Departamento de Ecologia, Universidade de Brasília, Brasília, DF 70919-970, Brazil.
Environ Pollut. 2011 Oct;159(10):2236-42. doi: 10.1016/j.envpol.2010.10.019. Epub 2010 Nov 13.
This study investigated changes in diversity of shrub-tree layer, leaf decomposition rates, nutrient release and soil NO fluxes of a Brazilian savanna (cerrado sensu stricto) under N, P and N plus P additions. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately. Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified.
本研究调查了在氮（N）、磷（P）和 N 加 P 添加下，巴西热带稀树草原（严格意义上的塞拉多）灌-乔层多样性、叶片分解速率、养分释放和土壤 NO 通量的变化。N 和 P 的同时添加比单独添加 N 或 P 更显著地影响密度、优势度、丰富度和多样性模式。与对照相比，P 和 NP 处理的叶片凋落物分解速率增加，但 N 处理的叶片凋落物分解速率没有差异。N 添加增加了 N 质量损失，而 N 和 P 的联合添加导致叶片凋落物中 N 的固定。如果没有 P，N 的应用也会增加土壤 NO 的排放。结果表明，如果 P 的可利用性没有与 N 的可利用性成比例增加，那么 N 的损失就会加剧。
