A physical geographer is preparing to take soil samples from an area that is 35% marshland. She suspects that environmental degradation is most severe in the marshland portion of the study area, so she wants to ensure that area is oversampled, and the non-marshland area under sampled.

(a) What type of spatial point sampling should she apply? (2')

(b) If she aimed to collect 200 samples, how many samples can she collect from the marshland area and the non-marshland area, respectively, using this sampling approach? Provide the procedures for your calculation. (4')