植物固碳是减缓全球气候变暖的有效途径.然而,农田尺度果园固碳能力目前还不清楚.该文采用涡度相关技术,研究粗砂土立地条件下12a生树龄生草免耕桃园生态系统碳交换和能量平衡各分量的动态变化.结果表明,在盛花期存在明显的固碳能力,日峰值为-0.33 mg/(m2·s)(以CO2计).在旺盛生长期波文比值在0.3以下,日净固碳值最高为-25.1 g/(m2·d)(以CO2计).落叶期存在明显的高CO2排放,日峰值为0.60 mg/(m2·s)(以CO2计).监测期内桃园生态系统日平均波文比值和净固碳量分别为(1.22±1.56)和(-2.90±6.63) g/(m2·d)(以CO2计),年净生态系统碳交换量(net ecosystem exchange,NEE)为-1052g/(m2-a)(以CO2计).以上结果揭示粗砂土12a生树龄生草免耕桃园生态系统有较强的固碳能力.该文为评价果园碳汇功能提供基础数据.%Plant carbon sequestration is an effective way to abate the global warming. However, the field-scale carbon exchange on a peach orchard remains yet unclear. Here, using an eddy covariance technique, the carbon exchange and energy balance were analyzed on a coarse-sand-field, no-tillage, 12-year-old-peach orchard. The results showed that during full flowering, the ability to sequestrate carbon was remarkable, it reached on the peak of-0.33 mg (CO2)/(m2·s). During rapid growth, the Bowen ratio was under 0.3 and daily net carbon sequestration reached on the peak of-25.1 g (CO2)/(m2·d). During the leaf fall stage, there was a great deal of CO2 emissions, the peak value of carbon sequestration reached 0.60 mg (CO2)/(m2-s). During monitoring period, the daily average of net carbon sequestration and Bowen ratio was (1.22±1.56) and (-2.90±6.63)g(CO2)/(m2-d), respectively. The net carbon sequestration could reach-1052g(CO2)/(m2·a) in a year. These results revealed that there were high carbon sequestration on a coarse-sand-field, no-tillage peach orchard. This research provides basic data for evaluating carbon sink function of orchard.
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