BIO 176: Exam 2 - Boreal Forest

Soils

Completely glaciated 10000 ybp Moist ,acidic, low nutrient soils Drainage varies widely, from saturated to well-drained

Black spruce communities

In colder, wetter sites. Moss carpet ground cover common Less diverse

The boreal forest is characterized by all of the following except: -- low diversity -- sharp transitions between habitat types -- dominated by conifers, mosses and lichens. -- includes different habitat types -- the boreal forest is characterized by cold temperatures

sharp transitions between habitat types

Boreal forests are how much more or less productive than temperate deciduous forests? [Use a previous chapter to find this answer.] -- 1/4 -- 1/2 -- 1 -- 1 1/2

1/2

Select the incorrect statement about boreal forests. -- Black spruce communities often have carpets of moss over large areas of their understories -- White spruce tend to dominate drier sites. -- White spruce communities tend to have more shrubs than black spruce communities -- Black spruce communities tend to have higher diversity

Black spruce communities tend to have higher diversity

Closed forests

Black spruce, white spruce, balsam fir (Picea mariana, Picea glauca, Abies balsamea) Mosses Shrubs and perennial herbs

Vegetation overall characteristics

Four layers, short (< 50′) Low tree diversity; high moss diversity Spruce (White=dry sites, Black=wet sites) Seral birches and aspen

Important determinants of boreal soils include all of the following except, [Rely on your understanding of past lectures to answer this question.] -- The acidity of soils helps slow decomposition -- Build up of organic matter helps create acid soils -- High moisture helps create acid soils -- Cold temperatures slow decomposition even more than they slow plant growth -- High productivity of boreal forests helps create a build up of organic matter

High productivity of boreal forests helps create a build up of organic matter

Fauna

Lynx Snowshoe hare Connecticut Warbler Great grey owl Northern hawk owl Lincoln's sparrow White-throated sparrow Hermit thrush

Why do spruces and firs dominate the boreal forest?

Spruces and firs have specific traits that allow them to tolerate the severe conditions in the boreal forest biome: -- Embolism-resistant, andrupture-resistant tracheids (extreme low temperature) -- Long-lived leaves (low nutrient soils) -- Sunken stomates, thick bark (low precipitation or frozen soils)

White spruce communities

In warmer, drier sites Mixed shrub, herb, moss understory common More diverse

Distribution

South of the arctic tundra North of deciduous forest, central grasslands, and montane and coastal forests Spans all longitudes

Disturbances - Insect outbreaks

Spruce bark beetle and spruce budworm

The boreal forest is bounded by all of the following except: -- Tundra, to the south -- Atlantic Ocean, to the east -- Rocky Mountains (in part), to the west -- No answer text provided

Tundra, to the south

Bogs

Wetland that accumulates peat, a deposit of dead plant material—often mosses