本研究在亚热带天然毛竹林开展野外氮添加试验,以硝酸铵为氮源,设置3个氮添加水平:0、20和80 kg N·hm^(-2)·a^(-1),分别对应对照组、低氮处理和高氮处理。在试验的第9年采集表层(0~15 cm)土壤和毛竹样品,测定土壤基本化学性...本研究在亚热带天然毛竹林开展野外氮添加试验,以硝酸铵为氮源,设置3个氮添加水平:0、20和80 kg N·hm^(-2)·a^(-1),分别对应对照组、低氮处理和高氮处理。在试验的第9年采集表层(0~15 cm)土壤和毛竹样品,测定土壤基本化学性质、微生物群落组成、酸性磷酸酶活性、叶片氮和磷含量、叶片磷组分、细根生物量和磷含量,分析氮添加对毛竹磷利用策略和磷获取策略的影响及其与环境因子的关系。结果表明:低氮和高氮添加均显著提高了叶片氮和磷含量,导致叶片氮磷比没有显著变化。与对照相比,仅高氮添加显著提高了叶片代谢磷、核酸磷和结构磷含量,但未改变各磷组分的占比。低氮和高氮添加下土壤有效磷含量和细根磷含量平均显著提高了31.4%和28.9%,但土壤有机磷含量显著降低了28.2%。细根磷含量与细根生物量、土壤丛枝菌根真菌丰度和有效磷含量均存在显著正相关关系。综上,长期氮添加通过增加地下碳分配来提高毛竹根系的磷吸收。展开更多
Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and s...Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and soil)and their individual contributions,particularly during on-and off-years,remain unclear.A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy,culm,and soil(partitioned into heterotrophic,rhizome,and stump respiration)and their contributions to net ecosystem productivity(NEP)in a representative Moso bamboo forest in the subtropical region of China.The average annual NEP of the Moso bamboo forest was 7.31±2.76 t C·ha^(-1).Specifically,the canopy's annual net C uptake was 17.30±3.23 tC·ha^(-1),accounting for 237%of NEP.In contrast,C emissions from heterotrophs,culms,rhizomes,and stumps were 5.37±1.20,2.18±1.05,1.29±0.04,and 1.15±0.33 t C·ha^(-1),accounting for73%,30%,18%,and16%of NEP,respectively.The NEP,net cumulative C uptake in the canopy,and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years,whereas C emissions from bamboo culms displayed opposite trends.These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems.展开更多
文摘本研究在亚热带天然毛竹林开展野外氮添加试验,以硝酸铵为氮源,设置3个氮添加水平:0、20和80 kg N·hm^(-2)·a^(-1),分别对应对照组、低氮处理和高氮处理。在试验的第9年采集表层(0~15 cm)土壤和毛竹样品,测定土壤基本化学性质、微生物群落组成、酸性磷酸酶活性、叶片氮和磷含量、叶片磷组分、细根生物量和磷含量,分析氮添加对毛竹磷利用策略和磷获取策略的影响及其与环境因子的关系。结果表明:低氮和高氮添加均显著提高了叶片氮和磷含量,导致叶片氮磷比没有显著变化。与对照相比,仅高氮添加显著提高了叶片代谢磷、核酸磷和结构磷含量,但未改变各磷组分的占比。低氮和高氮添加下土壤有效磷含量和细根磷含量平均显著提高了31.4%和28.9%,但土壤有机磷含量显著降低了28.2%。细根磷含量与细根生物量、土壤丛枝菌根真菌丰度和有效磷含量均存在显著正相关关系。综上,长期氮添加通过增加地下碳分配来提高毛竹根系的磷吸收。
基金sponsored by the National Natural Science Foundation of China(Grant Nos.32125027,31930075)Zhejiang A&F University Research and Development Fund(No.2022LFR006).
文摘Moso bamboo(Phyllostachys edulis)forests are a vital resource in subtropical China,known for their high carbon(C)sequestration capacity.However,the dynamic processes of C fluxes within each component(canopy,culm,and soil)and their individual contributions,particularly during on-and off-years,remain unclear.A 2-year field experiment was conducted to investigate the dynamics of C fluxes from the canopy,culm,and soil(partitioned into heterotrophic,rhizome,and stump respiration)and their contributions to net ecosystem productivity(NEP)in a representative Moso bamboo forest in the subtropical region of China.The average annual NEP of the Moso bamboo forest was 7.31±2.76 t C·ha^(-1).Specifically,the canopy's annual net C uptake was 17.30±3.23 tC·ha^(-1),accounting for 237%of NEP.In contrast,C emissions from heterotrophs,culms,rhizomes,and stumps were 5.37±1.20,2.18±1.05,1.29±0.04,and 1.15±0.33 t C·ha^(-1),accounting for73%,30%,18%,and16%of NEP,respectively.The NEP,net cumulative C uptake in the canopy,and C emissions from the respiration of heterotrophs and stumps were all significantly higher during on-years when compared to off-years,whereas C emissions from bamboo culms displayed opposite trends.These findings offer a new approach for quantifying the C budgets of Moso bamboo forests and provide valuable insights into the C cycling processes in forest ecosystems.
