Universidad Nacional Agraria La Molina. Facultad de Ciencias Forestales. Departamento Académico de Manejo Forestal

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Bosques y Gestión de Recursos Forestales

Understanding the factors that determine the distribution of plant communities allows us to identify how climate and soil gradients influence the presence and abundance of species. In this paper, environmental parameters that determine species distribution along an altitudinal gradient were identified in the Chanchamayo valley. Using ordination and classification techniques, twelve 1 ha permanent plots were analyzed according to species affinities with climate and soil parameters. The results revealed three distinct plant communities, primarily governed by altitude (m), solar radiation (kJ m⁻² day⁻¹), and exchangeable acidity (Al³⁺H⁺, meq/100 g). This pattern confirms that, at more local scales, topographic and edaphic factors are determining factors in species assembly.

A new record of Cedrela domatifolia W. Palacios is presented in Chanchamayo Valley, department of Junin, which adds to 11 the number of Cedrela (Meliaceae) species recorded in Peru. The most notorious vegetative character of the species are the prominent domatia in the axils of the secondary nerves of blades. At floral characters, the petals are red to fuchsia, an uncommon feature in the genus.