Nutrient losses in runoff from grassland and shrubland habitats in Southern New Mexico: I. rainfall simulation experiments
Nutrient losses in runoff from grassland and shrubland habitats in Southern New Mexico: I. rainfall simulation experiments
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DOI：
10.1007/bf00992871
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发表时间：
1999-04
期刊：
影响因子：
4
通讯作者：
W. Schlesinger;A. D. Abrahams;A. Parsons;J. Wainwright
中科院分区：
文献类型：
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作者：
W. Schlesinger;A. D. Abrahams;A. Parsons;J. Wainwright
在新墨西哥州奇瓦瓦沙漠的半干旱草地（Bouteloua eriopoda）和干旱灌木林（Larrea tridentata）进行降雨模拟试验。其目的是比较这些栖息地的氮（N）和磷（P）的径流，以评估土壤养分的流失是否与灌木入侵草地有关。径流损失从草和灌木为主的地块是相似的，并远远低于从裸露的地块位于灌丛。径流中总溶解态氮化合物的加权平均浓度最大的草地（1.72毫克/升）和最低的裸样地的灌木（0.55毫克/升）。径流中一半以上的N以溶解性有机化合物的形式存在。在草地和灌木样地，总氮流失量与总排放量高度相关。我们估计，径流中氮的年流失总量为0.25公斤/公顷/年的草原和0.43公斤/公顷/年的灌木-与这些栖息地荒漠化过程中土壤氮的消耗一致。两种生境的磷流失量都很小。
Rainfall simulation experiments were performed in areas of semiarid grassland (Bouteloua eriopoda)and arid shrubland (Larrea tridentata)in the Chihuahuan desert of New Mexico. The objective was to compare the runoff of nitrogen (N) and phosphorus (P) from these habitats to assess whether losses of soil nutrients are associated with the invasion of grasslands by shrubs. Runoff losses from grass- and shrub-dominated plots were similar, and much less than from bare plots located in the shrubland. Weighted average concentrations of total dissolved N compounds in runoff were greatest in the grassland (1.72 mg/1) and lowest in bare plots in the shrubland (0.55 mg/1). More than half of the N transported in runoff was carried in dissolved organic compounds. In grassland and shrub plots, the total N loss was highly correlated to the total volume of discharge. We estimate that the total annual loss of N in runoff is 0.25 kg/ha/yr in grasslands and 0.43 kg/ha/yr in shrublands — consistent with the depletion of soil N during desertification of these habitats. Losses of P from both habitats were very small.