Examinando por Autor "Macedo Cordova, Wilder"

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Cutting propagation technique of mahogany (Swietenia macrophylla) in microtunnels from the Peruvian Amazon
(2025-01-24) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Ordoñez Sanchez, Luis; Garcia Gonzales, Patricia; Mendoza Caballero, Wilfredo; Saavedra Ramirez, Jorge; Macedo Cordova, Wilder; Reategui, Keneth; Baselly Villanueva, Juan Rodrigo; Marin, Cesar
Swietenia macrophylla is a forest species of great commercial value that is categorized as vulnerable in Peru. Therefore, the objective of this study is to optimize a protocol for cutting propagation of S. macrophylla using microtunnels in the San Martín, Peruvian Amazon. Three experiments were conducted: sterilization, which tested ethyl alcohol (EA), Tween-80 (T), carbendazim (CZ), and combinations; a rooting experiment with different substrates and doses of indole-3-butyric acid (IBA); and an acclimation experiment of rooted cuttings, with different shade coverage and relative humidity conditions. The lowest contamination of S. macrophylla cuttings (9.75%) was achieved with the combined EA-CZ treatment; this treatment resulted in the lowest necrosis (9.1%) and survival of 86.50%. The best responses in rooting, root biomass, and cutting survival were presented by the combination of sterilized sand with 3,000 mg L-¹ of IBA, with averages of 73.89%, 0.036 g, and 2.22 cm, respectively. The best acclimation was obtained under 80% shade and 60% relative humidity, with an average survival rate of 91.67%. The general results were successful; therefore, they could be a valuable tool for the rescue, conservation, and restoration of ecosystems with cloned S. macrophylla trees that are resilient to climate change.
Estimates of Soil Organic Carbon in the Ojos de Agua and El Quinillal Forests in the Central Huallaga of Peru.
(Wiley., 2024-10-05) Mendoza Lopez, Karla; Ordoñez Sanchez, Luis; Valdez Andia, Manuel Jesus; Lozano Chung, Andi; Garcia Gonzales, Patricia E.; Saavedra Ramirez, Jorge; Macedo Cordova, Wilder; Baselly-Villanueva, Juan Rodrigo; Reategui, Keneth; Gaona Jimenez, Nery; Vallejos Torres, Geomar
The Peruvian Amazon has experienced large losses of forest cover due to changes in land use, contributing to increases in CO2 in the atmosphere. This study estimated the organic carbon content of forest soil in two forests "Ojos de Agua" and "El Quinillal" in the Central Huallaga of Peru, establishing three types of cover: (i) primary, (ii) intervened, and (iii) deforested. For this purpose, 24 plots of 100 m² were established and samples were extracted at a depth of 0-20 cm. The effect of the type of forest cover on soil carbon (Organic Carbon-SOC, Inorganic Carbon-SIC, Saturated Carbon-SC, Critical Carbon-CC, Saturated Carbon Deficit-SCD, and Organic Carbon-OC) was analyzed by means of an Analysis of Variance, correlation. Likewise, the relationship between carbon (C) and soil properties was evaluated by principal component analysis and correlation network. The results indicated that the highest SOC averages were found in the primary forests of Ojos de Agua and El Quinillal with 3.54% and 2.51%. The lowest values were found in the deforested forests with 1.34% and 1.46%. The calculation of the saturated C levels of the soil showed an average of 28.63% ± 2.14% and the saturated carbon deficit of 26.63% ± 2.45%, whereas the critical threshold of C showed an average of 2.21% ± 0.18%. The highest SOC content found in the Ojos de Agua primary forest is due to the presence of dominant forest species such as Manilkara bidentata and Brosimum alicastrum. Likewise, the C deficit in the soils of the study area is very alarming because it is very close to saturation levels, especially in deforested forests.
Forest land-use change affects soil organic carbon in tropical dry forests of the Peruvian Amazon
(CSIC (Consejo Superior de Investigaciones Científicas), 2024-10-22) Vallejos Torres, Geomar; Lozano Chung, Andi; Ordoñez Sanchez, Luis; Garcia Gonzales, Patricia; Gaona Jimenez, Nery; Mendoza Caballero, Wilfredo; Macedo Cordova, Wilder; Saavedra Ramirez , Jorge; Baselly Villanueva, Juan Rodrigo; Marin, Cesar
Aim of study: The loss of forest cover is a global problem that alters ecosystems, contributing to carbon emissions. This study measured the soil organic carbon (SOC) at different soil depth in tropical dry forests of the Huallaga Central in the Peruvian Amazon. Area of study: San Martín Region, Peruvian Amazon. Material and methods: A total of 24 plots of 100 m² were selected in primary (~200 years), intervened (~50 years since intervention), and deforested forests (10 years ago), with 120 soil samples collected across five depths. Soil texture (hydrometer), bulk density (cylinder method), SOC content, SOC density, and erodibility (K parameter) were calculated. Main results: SOC content in the 0-20 cm soil horizon was 79.5±21.3 t ha-¹ for the primary forest, 58.5±11.8 t ha-¹ for the intervened forest, and 41.8±10 t ha-¹ for the deforested forest. A soil erodibility K of 0.065 was observed for primary forests and 0.076 and 0.093 for intervened and deforested forests. In average, the SOC density obtained in this study was 7.6±5.1 t ha-¹ in the primary forest, 6.2±3.6 t ha-¹ in the intervened forest, and 4.7±2.7 in the deforested forest. Research highlights: Primary forests had the highest SOC content and SOC density, followed by intervened and deforested forests, while the opposite pattern was found for soil erodibility. These patterns were especially marked in the first 40 cm of soil depth.