Functional diversity indices are widely used in ecology to describe communities not only in terms of species diversity, but also including information on the amplitude of different functions and adaptations of community, including the responses to external perturbations and climate change. Nonetheless, so far, studies have applied functional diversity indices using only mean species trait values, often derived from databases and measured in different geographical regions compared to the study area. Freshwater macrophytes generally show very high intraspecific trait variability (ITV) in response to the challenges posed by the aquatic environment. Therefore, for these habitats, the measure of functional diversity indices without accounting for ITV could lead to a significant underestimation of the full functional space occupied by a community. This study aims to evaluate the performance of functional diversity indices on freshwater macrophytes (functional richness, functional evenness and functional divergence) including different levels of ITV. For this purpose, we sampled communities of submerged, floating and emergent macrophytes in six lake systems throughout Italy, collecting leaf functional traits and spectral reflectance traits measured on 3 to 8 individuals per sampling plot. We then compared the results of functional diversity indices calculated using: i) different levels of intra-plot variability; ii) mean trait values in each site; iii) overall mean trait values. With this study, we are able to quantify how much an approach based on ITV could go beyond a classical approach including only overall mean values. Eventually, we wish to promote the integration of ITV to fully understand the role and functioning of macrophyte communities. Towards this, the implementation of spectral traits represents a key step to upscale traits collection, enabling to gain a great amount of information on a vast scale in a relatively short time, offering more robust tools for exploring the spatial-temporal drivers of macrophytes.
Incorporating intraspecific trait variability into functional diversity indices of freshwater macrophyte communities to open new perspectives on the analysis of their dynamics
Alice Dalla Vecchia;Maria Beatrice Castellani;Erika Piaser;Paolo Villa;Rossano Bolpagni
2023
Abstract
Functional diversity indices are widely used in ecology to describe communities not only in terms of species diversity, but also including information on the amplitude of different functions and adaptations of community, including the responses to external perturbations and climate change. Nonetheless, so far, studies have applied functional diversity indices using only mean species trait values, often derived from databases and measured in different geographical regions compared to the study area. Freshwater macrophytes generally show very high intraspecific trait variability (ITV) in response to the challenges posed by the aquatic environment. Therefore, for these habitats, the measure of functional diversity indices without accounting for ITV could lead to a significant underestimation of the full functional space occupied by a community. This study aims to evaluate the performance of functional diversity indices on freshwater macrophytes (functional richness, functional evenness and functional divergence) including different levels of ITV. For this purpose, we sampled communities of submerged, floating and emergent macrophytes in six lake systems throughout Italy, collecting leaf functional traits and spectral reflectance traits measured on 3 to 8 individuals per sampling plot. We then compared the results of functional diversity indices calculated using: i) different levels of intra-plot variability; ii) mean trait values in each site; iii) overall mean trait values. With this study, we are able to quantify how much an approach based on ITV could go beyond a classical approach including only overall mean values. Eventually, we wish to promote the integration of ITV to fully understand the role and functioning of macrophyte communities. Towards this, the implementation of spectral traits represents a key step to upscale traits collection, enabling to gain a great amount of information on a vast scale in a relatively short time, offering more robust tools for exploring the spatial-temporal drivers of macrophytes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
