Examinando por Autor "Lozano, Andi"

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Carbon reserves in coffee agroforestry in the Peruvian Amazon
(Frontiers, 2024-12-11) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Pichis García, Roger; Ordoñez, Luis; García Gonzales, Patricia; Quinteros , Aníbal; Lozano, Andi; Saavedra Ramírez, Jorge; Tuesta Hidalgo, Juan C; Reategui, Keneth; Macedo Cordova, Wilder; Baselly Villanueva, Juan Rodrigo; Marín, César
Secondary forests and coffee cultivation systems with shade trees might have great potential for carbon sequestration as a means of climate change adaptation and mitigation. This study aimed to measure carbon stocks in coffee plantations under different managements and secondary forest systems in the Peruvian Amazon rainforest (San Martín Region).
Dominance of large trees in carbon storage of Peruvian Amazon forest
(Frontiers Media S.A., 2026-01-26) Lozano, Andi; Gaona Jimenez, Nery; Alvarado, Jaime W.; García Gonzáles, Patricia; Alva Arévalo, Alberto; Ordoñez, Luis; Saavedra Ramírez, Jorge; Tuesta Hidalgo, Juan C.; Vilela, Luis; Tuesta Hidalgo, Oscar A.; Baselly Villanueva, Juan Rodrigo; Chuchon Remon, Rodolfo Juan; Rengifo Del Águila, Sofía; Marin , César; Vallejos Torres, Geomar
Introduction: Forest carbon accumulation is crucial to mitigate ongoing climate change, as large individual trees store a substantial portion of the total carbon in biomass. In this study, large trees and carbon storage were estimated in five forests in the Peruvian Amazon. Methods: For the study, 100 plots were selected (twenty 500 m2 plots per forest site), distributed between 382 to 2086 meters above sea level. Various relationships were explored between the diameter at breast height (DBH) of the most abundant tree species and above- and below-ground carbon. The average carbon content in the tree was calculated based on 50% of the total tree volume at five sites of the Peruvian Amazon. Results: The site with most tree species (Alto Mayo Forest), had 59 tree species. The species Brosimum alicastrum, Ficus insipida, Manilkara bidentata, Inga sp., and Pourouma cecropiifolia showed an average aboveground carbon of 2.31, 3.09, 2.52, 2.78, 2.93 t ha-1, respectively, and values of 0.35, 0.48, 0.38, 0.42 and 0.43 t ha-1 of belowground carbon in trees with ≥ 46 cm DBH. Nectandra sp. showed an above and belowground carbon of 2.50 and 0.38 t ha-1 in trees with ≥ 46 cm DBH, while Cedrelinga catenaeformis showed averages of 5.21 and 0.74 t ha-1 of above and belowground carbon in trees with ≥ 61 cm DBH. Discussion: It was concluded that given the urgency of keeping carbon reserves out of the atmosphere, it is necessary to conserve trees larger than 41 cm, this also allows conserving forest biodiversity and microfauna by buffering the microclimate in the face of future climate changes.
Evaluación del prendimiento y desarrollo de clones de caucho (Hevea brasiliensis) propagados por injerto en la selva peruana
(Universidad Autónoma de Yucatán, 2024-07-15) Navarro, Jorge M.; Alva Arévalo, Alberto; Lozano, Andi; Alva Arévalo, Celso Misael; García Gonzales, Patricia; Gaona Jimenez, Nery; Baselly Villanueva, Juan Rodrigo; Saavedra Ramírez, Jorge; Vallejos Torres, Geomar
The latex yield in Hevea brasiliensis trees is highly variable; Therefore, it is important to propagate commercial clones of this species by grafting in order to standardize or improve latex yields and therefore improve the economic income of producers in this part of the Amazon region. Objective. To evaluate the attachment and development of rubber clones propagated by grafting in the Peruvian jungle. Methodology. Nine-month-old patterns installed in the field were used. These were grafted with budding rods from the commercial clones TR-1, FX-3864, RRIM-600, IAN-873 and MDF-180. A completely randomized block design was used with five treatments and three blocks with 15 experimental units; each containing 30 repetitions. The data obtained were subjected to analysis of variance and Tukey's multiple range test (p<0.05) and the Kruskal Wallis test. Results. The best results in attachment and number of shoots were obtained in grafts with clone MDF-180 with values of 73.33 % and 7.83 shoots respectively; Regarding days to the appearance of the shoot and length, clone TR-1 presented it with 36.63 days and 27.47 cm; The largest leaf area was presented by the graft with clone IAN-873 with 55.46 cm2, while the highest chlorophyll content was obtained in grafts with clone RRIM-600 with 47.18 SPAD. Implications. More studies are required to establish the quality and adaptability of rubber clones propagated by grafting in different site conditions and establish patterns of tree productivity in a short time; Likewise, it is desired to evaluate the quality and quantity of latex produced by these clones. Conclusions. These results indicate the feasibility of propagating Hevea brasiliensis through shoot grafting in the field, which opens great possibilities for propagating rubber trees with better commercial characteristics, particularly with greater latex production.
Impact of forest degradation on soil properties in the Peruvian Amazon
(Springer Nature, 2026-01-16) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Lozano, Andi; Saavedra , Harry; Alva Arévalo, Alberto; Ríos Vargas, Caleb; Saavedra Ramírez, Jorge; Tuesta Hidalgo, Juan; Tuesta Hidalgo, Oscar A.; Vilela, Luis; Valdez Andia, Manuel Jesús; Reategui, Keneth; Baselly Villanueva, Juan Rodrigo; Marín, César; Vento, Bárbara
Background: The Amazonian forests are increasingly threatened due to continuous changes in land use, particularly deforestation. This study aimed to quantify and analyze the vertical distribution of soil glomalin and its relationship with carbon, climate, and soil properties across three forest types of the Peruvian Amazon. A total of 18 plots were selected and sampled in forests with different vegetation cover types: deforested, disturbed, and primary forest. The vertical variation of total glomalin (TG), easily extractable glomalin (EEG), and the number of arbuscular mycorrhizal fungal (AMF) spores was estimated, as it was the relationships of these variables with soil depth, physical-chemical properties, and climate conditions. Results: The mean values for TG, EEG, and AMF showed vertical variations in the three forest cover types, with high values in disturbed forests and degraded soils. Overall, higher mean values were found in the surface soil layers compared to the deep layers. TG, EEG, and AMF were positively corelated with soil organic carbon (SOC) and soil organic matter (SOM). Moreover, the total nitrogen (N), SOC, OM, total phosphorus (P), and soil water content (SWC) presented higher values in the topsoil than the deep layers. Conclusions: The highest production of glomalin in disturbed forests is probably a response to degradation processes. This work is a contribution to expand knowledge about glomalin dynamics in forest soils of the Amazon rainforest and provides essential information for future soil ecosystem restoration practices in tropical forests.
Soil organic carbon balance across contrasting plant cover ecosystems in the Peruvian Amazon
(Instituto de Investigaciones Agropecuarias, INIA, 2023-10-31) Vallejos Torres, Geomar; Gaona Jimenez, Nery; Lozano, Andi; Paredes, Christopher I.; Lozano, Carlos M.; Alva Arévalo, Alberto; Saavedra Ramírez, Jorge; Arévalo López, Luis Alberto; Reategui, Keneth; Mendoza, Wilfredo; Baselly Villanueva, Juan Rodrigo; Marín, César
The Peruvian Amazon has been significantly affected by land use and climate change, decreasing decomposition processes, which cause a significant depletion of soil C stocks. In this study, we estimated soil organic C (SOC) mediated by different plant covers in coffee (Coffea arabica L.) plantations and secondary forests in several districts of the San Martín Region, Peru. We calculated the critical threshold, saturation point, and the organic C deficit of these Amazonian soils. The association between geography, soil physical-chemical characteristics, and SOC was estimated through principal component analysis. Across all sites of the study, SOC stock had an average value of 69.19 t ha-1, with 48.95 t ha-1 constituting inorganic C. The highest SOC stock (225.28 t ha-1) was observed under secondary forest in the Jepelacio district. The SOC stocks were positively correlated with altitude and CaCO3 content only in secondary forests. The current measured amount of organic C within 15 cm soil depth was 28.5 g C kg-1, which is very low and close to the critical threshold (20.6 g C kg-1) -estimated based on its clay and silt contents. Our SOC stocks measurements indicated a worrisome situation, as they are close to the critical threshold, which exposes this area to a greater and stronger degradation.
The conversion of forests to agricultural croplands significantly depletes soil organic carbon reserves, total nitrogen, and available potassium, reaching critical thresholds in the Peruvian Amazon
(Frontiers Media S.A., 2025-09-19) Solórzano Acosta, Richard Andi; Cruz Luis, Juancarlos Alejandro; Chuchon Remon, Rodolfo Juan; Romero Chávez, Lorena Estefani; Lozano, Andi; Gaona Jimenez, Nery; Vallejos Torres, Geomar
Introduction: Land-use change from primary forests to agricultural croplands can degrade soil quality by depleting soil organic carbon (SOC), total nitrogen (STN), and soil-available potassium (SAK). The magnitudes and thresholds of these losses in the Peruvian Amazon remain insufficiently quantified. Methods: We assessed six land-use systems—two primary forests and four croplands (coffee, cocoa, oil palm, camu camu)—collecting 72 surface soil samples (0–20 cm) from 12 subplots per system using pit sampling. SOC, STN, and SAK were measured with standard laboratory procedures and compared across land uses. Results: The humid primary forest (WE–PF) had the highest nutrient status (SOC 118.99 t C ha⁻¹; STN 0.35%; SAK 181.83 mg kg⁻¹). The lowest values occurred in croplands, especially camu camu (SOC 23.93 t C ha⁻¹; STN 0.08%). Forest-to-cropland conversion was associated with average reductions of 58.98% (SOC), 59.49% (STN), and 59.66% (SAK). Among crops, coffee showed the smallest deficit (18.04%), whereas camu camu showed the largest SOC deficit (30.92%). Discussion: Converting forests to croplands critically depletes SOC, STN, and SAK, indicating substantial nutrient losses and concomitant deterioration of soil quality. These findings support conserving primary forests and promoting agroforestry and soil-restorative practices to mitigate degradation in the Peruvian Amazon.