Interspezifische Interaktionen und globaler Wandel: können ökologische Prozesse aufrecht erhalten werden in Artengemeinschaften mit veränderter Artenzusammensetzung?
Zusammenfassung der Projektergebnisse
I investigated how changes in the diversity and composition of species in local communities affect the diversity and composition of their functional roles. The project consisted of three main parts. The first part was a study on the potential effects of climate-change induced range shifts on the diversity and composition of functional roles in local species communities; the second and third were methodological and involved the development of models for predicting species interactions from traits, and for combining data from species’ Eltonian and Grinellian niches into species distribution models. For the first part, I used a dataset on mutualistic plant-bird interactions from a regional seed-dispersal system in the Peruvian Andes. I modelled the potential future distribution of all frugivorous bird and plant species from the regional species pool based on climatic data. I then tested how this affected their functional diversity. Under several scenarios the models indicated a potential loss of functional diversity, especially at the lower end of the elevational gradient. In several sections of the gradient, functional roles of the species that were predicted to become locally extinct could to some degree be taken over by functionally similar species that were moving in from other communities. In addition, the models predicted potential mismatches in the functional diversity of the interacting species groups (plants and birds) indicating that even if species can shift their ranges, some species might not find suitable interaction partners in the future communities which could affect the local ecological processes. The simultaneous modelling of the potential distributions of interacting species groups is important for the assessment of the effect of future changes on species communities and the maintenance of ecological processes that involve species interactions. The second part of my project involved the advancement of models for predicting species interactions from species traits. Unfortunately, the modelling of future species interactions was less straightforward than I had anticipated. In order to assess if functional roles can be maintained in future species assemblages, some additional explorative studies were necessary. First, I confirmed that trait relationships between interacting bird and plant species (trait matching) that I had identified on the local scale in previous studies were consistent on the continental scale. In another study, I showed that species communities across South America have similar compositions in the functional roles of birds, despite almost complete changes in species composition between the communities. These findings are prerequisites for modelling species interactions based on proxies in species communities with altered species composition. I also developed a new methodological framework that characterizes species’ functional roles in ecological processes via their Eltonian niche. Instead of approximating a species’ functional role by its traits, the role is characterised by the traits of a species’ interaction partners. The new approach allows - for the first time - the inclusion of all species that participate in an ecological process, i.e. across all taxa and independent of their own traits. It also allows the quantification of each species’ contribution to an ecological process. Finally, the framework can be used to include information about both a species’ Eltonian and its Grinnellian niche. The characterization of species functional roles via the traits of their interaction partners presents a shift in perspective for functional diversity research. It will facilitate a new set of studies on species’ functional roles in ecological processes.
Projektbezogene Publikationen (Auswahl)
- (2018) Bringing the Eltonian niche into functional diversity. – Oikos 127: 1711-1723
Dehling DM, Stouffer DB
(Siehe online unter https://doi.org/10.1111/oik.05415) - (2018) Morphological trait matching shapes plant-frugivore networks across the Andes. – Ecography 41: 1910-1919
Bender IMA, Kissling WD, Blendinger PG, Böhning-Gaese K, Hensen I, Kühn I, Muñoz MC, Neuschulz E-L, Nowak L, Quitián M, Saavedra F, Santillán V, Töpfer T, Wiegand T, Dehling DM, Schleuning M
(Siehe online unter https://doi.org/10.1111/ecog.03396) - (2018) Similar functional roles despite high species turnover in plant-bird interactions along the Andes and across the Pacific. New Zealand Ecological Society Conference, Wellington
Dehling DM
- (2019) Projecting consequences of global warming for the functional diversity of fleshy-fruited plants and frugivorous birds along a tropical elevational gradient. – Diversity and Distributions
Nowak L, Kissling WD, Bender IMA, Dehling DM, Böhning-Gaese K, Schleuning M
(Siehe online unter https://doi.org/10.1111/ddi.12946)
