Montane Forest Diversity Influencing Pioneer Flora on Natural Landslides at the Western Side of Podacarpus National Park, South Ecuador | Diversidad Florística del Bosque Montano en el Occidente del Parque Nacional Podocarpus, Sur del Ecuador y su Influencia en la Flora Pionera en Deslizamientos Naturales

The present study comprises a comparison of the biodiversity of montane forests and its influence on natural disturbances, especially landslides. A total of 412 plant species, belonging to 185 genera and 75 families were registered in natural forests. A high endemism, with 58 endemic species, was found in the montane forest and paramo "ecotone" between 2600-2800 m, and around 3200m. Natural landslides were colonized by 218 species of 180 genera and 51 families. The main species diversity was grouped around 2700 m. Five different soil profiles with a median depth of 60 cm were dug. They contained three main types: Dystropepts, reddish to yellowish soil with high kaolinitic and geothitic clay content, sometimes with gibesite. Blackish soils, especially in humid, cold areas, of lighter color in humid areas of lower zones. Crayquets, rich in organic matter, were encountered at altitudes from 3000 - 34000 m. The soils of landslides were very acidic, with medium to very high nitrogen content, and median to low content of phosphorous and potassium. The TWINSPAN analysis of floristic affinity arranged the 170 landslide and 19 natural vegetation plots into three vegetation communities with 13 landscape units. A CANOCO analysis indicated that community I was determined by a high content soil organic matter and comprised undisturbed vegetation. Community II was delineated according to its soil acidity, exposition, and sandy-clay soils, and included mostly disturbed vegetation types at lower altitudes as well as two forest areas in Cajanuma (at 2500 m, wetern slopes) and Sabanilla (2800 m, estaren slopes). Community III was delineated by its clay soils and concentrated on the western side of the research area, including the forests of San Francisco at 2100 m. Colonization on both sides of the Andean chain is patchy, with different forest types functioning as genetic reservoirs for colonization. At this point the influence of the soil seed banks has not been studied.

El estudio realizó una comparación de la diversidad de los bosques montanos y su influencia en la recuperación de áreas disturbadas por impactos naturales, como son los deslizamientos en la gradiente altitudinal (2.100 a 3.400 m). En estos bosques se registraron 412 especies de plantas, pertenecientes a 185 géneros de 75 familias, con un alto endemismo de 52 especies. En los deslizamientos naturales se registró 218 especies correspondientes a 180 géneros y 51 familias, la mayor diversidad se agrupa a los 2.700 m. Los análisis de suelos se realizaron en la misma gradiente altitudinal, con una profundidad promedio de 60 cm en bosques y de 20 cm en deslizamientos. Los horizontes principales son:Drystropepts que son suelos rojos o pardo amarillentos, con arcilla tipo kaolinita y goethita. Suelos con epipedón muy negro en áreas húmedas y frí as y más claro en áreas más bajas. En altitudes entre 3.000 y 3.400 m., son Cryaquets, suelos ricos en materia orgánica. Mientras que los suelos en deslizamientos son muy ácidos, el contenido de nitrógeno es medio a muy alto, el fosforo y potasio son bajos y medianos respectivamente. El análisis de afinidad florí stica TWINSPAN ordenó a las 170 parcelas de deslizamientos y 19 de bosque en tres comunidades vegetales y 13 unidades de paisaje. Mientras que el análisis fí sico ambiental CANOCO, determinó que la comunidad I, está determinada por alto contenido de materia orgánica, la comunidad II la rige la acidez y la exposición, y la comunidad III está influenciada por suelos arcillo limosos.