Biodiv Sci ›› 2024, Vol. 32 ›› Issue (12): 24248.  DOI: 10.17520/biods.2024248  cstr: 32101.14.biods.2024248

• Original Papers • Previous Articles     Next Articles

Dynamics of litter production and its determinants in a subtropical mixed evergreen and deciduous broad-leaved forest in a karst ecosystem

Song Xiong1,2,5, Jiang Gan1,2, Yanjun Xie3, Xizhao Deng3, Guole Qin3, Wanxia Peng1,2, Fuping Zeng1,2, Zhili Zhan1,2, Weining Tan4, Guoqin Huang5, Hu Du1,2,*()()   

  1. 1. Key Laboratory of Agro-ecological Processes in Subtropical Region, Public Technology Center, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
    2. Huanjiang Observation and Research Station for Karst Ecosystems, Chinese Academy of Sciences, Huanjiang, Guangxi 547100, China
    3. College of Chemistry and Biology Engineering, Hechi University, Yizhou, Guangxi 546300, China
    4. Administrative Centre of Guangxi Mulun National Nature Reserve, Huanjiang, Guangxi 547100, China
    5. Center for Ecological Science, Jiangxi Agricultural University, Nanchang 330045, China
  • Received:2024-06-21 Accepted:2024-11-17 Online:2024-12-20 Published:2025-01-24
  • Contact: E-mail: hudu@isa.ac.cn
  • Supported by:
    Guangxi Natural Science Foundation(2023GXNSFAA026109);National Natural Science Foundation of China(42071073);National Natural Science Foundation of China(42277245);National Key Research and Development Program of China(2022YFF1300703);Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021366)

Abstract:

Aims: Litter constitutes a crucial component of forest ecosystems, playing significant roles in biogeochemical cycling, energy flow, and nutrient balance. Nevertheless, understanding the mechanisms by which biotic and abiotic factors influence litter production in heterogeneous natural forest ecosystems remains contentious. This study aims to investigate the long-term dynamics and influential factors affecting litter production in karst forests within subtropical regions.

Methods: In this study, we set up 151 litter traps, and collected litter monthly from 2018 to 2022 in a 25-ha karst evergreen and deciduous broad-leaved mixed forest dynamics plot in the Mulun National Nature Reserve, Guangxi Province. All litter in each trap was dried, classified and weighed.

Results: The average annual litter production in karst forests was 5,946.55 ± 77.27 kg/ha, with significant inter-annual variability. The proportion of each litter component ranked as follows: leaves (63.26%) > debris (24.89%) > twigs (12.79%). Seasonal patterns for total litter and leaf litter production were similar, displaying a bimodal trend with peaks in spring (March-April) and fall (September-October). Monthly dynamics of branch litter followed a unimodal pattern, peaking in autumn (around October), while debris showed a bimodal pattern with peaks in spring (May) and fall (October), respectively. The species diversity, convexity, mean diameter at breast height (DBH), were the main driving factors of litter production within a 5 m radius neighborhood around the traps. The results of the structural equation model indicated that the species diversity, DBH, and convexity have a direct influence on the total litter production, while slope had an indirect influence on the total litter production through altering species diversity.

Conclusion: Five years of continuous monitoring have revealed significant seasonal variations in litter production within the karst evergreen and deciduous broad-leaved mixed forest. Both biotic and topographic factors collectively affected the spatial variability of litter production.

Key words: litter, biodiversity, topography, karst ecosystems, Mulun

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