In Areas of Permafrost, Stands of Black Spruce Are Frequently

Multiple Choice

In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce often "lean over" (that is, they are displaced from their normal vertical alignment) . Which of the following best explains the unusual growth of these forests in this marginal habitat?

A) Branches are adapted to absorb more carbon dioxide with this displaced alignment.
B) Taproot formation is impossible, so trees developed shallow root beds.
C) Trees are tilted so snow prevents them from breaking or tipping over.
D) Trees tip so that they do not compete with each other for sunlight.