Theoretical models of plant range expansion require the assumption of occasional long‐distance seed‐dispersal events to explain post‐glacial migration rates. For the many forest herbs whose seeds are dispersed primarily by ants, there are few documented mechanisms of occasional long‐distance dispersal, so models of forest‐herb migration have been largely phenomenological. Here we show that viable seeds of Trillium grandiflorum, an ant‐dispersed forest herb in eastern North America, are dispersed via ingestion and defecation by white‐tailed deer. We also use data from the literature on movement patterns and gut retention times to model a deer‐generated seed shadow, showing that most seeds dispersed by deer should travel at least several hundred meters from parent plants, and occasionally >3 km. Our results provide a mechanism of long‐distance dispersal that has likely contributed to rates of post‐glacial migration and post‐agricultural forest colonization. Corresponding Editor: M. L. Cain

Summary 1The recovery of forest vegetation following abandonment of agriculture was followed by surveying forest herbs in central New York State at 25 sites where postagricultural forest occurred directly adjacent to old-woods (forest that has never been ploughed). 2 The abundance, richness and diversity of 50 forest herbs were on average lower in postagricultural forests than in old-woods. 3 Thirty of 39 forest herbs that were found in at least four stands were less frequent (number of plots present out of 60) in postagricultural forests than in old-woods. Three species ( Aster divaricatus , Dryopteris intermedia and Polystichum acrostichoides ) had significantly higher frequency in old-woods, while none was significantly more common in postagricultural forests. 4 Although differences among species in their frequency in the two forest types were not strongly related to dispersal mode, species with rapid clonal expansion were significantly more frequent in postagricultural stands. 5 Several species that were less frequent in postagricultural forests than in old-woods showed decreases in density in postagricultural forests with increasing distance from the adjacent old-woods.

Summary 0 Samples from 21 hedgerows "c[ 5 m wide\ with full!grown trees# in central New York included 28 forest herb taxa\ comprising nearly 69) of the forest herb taxa found in adjacent forest samples[ 1 We sampled three types of hedgerow[ Two types were attached to forest] remnant hedgerows "n 03#\ and regenerated hedgerows "n 00# that had grown up spon! taneously between open _elds in the last 49 years[ There were no signi_cant di}erences between remnant and regenerated hedgerows in the richness or abundance of forest herbs\ presumably indicating colonization of regenerated hedgerows[ Such colon! ization implies that hedgerows serve a corridor function[ 2 The species composition of forest herbs in hedgerows attached to forest stands showed a strong a.nity with that of the adjacent stand\ both for remnant and regenerated hedgerows[ 3 There was a distance e}ect within hedgerows[ Richness of forest herbs and similarity of composition to forest declined with distance along the hedgerow from forest\ implying colonization from the adjacent attached stand[ 4 The third type of hedgerow sampled\ isolated remnants "n 6#\ was not lower in richness or abundance of forest herbs than hedgerows attached to forest[ Keywords] colonization\ dispersal\ forest restoration\ isolation\ landscape ecology Journal of Ecology "0888# 76\ 119Ð121

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