城市园林不同生活型植物叶片碳、氮、磷生态化学计量特征及其对台风的响应

植物碳（C）、氮（N）、磷（P）含量及其化学计量比对于维持植物的正常生长发育具有重要意义。台风可能通过多种途径影响我国沿海城市园林植物的生长发育,并改变园林植物C、N、P含量及其生态化学计量特征。然而,相关研究鲜有报道,亟待深入。因此,在2020年8月黑格比台风登陆我国浙江省前后,我们对比研究了台风来临前、台风影响期间以及台风过境一周后,台州市主城区常见的乔、灌、草园林植物叶片C、N、P含量及其生态化学计量比变化特征。结果表明：（1）乔、灌、草园林植物叶片的C/N分别为27.3±0.6、42.9±1.4、25.4±2.2,C/P分别为208.8±9.3、194.1±9.6、88.5±5.7,N/P分别为7.7±0.4、4.9±0.2、4.2±0.5,表明研究区域城市园林植物受到N的限制。（2）不同生活型的园林植物叶片C、N、P含量受台风的影响存在不同程度的差异。C与N含量受台风的影响程度均表现为草本>灌木>乔木,P含量受台风的影响程度表现为草本>乔木>灌木。（3）不同生活型的园林植物叶片C、N、P生态化学计量比对台风的响应存在差异。C/N受台风的影响程度表现为草本>灌木>乔木,C/P受台风的影响程度表现为草本>乔木>灌木,而N/P受台风的影响程度表现为乔木>草本>灌木。台风影响一周后,乔、灌、草园林植物叶片C、N、P含量及生态化学计量比能够自我调节进行恢复。可见,台风会对不同生活型的园林植物叶片基础元素含量及生态化学计量比产生不同程度的影响,而园林植物可通过自身内稳态调节机制使台风的影响减小到最低。

The ecological stoichiometry of carbon, nitrogen and phosphorus in urban garden plants with different life forms and its response to typhoon Hagupit

The concentrations of carbon (C), nitrogen (N) and phosphorus (P), and their ecological stoichiometric ratios in plant tissues play an important role in maintaining the growth and development of plants. Although the typhoons could affect the growth and development of garden plants in coastal cities of China in many ways, the effects of typhoon on the ecological stoichiometric characteristics of carbon, nitrogen and phosphorus in urban garden plants have not been demonstrated. Therefore, the concentrations of C, N and P in leaves of common garden trees, shrubs and herbs were measured in Taizhou City, a coastal city in Zhejiang Province before one day, after one day and one week of Typhoon "Hagupit" in August 2020, respectively. Then, the short-term effects of typhoon "Hagupit" on the concentrations and stoichiometric ratios of C, N and P in these garden plant leaves were evaluated. The C/N ratio of the investigated garden trees, shrubs and herbs is 27.3±0.6, 42.9±1.4 and 25.4±2.2, respectively; the C/P ratio is 208.8±9.3, 194.1±9.6, 88.5±5.7, respectively; and the N/P ratio is 7.7±0.4, 4.9±0.2, 4.2±0.5, respectively, implying that the investigated urban garden plants are limited by N. The concentrations of C, N and P in garden plant leaves of different life forms were affected by the typhoon to varying degrees, but the concentrations of the measured bioelements gradually recovered to the original level after one week of typhoon impact. Both C and N concentrations in plant leaves were affected by typhoon followed as herb > shrub > tree, while the concentration of P in plant leaves was affected by typhoon followed as herb > tree > shrub. The differential responses of C, N and P stoichiometric ratios in garden plants to the typhoon "Hagupit" were observed among different plant life forms. The ratio of C to N in plant leaves were affected by the typhoon followed as herb > shrub > tree, the ratios of C to P in plant leaves were affected by the typhoon followed as herb > tree > shrub, and the ratio of N to P in plant leaves were affected by the typhoon followed as tree > herb > shrub, respectively. After one week of the typhoon "Hagupit", the concentrations and stoichiometric ratios of C, N and P in garden plants gradually recovered to the pre-typhoon level. In conclusion, the typhoon can have to a certain extent effects on C/N/P stoichiometry of garden plants of different life forms, and garden plants can minimize the impact of typhoon by regulating their homeostasis.