Research conducted by scientists at the State University of Campinas (UNICAMP) in São Paulo, Brazil, reveals that epiphytic tank bromeliads play a crucial role in boosting plant diversity and enriching the soil in the Atlantic Forest ecosystem. Published in the journal Plant and Soil, the study highlights how these unique plants contribute to nutrient availability, particularly in sandy soils that typically lack essential nutrients.
The Atlantic Forest, particularly in regions close to the sea, features species like the white jacaranda, or Jacaranda puberula, which thrive in acidic soils. Surprisingly, the presence of bromeliads in the treetops enhances the growth of these nutrient-demanding plants. These bromeliads collect water and organic debris, creating a nutrient-rich environment when the water overflows. This process fosters a new type of ecological interaction termed “remote plant interaction,” as it benefits ground-dwelling plants across physical distances.
In the experiments, caroba seedlings, when irrigated with bromeliad water, exhibited significantly enhanced nutrient profiles. Notably, the leaves showed a remarkable increase of 35% in potassium, 36% in phosphorus, and an additional 3% in iron content. Furthermore, the seedlings produced nearly twice as many leaves compared to those irrigated with rainwater alone. Tháles Pereira, the study’s lead author, emphasized the importance of bromeliads, stating, “Bromeliads can accumulate up to 50,000 liters of water per hectare in tropical forests.”
The research, which was part of Pereira’s doctoral studies with funding from FAPESP, integrates multiple projects focused on the resilience of ecosystems under climate change. Gustavo Quevedo Romero, a professor at UNICAMP who supervised Pereira, noted that epiphytic tank bromeliads not only inhabit tree canopies but also support soil communities, an ecological role previously underestimated. He added, “This study reveals a new ecological role for these plants and reinforces the need for their conservation.”
In a related finding, the team previously demonstrated that water from bromeliads could alter plant diversity in the soil beneath them. Some species are so adapted to nutrient scarcity that the influx of nutrients from bromeliad water could actually stunt their growth. While nutrient-rich patches may reduce the presence of certain species, they significantly enhance the functional diversity of the entire ecosystem, favoring plants that may struggle in less nutrient-rich environments.
The current study aimed to isolate the effects of bromeliad water on plant growth by eliminating other variables. Researchers collected water from bromeliads and rainwater directly from the field, using it to irrigate young caroba seedlings in a controlled greenhouse setting. The analysis revealed that bromeliad water contained twice the nitrogen, four times the calcium, and significant amounts of other nutrients compared to rainwater.
As the researchers continue their work, they are now investigating the impact of bromeliads on soil microbial communities. Pereira has been awarded a research internship at Pennsylvania State University to further explore this aspect.
The findings underscore the importance of preserving bromeliads and their ecosystems, as their decline could lead to significant losses in both biodiversity and ecological functions. The study highlights how interconnected our ecosystems are, demonstrating the vital roles even seemingly isolated plant groups can play in supporting overall forest health.
