The Lab

Presentation

Vianney Denis, Ph.D.

Assistant Professor

Tel: +886.920.270.950
email: vianney.denis(at)gmail(dot)com
skype: vianney.denis
Scholar profile: Vianney Denis

orcid.org/0000-0002-0914-5586

Vianney Denis on ResearchGate

The research in my laboratory focuses on broad-scale ecological processes in coral reefs and on the functional importance of reef organisms to the resilience of this ecosystem – We aim to understand how individual characteristics of reef organisms could influence their response to stressors, and how environmental changes could shape functions of the coral reef ecosystem and the services they provide to human society. Therefore, we develop a trait-based approach centered on the description of species performance and their role in the ecosystem. We have a specific interest on reef organisms from marginal community, i.e. species successfully colonizing and/or expanding in suboptimal environments. In particular, species expanding from shallow tropical locations to mesophotic zones and high-latitude areas may have developed specific features to survive a wide range of environmental conditions and could be the keys species for the future of the coral reefs. Overall, our work consists in analyzing how current human and climatic-modifications could reconfigure the coral reefs in the future and the functional consequences of these changes.

Keywords: Coral reefs, Ecosystem resilience, Functional ecology, Acclimatization and adaptation abilities, Anthropogenic disturbances, Environmental changes

Main research Topics

Chaikou -5m, Green Island, Taiwan

Coral Reef Communities Climate change and anthropogenic disturbances have caused a major decline of coral reef worldwide. I am interested in how human activities combined with seawater temperature increase and ocean acidification can affect the resilience of coral reef ecosystem. I am particularly into highlighting ecological vulnerability, and in investigating factors enforcing robustness of coral reef habitat. In Taiwan, I focus on the characteristics of the phase shifts and on identifying causes of reef degradation. I have a particular interest on feedback mechanisms to test the reversibility of this ecological process.

-5m, South-East Palau

Reef functionality Modifications in the structure and the functions of the ecological communities are highly important to document for our understanding on how environmental changes affect the ecosystems. I am combining information on life history strategy of reef organisms with their response to disturbance and abundance, so as to identify relevant set of life traits to describe modification in the role of coral reef ecosystem.

Seogwipo -15m, Jeju Island, South Korea

High-latitude coral assemblages As seawater temperature increases, high latitude locations could represent refuges for tropical taxa moving poleward. My work on these areas consists of identifying species concerned and the physiological characteristics allowing them to acclimatize marginal environmental conditions. I am investigating consequences of these mechanisms on the temperate assemblages, especially how the increase of tropical organism’s populations can affect benthic interactions. I am also interested by how degradation of tropical reefs can affect this scenario by reducing number of potential migrants to higher latitudes.

Chicken's Head -51m, Green Island, Taiwan

Mesophotic coral ecosystems Aside from migration toward higher latitudes, Mesophotic Coral Ecosystems (MCEs) could offer a temporary refuge for reef organisms to survive adverse conditions of shallow waters. My preliminary work around Taiwan consists of describing diversity and structure of MCEs. I am interested in the physiological mechanisms allowing coral species to colonize deeper environments and how this can affect the resilience of their shallow water counterparts after disturbances. I have a particular interest to analyze dynamic processes such as the coral recruitment in these habitats to investigate if mesophotic populations could be self-maintained.

Oulastrea crispata - polyp

Acclimative and Adaptive Abilities of Reef Organisms Different strategies can be defined from the response of reef organisms to environmental disturbances. I am analyzing response of corals to different stressors, especially the temperature, to identify contrasted acclimative and adaptive abilities among species. Organisms from marginal habitats, or exposed to environmental conditions significantly departing from optima, are particularly useful to our understanding of the future reef biodiversity. I also have a strong interest in analyzing how historical exposure to stress influences their response to disturbances.

Our Team