Most of our research efforts focus on plant communities, on how different plant species coexist together, interact between them and other trophic levels, and how these interactions affect ecosystem functions like productivity, soil nutrient circulation, soil protection and water use, and the associated ecosystem services. Given the expected effects of climate and land-use changes on plant biodiversity we also focus on the mechanism of adaptation and response of plant populations and communities to multiple environmental drivers (e.g. drought, mowing, grazing, fertilization, land-use abandonment etc). We combine extensive field experiments, including long-term research sites, with experiments in greenhouses and growth chambers to assess how species coexistence affect a variety of ecosystem functions.
As a tool to understand the mechanisms regulating species coexistence, adaptation and ecosystem functioning, and generalize results beyond given study systems, we heavily focus on plant functional traits. Functional traits, such as relative growth rate, root depth, resprouting abilities, storage of nutrients, seed size, nitrogen fixing abilities, reflect different strategies of organisms to adapt to local conditions and coexist with other organisms, by sharing or competing for similar resources. Differences in functional traits between organisms (i.e. functional diversity, or functional biodiversity) is thus the ideal interface to assess the links between community assembly and ecosystem service delivery. As a matter of fact, researchers are talking about a “biodiversity revolution” referring to the increasing use of functional traits of species, instead of only species taxonomy, to study how biodiversity affect ecosystems’ health. In this context, we have been dedicating a great deal of attention to develop integrated biodiversity indicators tool to monitor these changes, particularly using the freely available R platform, where we proposed a number of well accepted algorithms. These tools, together with other great tools proposed by other researchers, are freely available here, as the material accompanying our textbook on traits.
At present we are involved in several interrelated projects and, mainly, two research lines.
On one hand we focus on the temporal dynamics of plant communities and their effect on the stability of ecosystem functioning, particularly resistance and resilience to environmental changes. Ecologists have delineated many mechanisms that could maintain biodiversity stability and affect ecosystem resilience or resistance towards environmental changes. These mechanisms (compensation by species asynchrony, dominant species and portfolio effects) have been traditionally attributed to species diversity effects, but evidence is accumulating that they operate through differences in functional traits between species. We propose to test the importance of different stability mechanisms with globally available long-term datasets using permanent plots, regional data from meadow-systems and data from field and greenhouse sowing experiments. The data is being analyzed using a novel framework based on functional traits within and between species, including the development of new measures for species synchrony and functional redundancy. At present a project financed by the Spanish Government (PGC2018-099027-B-I00) is supporting this research line. Previously a project financed by the Czech Grant Agency (GA16-15012S) supported these activities. These projects resulted in producing a large collection of available temporal series of plant communities worldwide, the LOTVS dataset, i.e. Long-Term Vegetation Sampling. Recently, another project financed by the Fundacion Biodiversidad is allowing us to establish a network of permanent plots in the region of the Valencian Community, in 10 natural parks in the region. This network, called BioClima, will allow a regular monitor of different vegetation and habitat types in the region and their response to natural fluctuations and climate change.
Another main research line is on the importance of trait variability within species for coexistence and ecosystem functioning. Intraspecific trait variability can be caused by plasticity, which include also transgenerational parental effects, and by genetic variability. At the interface between genetic and epigenetic effects, transposable elements also cause rapid trait variability adaptation within species. These different causes of intraspecific trait variability represent a crucial research area for our group, because they affect species coexistence and can cause different effects on ecosystem functions, including for stabilizing effects of populations and communities. In several project we collaborate with Vitek Latzel, from the Czech Academy of Sciences, assessing effects of transgenerational plasticity on traits and the consequences for ecosystem functioning. Environmentally induced epigenetic change enables plants to remember past environmental interactions. In another project, coordinated by Lars Gotzenberger, we focus on differentiation between evolutionary relative Carex species and their intraspecific trait variability along abiotic and biotic gradients, particularly competition and productivity. Finally, in collaboration with the University of Tartu, Sirgi Saar is running a post-doc on the effect of intraspecific trait variability in crops, particularly the effect of genetic diversity between rice cultivars, their consequences for phenotypic variability and the effect of creating mixtures of different cultivars to develop weed control in rice cultivations.
