∙ In southern Chile, the most diverse forest ecosystems are located between 36° and 40° S, in the same areas where agriculture and industrial forestry are concentrated. We studied bird assemblages in Bosque Pehuén Park (39°25’S), along a human disturbance gradient from early successional forest mixed with grasslands to barely disturbed old-growth forest. We surveyed birds across all of the disturbance gradients at 18 points from 860 to 1260 m a.s.l. using point-count methods. Each point was surveyed five times per year, during the Austral summer of 2015 and 2016. Our results confirmed that there is a group of forest birds strongly related to old-growth forest, while others were characteristic of open areas. Secondary forests shared bird species with both old-growth forests and disturbed areas, and presented lower abundance of forest bird specialists. The old-growth forest bird community proved to be small and was dominated by Thorn-tailed Rayadito (Aphrastura spinicauda, Furnariidae) and White-crested Elaenia (Elaenia albiceps, Tyrannidae). Most studies in this region have taken place in secondary forests, which are characterized by a lower presence of specialists and the inclusion of birds from open areas. Here, we provide a reference bird community for Andean forests, and we argue that bird communities in secondary forests are not a good control to analyze the effects of human disturbances. We emphasize the need to conserve the last remnants of the old-growth forest found in these regions. Resumen ∙ Comunidades de aves a lo largo de un gradiente de sucesión post-perturbación en los bosques andinos del parque Bosque Pehuén, región de la Araucanía, sur de Chile En Chile, los bosques templados con mayor biodiversidad se encuentran entre 36° y 40°S, en las mismas áreas donde se concentran la actividad agrícola y las plantaciones forestales de árboles exóticos. Estudiamos los ensambles de aves en el parque Bosque Pehuén (39°25’S), a lo largo de un gradiente de perturbación humana desde bosques sucesionales tempranos mezclados con pastizales hasta bosques antiguos mínimamente perturbados. Usando puntos de escucha, registramos las aves presentes en 18 puntos distribuidos entre los 860 y los 1260 m s.n.m. cubriendo todo el gradiente de perturbación. Cada punto fue muestreado 5 veces por año, durante el verano austral de 2015 y 2016. Nuestros resultados confirmaron que hay un grupo de aves fuertemente relacionadas con bosques antiguos, mientras que otras fueron características de áreas abiertas. Los bosques secundarios compartieron especies de aves con bosques antiguos y zonas alteradas, y presentaron una menor abundancia de especialistas en aves de bosque. Se encontró que la comunidad de aves del bosque antiguo era pequeña, dominada por Rayadito Común (Aphrastura spinicauda, Furnariidae) y Fiofío Crestiblanco (Elaenia albiceps, Tyrannidae). La mayoría de los estudios en esta región se han llevado a cabo en bosques secundarios, que se caracterizan por una menor presencia de especialistas y la inclusión de aves de áreas abiertas. Aquí proporcionamos una comunidad de aves de referencia de los bosques andinos, y afirmamos que las comunidades de aves en los bosques secundarios no son un buen control para analizar los efectos de las perturbaciones humanas. Hacemos hincapié en la necesidad de conservar los últimos remanentes de bosques antiguos de estas regiones.

Large-scale urban tree donation campaigns are widely implemented worldwide as nature-based solutions for climate adaptation and mitigation; however, most programs lack individual-level traceability and post-donation monitoring, limiting accountability and evidence-based management. A fundamental prerequisite for longitudinal survival assessment is the existence of a reliable traceability infrastructure capable of linking individual trees to verified planting records over time. This study proposes and empirically evaluates a participatory digital traceability system that establishes this foundational infrastructure, conceptualized as a distributed data validation architecture for donation-based urban afforestation programs. The framework integrates (i) persistent digital identifiers, (ii) geospatial registration, (iii) distributed multi-stage validation, and (iv) structured citizen reporting, and is operationalized through an installation-free progressive web application (ArborizaCL). The approach was deployed in five real-world campaigns conducted in Valdivia, Chile (May–September 2025), registering 642 trees distributed to 240 participants. A total of 190 georeferenced planting reports were submitted, corresponding to an overall reporting rate of 29.6%. Reporting behavior varied substantially by institutional follow-up strategy: campaigns with active follow-up achieved a mean reporting rate of 54.0%, compared with 13.0% under passive strategies, yielding a 41.0 percentage point difference (315.8% relative increase). Spatial analysis of reported plantings showed a predominance of urban (51.1%) and peri-urban (42.1%) locations, enabling differentiated territorial assessment. These results indicate that while digital infrastructure enables traceability and transparent monitoring, sustained citizen engagement is strongly associated with institutional coordination mechanisms. Beyond environmental monitoring, the proposed framework contributes to information governance by demonstrating how participatory digital traceability systems can support distributed public-sector oversight and outcome-oriented evaluation. The framework provides a transferable methodological basis for strengthening monitoring capacity, transparency, and governance design in publicly funded afforestation initiatives and other distributed civic programs.