Examinando por Materia "biodiversity"

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Cover and land use changes in the dry forest of Tumbes (Peru) using sentinel-2 and google earth engine data
(MDPI, 2022-10-21) Barboza Castillo, Elgar; Salazar Coronel, Wilian; Gálvez Paucar, David; Valqui Valqui, Lamberto; Saravia Navarro, David; Gonzales, Jhony; Aldana, Wiliam; Vásquez Pérez, Héctor Vladimir; Arbizu Berrocal, Carlos Irvin
Dry forests are home to large amounts of biodiversity, are providers of ecosystem services, and control the advance of deserts. However, globally, these ecosystems are being threatened by various factors such as climate change, deforestation, and land use and land cover (LULC). The objective of this study was to identify the dynamics of LULC changes and the factors associated with the transformations of the dry forest in the Tumbes region (Peru) using Google Earth Engine (GEE). For this, the annual collection of Sentinel 2 (S2) satellite images of 2017 and 2021 was analyzed. Six types of LULC were identified, namely urban area (AU), agricultural land (AL), land without or with little vegetation (LW), water body (WB), dense dry forest (DDF), and open dry forest (ODF). Subsequently, we applied the Random Forest (RF) method for the classification. LULC maps reported accuracies greater than 89%. In turn, the rates of DDF and ODF between 2017 and 2021 remained unchanged at around 82%. Likewise, the largest net change occurred in the areas of WB, AL, and UA, at 51, 22, and 21%, respectively. Meanwhile, forest cover reported a loss of 4% (165.09 km2 ) of the total area in the analyzed period (2017–2021). The application of GEE allowed for an evaluation of the changes in forest cover and land use in the dry forest, and from this, it provided important information for the sustainable management of this ecosystem
Spatial distribution, tree host associations, and deforestation threats on two stingless bee species in the Peruvian Amazon
(Ecological Society of Korea, 2025-07-02) Demetrio, Richar; Muñoz Schrader, Ornella; Faria, Julianna; Baselly Villanueva, Juan Rodrigo; Cardenas, David; Isuiza, Maite; Delgado, Cesar; Ruzo, Andres; Espinoza, Rosa V.
Background: Stingless bees (Apidae: Meliponini) are critical pollinators in the Peruvian Amazon, sustaining biodiversity, crop productivity, and indigenous livelihoods. Despite their ecological and economic importance, the effects of deforestation and illegal logging on their populations remain poorly understood. Nesting tree loss, habitat fragmentation, and changes in elevation influence stingless bee distribution, yet conservation efforts remain insufficient due to a lack of spatial data on their vulnerability. Results: This study examines the spatial distribution, elevation trends, and deforestation threats affecting Melipona eburnea and Tetragonisca angustula, with a focus on tree nesting preferences in the Biosphere Reserve Avireri-Vraem. Using literature reviews, field observations, and GPS surveys, we assessed species distribution patterns, deforestation risks, and nesting tree associations. Our findings reveal that over 50% of their habitats overlap with high deforestation risk zones, largely driven by illegal logging of key nesting trees. Elevation analysis indicates species-specific adaptations, with M. eburnea predominantly in lowland regions, while T. angustula is more frequent at higher altitudes. GPS fieldwork identified strong associations with specific host trees, notably Guarea guidonia and Ficus insipida, with larger trees (> 60 cm DBH) serving as critical nesting sites. Several of these, including Aniba gigantiflora and Cedrelinga cateniformis, are among the most ilegally harvested species, intensifying threats to bee populations. Conclusions: Deforestation-driven habitat loss and fragmentation pose an immediate threat to stingless bee populations by reducing nesting availability, limiting pollination networks, and disrupting genetic exchange. Our findings emphasize the urgent need for targeted conservation strategies, including the preservation of key nesting trees, the establishment of biological corridors, and the promotion of sustainable forestry practices. Given the role of stingless bees as keystone pollinators, their protection is crucial for maintaining biodiversity and ecosystem stability. Recognizing stingless bee habitats under a Rights of Nature framework would provide a legal mechanism to safeguard their nesting sites from further exploitation. Furthermore, strengthening community-led conservation efforts in high-risk areas can enhance long-term resilience. This study provides a baseline for future conservation policies, bridging scientific data and indigenous knowledge to protect Amazonian stingless bees and their ecosystems.
TOMOGRAFÍA ACÚSTICA, UNA TECNOLOGÍA PARA LA SELECCIÓN DE ÁRBOLES SEMILLEROS EN LA AMAZONÍA PERUANA
(Revista del Instituto de Investigaciones de la Amazonía Peruana, 2024-12-02) Baselly Villanueva, Juan Rodrigo; Fernández Sandoval, Ándres; Macedo Ramírez, Arturo Tomas; Salazar Hinostroza, Evelin Judith; Chumbimune Vivanco, Sheyla Yanett; Pérez Arirama, Jorge Enrique; Vallejos Torres, Geomar; Macedo Ladeira Carvalho, Ana Márcia
La forestación y reforestación ayudan a frenar la deforestación; pero las plantaciones en el Perú muestran baja productividad debido al uso de semillas de calidad genética deficiente. La selección en masa es la primera fase de los programas de mejoramiento, evaluando características dasométricas y morfométricas. Sin embargo, la evaluación de la sanidad interna se evalúa con técnicas poco precisas. El estudio tuvo por objetivo demostrar que la tomografía acústica es clave para seleccionar de árboles semilleros en la Amazonıá peruana. Se evaluaron las especies Anaueria brasiliensis, Aspidosperma parvifolium, Bertholletia excelsa, Cedrelinga cateniformis, Dipteryx micrantha, Nectandra cuspidata y Schefflera morototoni. Se utilizó el tomógrafo acústico para evaluar la sanidad, se analizóla incidencia por especie y el porcentaje de afectación mediante la prueba de Kruskal Wallis; y se evaluó la asociación de la sanidad con variables dasométricas. Anaueria brasiliensis presentó la mayor afectación (45,4%), mientras que Bertholletia excelsa y Cedrelinga cateniformis mostraron los menores porcentajes (0,9%). Existió diferencias significativas para el porcentaje de afectación de los árboles candidatos (p < 0,05) y presentaron fuertes asociaciones positivas con las variables dasométricas. Este estudio confirma que la tomografía acústica es fundamental en la selección de árboles semilleros en la amazonıá peruana.