Photo by José Luis Margalet. CULTIVE laboratory pond
When we talk about the conservation of aquatic ecosystems, we often focus on the species that inhabit them or on the loss of biodiversity. However, contemporary ecology poses a deeper question: how do organisms influence the functioning of ecosystems?
Answering this question is key to understanding and thus managing wetlands in a context of global change.
Wetlands—lagoons, marshes, peatlands, ponds, or estuaries—are ecosystems where water shapes the biological structure and ecological processes. Although they occupy a relatively small area, they perform essential ecosystem functions: they regulate the water cycle, store carbon, support high biodiversity, and act as buffers against environmental disturbances.
But understanding how they function requires going beyond identifying their biodiversity; it requires understanding the ecological roles of the species that inhabit them, the trophic dynamics, and the biogeochemical processes that ultimately determine the resilience of these ecosystems to environmental changes.
From species to functional traits
Traditionally, ecology has described ecosystems based on species composition. However, this approach is limited in explaining how ecosystems function and how they respond to environmental changes.
Recent work by several members of the Global Change Research Institute (IICG-URJC) and the High-Performance Group in Biodiversity and Freshwater Ecology (AQUA) at Rey Juan Carlos University has demonstrated that approaches based on functional traits offer a different perspective: instead of focusing solely on which species are present, they analyze the biological characteristics of organisms—such as body size, diet, reproductive strategy, and habitat—that determine how they interact with the environment and with each other.
These traits allow for a direct link between biodiversity and ecosystem processes such as primary production, nutrient recycling, and energy flow. In this way, functional traits become a key tool for connecting community ecology with ecosystem ecology, one of the major conceptual challenges of modern ecology.
Furthermore, functional traits allow us to understand how organisms act as vectors of energy and matter between adjacent ecosystems, contributing to the coupling between aquatic and terrestrial environments.
Trait-based approaches offer a unique opportunity to advance wetland conservation and management. These approaches allow us to:
- identify which biological characteristics are key to ecosystem functioning,
- understand how communities respond to environmental disturbances,
- predict the effects of global change on aquatic ecosystems,
- design conservation strategies based on processes, not just species.
Realizing the full potential of trait-based approaches involves changing the way we study and manage wetlands: not just protecting species but understanding the mechanisms that underpin ecosystem functioning.
Functional traits and functioning of wetlands
In aquatic ecosystems, the functional traits of organisms influence how communities are structured and how ecosystems function.
For example:
- body size influences metabolism and trophic interactions,
- diet determines the flow of energy between trophic levels,
- habitat use influences ecological connectivity,
- life strategies affect the stability of communities.
Analysing these traits allows us to understand how biological communities contribute to ecosystem functioning and how they respond to environmental factors such as temperature, nutrient availability, and human disturbances.
Thus, ontogenetic changes—that is, modifications in habitat use, diet, or ecological role throughout the life cycle of organisms—acquire particular relevance, as they can alter trophic interactions and energy flows between aquatic and terrestrial ecosystems.
In this sense, wetlands are especially interesting systems because multiple ecological processes and a great diversity of biological strategies converge within them.
Global change and the need for new approaches
Globalization and human activities are profoundly altering biodiversity and the functioning of aquatic ecosystems. However, understanding how these changes affect ecological processes remains one of the great challenges in ecology.
One of the key problems is that the relationship between biodiversity and ecosystem functioning is still not fully understood, especially at large scales and in aquatic ecosystems.
In the context of climate change, alterations in trophic dynamics, the structure of food webs, and aquatic-terrestrial coupling mediated by the ontogenetic processes of insects, amphibians, and fish can modify the resilience of aquatic ecosystems, which are increasingly threatened by global warming. These changes can generate cascading effects that impact the long-term functioning and stability of ecosystems.
Wetlands as natural laboratories
In this context, wetlands can be understood as true natural laboratories. Due to their isolation, low nutrient levels, and simplified food webs, these aquatic ecosystems respond quickly and visibly to environmental changes, making them ideal systems for studying ecological change over time. Thus, they are spaces where it is possible to observe how the dynamics of food webs, as well as the functional traits of organisms, translate into ecological processes and how these processes determine the stability and resilience of ecosystems.
Sometimes, a small wetland is enough to understand complex ecological dynamics.
From theory to practice: an experimental pond
With this idea in mind, initiatives are emerging that seek to bring these scientific approaches to the field. At the Organism Culture Laboratory (CULTIVE) of the IICG-URJC, the creation of an experimental pond represents an opportunity to observe, on a small scale, the processes that structure aquatic ecosystems.
More than just a body of water, the experimental pond is a setting where the functional traits of organisms, the interactions between species, and the processes that sustain ecosystem function can be studied.
The biodiversity present in the pond reflects the complexity of these systems. It is home to emergent aquatic plants such as Typha and Juncus, detritivorous macroinvertebrates like lumbriculids, filter feeders like Daphnia, predatory insects such as predaceous diving beetles and odonates (both anisoptera and damselflies), and vertebrates such as amphibians.
Each of these organisms contributes distinct functional traits and plays a specific role in the food web and the functioning of the ecosystem: from water purification and nutrient recycling to the regulation of food chains and ecological connectivity.
In a context of global change, the Cultive experimental pond thus becomes a privileged space for connecting ecological research with conservation and environmental education, transforming a small wetland into a tool for better understanding and managing aquatic ecosystems.
References:
Gutiérrez‑Cánovas, C., Stubbington, R., von Schiller, D., Bolpagni, R., Colls, M., Datry, T., Marcé, R., & Bruno, D. (2024). Use of trait concepts and terminology in freshwater ecology: Historic, current, and future perspectives. Freshwater Biology, 69(4), 477–495. https://doi.org/10.1111/fwb.14230
Lavorel, S., & Garnier, E. (2002). Predicting changes in community composition and ecosystem functioning from plant traits: Revisiting the Holy Grail. Functional Ecology, 16(5), 545–556. https://doi.org/10.1046/j.1365-2435.2002.00664
Martini, S., Larras, F., Boyé, A., Faure, E., Aberle, N., Archambault, P., Bacouillard, L., Beisner, B. E., Bittner, L., Castella, E., Danger, M., Gauthier, O., Karp‑Boss, L., Lombard, F., Maps, F., Stemmann, L., Thiébaut, E., Usseglio‑Polatera, P., Vogt, M., & Ayata, S. D. (2021). Functional trait‑based approaches as a common framework for aquatic ecologists. Limnology and Oceanography, 66(3), 965–994. https://doi.org/10.1002/lno.11655
McGill, B. J., Enquist, B. J., Weiher, E., & Westoby, M. (2006). Rebuilding community ecology from functional traits. Trends in Ecology & Evolution, 21(4), 178–185. https://doi.org/10.1016/j.tree.2006.02.002
Sánchez-Hernández, J. (2025). Climate-induced shifts in ontogenetic niches threaten ecosystem coupling. Trends in Ecology & Evolution, 40(3), 224–227. https://doi.org/10.1016/j.tree.2024.11.018
Sánchez Hernández, J., et al. (2024). Guía de la biota de la charca del Laboratorio CULTIVE (Centro de Apoyo Tecnológico, URJC). Learning object. https://hdl.handle.net/10115/36155
Violle, C., Navas, M.‑L., Vile, D., Kazakou, E., Fortunel, C., Hummel, I., & Garnier, E. (2007). Let the concept of trait be functional! Oikos, 116(5), 882–892. https://doi.org/10.1111/j.2007.0030-1299.15559