One example of imbibition in nature is the absorption of water by hydrophilic colloids.  Matrix potential contributes significantly to water in such substances. Dry seeds germinate in part by imbibition. Imbibition can also control circadian rhythms in Arabidopsis thaliana and (probably) other plants. The Amott test employs imbibition.
Proteins have high imbibition capacities, so proteinaceous pea seeds swell more than starchy wheat seeds.
Imbibition of water increases imbibant volume, which results in imbibitional pressure (IP). The magnitude of such pressure  can be demonstrated by the splitting of rocks by inserting dry wooden stalks in their crevices and soaking them in water, a technique used by early Egyptians to cleave stone blocks.
Skin grafts (split thickness and full thickness) receive oxygenation and nutrition via imbibition, maintaining cellular viability until the processes of inosculation and revascularisation have re-established a new blood supply within these tissues.