早春和夏季氮磷添加对内蒙古典型草原退化群落碳交换的影响

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吕亚香¹^,², 戚智彦¹^,², 刘伟¹, 孙佳美¹^,^*(

), 潘庆民¹^,²

Effects of nitrogen and phosphorus addition at early-spring and middle-summer on ecosystem carbon exchanges of a degraded community in Nei Mongol typical steppe

LÜ Ya-Xiang¹^,², QI Zhi-Yan¹^,², LIU Wei¹, SUN Jia-Mei¹^,^*(

), PAN Qing-Min¹^,²

图3. 不同时期氮磷添加对净生态系统碳交换(NEE, A)、生态系统呼吸(ER, B)和总生态系统生产力(GEP, C)的影响(平均值±标准误)。不同小写字母表示相同时期添加养分的各处理间差异达到显著水平(p< 0.05)。CK, 对照((0 g N + 0 g P)·m^-2·a^-1); N, 氮添加(10.5 g·m^-2·a^-1); P, 磷添加(7 g·m^-2·a^-1); NP, 氮磷共同添加((10.5 g N + 7 g P)·m^-2·a^-1)。

Fig. 3. Effects of timing of nitrogen and phosphorus addition on net ecosystem carbon exchange (NEE, A), ecosystem respiration (ER, B) and gross ecosystem productivity (GEP, C)(mean ± SE). Different lowercase letters indicate significant difference between treatments of nutrient addition at the same date (p < 0.05). CK, control ((0 g N +0 g P)·m ^-2·a^-1); N, nitrogen addition at a rate of 10.5 g·m^-2·a^-1; P, phosphorus addition at the rate of 7 g·m^-2·a^-1; NP, nitrogen in combination with phosphorus addition at the rates of 10.5 and 7 g·m^-2·a^-1, respectively.