Effective dispersal of fern spore and the ecological relevance of zoochory.

The mechanisms of fern dispersal are under-studied and there are few data to support the vectors assumed to drive patterns of sporophyte occurrence and speciation. Although wind is generally the fern spore dispersal vector described in the literature, there has always been competing evidence supporting alternate vectors. Despite this, established patterns of dispersal are generally discussed in the context of wind. The assumptions around wind as a dispersal vector and the possibilities of single-spore establishment have confounded discussions on effective dispersal of fern spore, fern meta-population dynamics, and fern speciation. In this study, I review (i) the importance of spore load across taxa, (ii) evidence for vectors of fern spore, (iii) the environmental tolerances of fern life stages, and (iv) the relevance of, and constraints on, different dispersal vectors in the context of increasingly hazardous landscape matrices. I conclude that whilst wind is an important dispersal vector in non-hazardous landscapes, directed dispersal by an animal vector to isolated safe sites in a hazardous landscape matrix may be key for fern metapopulations and communities.