Feedback of trees on nitrogen mineralization to restrict the advance of trees in C4 savannahs
Feedback of trees on nitrogen mineralization to restrict the advance of trees in C4 savannahs
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树木对氮矿化的反馈限制了 C4 稀树草原树木的进步
DOI：
10.1098/rsbl.2015.0572
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发表时间：
2015
期刊：
影响因子：
3.3
通讯作者：
February
中科院分区：
文献类型：
--
作者：
Higgins;Keretetse;February
遥感研究表明，大草原正在转变为更多以树木为主的状态；然而，渐进的氮限制可能会延缓这种被认为是由二氧化碳驱动的入侵。我们在季节性温度和降雨量变化的背景下，通过操纵降雨量以及草和树木元素的覆盖度，分析了对稀树草原氮矿化速率的控制。我们发现氮矿化的季节性模式受到降雨的强烈影响，而人为地增加降雨可以提高矿化率。此外，有草的地块的矿化率要高得多，而有树木的地块的矿化率要低得多。我们的研究结果表明，将草原从草为主转变为树木为主的状态可以大大降低氮矿化率，从而可能对二氧化碳引起的树木入侵草原产生负反馈。
Remote sensing studies suggest that savannahs are transforming into more tree-dominated states; however, progressive nitrogen limitation could potentially retard this putatively CO2-driven invasion. We analysed controls on nitrogen mineralization rates in savannah by manipulating rainfall and the cover of grass and tree elements against the backdrop of the seasonal temperature and rainfall variation. We found that the seasonal pattern of nitrogen mineralization was strongly influenced by rainfall, and that manipulative increases in rainfall could boost mineralization rates. Additionally, mineralization rates were considerably higher on plots with grasses and lower on plots with trees. Our findings suggest that shifting a savannah from a grass to a tree-dominated state can substantially reduce nitrogen mineralization rates, thereby potentially creating a negative feedback on the CO2-induced invasion of savannahs by trees.
自然资源 加州农业 标题 蓝橡树可提高加州橡树林地的土壤质量 永久链接
DOI：
--
发表时间：
2003
期刊：
影响因子：
--
作者：
A. Randy;Horwath;R. William;Tate
通讯作者：
Tate