Response of soil fauna to simulated nitrogen deposition: a nursery experiment in subtropical China.
We studied the responses of soil fauna to a simulated nitrogen deposition in nursery experimental plots in Subtropical China. Dissolved NH4NO3 was applied to the soil by spraying twice per month for 16 months, starting in January 2003 with treatments of 0, 5, 10, 15 and 30 gN/(m2 x a). Soil fauna was sampled after 6, 9, 13 and 16 months of treatment in three soil depths (0-5 cm, 5-10 cm, 10-15 cm). Soil available N increased in correspondence with the increasing N treatment, whereas soil pH decreased. Bacterial and fungal densities were elevated by the N treatment. Soil fauna increased in the lower nitrogen treatments but decreased in the higher N treatments, which might indicate that there was a threshold around 10 gN/(m2 x a) for the stimulating effects of N addition. The N effects were dependent on the soil depth and sampling time. The data also suggested that the effects of the different N treatments were related to the level of N saturation, especially the concentration of NO3- in the soil.
Xu
Guo-Liang
GL
Institute of Ecology, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China. xugl@scbg.ac.cn
Mo
Jiang-Ming
JM
Fu
Sheng-Lei
SL
Gundersen
Per
P
Zhou
Guo-Yi
GY
Xue
Jing-Hua
JH
D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D044822:Biodiversity; D002681:China; D015169:Colony Count, Microbial; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000494:pharmacology*; D012988:Soil Microbiology; D014329:Tropical Climate
D009566:Nitrates; D009584:Nitrogen