不同园林植物土壤呼吸及影响因子特征

Soil Respiration and Impact Factors of Different Green Plants in Zhengzhou City

以郑州市4种园林植物(合欢、龙爪槐、紫叶李和海棠)为试材,采用动态密闭气室红外CO2分析仪(IRGA)法测定了不同园林植物土壤根区土壤呼吸特征,并通过测定园林植物根区土壤养分含量和酶活性等土壤环境因子(土壤温度和湿度等),研究不同园林植物根区土壤呼吸影响因子,为城市园林植被建设及景观配置提供科学依据。结果表明:(1)不同园林植物大气温度的日变化趋势均为单峰曲线;大气湿度日变化均呈"V"字形变化趋势;0—10cm土壤温度与大气温度变化趋势相一致,在14:00左右达到峰值;土壤湿度均呈"V"字形变化趋势,在14:00达到最低,此后有所回升;(2)在日变化尺度上,4种园林植物土壤呼吸均表现为单峰型,且峰值出现的时间基本一致,在14:00左右达到最大,最低值出现在早上6:00,相同时间土壤呼吸速率基本表现为合欢>龙爪槐>紫叶李>海棠;(3)4种园林植物土壤呼吸与土壤温度和土壤湿度之间关系以指数方程拟合最好;(4)4种园林植物土壤养分含量和土壤酶活性的变化趋势相一致,表现为合欢>龙爪槐>紫叶李>海棠,而4种园林植物根区土壤全磷含量差异不显著(p>0.05);(5)偏相关性分析可知,不同园林植物土壤呼吸均与土壤养分和土壤酶活性呈现出一定的相关性,其中合欢和龙爪槐的相关系数高于紫叶李和海棠。

To explore soil respiration and impact factors under different green plants in Zhengzhou City by IRGA,taking four green plants(Albizzia julibrissin,Sophora pendula,Prunus cerasifera and Chaenomeles speciosa)as experimental materials,we investigated the soil nutrients,soil enzyme activities(0—10cm)and other environmental factors,and used exponential model to analyze the relations between soil respiration and soil temperature and humidity,to provide the scientific basis for the ecological landscape configuration,and to choose suitable greening plants and urban greening construction.The results showed that:(1)the daily air temperature showed a single peak curve,and daily atmospheric moisture had a variation trend of‘V'shape,soil temperature at 0—10cm depth had a same variation trend with atmospheric temperature,which the peak occurred at 14:00,and soil moisture had a variation trend of‘V'shape with the local fluctuation;(2)the daily soil respiration rate showed a single peak curve,and the daily maximum of soil respiration rate occurred at 14:00and the minimum of soil respiration rate occurred at 6:00,and at same time in a day,the soil respiration rates decreased in the order:Albizzia julibrissin>Sophora pendula>Prunus cerasifera>Chaenomeles speciosa;(3)it was found that soil respiration was extremely significantly correlated with soil temperature and soil moisture content,thier relation could be described by exponential equation(p<0.05);(4)the soil nutrients and soil enzyme activities under these four green plants decreased in the sequence:Albizzia julibrissin>Sophora pendula>Prunus cerasifera>Chaenomeles speciosa,while the total soil phosphorus had no difference under these four green plants(p>0.05);(5)through the partial correlation analysis to exclude other environment factors,we found that soil respiration had a correlation with soil nutrients and soil enzyme activities to some degree,and the correlation coefficient under Albizzia julibrissin and Sophora pendula were higher than those under Prunus cerasifera and Chaenomeles speciosa.