Temporal changes in the abundance of invasive plants in a tropical montane forest fragment of Costa Rica
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| Author: | |
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| Status: | Versión publicada |
| Publication Date: | 2026 |
| Description: | Introduction: Invasive plants can restructure forest understories by suppressing native regeneration, particularly in fragmented secondary forests. Understanding the population structure of potential invaders and their effects on native understory communities is essential for managing these ecosystems. Objectives: To evaluate the population structure of two species with invasive potential, Coffea arabica and Syzygium jambos, and compare them with the increasingly abundant native species Inga densiflora, as well as quantify their effects on the abundance of understory plants in a 25 ha secondary montane forest fragment in Costa Rica’s Central Valley over a period of 19 years. Methods: All stems ≥ 30 cm tall were recorded across 70 plots of 4 m², totaling 809 individuals. The size distributions of the three focal species (C. arabica, S. jambos, and I. densiflora) were characterized, and model selection was based on the Akaike Information Criterion (AIC) to identify the best predictor of understory abundance. A negative binomial regression was selected to account for substantial overdispersion, using the abundance of each focal species and canopy cover as predictors. Sampling sufficiency was evaluated using cumulative abundance curves. Results: Native understory species comprised 62.3 % of individuals, while C. arabica, I. densiflora, and S. jambos represented 9.0 %, 11.2 %, and 17.4 %, respectively. All three focal species exhibited populations dominated by seedlings and juveniles, with most individuals < 10 cm diameter and < 0.5 m height. Of the two invasive species, only S. jambos showed a significant effect on the understory community, exhibiting a modest but consistent negative association with understory plant abundance (β = -0.046, p = 0.041). Neither C. arabica, the native species I. densiflora, nor canopy cover had significant effects. Sampling curves stabilized after approximately 60 plots, indicating adequate sampling effort. Conclusions: S. jambos was the most ecologically impactful of the three focal species, with the potential to suppress native recruitment as its population expands. These findings underscore the need for targeted management of S. jambos in fragmented secondary forests to prevent long-term degradation of understory diversity. |
| Country: | Portal de Revistas UCR |
| Institution: | Universidad de Costa Rica |
| Repositorio: | Portal de Revistas UCR |
| Language: | Inglés |
| OAI Identifier: | oai:portal.revistas.ucr.ac.cr:article/4228 |
| Online Access: | https://revistas.ucr.ac.cr/index.php/rrbt/article/view/4228 |
| Keyword: | understory suppression; forest fragmentation; Syzygium jambos; secondary forests; invasion ecology supresión del sotobosque; fragmentación del bosque; Syzygium jambos; bosques secundarios; ecología de invasiones |