Oscar is community ecologist focused on answering two fundamental questions in ecology. 1) Which are the determinants of species coexistence and exclusion within ecological communities, and 2) Which are the consequences of these coexistence dynamics for ecosystem functioning? Approaches to tackle these questions include the combination of ecological theory with observational studies, manipulative experiments and a strong component of statistical modelling. He has just started MESSY lab (Mediterranean Ecological Studies and SYnthesis lab) at the University of Cádiz (Spain), which aims to investigate mechanisms of species coexistence across multiple trophic levels in both terrestrial and marine ecosystems.

Oscar es un ecólogo de comunidades centrado en contestar dos preguntas fundamentales en Ecología. 1) ¿Cuáles son los determinantes de coexistencia y exclusión de especies en las comunidades ecológicas?, y 2) ¿Cuáles son las consecuencias de estas dinámicas de coexistencia para el funcionamiento de los ecosistemas? Las aproximaciones para manejar estas preguntas incluyen la combinación de teoría ecológica con estudios observacionales, experimentos manipulativos y un fuerte componente de modelización estadística. Oscar acaba de empezar MESSY lab (Laboratorio de Estudios Ecológicos Mediterráneos y Síntesis) en la Universidad de Cádiz (España), el cual tiene por intención investigar los mecanismos de coexistencia de especies contenidas en múltiples niveles tróficos tanto para ecosistemas terrestres como marinos.

 

 

Multitrophic networks and species coexistence

 

Most of my current research efforts are focused on understanding how the structure of species interactions modulates biodiversity. We have recently shown that niche and network studies devoted to understand biodiversity maintenance have clear parallelisms in their theoretical concepts and associated methodological tools (Godoy et al. 2018). This effort of integrating different ecological domains is exciting because it is opening novel paths for future research. Specifically, we have now the opportunity to study the joint effect of competitive/facilitative interactions occurring within trophic levels and the antagonistic/mutualistic interactions between trophic levels on determining the maintenance of species diversity in multitrophic networks. In other words, we have now to possibility to understand in an integrative way how several guilds of species such as plant, herbivores, and pollinators coexist all together. With the theoretical framework solved, the challenge we face now is obtaining empirical information of the strength and structure of all these type of interactions. We have done some progress under heterogeneous environments (see Lanuza, Bartomeus and Godoy (2018)) but definitely more efforts are needed in both terrestrial and marine ecosystems.

 

Phylogeny and plant functional traits

Starting my research career as an ecophysiologist gave me the perspective from the very beginning of the importance of functional strategies and evolutionary histories on plant performance. Plant invasions and coexistence can be considered two sides of the same coin, and under such framework, I have explored the role of trait phenotypic plasticity in determining species invasiveness (Godoy, Valladares & Castro-Díez 2011), and the effect of phylogenetic relatedness on species coexistence (Godoy, Kraft & Levine 2014). The lab is committed to keep doing research in three key lines. These are i) the role of functional traits and species relatedness in mediating the structure of competitive and trophic networks, ii) the influence of intraspecific trait variation in the population dynamics of competing species, and iii) the effect of trait evolution on eco-evolutionary dynamics and community assembly. Although it is true that each aspect can be studied in isolation, their combination has the intention to relate processes scaling from genes to communities.

Ecosystem functioning

The study of the mechanisms underlying community assembly through tools associated with population models is a powerful way to describe species’ abundance and their changes across years. But more importantly, it provides a direct link to combine diversity maintenance mechanisms with those related to the functioning of ecological communities. Despite being this combination clear from a theoretical point of view, few have been the attempts to rigorously obtain such experimental linkages and none yet have done so under multispecies and multitrophic communities. We believe accomplishing this task is critical to predict reasonable well the amount and stability of several ecosystem functions critical to human welfare such as biomass production, nutrient cycling, food production, or carbon storage under current global change scenarios.

In sum, as the reader will have noticed, the spectrum of research aims is wide but interrelated. It is an exciting time to be an ecologist and here at MESSY lab we are open to discuss research possibilities for PhD students and Postdocs.

Recommended reading

Functional Ecology has published several papers central to my research. A classic one that I always recommend a close reading is Ghalambor et al. (2007) “Adaptive versus non‐adaptive phenotypic plasticity and the potential for contemporary adaptation in new environments” The authors in this paper highlight the importance of understanding that phenotypic plasticity (strictly understood as the ability of one genotype to produce several phenotypes when exposed to different environments) encompasses diverse adaptive and non-adaptive responses. This fact has important implications to explore limits to phenotypic expression as the degree of adaptation to new environments broadly depends on how close the species’ trait profiles match environmental constrains.  Beyond the focus on phenotypic plasticity, the paper is a great reading to think about genetic and environmental limits/constrains to species interactions. For the particular case of the paper, the emphasis of such limits are put with respect to abiotic stressors, but it can be easily extrapolated to adaptive/non-adaptive responses to competition or to trophic interactions.

More recently, I enjoyed reading Wagg et al. (2017) “Functional trait dissimilarity drives both species complementarity and competitive disparity” The authors perform a detailed experiment to understand how trait differences between species drive both complementarity effects related to community functioning (i.e. biomass production) and competitive asymmetries related to competitive dominance and exclusion.  The authors document that there is not a unique set of trait differences driving both types of mechanisms and these mismatches are indirectly influenced by the overall trait composition of the community assembled. For me, this is an important result because suggests that we should be much more careful with the use of functional trait information to infer competition processes and/or community productivity.  Even more importantly, the relevance of this paper comes from the fact that is among the first to connect experimentally the fields of species coexistence and ecosystem functioning.

Finally, I found particularly interesting Hertäg and Vorburger (2018) “Defensive symbionts mediate species coexistence in phytophagous insects”. I have never worked with phytophagous insects but I could understand this paper easily as the authors did a great job in using general principles from ecology and species interactions to study underlying coexistence mechanisms. This fact shows the importance of using common concepts across study systems to build a solid ecological theory. The paper is also exciting because it shows the importance of the joint effect of mutualistic and antagonistic interactions on mediating competitive interactions between insects. This paper is a clear example of the necessity to include information of species interactions from different sources to acquire a more holistic view of how species coexist in multitrophic networks.

I am greatly enjoying being an associated editor at Functional Ecology. It is a unique opportunity to keep learning and I do hope to contribute to the continued success of this outstanding journal.

 

References

Ghalambor, C.K., McKay, J.K., Carroll, S.P. & Reznick, D.N. (2007) Adaptive versus non‐adaptive phenotypic plasticity and the potential for contemporary adaptation in new environments. Functional Ecology, 21, 394-407.

Godoy, O., Bartomeus, I., Rohr, R.P. & Saavedra, S. (2018) Towards the integration of niche and network theories. Trends in Ecology & Evolution, 33, 287-300.

Godoy, O., Kraft, N.J. & Levine, J.M. (2014) Phylogenetic relatedness and the determinants of competitive outcomes. Ecology letters, 17, 836-844.

Godoy, O., Valladares, F. & Castro‐Díez, P. (2011) Multispecies comparison reveals that invasive and native plants differ in their traits but not in their plasticity. Functional Ecology, 25, 1248-1259.

Hertäg, C. & Vorburger, C. (2018) Defensive symbionts mediate species coexistence in phytophagous insects. Functional Ecology, 32, 1057-1064.

Lanuza, J.B., Bartomeus, I. & Godoy, O. (2018) Opposing effects of floral visitors and soil conditions on the determinants of competitive outcomes maintain species diversity in heterogeneous landscapes. Ecology letters, 21, 865-874.

Wagg, C., Ebeling, A., Roscher, C., Ravenek, J., Bachmann, D., Eisenhauer, N., Mommer, L., Buchmann, N., Hillebrand, H. & Schmid, B. (2017) Functional trait dissimilarity drives both species complementarity and competitive disparity. Functional Ecology, 31, 2320-2329.