Table 1.

Definitions

Concept	Definition
Boundary clumping	One of the elements of metacommunity structure that describes how the edges of species boundaries are distributed along an environmental gradient
Coherence	One of the elements of metacommunity structure, it is the response of species to an environmental gradient quantified with the number of embedded absences of a species distribution among sites
Environmental filtering	Restriction of species that persist within a community on the basis of their tolerance of the abiotic environment
Host switching	The switching of parasitic organisms to novel hosts
Nestedness	Ranges of species that occupy a smaller portion of the environmental gradient are contained within the ranges of those that occupy a larger portion of the gradient
Niche based processes	Interspecific biotic interactions and abiotic conditions affecting persistence of species in a given community over time
Phylogenetic structure	Phylogenetic relatedness of co-occurring species in time and space
Species turnover	One of the elements of metacommunity structure that describes the number of species replacements along the metacommunity
Spillover transmission	Inter-species transmission from a maintenance host to a non-maintenance host
Spillback transmission	Transmission from a non-maintenance host back into the maintenance host species from which it originated