Lecture 18: Chapter 18- Terrestrial Ecosystems Flashcards
Know the distribution and dominant plant life forms and soils of the world’s 8 major biomes
Be able to rank the biomes in terms of climate (MAT, MAP, seasonality) and plant productivity
*Humid tropical- tropical rainforest, savanna
*Dry-desert, grassland
*Moist subtropical mid latitude- warm temperate deciduous/ coniferous forest, mediterranean
*Moist continental-cool temperate deciduous/ coniferous forest, boreal forest
*Polar-tundra
Discuss why biomes are also known as “potential natural vegetation” and discuss typical land usage in each biome
Major biogeographical realms
Oceania
Nearctic
Neotropic
Paleartic
Afrotropic
Antarctic
Indo-Malay
Australiasia
Indo-malay
python- non venomous and kills prey with constriction
Main plants used to classify biomes
trees, shrubs, grasses (graminoids)
Graminoids
maintain a higher proportion of biomass in photosynthetic tissue (leaves) because little energy is required for support tissues (stems)
Shrubs
invest fewer resources in stems and other supporting structures than trees
Trees
woody tissue allows for increased height and access to light, but increase cost (maintenance respiration)
8 major terrestrial biomes
Forests (tropical, temperate, confier/boreal)
shrublands
tundra
desert
tropical savanna
temperate grasslands
Require 1000 mm of precipitation a year
forests
In terms of precipitation, ranks grassland, savanna, and forest
grassland<savanna< forest
trees require more water than shrubs and grasses
Arctic Tundra
-tundra is a frozen plain that is located at the highest latitudes of the Northern Hemisphere
-climate is very cold with long and cold winters. growing season 2-5 months.
-presence of permafrost (Gelisols): chills the soil, diminished soil aeration, and slows plant growth
-have an active layer (surface layer) that thaws and freezes seasonally -> creates patterned ground like polygons
*few species and slow growth. taller plants not supported
Conifer forests
-cool temperate (mountain ranges) and boreal zones
-dominated by needle-leaf evergreen trees
-cool wet summer and cold winter
-boreal forests typically cover formerly glaciated land
Temperate forests
-temperate climate
-more than 1000 mm precipitation per year
-longer growing season than boreal forest
-warmer summer
-broad leaf deciduous and evergreen
-ultisols, inceptisols, and alfisols
Temperate forests
-temperate climate
-more than 1000 mm precipitation per year
-longer growing season than boreal forest
-warmer summer
-broad leaf deciduous and evergreen
-ultisols, inceptisols, and alfisols
Temperate grasslands
-grazing and human activities can suppress plant growth
-occur in midlatitudes in midcontinental regions where annual precipitation is reduced as air masses move inland
Deserts
-low infrequent moisture
-arid regions
-25-35% of earths landmass
-rain shadow of mountains or far inland
-aridisols and entisols
Temperate shrublands
-hot dry summers and cool moist winters
-fire
-xeric broadleaf evergreen shrubs
-dwarf trees
-herbaceous understory
-eg. chaparral California
-adaptations of shrubland: drought resistance thick leaves to minimize respiration
-alfisols and entisols
tropical savannas
-two layer vertical structure with grasses on the understory and trees and shrubs
-fire adapted vegetation
-woody vegetation is short lived (several decades)
-oxisols, entisols, and alfisols
tropical forests
-broadleaf evergreen plants with complex multi story canopy (lianas, epiphytes, strangler figs)
-high diversity of plant and animal life
-high productivity
-6% land surface
-home to many primates
-most life takes place in the canopy NOT the understory
-oxisols and ultisols
