Effects of Different Ecological Groups of Earthworms on the Distribution of Litter into Aggregates
[Objective]By studying the transformation and distribution patterns of litter-derived carbon in soil under the action of different ecotypes of earthworms,providing theoretical basis and data support for ex-ploration of the impact of earthworms on the carbon sequestration and sink enhancement potential of soil in poplar plantations.[Methods]The leaves of poplar seedlings enriched with 13C were marked by pulse labeling method.Three different ecotypes of earthworms were inoculated to study the distribution of litter source carbon in water-stable aggregates of coarse aggregates(d＞2 mm),fine aggregates(2≥d＞0.25 mm),microaggregates(0.25≥d＞0.053 mm)and silt-clay aggregates(d≤0.053 mm)under the action of different ecotypes of earthworms.[Results]After inoculation of earthworms,the incorporation and distribu-tion of litter source carbon into the soil were significantly promoted,and the soil δ13C value was signific-antly increased.The enhancement range of epigeic earthworms was the lowest,in contrast,that of epi-en-dogeic and anecic types was the highest.The δ13C values of soil water stable aggregates of different particle sizes increased significantly under the action of earthworms.The δ13C values of four kinds of soil aggregates were the lowest in silt-clay aggregates,and the highest in coarse aggregates and fine aggreg-ates.The effect of Eisenia foetida on the incorporation of litter into soil aggregates was lower than that of Amynthas corticis and Pheretima guillelmi.[Conclusion]After 120 days of short-term culture,different eco-types of earthworms significantly promotes the incorporation and distribution of litter-derived carbon into the soil,and significantly increases the accumulation of litter source carbon in coarse aggregates and fine aggregates.With the participation of epi-endogeic and anecic types,the distribution of carbon to aggreg-ates from litter is significantly increased.We suggest that the application of forest litter residues should be appropriately increased in the process of forestry production and management,and the cooperation and competition among different ecotypes of earthworms should be taken into account.Multiple types of earth-worms should be inoculated to improve or enhance the potential of earthworms to regulate soil organic car-bon(SOC)dynamics in the forestry ecosystem,accelerating the incorporation and distribution of exogen-ous organic matter into the soil.
万方数据
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