摘要
氮(N)是控制植物结构和功能以及维持生态系统稳定的重要营养元素之一,外源输入氮素的有效性及形态的差异对植物的生长发育和生理特征产生显著的影响。由于全球气候变化和人类活动的干扰,大气氮沉降量日益增加,氮形态也发生改变,严重破坏植物的正常生长和生态系统的平衡稳定,已成为研究学者关注的热点问题。本文综述了不同氮输入水平和形态对植物的生长、光合作用、养分吸收以及代谢酶活性等方面的影响,归纳出:①适量氮输入能促进植物生长、光合作用和养分吸收能力,但当超出植物承受的阈值后,则对其产生抑制作用;②由于植物对氮素形态吸收偏好的差异,铵态氮(NH4+-N)和硝态氮(NO3--N)对植物的生长、光合作用、养分吸收以及代谢酶活性的影响效果不同,且适宜铵硝配比相较于单一某种氮素添加对大多数植物的促进作用更显著。提出未来的研究方向应着重考虑4个方面:①开展大尺度的长期监测控制实验;②利用分子生物学技术深入探究氮形态对植物影响的微观机理;③重点关注土壤根际环境对植物根系氮素吸收的影响;④综合分析氮输入与其他环境因子的交互作用,准确评估典型植物种群动态及群落结构变化。本研究为探究外源氮输入下植物生长生理机制和实现植物生产系统的可持续性提供理论参考。
Nitrogen(N)is one of the most important nutrient elements controlling plant structure and function and maintaining ecosystem stability.The differences in exogenous N availability and form have significant effect on plant growth and physiological traits.Due to global climate change and intensified human activities,the mobility and deposition of N into terrestrial ecosystems increase rapidly and the form of N deposition is also changing,which seriously damages the normal growth of plants and the balance and stability of ecosystem,and has become a hot topic.We summarized the effects of different N addition levels and forms on plant growth,photosynthesis,nutrient absorption,and metabolic enzyme activity.We concluded that:(1)proper N input could promote plant growth,photosynthesis,and nutrient absorption capacity,but has inhibiting effect on plants once exceeding the threshold of plant tolerance;(2)due to the difference in plant preference for N form absorption,the effects of ammonium or nitrate N on plant growth,photosynthesis,nutrient absorption,and metabolic enzyme activity are different,and the appropriate ratio of ammonium and nitrate N has a more significant promotion effect on most plants than the addition of a single N form.Four important research directions should be considered in future:(1)carrying out large scale longterm positioning observation of manipulative experiments;(2)exploring the microscopic mechanism of N form affecting plants using molecular biology techniques;(3)focusing on the effect of soil rhizosphere environment on root N uptake;(4)comprehensively analyzing the interaction between N addition and other environmental factors and accurately assessing typical plant population dynamics and community structure changes.Our study provides theoretical reference for exploring the mechanism of plant growth and physiology and enabling sustainability of plant production systems under exogenous N addition.
作者
张秦泽
郝广
李洪远
ZHANG Qinze;HAO Guang;LI Hongyuan(College of Environmental Science and Engineering,Nankai University,Tianjin 300350,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2024年第3期878-887,共10页
Chinese Journal of Ecology
基金
国家自然科学基金项目(32171853)资助。