What did the 1980 mount saint helens volcanic eruptions teach environmental scientists?
planting douglas fir trees was essential to recovering the forests.
many of the initial pioneering species actually survived the eruptions. seeding the slopes was necessary to prevent erosion.
salvage logging was essential to protecting the area from fire and insect threats.

Zoo geographic regions are characterized by the presence of specific groups of animals these regions are determined by the taxonomic or phylogenetic relationships of animals. the map shows the zoogeographic regions proposed by the naturalist alfred russel wallace in 1876. the similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between the organisms in both locations ?

Which of the following forest management practices is best for reestablishing areas of forest?

Are the layers of rock above and below the coal older or younger?