Cambios morfológicos y formación de anillos de crecimiento por estrés hídrico bajo condiciones controladas en plantas de Acacia macracantha Wild. y Cinchona officinalis L. en el cantón Loja., Ecuador.

Climate variations have a significant impact on ecosystems, leading to internal changes in plant morphology and anatomy. Therefore, the objective of this study was to assess how water stress influences morphology and the formation of tree-rings in Acacia macracantha Wild. and Cinchona officinalis L. For this purpose, the plants were subjected to four water stress treatments (T1, T2, T3, T4) and a control group (T0), each treatment involving 20 individuals. To evaluate plant morphology, bi-weekly measurements of height, diameter, leaf count, and phytosanitary status were carried out for 24 months. To analyze the formation of tree-rings, transverse anatomical cuts of the stem were made, and the ICY Imagine Analysis software was used to demarcate the anatomical tissues. Finally, statistical analysis was conducted using the R programming environment. Time series graphs of the morphological variables were obtained for each treatment, as well as boxplot diagrams. Non-parametric Kruskal-Wallis and Wilcoxon tests were applied (α = 0.05). Regarding morphology, the results showed significant differences between the control group (T0) and the water stress treatments in A. macracantha and C. officinalis. Furthermore, A. macracantha showed a high mortality rate in the T2 and T4 treatments, while C. officinalis had a high mortality rate in all water stress treatments. At the anatomical level, C. officinalis demonstrated faster vascular cambium regeneration compared to A. macracantha. In conclusion, eight weeks of water stress for A. macracantha Wild., and four weeks for C. officinalis led to the formation of false rings, especially in the control group, and true rings were more evident in the water stress treatments, although they showed little synchronization with drought periods. A. macracantha proved to be more resistant to long periods of drought, with better growth and development of morphological variables. However, under high temperatures, A. macracantha does not tolerate water stress, which affects its phytosanitary condition and increases the mortality rate. In the case of C. officinalis, despite receiving constant irrigation, it exhibits less growth and development of morphological variables due to its genetic and its ecological requirements. Therefore, it is essential to conduct further long-term monitoring studies to understand the physiological response of these forest species to potential extreme climate changes. Keywords: Morphological changes, tree rings, water stress, faique and cascarilla

• मुख्य लेखक: Verdesoto Tigreros, Tania Estefanía (author)
• स्वरूप: bachelorThesis
• भाषा: spa
• प्रकाशित: 2023
• विषय: CAMBIOS MORFOLOGICOS; ANILLOS DE CRECIMIENTO; ESTRES HIDRICO
• ऑनलाइन पहुंच: https://dspace.unl.edu.ec/jspui/handle/123456789/27820