کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5742565 | 1617764 | 2017 | 5 صفحه PDF | دانلود رایگان |
- Experimental atmospheric nitrogen (N) deposition suppresses soil decay processes.
- Forest floor mass increases with an increase in litter N concentration.
- Forest conditions positively affect non-native earthworm introduction.
- Activity of Lumbricus terrestris increases under experimental N deposition.
- Earthworm activity may negate soil carbon storage under experimental N deposition.
When temperate forests of North America are exposed to long-term experimental levels of atmospheric nitrogen (N) deposition that mimic predicted future rates, elevated concentrations of inorganic N suppress microbial decay processes and increase the mass of the forest floor, storing more carbon (C) as soil organic matter. However, when non-native earthworms were serendipitously introduced to forests subjected to long-term experimental atmospheric N deposition, the greater forest floor mass with a higher N concentration had a positive effect on earthworm activity by increasing earthworm abundance and consumption of the forest floor. Here, we present evidence from a long-term experimental N deposition study showing how the abundance of the introduced earthworm, Lumbricus terrestris, increased significantly under elevated rates of atmospheric N deposition (+363%) in one of four study sites and contributed to a decline in the forest floor (â50%). In addition, mineral soil C (+97%) and N (+117%) concentrations increased as earthworms redistributed a greater proportion of organic matter belowground under experimental N deposition. We conclude that earthworm-induced changes to the forest floor can supersede a decline in microbial decay under experimental N deposition that has previously increased both forest floor mass and turnover time, thereby potentially negating increases in soil C storage.
Journal: Applied Soil Ecology - Volume 120, November 2017, Pages 206-210