The Journal of Ecology Editors are delighted to announce that Fernando Maestre is our Eminent Ecologist award winner for 2024!
In recognition of his work, we asked Fernando to put together a virtual issue of some of his favourite contributions to the journal. Fernando has also written this blog series, and was interviewed by Richard Bardgett about about how he started his career in ecology, how he uses his work to inform decision making, and the advice he’d give to someone about to embark on a career in ecology. Fernando’s full blog series can be found here: Part 1 | Part 2 | Part 3 | Part 4 👇| Part 5 (coming soon)
Part IV. Going global: the value and power of observational studies and scientific collaboration
A key characteristic of my work so far is its collaborative nature. Since I started my journey as a scientist, I’ve had the chance to work with over 400 colleagues from over 50 countries. As I like to say, four eyes can see more than two, and six can see more than four. Working with so many colleagues from different regions, backgrounds, and expertise has allowed me to tackle problems that would have been impossible to address by myself/our research group and has taken our research program to another level. Plus, above all other considerations, it has been a wonderful and very enjoyable experience that has allowed me to learn a lot and to make new friends and colleagues from all over the world.
In Spain we say that dreaming is free, and as a PhD student I already dreamed of conducting large-scale research across drylands worldwide to evaluate the relationship between ecosystem structure and functioning, and how this relationship is influenced by abiotic factors such as soil properties and climatic conditions. As expected, at the time I did not have the contacts, funding, and capabilities to do this type of work. So, I started to explore these questions across small regional gradients in SE Spain (e.g., Maestre 2004, Maestre & Cortina 2004) and keept dreaming about expanding the geographical scope of this work. The opportunity to do so came after returning to Spain in 2005 as my “Ramón y Cajal” fellowship came with 14K € for research expenses. With these funds, lots of illusion and the initial help of the first lab members (Santiago Soliveres, Pablo García-Palacios, and Andrea Castillo-Monroy) and URJC colleagues (Adrián Escudero, Ana Sánchez, Arantzazu Luzuriaga, and Isabel Martínez), I established an aridity gradient to study structure-functioning relationships in semi-arid steppes and shrublands from central to SE Spain using different observational surveys.
The ninth article of this virtual issue (Gross et al. 2013) derives from one of these surveys, and is the result of a wonderful collaboration with Nicolas Gross and Yoann Le Bagousse-Pinguet, scientists at INRAE and CNRS, respectively. They crossed the Pyrenees in 2011 to embark on a memorable road trip with other lab members (Drs. José Luis Quero, Enrique Valencia, and Miguel García-Gómez) to assess how biotic interactions and aridity determine the functional structure of semi-arid shrublands sampled along such an aridity gradient. That field trip was the beginning of a fruitful long-term collaboration and friendship that has been reinforced over the years and subsequent visits (both Nicolas and Yoann were postdoctoral researchers in my lab from 2015 to 2017) to the present day (see for instance Gross et al., 2024). But getting back to that paper, for this study we followed a functional trait-based and multiscale approach (from the regional species pool, down to the plant neighborhood scale) to evaluate the relative importance of random processes, abiotic factors and biotic interactions in determining trait distributions of semi-arid Mediterranean communities. We found that the functional structure of the semi-arid communities was clearly non-random, with habitat filtering (HF, trait convergence) and niche differentiation (trait divergence) acting independently on different traits to determine community structure along the aridity gradient studied. At the plant neighborhood scale, the spatial distribution of species was also clearly not random, suggesting that competition and facilitation impacted on the observed changes in the functional diversity of the shrubland communities surveyed. I learned a lot from this study, which uses a very elegant (in my humble opinion) framework and clear hypotheses (see Fig. 1 in Gross et al., 2013) that allowed us to move forward from the examination of patterns to the development of mechanistic trait-based approaches to study plant community assembly.
The tenth article of the virtual issue (Gaitán et al. 2014) also stems from a very enjoyable collaboration with Argentinian colleagues, and derives from the PhD of Juan Gaitán. Juan worked at the time in the Argentinean National Institute of Agriculture and Livestock Technology, and in collaboration with other colleagues from that institution oversaw the MARAS survey, an impressive, standardized survey of vegetation and soil characteristics of more than 400 dryland rangelands across Patagonia (see Oliva et al. 2020 for more details). Juan approached me with the possibility of using the amazing MARAS data for his PhD, and we embarked on a fruitful and very enjoyable collaboration that also took me to Argentina to discover and learn from Patagonian ecosystems, which are some of the most amazing places I’ve had the chance to visit. In Gaitán et al. (2014), we used 311 Patagonian rangelands from the MARAS survey to evaluate the relative importance of climate (temperature and precipitation) and vegetation structure (grass and shrub cover, species richness) as drivers of above-ground net primary productivity (ANPP), precipitation-use efficiency (PUE) and precipitation marginal response (PMR). We used structural equation modelling to show that vegetation structure and climate had similar strengths as drivers of ecosystem functioning across this large environmental gradient. These findings suggested that maintaining and enhancing vegetation cover and species richness, particularly that of grasses, could reduce the adverse effects of climate change on ecosystem functioning in Patagonian rangelands.
I really enjoyed working along the Spanish and Argentinian gradients, which delivered multiple relevant articles and were fundamental to fine tuning field protocols, setting up efficient soil analyses protocols in the lab for processing hundreds of samples, learning about appropriate statistical analyses, and acquiring the skills and logistics needed to manage large-scale surveys, such as those I dreamed of during my days as a PhD student. This objective was a little bit closer when funding from “Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo” in 2006 allowed us to expand the Spanish gradient work using the same field protocols we designed in Spain to drylands from Mexico, Venezuela, Argentina, Chile, and Ecuador. And it became a reality when I was awarded a Starting Grant by the European Research Council in 2009 (the BIOCOM project). This project, and the resources that came with it, allowed us to expand our Spain-Latin American network to become global and conduct the BIOCOM survey, the first ever global field survey focusing on dryland ecosystems. I had the privilege to coordinate this global survey, which involved the survey of 236 drylands from 21 countries using standardized protocols and the collaboration of over 100 scientists, students, and technicians. This survey has produced more than 50 scientific articles in peer-reviewed journals (see the dedicated Google Scholar page of the BIOCOM project for an overview), including several in Journal of Ecology.
In Le Bagousse-Pinguet et al. (2017) we tested the environmental filtering hypothesis, which predicts that the abiotic environment selects species with similar trait values within communities, across global drylands. For doing so we quantified the functional structure and diversity of 124 dryland communities from the BIOCOM survey using the mean, variance, skewness and kurtosis of the distributions of two key plant traits (maximum plant height and specific leaf area, SLA). Precipitation seasonality was the main driver of maximum plant height, and interacted with mean annual temperature and precipitation. Soil pH mediated the filtering effects of climate and sand content on SLA. Our results also revealed that communities characterized by a low variance can also exhibit low kurtosis values, indicating that functionally contrasting species can co-occur even in communities with narrow ranges of trait values. These findings indicated that species with functionally contrasting strategies can still co-occur locally, even under prevailing environmental filtering. I learned a lot working on this paper, which was also important for me because it set the basis for subsequent and more comprehensive assessment of trait functional diversity in drylands (Maestre et al. 2021; Gross et al. 2024) and its role in ecosystem functioning (Le Bagousse-Pinguet et al. 2021).
In the last article of this virtual issue (Ochoa-Hueso et al. 2018) we studied the drivers of the “fertile island” effect across global drylands. Perennial vegetation patches enhance dust capture, intercept water and nutrients from surface run-off after rainfall events and have greater biological activity compared to adjacent areas in drylands, leading to the formation of the so-called fertile islands under them. In this work we aimed to understand the factors controlling the magnitude and variability of these fertile islands across global drylands. The most fertile islands, i.e. those where a higher number of functions were simultaneously enhanced, were found at lower elevation sites with greater soil pH values and sand content under semiarid climates, particularly at locations where the presence of tall woody species with a low-specific leaf area increased fungal abundance beneath plant canopies, the main direct biotic controller of the fertile island effect in the drylands studied. Positive effects of fungal abundance were particularly associated with greater nutrient contents and microbial activity (soil extracellular enzymes) under plant canopies. Our results indicate that the formation of fertile islands in global drylands largely depends on: i) local climatic, topographic and edaphic characteristics, ii) the structure and traits of local plant communities, and iii) soil microbial communities. Finally, our findings suggest that forecasted increases in aridity may enhance the formation of fertile islands in drylands worldwide. I always wanted to work on a paper like this since my early PhD days, when I started to read about fertile islands and their importance in drylands. Doing so in collaboration with colleagues like Raúl Ochoa-Hueso, who did an excellent job leading this work, was a real treat. Revisiting this paper brought back wonderful memories of discussions with Raúl and friends like David Eldridge and Manuel Delgado-Baquerizo about this work in Australia, where I had the opportunity to spend a few amazing months in 2015 working at the Hawkesbury Institute for the Environment and learning more about this very special and unique place that is Australia.
While I am not objective on this issue, I think that this final set of papers nicely illustrates the value of field data and international collaboration, and the important role that observational field studies have for improving our understanding of the natural world. In these times where big data, artificial intelligence, and computational approaches are receiving lots of attention it is important to revendicate the need for and importance of field data from understudied regions. These data are fundamental for addressing some of the most pressing challenges we are facing, such as understanding the impacts of climate change on ecosystems or how to effectively mitigate land degradation and desertification. These challenges are global by nature, so global must be the approaches we follow to study them. And there is no better way of doing global research than by engaging and working with colleagues from all over the world. While challenging and very time-consuming, coordinating global surveys like BIOCOM has not only taken our research to new heights, but undoubtedly has made me a better scientist and to appreciate the challenges that colleagues from developing countries face daily to work. Because one thing is agreeing on the need to fill data gaps from many regions in the Global South and another very different thing is filling them. And surveys like BIOCOM, while far from perfect, can go a long way towards this aim.
Fernando T. Maestre, King Abdullah University of Science and Technology.
Literature cited
Gaitán, J. J., Oliva, G. E., Bran, D. E., Maestre, F. T., Aguiar, M. R., Jobbágy, E. G., Buono, G. G., Ferrante, D., Nakamatsu, V. B., Ciari, G., Salomone, J. M., & Massara, V. (2014). Vegetation structure is as important as climate for explaining ecosystem function across Patagonian rangelands. Journal of Ecology, 102, 1419–1428.
Gross, N., Börger, L., Soriano-Morales, S. I., Le Bagousse-Pinguet, Y., Quero, J. L., García-Gómez, M., Valencia-Gómez, E., & Maestre, F. T. (2013). Uncovering multiscale effects of aridity and biotic interactions on the functional structure of Mediterranean shrublands. Journal of Ecology, 101, 637–649.
Gross, N., Maestre, F. T., Liancourt, P., Berdugo, M., Martin, R., Gozalo, B., Ochoa, V., Delgado-Baquerizo, M., Maire, V., Saiz, H., Soliveres, S., Valencia, E., Eldridge, D. J., Guirado, E., Jabot, F., Asensio, S., Gaitán, J. J., García-Gómez, M., Martínez, P., … Le Bagousse-Pinguet, Y. (2024). Unforeseen plant phenotypic diversity in a dry and grazed world. Nature, 632, 808–814.
Le Bagousse-Pinguet, Y., Gross, N., Maestre, F. T., Maire, V., de Bello, F., Fonseca, C. R., Kattge, J., Valencia, E., Leps, J., & Liancourt, P. (2017). Testing the environmental filtering concept in global drylands. Journal of Ecology, 105, 1058–1069.
Le Bagousse-Pinguet, Y., Gross, N., Saiz, H., Maestre, F. T., Ruiz, S., Dacal, M., Asensio, S., Ochoa, V., Gozalo, B., Cornelissen, J. H. C., Deschamps, L., García, C., Maire, V., Milla, R., Salinas, N., Wang, J., Singh, B. K., & García-Palacios, P. (2021). Functional rarity and evenness are key facets of biodiversity to boost multifunctionality. Proceedings of the National Academy of Sciences, 118, e2019355118.
Maestre, F. T. (2004). On the importance of patch attributes, environmental factors and past human impacts as determinants of perennial plant species richness and diversity in Mediterranean semiarid steppes. Diversity and Distributions, 10, 21–29.
Maestre, F. T., Benito, B. M., Berdugo, M., Concostrina-Zubiri, L., Delgado-Baquerizo, M., Eldridge, D. J., Guirado, E., Gross, N., Kéfi, S., Le Bagousse-Pinguet, Y., Ochoa-Hueso, R., & Soliveres, S. (2021). Biogeography of global drylands. New Phytologist, 231, 540–558.
Maestre, F. T., & Cortina, J. (2004). Insights into Ecosystem Composition and Function in a Sequence of Degraded Semiarid Steppes. Restoration Ecology, 12, 494–502.
Ochoa-Hueso, R., Eldridge, D. J., Delgado-Baquerizo, M., Soliveres, S., Bowker, M. A., Gross, N., Le Bagousse-Pinguet, Y., Quero, J. L., García-Gómez, M., Valencia, E., Arredondo, T., Beinticinco, L., Bran, D., Cea, A., Coaguila, D., Dougill, A. J., Espinosa, C. I., Gaitán, J., Guuroh, R. T., … Maestre, F. T. (2018). Soil fungal abundance and plant functional traits drive fertile island formation in global drylands. Journal of Ecology, 106, 242–253.
Oliva, G., dos Santos, E., Sofía, O., Umaña, F., Massara, V., García Martínez, G., Caruso, C., Cariac, G., Echevarría, D., Fantozzi, A., Butti, L., Bran, D., Gaitán, J., Ferrante, D., Paredes, P., Domínguez, E., & Maestre, F. T. (2020). The MARAS dataset, vegetation and soil characteristics of dryland rangelands across Patagonia. Scientific Data, 7, 327.