Acaulescent palms are resilient to disturbances: experimental and global evidence

Natural or anthropogenic disturbances influence aerial biomass and drive distinct resilience strategies in plants. Resprouting ability is considered one of the primary response traits in post-disturbance recovery. The afforestation of many Cerrado ecosystems (the world's most species-rich tropical savanna) generates a change in the environment of native plants. In this study, we investigated the responses of acaulescent palm species to different disturbances in the Brazilian Cerrado and globally. We hypothesised that acaulescent palms share functional traits that support persistence across disturbance regimes, regardless of geographic origin.

We first investigated the effects of disturbance (biomass removal) on two acaulescent palms from the Cerrado, Allagoptera campestris and Syagrus loefgrenii, subjected to different historical contexts (unaffected, under a pine afforestation, and under a Cerrado regeneration). We assessed and compared above- and belowground traits of plants from areas with different histories. We then assessed the resprouting ability after the removal of the aboveground biomass and compared the number of leaves, plant height and number of ramets to the pre-removal state over one year. To place our findings in a broader context, we compiled a global database of acaulescent palms (APALM) and conducted a meta-analysis of disturbance responses.

The two target species altered their morphological traits in response to environmental changes caused by long-term pine cultivation. Yet, the target species were able to resprout after the removal of aboveground biomass. Almost 10% of all palm species are acaulescent (geophytes). The meta-analysis showed that disturbances had either positive or non-significant effects on belowground traits across species.

Acaulescent palms are resilient to disturbances. Even when exposed to repeated disturbances, they manage to resprout and recover due to their multiple morphological adaptations. The diversity observed in belowground system architecture, ranging from differences in ramification to shifts in growth habit under varying conditions, illustrates adaptive capacity in disturbance-prone ecosystems.