Radiodating:
dating of samples or finds by analysing the decay of radioactive elements.

Resilience of an ecosystem:
resilience is the capacity of a system to return to the initial conditions (or to statistically equivalent conditions) after being altered by some disturbance.

Resistance of an ecosystem:
resistance is the capacity of a system to maintain its general conditions during and after a disturbance.

Rio:
internal canal in the city of Venice.

Riparian vegetation:
vegetation situated near the banks of watercourses and lakes. Riparian vegetation regulates the flow of nutrients and the quantity of light available for primary production in the waters.