施氮和增温对降香黄檀幼苗生长发育和生理特征的影响

采用添加氮素模拟氮沉降和人工气候箱模拟增温的方法，设置了对照、施氮、增温以及增温×施氮交互作用4个处理，分析不同处理对降香黄檀（Dalbergia odorifera T.Chen）幼苗生长形态变化、生物量的积累、叶片和根系生理方面的影响。结果显示：与对照相比，增温、施氮以及增温×施氮交互作用均促进了降香黄檀幼苗的生长形态发育、增加了生物量的积累、光合参数、最大光化学量子产量、叶片硝酸还原ø及根系活力，但降低了叶片相对电导率和丙二醛含量；增温×施氮交互作用下降香黄檀幼苗的生物量积累、光合参数、最大光化学量子产量、叶片硝酸还原ø及根系活力的增幅最大，而叶片相对电导率和丙二醛含量降幅最显著；隶属函数分析结果表明，增温×施氮交互作用对降香黄檀幼苗生长发育的促进效果最好，其次为单独增温，最后为施氮处理。

Effects of nitrogen addition and warming on growth,development, and physiological characteristics of Dalbergia odorifera T. Chen seedlings

To investigate the effects of nitrogen deposition and climate warming on the growth and physiological characteristics of one-year-old Dalbergia odorifera T. Chen seedlings, nitrogen deposition and temperature increase were simulated in an artificial climate chamber. Four treatments, including control, nitrogen addition (+ 30 kg N·ha^-1·a^-1), warming (32℃ during the day and 29℃ at night), and warming × nitrogen addition (+ 30 kg N·ha^-1·a^-1, 32℃ during the day and 29℃ at night), were designed to analyze the effects of different treatments on growth, morphological changes, biomass accumulation, and leaf and root physiology in D. odorifera seedlings. Results showed that:(1) Compared with the controls, growth, morphological development, biomass accumulation, photosynthetic parameters, maximum photochemical yield, nitrate reductase, and root activity in the D. odorifera seedlings increased under all treatments, while relative conductivity and malondialdehyde content in leaves decreased. (2) The changes in biomass accumulation, photosynthetic parameters, maximum photochemical yield, nitrate reductase, and root activity showed the greatest increase in the warming × nitrogen treatment, while relative conductivity and malondialdehyde content in leaves showed the greatest decrease in this treatment. (3) Membership function analysis showed that the warming × nitrogen treatment had the best promotion effect on the growth and development of D. odorifera seedlings, followed by warming only treatment, and nitrogen only treatment. These results indicated that short-term warming × nitrogen treatment had better promotion effects on the growth and ecophysiological adaptations of D. odorifera seedlings than single warming or nitrogen application.