Ecologists investigated the ecological recovery of degraded peat bogs after commercial peat extraction was halted.
They recorded the number of Sphagnum moss species on several regenerating bog sites where extraction had ceased between 2 and 50 years ago. Each regenerating site was compared with a nearby undisturbed, pristine 'control' peat bog.
Because different bog locations naturally support different total numbers of moss species due to baseline microclimates, the ecologists expressed the number of Sphagnum species on each regenerating bog as a percentage of the species count on its paired pristine control bog.
Explain why the ecologists presented their data as percentages of the pristine control bogs rather than using raw species counts.
Sphagnum mosses create unique structural microhabitats, such as hummocks and hollows. Suggest two reasons why an increase in the diversity of Sphagnum moss species on a peat bog leads to an increase in the diversity of invertebrate species.