Authors:S. Burrascano, R. Copiz, E. Del Vico, S. Fagiani, E. Giarrizzo, M. Mei, A. Mortelliti, F. M. Sabatini, and C. Blasi
In recent decades, the European populations of wild boar have grown substantially, as has the impact of this species, owing above all to its rooting activity. Our aim was to investigate the relationships between vascular plant understorey and wild boar rooting intensity. The questions we addressed are: does rooting intensity influence understorey species composition and diversity? Which functional traits are associated with different levels of rooting? We performed a comparative analysis of plant communities in areas with contrasting levels of rooting intensity within a Mediterranean deciduous lowland forest in central Italy. Besides comparing species composition and diversity, we tested the association between species traits and rooting levels through fourth-corner analysis. We found that contrasting levels of rooting were associated to different understorey species composition and evenness, while we observed no significant difference in species richness. In contrast with our expectations, sites with lower rooting returned i) lower evenness values and ii) a higher proportion of species characterized by traits related to resistance or response to herbivory, i.e., spinescence, clonality, endozoochory, underground storage organs, and low height values. Our findings suggest that current vegetation patterns partly depend on the legacy effect of past rooting disturbance, since the areas currently subjected to low rooting intensity were likely to be intensely rooted in the past. These areas may have developed a marked dominance of clonal thorny species that, in turn, inhibited further feeding activities by wild boar.
Authors:X. Li, Y. Nie, X. Song, R. Zhang, and G. Wang
Different components of biodiversity may vary differently since species diversity was considered to be determined by resource availability but functional diversity was related to partitioning of niche space. Moreover, the harsh or benign conditions may result in different niche space partitioning by the coexisting species. For example, in harsh environments niche differentiation may be stronger resulting in higher functional diversity. In this study, we investigate species diversity and functional diversity along a south-to north-facing slope gradient with different resource availability in a sub-alpine meadow. Our results indicate that the patterns of species diversity and functional diversity are not consistent along this gradient. Both species richness and Shannon index of diversity increased, but functional diversity slightly decreased or changed a little from south-to north-facing slope. Moreover, these two components formed a quadratic relationship. Soil water content (SWC) was the limiting resource along this gradient. On one hand, it determined the species diversity; on the other hand, it also influenced functional diversity via affecting niche differentiation and species trait pool. In conclusion, functional diversity was determined by both species richness and niche differentiation with the influence of soil water content.
Environmental changes have been rapidly increasing in the last decades, causing unprecedented shifts in biodiversity. The impacts of biodiversity changes on ecosystem processes depend on the traits of affected species and their functional redundancy at the community level. The generated data on biodiversity-functioning in marine environments are still fragmentary and predictions on how species, communities and ecosystems will respond to the ongoing global changes are still uncertain. This selection of manuscripts presents the efforts of researchers around the world towards a better understanding on the mechanisms driving biodiversity and functioning patterns in marine ecosystems. The issue is composed of studies about first records of diversity and single species patterns in overlooked marine communities, effects of pollution in shaping species composition, foundation species and the impact of their loss on local communities, and the relevance of ecological interactions and species’ traits in structuring marine food webs. We conclude that more field and experimental studies combined to modelling are needed for understanding mechanisms that currently determine the structure and functioning of ecosystems and for improving predictions under global change scenarios.
Wright, I.J. and M. Westoby. 1999. Differences in seedling growth behaviour among species: trait correlations across species, and trait shifts along nutrient compared to rainfall gradients. J. Ecol. 87: 85-97.
Haddad, N.M., M. Holyoak, T.M. Mata, K.F. Davies, B.A. Melbourne and K. Preston. 2008. Speciestraits predict the effects of disturbance and productivity on diversity.