Factores ambientales de las plantaciones forestales exóticas y limitación en el establecimiento de especies nativas en los Cerros Orientales de Bogotá

Abstract

The establishment of forest plantations is recognized as an important strategy for ecosystem management and conservation. However, their potential negative impacts, such as reduced biodiversity and ecosystem homogenization, have also been debated. This study investigates how environmental factors in exotic Eucalyptus globulus and Acacia melanoxylon plantations in the Eastern Hills of Bogotá limit or favor the survival and growth of native species. During 2019 and 2022, variables such as slope, soil physical and chemical properties, canopy and understory composition and structure, as well as the shade tolerance strategy of native species were evaluated. It was hypothesized that the survival and growth of native species would be higher in plantations with lower slopes, canopy and understory cover, and higher levels of soil phosphorus and organic carbon, and that shade-tolerant species would show greater survival and growth. Acacia melanoxylon plantations showed higher levels of soil organic carbon, while mixed plantations showed greater basal area and density. Eucalyptus globulus plantations had greater herbaceous cover and available phosphorus. Shade-tolerant species survived more than shade-tolerant species, and individual density in plantations favored the survival of native species. Growth in height and diameter of native species was greater in Acacia melanoxylon plantations and under site conditions with lower slopes, canopy coverage, density, and basal area. Shade tolerance of native species was not a determining factor for their growth. It was concluded that site characteristics and management of exotic plantations significantly affect the regeneration of native species during their establishment stage, affecting survival and growth differently. This suggests the need for silvicultural practices that promote biodiversity and ecological restoration under the canopy of forest plantations.