The seed dispersal effectiveness (SDE) framework provides a mechanistic
approach to evaluate evolutionary and ecological characteristics of
animal-mediated seed dispersal, by synthesising the quantity and the
quality of the dispersal that a plant species receives from each of its
animal dispersers. However, the application of the SDE framework has
been largely restricted to plant–frugivore interactions, whereas
animal-mediated seed dispersal results from plant–disperser interactions
that cover a continuum from pure mutualisms to antagonisms.
In the article "A seed dispersal effectiveness framework across the mutualism–antagonism continuum", recently published in Oikos, an international team of researchers (including Nacho Villar and Luis Santamaría from the SEG) propose an extended SDE framework aiming at including plant–disperser interactions in the full mutualism–antagonism
continuum, ranging from pure mutualisms (frugivores) to conditional
mutualisms (scatter-hoarding granivores and folivores) and antagonisms
(pure granivores).
Examples used to
illustrate how it can be applied to compare effectiveness among
plant–disperser interaction types indicate that vertebrate species differ more in the
number of seeds they deposit away from the mother plant (quantity), than
in the effects such dispersal processes have on seed fate (quality).
Scatter-hoarding granivores provide the most effective dispersal due to
high removal rates, closely followed by frugivores due to high
deposition rates. Folivores and pure granivores provide low quantity
dispersal, but of high and moderate quality, respectively. These early
comparative insights illustrate the necessity and usefulness of more
standardized data collection protocols, for which we provide
recommendations.
Applying the eSDE framework can reveal broad-scale
patterns across and within plant–disperser interaction types, which will
advance our evolutionary understanding of plant–animal interactions.
This will provide new insights into the consequence of anthropogenic
impacts on vertebrate-mediated seed dispersal in a world in which
plant–animal interactions are increasingly threatened.
Reference: van Leeuwen, C.H.A., Villar, N., Mendoza Sagrera, I., Green, A.J.,
Bakker, E.S., Soons, M.B., Galetti, M., Jansen, P.A., Nolet, B.A. and
Santamaría, L. (2022), A seed dispersal effectiveness framework across
the mutualism–antagonism continuum. Oikos e09254. https://doi.org/10.1111/oik.09254