Abstract
Plants with animal-dispersed fruits seem to overcome the barriers that limit their spread into new habitats more easily than other invasive plants and, at the same time, they pose special difficulties for containment, control or eradication. The effects of animals on plant propagules can be very diverse, with positive, neutral or negative consequences for germination and recruitment. Moreover, the environmental conditions where the seeds are deposited and where the post-dispersal processes take place can be crucial for their fate. Prunus mahaleb is a fleshy-fruited tree invading natural grasslands in the Argentine Pampas. In this study, we analyzed the importance of pulp removal, endocarp scarification and the effects of vectors on its germination response, by means of germination experiments both in the laboratory and under semi-natural conditions. Our laboratory results demonstrated that endocarp scarification enhances germination and suggests that vestiges of pulp on the stones have inhibitory effects. Frugivores exert a variety of effects on germination responses and this variation can be explained by their differing influence on pulp removal and endocarp scarification. Most frugivores produced a positive effect on germination under laboratory conditions, in comparison to intact fruits and hand-peeled stones. We observed different degrees of pulp removal from the surface of the stones by the dispersers which was directly correlated to the germination response. On the other hand, all the treatments showed high germination responses under semi-natural conditions suggesting that post-dispersal processes, like seed burial, and the exposure to natural conditions might exert a positive effect on germination response, attenuating the plant's dependence on the dispersers’ gut treatment. Our results highlight the need to consider the whole seed dispersal process and the value of combining laboratory and field tests.
Highlights
Invasive species constitute a central component of global change, as well as other novel organisms [1]
We evaluate the importance of pulp removal and mechanical and chemical endocarp scarification, analyzing the effects that different vectors have on seed germination and we compare germination responses under different experimental conditions during a two-year-study
Intact fruits did not show any signs of germination and, pulp removal resulted in germination, the hand-peeled stones showed low germination rates demonstrating that the endocarp plays an important role in the dormancy of P. mahaleb seeds
Summary
Invasive species constitute a central component of global change, as well as other novel organisms (range-expanding species, genetically modified organisms, synthetic organisms, emerging pathogens) [1]. Plants with animal-dispersed fruits seem to overcome the barriers that limit their spread into new habitats more than other invasive plants [4,5,6]. Many of these species maintain diffuse interactions with a range of dispersal agents in their native ranges, and the life-history traits associated with this behavior may play a key role for facilitating the establishment of novel dispersal mutualisms in invaded regions [4,7,8,9,10]. A better understanding about the role of generalist frugivores in invasive plant dispersal is crucial for orientating management decisions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
