BACKGROUND:

In the previous lab students looked at soils from granite and serpentinite parent rocks.  In this lab students will look at the resulting natural vegetation that grows on each of the soils.  They will see that serpentinite soil does not have much vegetation other than shrub bushes and grass.  Granitic soil, however, can support large trees.  This lab illustrates how important soils are to developing plant  communities and how the plants can adapt to the soil.Gymnosperm  Granitic soil can support the most diverse ecosystems because it supports vegetation that in turn supports the most organisms.  The soil, in a way, selects the ecosystem that it can support.

PROCEDURE:

1. Students should look carefully at the specimens in their packet.   They should describe what they see and state how many different items they see and then have them draw an ecosystem for each type.  In the picture, make sure that they draw more animals that live on vegetation on the granitic soil, especially more birds, rodents, larger mammals, fungi, and more grasses.  The serpentinite soil should have just grass and shrub vegetation with gophers, small rodents, and a few birds.  Tell students to use their imagination.
   

2. Students should also think back to the previous lab and try to figure out what type of soil is more suitable for gymnosperms (pines).  They should be able to realize that gymnosperms prefer acidic soil.  The serpentinite soil produces basic soil, which does not support lush vegetation.
   

3. Make sure students realize that the climate in these two areas are the same, but that sometimes climate is a delineating factor for what can live on a given area.  In this lab, soil is the dominant factor in selecting the ecosystem.