Differential responses of litter decomposition to increased soil nutrients and water between two contrasting grassland plant species of Inner Mongolia, China
Differential responses of litter decomposition to increased soil nutrients and water between two contrasting grassland plant species of Inner Mongolia, China
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DOI：
10.1016/j.apsoil.2005.12.009
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发表时间：
2006-12-01
影响因子：
4.8
通讯作者：
Zhou, ZhiYong
中科院分区：
文献类型：
--
作者：
Liu, Ping;Huang, Jianhui;Zhou, ZhiYong
土壤化学和物理条件是控制凋落物分解的关键因素。研究了土壤氮（N）、磷（P）和水分含量增加对两种草地优势植物（即双齿葱属植物菲施）分解速率和相关养分动态的影响。来自Prokh。& Ikonn.-加和克氏针茅（Stipa krylovii Roshev.）与中国内蒙古典型草原的生活型和组织化学形成鲜明对比。试验包括尿素（0、8、16和32 gN/m2）和尿素与重钙（0、8 gN/4 gP、16 gN/8 gP和2 32 gN/16 gP/m2）的混合施肥（加水和不加水）。我们发现，这两个物种之间的比率，以及在响应水和添加率的N和P，凋落物分解的显着差异。单独或与P的混合物中添加N刺激凋落物分解的速率在这两个物种。加入水显著增加了A的衰减常数k值。bidentatum，而S.克雷洛维。凋落物中N和P的含量。bidentatum和S. krylovii都增加相应的增加率的N或混合N和P添加。我们的研究结果清楚地表明，高质量的凋落物的分解更容易受到土壤水分状况的限制，而低质量的凋落物是更敏感的养分供应。研究结果表明，在建立草地生态系统碳循环和养分动态模型时，应考虑不同凋落物质量的植物种类; bidentatum比S. krylovii对内蒙古半干旱草原碳循环和养分动态的影响。(c)2006 Elsevier B. V.保留所有权利。
Soil chemistry and physical conditions are the key factors controlling litter decomposition. We studied the effects of increased soil nitrogen (N), phosphorus (P), and water on the decomposition rates and associated nutrient dynamics of two dominant grassland plant species (i.e. Allium bidentatum Fisch. ex Prokh. & Ikonn.-Gal. and Stipa krylovii Roshev.) with contrasting life forms and tissue chemistry in a typical steppe of Inner Mongolia, China. The treatments included addition of urea at the rates equivalent to 0, 8, 16, and 32 gN/m(2) and additions of mixed urea and triple superphosphate at the rates equivalent to 0, 8 gN/4 gP, 16 gN/8 gP, and 2 32 gN/16 gP/m(2) with and without water added. We found marked differences between the two species in the rates, as well as in the responses to water and addition rates of N and P, of litter decomposition. Additions of N alone or in mixture with P stimulated the rate of litter decomposition in both species. Adding water significantly increased the values of decay constant, k, in A. bidentatum, but not in S. krylovii. N and P concentrations in litters of A. bidentatum and S. krylovii all increased corresponding to increases in the rates of N or mixed N and P additions. Our results clearly indicate that the decomposition of high quality litter is more likely to be limited by soil moisture regimes, while that of low quality litter is more sensitive to nutrient availability. Our findings suggest that plant species with different litter qualities should be taken into consideration when we are to model the carbon cycle and nutrient dynamics in grassland ecosystems and that A. bidentatum is expected to contribute more than S. krylovii to the carbon cycle and nutrient dynamics of the semi-arid grasslands of Inner Mongolia. (c) 2006 Elsevier B.V. All rights reserved.