Warming effects on the colonization of a coastal ecosystem by Furcraea foetida (Asparagaceae), a clonal invasive species

Abstract

Global warming is expected to cause significant changes in the distribution of species worldwide, altering ecosystem function and services. These impacts can be exacerbated by synergism with other global change drivers, such as biological invasions. Furcraea foetida (Asparagaceae) is a CAM species native to Central America and northern South America that is currently invading coastal ecosystems in the Atlantic Forest biome in Brazil. The species propagates clonally by bulbils, forming dense clusters that exclude native species. We addressed whether warming may favor or impair development of F. foetida bulbils based on functional traits and assessed whether plant cover of native species influenced F. foetida establishment in a rocky shore ecosystem. We used open-top chambers during summer and autumn, which increased air temperature during daylight hours by 0.4 °C relative to ambient conditions. This short-term warming effect increased the leaf length of bulbils but had no effect on number of leaves, dry mass, specific leaf area, leaf dry matter content (LDMC), or photosynthetic efficiency of photosystem II (Fv/Fm). However, an increase in vegetation cover decreased LDMC and helped maintain high Fv/Fm, having an indirect positive effect on F. foetida establishment that suggests a facilitation interaction in this extreme environment. Even though the manipulated temperature did not reach IPCC (Intergovernmental Panel on Climate Change) forecasts for 2100, our data show that even small, short-term changes in temperature affected plant performance. Thus, we suggest that F. foetida may be favored in a scenario of climate change, increasing its negative effects on biodiversity of coastal ecosystems.