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在植物叶片氮、磷化学计量学研究中,氮磷比常作为判断土壤养分限制性的指标,其适用范围从海洋、湖泊等水生生态系统扩展到陆地生态系统。以生长在民勤绿洲的毛瓣白刺(Nitraria praevisa)和唐古特白刺(N.tan-gutorun)为研究对象,分别测定叶片N、P含量以及沙堆各层土壤有机质、N、P含量,以探讨两种白刺叶片及其沙堆土壤化学计量学特征的关系。研究结果表明:①白刺叶片的N、P含量之间存在显著的正相关关系;②两种白刺沙堆各项土壤养分指标差异极显著(P<0.01);③毛瓣白刺沙堆土壤的N含量在0~20 cm土层存在富集现象,唐古特白刺沙堆土壤的有机质、N、P含量在20~40 cm土层存在富集现象;④在水分为最主要的限制性因子的荒漠生态系统中,能否以叶片N∶P作为判定营养元素限制性的标准,值得进一步探讨。
In plant nitrogen and phosphorus stoichiometry, nitrogen and phosphorus ratio is often used as an indicator of soil nutrient restriction, and its scope of application extends from aquatic ecosystems such as oceans and lakes to terrestrial ecosystems. Nitraria praevisa and N. tan-gutorun grown in Minqin Oasis were used to determine the content of N and P in leaves and the contents of soil organic matter, N and P in soil layers In order to investigate the relationship between the stomatal characteristics of two types of Nitraria leaf and its sandy soil. The results showed that: (1) There was a significant positive correlation between N and P content in the leaves of Nitraria; (2) There was significant difference (P <0.01) Enrichment of soil N content was observed in 0 ~ 20 cm soil layer. Enrichment of organic matter, N and P content in the soil layer of 20 ~ 40 cm soil layer was observed in Nitratia tangutorum littoral. ④When the water content was the main limitation Sexual factors in the desert ecosystem, whether the leaves N: P as a criterion for determining nutrient limits, it is worth further study.