Abandoned coffee plantations: biodiversity conservation or path for non-native species? Case study in a neotropical montane forest

Abstract

Abandoned shade coffee plantations are commonplace in Neotropical mountains. Their secondary successional regrowth supports local biodiversity. However, cultivation termination exposes the land to introduced colonizing plants, altering vegetation traits and creating novel communities. We report the vegetation and discuss the possible successional trajectory of a coffee plantation abandoned ~60 years ago on a sloped terrain within a montane forest. Four 400m 2 plots were surveyed and woody individuals >1cm in diameter were tallied, soils were analyzed and microclimate was recorded. The importance value index was calculated for each species, as well as species richness, diversity, equity, stem density, and basal area (BA). Trunk-stem diameter distribution was assessed. Multivariate analyses related vegetation and environment. Seventy-six species/morphotypes from 28 families were recorded. Plots contrasted in their dominant canopy trees ( Syzygium jambos (rose- apple), Croton megalodendron (croton) or Ocotea fendleri (laurel)), species richness (23-37 species), Shannon diversity (2.65- 3.23), stem density (3450-8150 ha -1 ) and BA (19.9-50.7m 2 ·ha -1 ). The main discriminating factor was the predominance of rose- apple in one plot aided by active cultivation nearby and by its life history traits. Succession was greatly influenced by the colonization potential and fast growth of rose-apple, establishing a novel forest community type. The answer to the question in the title will depend of the effective protection against non-native invading species. Currently, considering the level of human perturbation in Neotropical montane forests, such protection appears to be hard to achieve.