Small ecosystems, big insights: tank bromeliads as model systems to investigate human-induced global changes

The impacts of global change on biodiversity and ecosystems have become a pressing concern for researchers, necessitating the selection of suitable model systems for empirical investigation. For decades, natural microcosms, particularly tank bromeliads, have proven invaluable in addressing fundamental questions in ecology and evolution. Their natural environmental conditions, high multitrophic diversity and small size facilitate both realistic and highly replicable controlled experiments across the Neotropics. Tank bromeliads have thus emerged as effective model systems for studying various anthropogenic impacts. This review synthesizes studies employing bromeliads in space-for-time substitution approaches and experiments simulating human-induced changes in temperature, precipitation, habitat and biodiversity loss, detritus quality, ecological interactions and ecosystem processes. These studies consistently reveal the profound effects of human drivers on organismal vulnerability, ecological dynamics, food webs and ecosystem functioning. By enabling the investigation of multiple ecological questions across scales and levels of biological organization, these 'big answers from small worlds' provide critical insights into the impacts of global changes on complex systems. These findings from bromeliad microecosystems can be used as guiding strategies to preserve and manage natural freshwater ecosystems amidst ongoing global change. This article is part of the theme issue 'Life in natural microcosms'.