DSpace Collection:
http://hdl.handle.net/10261/310
2024-03-28T13:38:59ZTrait-based approaches as ecological time machines: Developing tools for reconstructing long-term variation in ecosystems
http://hdl.handle.net/10261/350955
Título: Trait-based approaches as ecological time machines: Developing tools for reconstructing long-term variation in ecosystems
Autor: Brown, Kerry A.; Bunting, M. Jane; Carvalho, Fabio; de Bello, Francesco; Mander, Luke; Marcisz, Katarzyna; Mottl, Ondrej; Reitalu, Triin; Svenning, Jens-Christian
Resumen: Research over the past decade has shown that quantifying spatial variation in ecosystem properties is an effective approach to investigating the effects of environmental change on ecosystems. Yet, current consensus among scientists is that we need a better understanding of short- and long-term (temporal) variation in ecosystem properties to plan effective ecosystem management and predict future ecologies.
Trait-based approaches can be used to reconstruct ecosystem properties from long-term ecological records and contribute significantly to developing understandings of ecosystem change over decadal to millennial time-scales.
Here, we synthesise current trait-based approaches and explore how organisms' functional traits (FTs) can be scaled across time and space. We propose a framework for reconstructing long-term variation in ecosystems by means of analysing FTs derived from palaeoecological datasets. We then summarise challenges that must be overcome to reconcile trait-based approaches with palaeo-datasets. Finally, we discuss the benefits and limitations of trait-based reconstructions of ecosystem temporal dynamics and suggest future directions for research.
Reconstructing environmental properties through time vis-à-vis FTs can be separated into two parts. The first is to record trait data for organisms present in modern ecosystems, and the second is to reconstruct temporal variability in FTs from palaeoecological datasets, capturing changes in trait composition over time. Translating palaeoecological datasets into FTs is challenging due to taphonomic, taxonomic and chronological uncertainties, as well as uniformitarian assumptions. Explicitly identifying and addressing these challenges is important to effectively calculate changes in FT through time.
Palaeo-trait research offers insights into questions related to short- and long-term ecosystem functioning, environmental change and extinction and community assembly rules across time. As work in this area matures, we expect that trait-based approaches integrating palaeoecology and neo-ecology will improve understanding of past ecologies and provide a deeper insight of their implications for present-day and future ecosystem management and conservation.2024-03-19T11:53:50ZSex-driven neighborhood effects on herbivory in the dioecious Mediterranean palm Chamaerops humilis L.
http://hdl.handle.net/10261/350923
Título: Sex-driven neighborhood effects on herbivory in the dioecious Mediterranean palm Chamaerops humilis L.
Autor: Muñoz-Gallego, Raquel; Wiegand, T.; Traveset, Anna; Fedriani, José M.
Resumen: Although it is well recognized that the strength of plant–herbivore interactions can vary with the plant sex, the distance, and the density of conspecific neighbors, no study has yet assessed their combined influence. Here, we filled this knowledge gap by focusing on the dioecious palm Chamaerops humilis L., and its two main herbivores, the invasive moth Paysandisia archon Burmeister and the feral goat Capra hircus L. We evaluated levels and spatial patterns of herbivory, as well as those of plant size and number of inflorescences in two palm populations in Mallorca (Balearic Islands, Spain). Our spatial point pattern analyses revealed that palms not affected by moth herbivory or goat florivory were spatially aggregated, goats fed more strongly upon inflorescences in palms with more neighbors, but they consumed more leaves in isolated palms. Interestingly, we could reveal for the first time that plant sex is a key plant trait modulating neighborhood effects. For instance, whereas aggregated female palms experienced lower intensity of goat florivory than isolated ones, male palms showed the opposite pattern. Palm size and number of inflorescences also showed sex-related differences, suggesting that sexual dimorphism is a key driver of the observed neighborhood effects on herbivory. Our study highlights the importance of considering relevant plant traits such as sex when investigating plant neighborhood effects, calling for further research to fully understand the dynamics governing plant–herbivore interactions in dioecious systems.2024-03-19T10:34:37ZSeedling responses to moderate and severe herbivory: a field-clipping experiment with a keystone Mediterranean palm
http://hdl.handle.net/10261/350878
Título: Seedling responses to moderate and severe herbivory: a field-clipping experiment with a keystone Mediterranean palm
Autor: Garrote, Pedro J.; Bugalho, Miguel N.; Fedriani, José M.
Resumen: Plant–ungulate interactions are critical in shaping the structure of Mediterranean plant communities. Nevertheless, there is a dearth of knowledge on how plant intrinsic and extrinsic factors mediate the sign and strength of plant–ungulate interactions. This is most relevant when addressing natural or assisted restoration of plant communities in human-disturbed areas.
We conducted field-clipping experiments simulating how different intensities of ungulate herbivory may affect the natural regeneration and establishment of the Mediterranean dwarf palm (Chamaerops humilis), a keystone species in Mediterranean ecosystems. We quantified seedling survival and size in two human-disturbed sites (SW Spain) where wild and domestic ungulates exert high herbivory pressure on vegetation.
Severe clipping and seedling aging reduced rates of seedling survival. In contrast, moderate clipping did not affect seedling survival, suggesting a certain degree of C. humilis tolerance to herbivory. Severe clipping reduced seedling height strongly but not seedling diameter, and these effects seem to have decreased seedling survival. Nurse shrubs increased seedling size, which likely improved seedling survival. We also found seedling compensatory growth which varied between study sites.
Field-clipping experiments can help disentangle effects of plant extrinsic and intrinsic factors on the sign and strength of plant–ungulate interactions and their ecological consequences on the dynamics of human-disturbed ecosystems. We call attention to the importance of appropriately managing scenarios of severe herbivory and summer droughts, particularly frequent in Mediterranean ecosystems, as synergic effects of such key drivers can negatively affect the structure and dynamics of plant communities and endanger their conservation.2024-03-19T08:33:23ZSeed dispersal effectiveness in fragmented and defaunated landscapes
http://hdl.handle.net/10261/350861
Título: Seed dispersal effectiveness in fragmented and defaunated landscapes
Autor: Fedriani, José M.; Wiegand, T.; Garrote, Pedro J.; Leiva, María José; Ayllón, Daniel
Resumen: Landscape fragmentation and defaunation have major impacts on plant dispersal and dynamics. However, whether the impact of such perturbations on seed dispersal and recruitment change in sign and strength across habitats and spatial scales, and whether they amplify or buffer each other, remains largely unknown. To evaluate, for the first time, the joint impact of fragmentation and defaunation on seed dispersal effectiveness (SDE) across spatial scales (e.g., short- and long-distance seed dispersal), we utilized the long-term field data of a mammal-dispersed tree (Pyrus bourgaeana) in a spatially explicit individual-based model. By means of simulation experiments, we evaluated the effects of different levels of landscape fragmentation and defaunation on SDE and tree recruitment. Our simulation results revealed that the direction and magnitude of the fragmentation effect on SDE depended on its strength (mild, severe) and the spatial scale considered. Severe fragmentation decreased SDE for short- and intermediate-distance seed dispersal. Interestingly, mild and severe fragmentation increased SDE of long-distance seed dispersal, suggesting a positive effect of such perturbations (i.e., an increase in the proportion of successful long-distance dispersal events). Though defaunation had a consistently negative effect on overall SDE, its magnitude was highly species- and spatial–scale-dependent. The impact of defaunation on seed dispersal distance was also species-specific: the proportion of long-distance dispersal increased under total badger (Meles meles) defaunation but decreased under total fox (Vulpes vulpes) defaunation. A pervasive integration of seed dispersal distance into the SDE framework is essential to most comprehensively understand the scale-dependent nature of human activity impacts on plant dynamics. In the long term, strong perturbations (landscape fragmentation and defaunation) could select either for or against long-distance seed dispersal, altering in different ways the ability of plants to cope with climate change.2024-03-19T08:01:35Z