indicator species, such as lichens, generally have a ------ tolerance for a -----?

Question

a- narrow, critical factor
b-narrow, number of physical factors
c-broad, number of critical factors
d- average , number of physical factors
e- broad, critical factor

Answer 1

this one's making too much hasty generalization.

lichens have varied tolerances just like your different macroinvertebrates and other organism that are used as biological indicators.

i came across a literature though that said that lichens are more abundant in undisturbed areas thus they must have NARROW tolerance for a CRITICAL FACTOR. most studies focus on Sulfur and Phosphorus as critical factors.

i can be sure of one thing though, in a polluted area, lichen species diversity is low while in unpolluted area, lichen species diversity is high...thus arriving at A.

Answer 2

I would say "C". Lichens are very hardy organisms. They can live on rocks for gods sake. They are very drought resistant, get their minerals leached from the rock and have photosynthetic bacteria that produce their necessary sugars.

Answer 3

a. Lichens area very sensitive to contamination.

Answer 4

Do your own homework.

P.S. It's the obvious answer.