225 m2, G7: 1600 m2). The contents of four recalcitrant components (condensed tannins, total phenol, lignin, cellulose) in foliar litter of two native species (Cinnamomum camphora and Toona ciliata) placed in litterbags at different locations in the forest gaps were evaluated. The litterbags placed under closed canopy were used as the control. Litterbags with air-dried leaves of C. camphora and T. ciliata were placed at center, edge of the gap and under the closed canopy in November 2013, and collected in December 2013, February 2014, May 2014 and August of 2014 for lab analysis. Important findings The results showed that: 1) Forest gap size had significant effect on the content of condensed tannins, total phenol and lignin for T. ciliata in gap center. However, the forest gap size had no significant effect on the content of recalcitrant components in the litters of C. camphora and cellulose content of T. ciliata. With the increase of gap size, except for cellulose content, the other three recalcitrant components content in small and medium sized gaps (G1-G5) were significant lower than in large gaps (G6, G7). 2) The condensed tannis content of T. ciliata at the gap center were significant lower than at the gap edge. The lignin contents at gap center of G3 was significant reduced in the C. camphora litter. The condensed tannins, total phenol, and lignin contents of T. ciliata litter in small and medium gaps significantly decreased. 3) The contents of the four recalcitrant components in both species’ foliar litter changed with time. The contents of condensed tannins and cellulose decreased and the content of lignin increased significantly with time, however, the total phenol content increased initially, and then decreased. Therefore, small and medium sized gaps (100-900 m2) could be the optimal gap sizes to promote the degradation of litter recalcitrant components for two native species in P. massoniana plantations.

Key words: forest gap size, Pinus massoniana plantations, recalcitrant components