不同磷环境下种间关系对羊草和冷蒿生物量及氮磷吸收利用效率的影响

Effect of Interspecies Relationships on Nitrogen and Phosphorus Uptake and Utilization Efficiency of Leymus chinensis and Artemisia frigida Under Different Phosphorus Environment

为研究羊草(Leymus chinensis)和冷蒿(Artemisia frigida)在不同磷环境下的种间关系以及对磷素适应策略的变化,采用室内沙培模拟试验,在不同磷处理(P1=2.5mg/kg、P2=25mg/kg)下设置羊草单种、冷蒿单种和两者混种的种植方式,测定了不同处理下羊草和冷蒿的生物量、氮磷含量和氮磷吸收及利用效率。结果表明:(1)低磷环境下,混种处理中羊草的生物量增加了61.23%,其氮、磷吸收效率分别提高46.00%和24.29%,冷蒿的生物量增加了95.77%,其氮、磷吸收效率分别提高了71.00%和115.87%。表现为羊草和冷蒿混种后出现正相互作用,且对冷蒿的正向影响更大。低磷环境下冷蒿可能有较强的生存能力,通过调整策略积极地适应胁迫环境,最终成为草地退化群落的优势物种;(2)高磷环境下,混种处理中羊草的生物量提高了46.59%,其氮、磷吸收效率分别提高了30.71%和12.53%,冷蒿的生物量下降了29.27%,其氮、磷吸收效率分别下降了29.80%和12.09%。两植物的相互关系表现为负相互作用,羊草较冷蒿能更有效获取并同化资源,竞争能力相对较强,可能是成为典型草原优势物种的原因之一。

Leymus chinensis and Artemisia frigidaare respectivelytypical dominant species and late degraded dominant species of grassland in Inner Mongolian.To investigate the relationship between the two species and their adaptation strategy under different phosphorus environment(P1=2.5mg/kg,P2=25mg/kg),apot experiment,designed to simulate growth of Leymus chinensis and Artemisia frigida inthe field,was conducted to determine biomass,nitrogen and phosphorus contents,uptake and utilization efficiency of nitrogen and phosphorus.The planting patterns was Leymus chinensis,Artemisia frigida and mixed plantings.Results showed that:1)Under low-phosphorus environment,the biomass of Leymus chinensis increased by 61.23%,nitrogen and phosphorus uptake efficiency increased by 46.00% and24.29%,while the biomass of Artemisia frigidaincreased by 95.77%,and its nitrogen and phosphorus uptake efficiency increased by 71.00%and 115.87%,respectively.The positive interaction between Leymus chinensis and Artemisia frigida results in greater positive effect on Artemisia frigida.Artemisia frigida may have strong survivability under low-phosphorus environment,and actively adapts to the environmental stress through adaptive strategies such as increasing its nitrogen and phosphorus uptake efficiency and eventually becomes thedominant species of degraded grassland communities.2)Under high-phosphorus environment,the biomass of Leymus chinensis increased by 46.59%and its nitrogen and phosphorus uptake efficiency increased by 30.71%and 12.53%,respectively.The biomass of Artemisia frigida decreased by 29.27%,and its nitrogen and phosphorus uptake efficiency decreased by 29.80%and 12.09%.There was the negative interaction between the two plants.Leymus chinensis can acquire and assimilate resources more efficiently than Artemisia frigida,and its competitive ability is relatively stronger,which may be one of the reasons why it has become a typical dominant species of typical grassland.