Figure 1. (A) Studies using pollen DNA metabarcoding or related methods to demonstrate proof-of-concept or applied questions in global change ecology (GCE) (n=80). (B) Studies characterized by pollen source (n=80). Bee nests included pollen collected from honeybee hives with a pollen trap (n=20) and pollen provisions taken from solitary cavity nesting bees (n=15). Insects were predominately net or hand collected foraging bees (n=16) but some flies (Syrphidae) (n=7) and moths (n= 3) were also focal subjects. Pollen sourced from bats (n=1), soil (n=1), a glacial core (n=1), and a commercially sourced pollen diet supplement (n=1) were categorized as Other.