lichens are found to be very sensitive to the levels of contaminants like Sulphur dioxide in air.They can commonly be found growing on barks of trees as a thin greenish white crust.
a)What is the difference between the lichen on trees near busy roads and trees some distance away?
b)On the trees near roads, compare the incidence of lichen on the side facing the road and on the side away from the road
2007-01-27 00:46:49 · 2 answers · asked by Shruti G 1 in Science & Mathematics ➔ Biology
Well what you would expect is that there would be more lichen growing on trees farther from the busy road, since there would be less pollution. The pollution by the road would kill off any lichen that would want to grow.
As for the second part, I don't think there would be a difference on one side of the tree. If pollutants like sulphur dioxide are in the air, then they would be able to go around the whole tree and affect any lichen on both sides - but maybe you should go out and look at a tree to be sure.
2007-01-27 01:05:45 · answer #1 · answered by citrus punch 4 · 0⤊ 0⤋
BE cautious with b).
The direction of sunlight may be as important as the direction of the road. Don';t be confused by coincidence.
2007-01-27 01:27:35 · answer #2 · answered by Jerry P 6 · 0⤊ 0⤋