This work was carried out with the purpose of generating ecological and silvicultural information oriented to sustainable management. The horizontal structure was evaluated using the importance value index of Curtis and Macintosh, the vertical structure using Finol’s methodology. Through the sociological position index, the percentage natural regeneration and the extended importance value index were estimated in order to infer the permanence of the forest ecosystem. The floristic composition was represented by species of the families Anacardiaceae, Apocynaceae, Fabaceae, Santalaceae, Rhamnaceae, Sapotaceae, Simarubaceae, Ulmaceae, Zygophyllaceae, Capparidaceae, Borraginaceae and Achatocarpaceae. In the horizontal structure, the species with the highest rank was Acacia praecox, followed in order of importance by Schinopsis balansae, Aspidosperma quebracho blanco and Prosopis kuntzei. According to sociological position, Acacia praecox was the most representative species, followed by Patagonula americana, Schinus longifolius, Proposis kuntzei and Aspidosperma quebracho blanco. The species with the best regeneration values were Achatocarpus nigricans and Acacia praecox in the shrub layer and Patagonula americana in the tree layer. The extended importance index consolidated the category of Acacia praecox in the community and gave a better category to Schinopsis balansae, Aspidosperma quebracho blanco, Prosopis kuntzei and Patagonula americana.

A topic of current interest in forestry science concerns the regeneration of degraded forests and areas. Within this topic, an important aspect refers to the time that different forests take to recover their original levels of diversity and other characteristics that are key to resume their functioning as ecosystems. The present work focuses on the premontane rainforests of the central Peruvian rainforest, in the Chanchamayo valley, Junín, between 1,000 and 1,500 masl. A total of 19 Gentry Transects of 2 × 500 m, including all woody plants ≥2.5 cm diameter at breast height were established in areas of mature forests, and forests of different ages after clear-cutting without burning. Five forest ages were considered, 5-10, 20, 30, 40 and ≥50 years. The alpha-diversity and composition of the tree flora under each of these conditions was compared and analyzed. It was observed that, from 40 years of age, Fisher’s alpha-diversity index becomes quite similar to that characterizing mature forests; from 30 years of age, the taxonomic composition by species reached a similarity of 69–73%, like those occurring in mature forests. The characteristic botanical families, genera and species at each of the ages were compared, specifying that as the age of the forest increases, there are fewer shared species with a high number of individuals. Early forests, up to 20 years of age, are characterized by the presence of Piperaceae; after 30 years of age, they are characterized by the Moraceae family.

The heat collection evaporator was modeled based on equilibrium homogeneous theory, and the Runge-Kutta calculation method was used to analyze and solve the flow in the heat collection evaporator. The influence of environmental factors such as solar irradiance, ambient temperature and wind speed on the variation of refrigerant pressure in two kinds of heat collecting evaporator was analyzed under the set working conditions. The results show that the solar energy irradiance has a great influence on the pressure drop in the tube of serpentine heat collecting evaporator, and the maximum pressure drop of the refrigerant in the tube is 16.3%, minimum pressure drop is 7.8%. However, it has little influence on the pressure drop of the tube sheet evaporator. The maximum pressure drop in the refrigerant tube of the tube sheet evaporator is 4.8%, minimum pressure drop is 1.8%. When the irradiance reaches 800 W/m², the refrigerant in the serpentine-tube evaporator has been completely vaporized at 6 m, it’s completely vaporized at 3 m.