The ease at which materials can be transported across a membrane depends on the membrane permeability. Membrane permeability is basically the ease at which materials are transported across membrane . As we know that upon increasing the viscosity of any fluid it's resistance to deformation increases or it applies a greater resisting force if we try to change the shape of the membrane thus reducing the permeability of the membrane. the increase in cholesterol increases the viscosity of the membrane thus reducing it's permeability.
I think the answer would be lichens, because lichens are formed during primary succession as a pioneer species. During secondary succession, grasses are usually the pioneer species.
