Composition and structure of a humid montane forest on the Pasochoa volcano, Ecuador

In a one-hectare plot in humid montane forest on Volcán Pasochoa (3,260–3,300 m), one of the last remnants of the inter-Andean forest between the two Ecuadorean cordilleras, there were 1,058 trees ≥ 5 cm dbh in 32 different species with a total basal area of 25.7 m². The most common species were Miconia theaezans, Piper andreanum , and Miconia pustulata with 32%, 14% and 8% of the individuals, respectively. Three species ( Hesperomeles lanuginosa, Boehmeria fallax and Lamiaceae sp.) were represented by only a single individual. Melastomataceae was the most important family with six species, over 50% of the individual trees, and 68% of the basal area. Other important families were Piperaceae and Asteraceae. The abundance of assumed pioneer species suggests that either the forest has been altered by humans in the past, or that their dominance is a part of the dynamic regeneration of a forest growing on steep slopes with inclinations between 36 and 120% in the plot. The diameter class distribution of Miconia corymbiformis and Axinaea macrophylla shows a light-demanding species behavior. Trees with multiple stems characterize this forest perhaps in order to distribute their weight on such steep slopes.