An ecologist wants to investigate how the distribution of a wildflower species changes as soil moisture decreases from a river bank to a dry meadow.
Which of the following describes the most suitable sampling method and the correct reason for its choice?
Systematic sampling using a transect line, because it allows patterns in species distribution to be identified along an environmental gradient.
Random sampling using random coordinates, because it allows patterns in species distribution to be identified along an environmental gradient.
Systematic sampling using a transect line, because it provides a completely unbiased estimate of the total population size of the wildflowers.
Random sampling using random coordinates, because it ensures that areas with very low moisture are ignored during sampling.