Influence of Climate, Soil, and Topography on the Phenotypic Traits of <i>Juglans neotropica</i> Diels Matrix Trees in Natural and Artificial Populations of the Loja and Zamora-Chinchipe Provinces of Ecuador

Zone 7, located in the south of Ecuador, stands out as a megadiverse region due to the combined influence of the distinctive characteristics of the climate, soil, and topography of the Coastal Marine, Andean Sierra, and Eastern Jungle. The research focused on analyzing the impact of climate, soil, and slope on the phenotypic characteristics of the parent trees of J. neotropica populations, both natural and artificial. Six provenances were selected: The Tundo, The Victoria, The Tibio, The Za&ntilde;e, and The Argelia. It is noteworthy that the latter is a planted forest that has naturalized over time. In the last two decades, a decrease in precipitation, an increase in temperature, relative humidity below 70%, and soil moisture below 60% were observed. Regarding the soil, the physical properties were similar, with mountainous relief and a texture ranging from loam to clay loam to sandy loam, and chemically neutral to slightly acidic. All provenances were found on slopes greater than 45%. Phenology varied by a maximum of one month between provenances in terms of presence, leaf fall, and fruit maturation. The age of the trees varied between provenances, with The Tundo being the oldest at 355 years and The Argelia the youngest at approximately 76 years. The results showed a wide diversity in phenotypic characteristics, ensuring a high adaptability of J. neotropica populations, a key species for the health of mountainous ecosystems.