Examinando por Autor "Quispe Melgar, Harold Rusbelth"

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Climate change and tree cover loss affect the habitat suitability of Cedrela angustifolia evaluating climate vulnerability and conservation in Andean montane forests
(PeerJ Inc., 2025-02-27) Ames Martínez, Fressia N.; Capcha Romero, Ivan; Guerra, Anthony; Inga Guillen, Janet Gaby; Quispe Melgar, Harold Rusbelth; Galeano, Esteban; Rodríguez Ramírez, Ernesto C
Background. Because of illegal logging, habitat fragmentation, and high value timber Andean montane forest Cedrela species (such as Cedrela angustifolia), is endangered in Central and South America. Studying the effects of climate change and tree cover loss on the distribution of C. angustifolia will help us to understand the climatic and ecological sensitivity of this species and suggest conservation and restoration strategies. Methods. Using ecological niche modeling with two algorithms (maximum entropy (MaxEnt) and Random Forest) under the ecological niche conservatism approach, we generated 16,920 models with different combinations of variables and parameters. We identified suitable areas for C. angustifolia trees under present and future climate scenarios (2040, 2070, and 2100 with SSP 3-7.0 and SSP 5-8.5), tree cover loss, and variables linked to soil and topography. Results. Our results demonstrated 10 environmental variables with high percentage contributions and permutation importance; for example, precipitation seasonality exhibited the highest contribution to the current and future distribution of Cedrela angustifolia. The potential present distribution was estimated as 13,080 km2 with tree cover loss and 16,148.5 km2 without tree cover loss. From 2040 to 2100 the species distribution will decrease (from 22.16% to 36.88% with tree cover loss variation). The results indicated that Bolivia displayed higher habitat suitability than Ecuador, Peru, and Argentina. Finally, we recommend developing conservation management strategies that consider both protected and unprotected areas as well as the impact of land-use changes to improve the persistence of C. angustifolia in the future.
Low seed viability and germination in Polylepis flavipila hinder forest restoration: The role of seed mass and maternal effects
(Elsevier B.V., 2024-12-05) Huayta Hinojosa, L. David; Quispe Melgar, Harold Rusbelth; Lagones Poma, Katherine Lucero; Llacua Tineo, Yashira Stefani; Ames Martínez, Fressia Nathalie; Renison, Daniel
Seed physiological quality is usually determined by the interaction between genetics and the mother tree’s environment, as well as by intrinsic characteristics, such as seed mass. In the Andean highlands, massive sapling production for forest restoration projects is constrained by seed availability and quality. There, species of the genus Polylepis dominate the remnant forests. The associations of seed viability with seed mass and maternal effects were evaluated in P. flavipila, a threatened tree species endemic to the Peruvian Andes. The characteristics and environments of 18 mother trees from two sites were measured, and seed quality was assessed in three tests. Seed mass was 3.49 ± 1.76 mg (range: 0.5–16 mg) and showed the greatest variability within mother trees, followed by variability among trees and among sites. Viability rates, standard germination and greenhouse germination (2.06 ± 1.35 %, 0.59 ± 0.89 % and 0.64 ± 1.11 %; respectively) were low at both sites. These results were attributed to the presence of seeds with non-viable or absent embryos. Seed viability increased with seed mass and mother tree height, and was positively associated with number of seedlings (r = 0.56). The deficient seed viability and germination found in P. flavipila are the lowest reported for the genus. The low seed physiological quality detected is a risk factor that exacerbates the species’ degree of threat, posing a challenge for sapling production. The reported associations of P. flavipila seed viability with seed mass and maternal char acteristics and environment may guide the selection of better seed quality and serve as a basis for future studies on the challenges and limitations of the reproductive biology of this species
Performance and physiological quality of Escallonia resinosa seeds: prospects for their use in reforestation and restoration
(John Wiley and Sons Inc, 2022-12-10) Huayta Hinojosa, Luis David; Nolasco Lozano, Emily Gisella Ninfa; Guerra, Damaris; Hermoza Gamboa, Joel; Quispe Melgar, Harold Rusbelth
In the Andes, many native forest species are not used in reforestation or restoration programs mainly due to a lack of information about their propagation. In this study, we evaluated the performance of the seeds of Escallonia resinosa by analyzing fruit and seed productivity and characteristics, seed physiological quality, and the germination rate of seeds collected at different stages of fruit physiological maturity, using tetrazolium and standard germination tests. Our results show an estimated production (mean ± SD) of 34,252.5 ± 25,900 fruits per tree and 26.5 ± 20 million seeds per tree. Seed length was 1.0 ± 0.13 mm and seed weight was 12.4 ± 1 μg. We recognized two different morphological types of seeds: Type I seeds (lacking testa) were unviable, whereas all Type II seeds (with testa) germinated. Seed viability and germination rates were 10.5 and 48.6%, respectively; therefore, the viability test underestimated the actual germination rate. Morphological or microsite variables of the parent tree did not influence seed viability or germination. Germination rates were highest (41.8 ± 2.5%) for the seeds of fruits harvested at the initial maturity stage (green fruits). Our results show that E. resinosa is a species with potential for reforestation and restoration projects in the Andes: it has high seed production and good germination performance, and seeds can be harvested from fruits collected at different stages of physiological maturity.
Seedling Production of Retrophyllum rospigliosii in Nurseries and Potential Reforestation Areas Using Modeling Techniques
(MDPI, 2024-12-11) Camarena Yupanqui, Rozly Clarita; Orellana Mendoza, Edith; Bernaola Paucar, Rosario Marilu; Ames Martínez, Fressia Nathalie; Loardo Tovar, Harold; Quispe Melgar, Harold Rusbelth
The success of reforestation and restoration projects depends on several factors, with proper seedling management and the selection of an appropriate planting area being crucial. In Peru, the populations of Retrophyllum rospigliosii (Pilg.) C.N.Page (Ulcumano) have been decreasing due to intensive logging of one of the most valuable woods in South America's tropical forests. There are few studies that unify the production of plants through seeds in nurseries and the identification of suitable areas to place the plants produced. Our study has two components. The first aimed to optimize the plant production process through an experiment that evaluated the effects of three doses of controlled-release fertilizer (CRF) (4.2, 8.4, and 12.6 g/L) and two container sizes (115 and 180 cc) on the morphological quality of seedlings in the nursery. The second component involved identifying potential reforestation areas using ecological niche modeling, based on climatic and edaphic variables. The results indicated that the 4.2 g/L CRF treatment for both container sizes had a significant positive effect on seedling growth. The average germination rate was 85% at 120 days. At six months after seedling transplantation, treatments of 4.2 g/L CRF in 115 cc and 180 cc containers were shown to have the best positive effect on morphological variables of seedlings, with a root collar diameter of 3.76 mm and a height of 13.25 cm. Regarding the potential niche models, an area of 6321.97 km² with ideal conditions for reforestation with R. rospigliosii was estimated, with the departments of Huánuco, Pasco, Junín, and Cusco showing the highest potential. Based on this, it is estimated that over three million plants are needed for large-scale reforestation projects. Integrating silvicultural studies with niche models is a valuable tool for supporting reforestation and ecosystem restoration projects.