Herbaceous layer development during spring does not deplete soil nitrogen in the Portuguese montado |
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出 版 社：Journal of Arid Environments |
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发表时间：2011 |
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台 站：鼎湖山森林生态系统定位研究站 |
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作 者：李跃林（4）
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点 击 率：578186 |
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关 键 字(英文)：Biomass development of the herbaceous,vegetation |
| 摘 要(英文)：Nitrogen (N) content in the soil and in the herbaceous biomass were monitored during spring of 2004-2006 to determine how the herbaceous layer development influences soil N availability in the montado ecosystem of southern Portugal. Highest (246.6±52.7gm-2) and lowest (123.2±89.5gm-2) peak biomass occurred in 2006 and 2005 respectively. Total soilNwithin the top 20 cmsoil profile ranged
between 0.2±0.1% in February and 0.41±0.2% in May,while available soil N was lowest (5±2μgg-1 soil)in February but increased three-to-five fold in March and was >17.5μgg-1 soil at senescence in May. Significant (p<0.001) increase in total N in the aboveground pool occurred between February and May.There was however, no decay in soil N content. Instead, the herbaceous vegetation enhanced soil N input and N retention in the ecosystem. Most of the herbaceous plants were annuals with large reserves of organic N at senescence, which returned to the soil as detritus. The herbaceous vegetation is a critical component of the montado that contributes to N recharge and cycling within the ecosystem. |
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 李跃林4-2011-Journal of Arid Environments-Herbaceous layer development during spring does not deplete soil nitrogen in the Portuguese montado.pdf |
