Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA.
Seed dispersal by a frugivorous marsupial shapes the spatial scale of a mistletoe population
Article first published online: 13 JAN 2009
© 2009 The Authors. Journal compilation © 2009 British Ecological Society
Journal of Ecology
Volume 97, Issue 2, pages 217–229, March 2009
How to Cite
García, D., Rodríguez-Cabal, M. A. and Amico, G. C. (2009), Seed dispersal by a frugivorous marsupial shapes the spatial scale of a mistletoe population. Journal of Ecology, 97: 217–229. doi: 10.1111/j.1365-2745.2008.01470.x
- Issue published online: 11 FEB 2009
- Article first published online: 13 JAN 2009
- Received 19 May 2008; accepted 24 November 2008; Handling Editor: Richard Bardgett
- Dromiciops gliroides;
- fruit resource tracking;
- principal coordinates analysis of neighbour matrices;
- spatial patchiness;
- southern Argentina;
- Tristerix corymbosus
- 1Seed dispersal is considered critical for shaping the spatial structure of plant populations, though little empirical effort has been made to interpret this effect in terms of the scale at which plant species are distributed and cope with environmental heterogeneity. We assessed the spatial role of seed dispersal in Tristerix corymbosus, a mistletoe dispersed exclusively in the temperate forests of Patagonia by the endemic marsupial Dromiciops gliroides.
- 2We examined how fruit resource tracking and seed dispersal by the marsupial affects mistletoe recruitment, employing a spatially explicit approach aimed at breaking down the spatial structure of the mistletoe and marsupial populations at different scales.
- 3In a single fruiting season, we evaluated the abundance of mistletoe fruits, adult plants, dispersed seeds and recruits (seedlings and saplings), as well as the abundance of marsupials, along a 1500-m linear transect.
- 4Both mistletoe and marsupial abundances were distributed hierarchically in space, with large patches containing smaller ones. Marsupial patchiness matched that of mistletoe fruits, at least at a broad scale within the transect. Marsupial abundance also varied at a large-scale, being conditioned by habitat features and decreasing progressively along the transect. Mistletoe seed rain accounted for the patchiness of adult plants and fruits, and for the large-scale pattern of marsupial activity. The spatial pattern of mistletoe recruitment closely matched seed rain.
- 5Synthesis. Seed dispersal by marsupials shaped the scale of mistletoe recruitment in two ways. First, marsupials created a spatial match between mistletoe adults and recruits as a result of fruit resource tracking. Second, they generated patchiness in mistletoe offspring at a larger scale than in adults. Dispersal process performed as a strong demographic filter capable of changing the mistletoe spatial structure from adults to recruits, despite a low frequency of far-from-adult dispersal events. Similar effects of scale shaping by seed dispersers may be generalized among plants in which there is a sharp spatial match between fruits and frugivores, and whose dispersed seeds have a higher probability of recruiting than undispersed ones.