Impacto del estrés hídrico en la anatomía de la madera y la morfología de cedrela montana moritz ex turcz. y handroanthus chrysanthus (jacq.) s.o.grose. bajo condiciones de invernadero

Climate change has a direct influence on plant diversity ecosystems at different levels. The present study seeks to understand how hydric variations impact the anatomical and morphological development of Cedrela montana Moritz ex Turcz. and Handroanthus chrysanthus (Jacq.) S.O.Grose, native species of the Andean forest and dry forest from southern Ecuador. The information related to the monitoring of ecological and dasometric variables (height, diameter, number of leaves, phytosanitary status and mortality) was analyzed in five treatments: control or witness (T0), moderate drought with and without fertilizer (T1, T3), and severe drought with and without fertilizer (T2 and T4). For the anatomical analysis of xylem and phloem, transverse microscopic cuts of the stem of the seedlings were made for stained with a combination of AstraBlau and Safranina and finally they were sealed with synthetic Canada Balsam (Loba Chemie). To determine the increase of xylem and phloem, several photographs of the cross cuts were taken with the help of a high resolution Olympus BX41TF microscope and Infinity Analyze v5 and Infinity Capture software, after that, with the ICY bioanalysis software, qualitative analysis was performed to identify changes in anatomical structures: growth rings, vessels, fibers, rays, parenchyma and vascular cambium. Additionally, to identify the changes in the morphological variables, a statistical analysis was carried out by using boxplots, Principal Component Analysis and correlation matrices (with an r significant with p <0.05) through the statistical programming platform R. The results obtained allowed to determine that the resistance to water stress depends mainly on each species, as each one develops changes in its anatomical and morphological structure in order to adapt to the conditions of the environment. C.montana compared to H. chrysanthus showed a lower increase in xylem. For C. montana, the fertilization influenced the recovery of the vascular cambium, showing a greater restoration in the treatment of moderate drought and fertilization (T3). For its part, H. chrysanthus obtained a greater recovery of the Control (T0). C. montana showed immediately its response to induced stress thanks to the loss of foliage, but it showed high resistance to different levels of stress, especially due to its very wide bark. Both species presented a strong correlation between the height and diameter variables showing this pattern in all treatments. With this research, the resilience of forest species to climate change was demonstrated, specifically due to water stress. Therefore, it is necessary to carry out more in-depth studies about the adaptability of forest species to climate changes to contribute with information regarding the capacity of their resistance. Key words: Cedrela montana (Cedro), Handroanthus chrysanthus (Guayacan), water stress, morphological variables, xylem, phloem.

• Autor principal: Barrera Jiménez, Estefanía del Rocío (author)
• Formato: bachelorThesis
• Idioma: spa
• Publicado em: 2021
• Assuntos: MADERA; ESTRÉS HÍDRICO; FLOEMA
• Acesso em linha: https://dspace.unl.edu.ec/jspui/handle/123456789/23735