Effects of inorganic nitrogen and litters of Masson Pine on soil organic carbon decomposition

• Published in: PloS one 2019-09, Vol.14 (9), p.e0222973-e0222973
• Main Authors: Yu, Xin, Chao, Lin, Zhang, Weidong, Chen, Longchi, Yang, Qingpeng, Zhang, Guangjie, Wang, Silong
• Format: Article
• Language: English
• Subjects: Absorptivity; Bacteria - metabolism; Biochemistry; Biology; Biology and Life Sciences; Biomineralization; Carbohydrates; Carbon; Carbon - analysis; Carbon - metabolism; Carbon Cycle; Decomposition; Ecology; Ecology and Environmental Sciences; Ecosystem biology; Ecosystems; Environmental changes; Fluxes; Forests; Fungi; Fungi - metabolism; Incubation; Laboratories; Leaf litter; Leaves; Lignin; Microbiota; Microorganisms; Mineralization; Nitrogen; Nitrogen - metabolism; Organic carbon; Organic matter; Organic matter in soil; Organic soils; Organs; Pine trees; Pinus - chemistry; Pinus - microbiology; Plant Leaves - chemistry; Plant Leaves - microbiology; Plant Roots - chemistry; Plant Roots - microbiology; Priming; Roots; Soil - chemistry; Soil fertility; Soil Microbiology; Soil organic matter; Soil respiration; Soils; Transport
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0222973

Soil organic matter (SOM) mineralization represents one of the largest fluxes in the global carbon cycle. Numerous studies have shown that soil organic carbon decomposition was largely changed owing to the addition of litter, however very few studies have focused on the role of plant organs in the priming effects (PEs). Here, we studied the effects of different Pinus massoniana organs (fresh leaf, leaf litter, twigs, absorptive fine roots, and transport fine roots) on C4 soil respiration by applying the 13C isotopic natural abundance method. Results showed that the effects of plant organs on PEs were significantly different at the end of 210 days incubation, which can be ascribed to contrasting organs traits especially non-structural carbohydrates and water-soluble compounds. Transport fine roots and fresh leaf induced positive PE, whereas absorptive fine roots induced negative PE. Leaf litter did not change the native SOC decomposition. Plant organ addition can change the microbial community and result in the reduction of bacteria-to-fungi ratio. Our results suggest that with regard to determining the PE of the entire ecosystem, using fresh leaf to represent leaf litter and aboveground to represent underground is implausible.