Conservation and restoration studies in fragmented landscapes usually focus on the fragments and less on the surrounding habitat. This surrounding habitat is usually called ‘the matrix’ (remember there is no spoon). Fragments, for instance forest fragments, are seen as islands in a ‘sea’ of uninhabitable matrix, and species richness in fragments is usually explained using the theory of island biogeography.

As I suggested, you don’t need a Breehorn for all island biogeography studies. The theory is also popular on shore. In many of these cases (like in my own bird study in Ethiopia), the matrix is no uninhabitable sea at all, and in recent literature the matrix is gaining more and more attention to explain the diversity of mammals, or birds.

This trend of increasing interest in the matrix has resulted in the increasing popularity of the annoying alliteration ‘(the) matrix matters’. I wonder who coined this term.

The oldest record in Web of Science is an editorial titled Matrix matters" by Libby and Lee about metalloproteinases in the extracellular matrix between cells, published in 2000 in Circulation 102:1874-1876. Cells were also seen as islands and the extracellular matrix as an inert support structure.
In ecology, it first showed up in 2001, in an article by Ricketts in American Naturalist: “The matrix matters: Effective isolation in fragmented landscapes” (American Naturalist 158:87-99).
Between 2003 and 2006, the “matrix matters” was used in the title of four other publications (one letter about seed dispersal, and three publications, about "forest birds, ectomycorrhizal fungi and mobile critters in patches of seagrass respectively).

Are there other popular alliterations in article titles?