Canopies in Aquatic Ecosystems: Integrating Form, Function, and Biophysical Processes

This Research Topic focuses on the interplay between physical and biological processes in aquatic canopies, including (but not limited to) fluid dynamics, mass transport, nutrient cycling, and light availability. Previous work in terrestrial canopy ecosystems has revealed the complex interactions between hydrodynamics (including turbulent fluxes), gas exchange, light availability, and primary production. In aquatic sciences, the notion of canopy remains less developed. Over the past decade, however, research on underwater canopies has increased and shifted to a more integrated approach with the emergence of the algal and/or coral canopy concept. Through this research topic, we want to provide a platform to support further exploration of this concept. Our definition of canopy is very broad; we do not restrict the concept to macroscale algae and corals. Any biological or physical entity displaying canopy-like characteristics (e.g.: plankton clouds) is of interest to our understanding of this notion. Additionally, we acknowledge that underwater canopies are not usually static structures but can change over time and space. There are a multitude of approaches to the idea of the canopy; a few examples include:

- the photosynthetic canopy and its role in light availability
- the role of canopy structures in local hydrodynamics
- the role of canopies in nutrient fluxes, cycling, and fixation
- the functional ecology of canopies creating specific niches within ecosystems
- the (symbiotic) interactions between canopy-forming and other organisms

Oftentimes, studies focus on a single aspect of the canopy, creating a one- dimensional image of its function in a given ecosystem. Combining different approaches, however, would give us much more insight into the importance and function of canopies in aquatic ecosystems. As an example, we could go from knowledge on how the local fluid dynamics are impacted by the presence of a canopy (one-dimensional image) to exploring how the presence of a canopy, by changing local flow patterns, influences local nutrient fluxes, sedimentation rates, and/or larval settlement (multidimensional approach).
At this point, we believe most of the approaches to the canopy concept mentioned above are built on a strong foundation of data and analysis tools that can now be combined into a multidimensional approach. We therefore strongly encourage contributors to seek out collaborations, to share expertise and data across fields, and to integrate and discuss various approaches in their manuscripts.

We welcome contributions from all fields (biology, mathematics, engineering, physics, geology, chemistry, oceanography…) and encourage the use of varied tools such as empirical data, physical and computational simulations, mathematical modeling, and field data. This topic is open to original research papers, (mini) reviews, opinion papers, methods papers, and perspectives papers.