苏北沿海C₃、C₄植物养分元素利用效率差异分析

摘 要

稳定C同位素组成(delta;¹³C)不仅受自身光合作用的控制，还受外界环境影响，因而利用植物delta;¹³C信息可以揭示植物的生理生态特征以及外界环境因素的变化情况。土壤盐分在盐碱地和滨海湿地中含量较高，是植物delta;¹³C组成的重要影响因素，但delta;¹³C除受盐分影响，还受养分元素及土壤大量元素的影响。以苏北沿海为对象，通过稳定C同位素技术测量植物不同器官（根、茎、叶）中delta;¹³C组成，探讨C₃、C₄植物的养分利用效率差异、水分利用效率，并从植物N、P元素含量和土壤金属离子 Na 、Ca² 、K 等角度探求C₃、C₄植物对盐生环境的不同响应特征。探讨土壤盐分与植物delta;¹³C的关系对研究植物耐盐性、改良盐碱地以及保护和恢复滨海湿地的生态环境具有重要的理论和实际意义。

关键词：稳定性同位素；C₃植物； C₄植物；分元素利用效率

Analysis of Differences in Utilization Efficiency of C₃ and C₄ Plant Nutrients in Coastal Areas of Northern Jiangsu Province

ABSTRACT

Stable carbon isotope composition (delta;¹³C) is not only controlled by its own photosynthesis, but also affected by the external environment. Therefore, using plant delta;¹³C information can reveal the physiological and ecological characteristics of plants and the changes of external environmental factors. Soil salinity is high in saline-alkali land and coastal wetland, which is an important factor affecting the composition of delta;¹³C. However, delta;¹³C is affected by nutrients and soil elements. Taking the coastal carbonous isotope technique as a target, the composition of delta;¹³C in different organs (roots, stems and leaves) of plants was measured by stable carbon isotope technique. The differences in nutrient use efficiency and water use efficiency of C₃ and C₄ plants were discussed, and the contents of nitrogen and phosphorus in plants were determined. And the soil metal ions Na , Ca² , K and other angles to explore the different response characteristics of C₃ and C₄ plants to the salt environment. To explore the relationship between soil salinity and plant delta;¹³C has important theoretical and practical significance for studying plant salt tolerance, improving saline-alkali land and protecting and restoring the ecological environment of coastal wetlands.

Key words: stable isotope; C₃ plant; C₄ plant; elemental utilization efficiency

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