Universidade Federal de Lavras, Lavras, MG, CEP: 37200-000, Brasil.
Instituto de Ciências da Natureza, Universidade Federal de Alfenas, Rua Gabriel Monteiro da Silva, nº700, Centro, Alfenas, MG, CEP: 37130-001, Brasil.
J Plant Res. 2023 Sep;136(5):665-678. doi: 10.1007/s10265-023-01468-2. Epub 2023 May 23.
Precipitation is an important climatic element that defines the hydrological regime, and its seasonal variation produces annual dry and wet periods in some areas. This seasonality changes wetland environments and leverages the growth dynamics of macrophytes present, including Typha domingensis Pers. This study aimed to evaluate the influence of seasonal variation on the growth, anatomy and ecophysiology of T. domingensis in a natural wetland. Biometric, anatomical and ecophysiological traits of T. domingensis were evaluated over one year at four-month intervals. Reductions in photosynthesis were evidenced at the end of the wet periods and during the dry periods, and these reductions were associated with thinner palisade parenchymas. Increased stomatal indexes and densities as well as thinner epidermis observed at the beginning dry periods can be associated with higher transpiration rates during this period. The plants maintained their water contents during the dry periods, which may be related to the storage of water in leaf trabecular parenchyma, as this is the first time that results indicate the function of this tissue as a seasonal aquiferous parenchyma. In addition, increasing proportions of aerenchymas were evident during the wet periods, which may be related to a compensation mechanism for soil waterlogging. Therefore, the growth, anatomy and ecophysiology of T. domingensis plants change throughout the year to adjust to both the dry and wet periods, providing conditions for the survival of the plants and modulating population growth.
降水是定义水文状况的重要气候要素，其季节性变化在某些地区产生了年度干湿期。这种季节性变化改变了湿地环境，促进了存在的大型植物的生长动态，包括香蒲。本研究旨在评估季节性变化对天然湿地中香蒲生长、解剖结构和生理生态的影响。在一年的时间里，每四个月评估一次香蒲的生物计量、解剖和生理特征。在湿期结束和干期期间，光合作用减少，这与栅状薄壁组织变薄有关。在干期开始时观察到的气孔指数和密度增加以及表皮变薄可能与该时期较高的蒸腾速率有关。植物在干期保持水分含量，这可能与叶小梁薄壁组织中水分的储存有关，因为这是首次表明该组织作为季节性水生薄壁组织的功能。此外，在湿期期间，通气组织的比例增加，这可能与土壤积水的补偿机制有关。因此，香蒲植物的生长、解剖结构和生理生态全年都在变化，以适应干湿期，为植物的生存提供条件并调节种群增长。
