Understanding the Long-Term Impact of Bamboos on Secondary Forests: A Case for Bamboo Management in Southern Brazil

As secondary forests become more common around the world, it is essential to understand successional pathways to ensure their proper forest management. Despite optimism about secondary forests in terms of landscape restoration, the influence of invasive species on their development has been poorly explored. Here, forest plots in the Araucaria Forest, Southern Brazil, are used to compare forest dynamics over a 14-year period between unmanaged bamboo forest development (control) and the removal of bamboo. Six control plots (15 x 15 m) were monitored for all adult trees since 2007 alongside six adjacent removal plots; after the initial measurement of the control in 2007, all plots were measured bi-annually from 2010 to 2020. Comparisons were based on tree species diversity, composition, and structure parameters. Removal plots show a trend towards developing a forest composition with more secondary and late successional species while the control plots demonstrate succession restricted to the pioneer trees that regenerated immediately after bamboo die-off (2005-2006). Without the presence of bamboos, removal plots are mirroring the well-known successional pathway typical of the Araucaria Forest. Conversely, bamboos are effectively arresting successional development in the control, resulting in lower levels of diversity and less complex forest structure. For the first time, this study presents a direct analysis of the influence of bamboos on forest succession, providing evidence on which practices to manage bamboo forests can be developed so these secondary forests can fulfill their ecological and economic potential.

Automated summary

The study demonstrates that removal plots tend to develop a forest composition with more secondary and late successional species, while control plots are restricted to pioneer trees. Without bamboos, removal plots mirror the well-known successional pathway typical of the Araucaria Forest, while bamboos effectively arrest successional development in the control, resulting in lower diversity and less complex forest structure.