Chapter 23: Terrestrial Ecosystems Flashcards
Major regional ecological community of plants and animals;
Usually corresponds to plant ecologists’ and European ecologists’ classification of plant formations and life zones
biomes
Of leaves, shed during a certain season (winter in temperate regions; dry season in the tropics);
Of trees, having deciduous parts
deciduous
Applied to trees and shrubs for which there is no complete seasonal loss of leaves;
2 types:
- Broadleaf
- Needle-leaf
evergreen
Plant-like outgrowths developed by many large trees;
They function as prop roots to support trees rooted in shallow soil that offer poor anchorage
buttresses
tropical forest
Its types are classified by seasonality of rainfall:
- Tropical rain forests, which have high seasonal rainfall and are dominated by broadleaf evergreen trees
- Dry tropical forests, which have varying lengths of dry season and are dominated by drought-deciduous trees
tropical rain forest vertical stratification
From top to bottom:
- Emergent canopy
- Upper canopy
- Lower canopy
- Understory
- Ground cover
Tropical rain forest vertical layer that includes trees widely spaced
30 or more meters aboveground
emergent canopy
Tropical rain forest vertical layer that includes medium-spaced crowns
About 15 to 30 meters aboveground
upper canopy
Tropical rain forest vertical layer that includes low trees
About 5 to 15 meters aboveground
lower canopy
Tropical rain forest vertical layer that includes shrubs and saplings
About 1 to 5 meters aboveground
understory
Tropical rain forest vertical layer that includes herbs and ferns
About 0 to 1 meters aboveground
ground cover
A broad category of forests found between the tropical and subtropical regions and the barren, treeless lands of the far north and extreme south
temperate forest
3 main categories of temperate forest
- Coniferous forests
- Mixed broadleaved/coniferous forests
- Broadleaved forests
Forest dominated by needle-leaf evergreen trees and found primarily in a broad circumpolar belt across the Northern Hemisphere and on mountain ranges, where low temperatures limit the growing season to a few months each year;
The largest expanse of this type of forest is the boreal forest, or taiga
conifer forest
The northern circumpolar boreal forest;
The largest biome on Earth;
Characterized by a cold continental climate, consists of 4 major zones:
- Forest ecotone
- Open boreal woodland
- Main boreal forest
- Boreal-mixed forest ecotone
taiga
A biome characterized by semiarid regions with seasonal rainfall;
Has tall grasses and occasional trees
tropical savanna
This climate has recurring drought, and much of the diversity of vegetation cover reflects differences;
At its worst where precipitation is lowest and the temperatures are high
temperate grassland
3 main types of the native grasslands of North America, influenced by declining precipitation from east to west, distinguished by the height of the dominant species
- Tallgrass prairie
- Mixed-grass prairie
- Shortgrass prairie
A narrow belt of tall grasses dominated by big bluestem that once ran north and south adjacent to the deciduous forest of eastern North America;
Presence maintained by fire;
Largely destroyed by cultivation
tallgrass prairie
Grassland in mid North America, characterized by great variation in precipitation and a mixture of largely cool-season shortgrass and tallgrass species
mixed-grass prairie
Westernmost grasslands of the Great Plains, characterized by infrequent rainfall, low humidity, and high winds;
Dominated by shallow-rooted, sod-forming grasses
shortgrass prairie
Name given to Eurasian grasslands that extend from eastern Europe to western Siberia and China
steppe
Extensive grasslands in the east of the interior of South Africa, largely confined to high terrain
veld
Temperate South American grassland, dominated by bunchgrasses;
Much of the moister ones are under cultivation
pampas
Dominated by evergreen shrubs and sclerophyll trees, this biome has adapted to the distinctive climate of summer drought and cool, moist winters;
The shrublands are fire-adapted and highly flammable
mediterranean or chaparral
Describes vegetation that possesses small leaves, thickened cuticles, glandular hairs, and sunken stomata — all characteristics that function to reduce water loss during the hot, dry summer period;
This type of vegetation is found in all five regions of the mediterranean ecosystems
sclerophyllous
Area in an arctic or alpine (high mountain) region, characterized by bare ground, absence of trees, and growth of mosses, lichens, sedges, forbs, and low shrubs
tundra
A type of ecosystem that results from dry descending air masses within the regions between 15 degrees N and 30 degrees S latitude, the rain shadows of coastal mountain ranges, and remoteness from oceanic moisture
desert
4 broad types of desert
- Hot
- Cold
- Extreme
- Semidesert
This type of desert ranges from those lacking vegetation to ones with some combination of chenopods, dwarf shrubs, and succulents
Ex: Mojave Desert
Hot desert
A desert that has a continental climate, with warm summers and prolonged cold winters;
Its vegetation falls into 2 main associations:
- Sagebrush
- Shadscale
Ex: Gobi Desert
Cold desert
A climate characterized by long winters and short, cool-to-mild summers;
Also called subarctic climate
boreal
A climate characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant and animal life
arid
Permanently frozen soil in arctic regions
permafrost
Forest harvesting procedure in which all trees on the site are cut and removed
clear-cutting
extent of deforestation since Pleistocene
Globally, about half of the forest that was present under modern (post-Pleistocene) climatic conditions — and before the spread of human influence — has disappeared largely through the impact of human activities
