Ecology Exam 5 pt 1

Terrestrial Biomes

defined by their dominant vegetation, it is not always easy to tell where one biome ends and another begins

Dominant Vegetation

defines terrestrial biomes, determined by the average yearly temperature and precipitation

5 Types of Terrestrial Biomes

forest

woodland

shrubland

savanna

temperate grassland

Forests

type of terrestrial biome, dominant vegetation = trees with a closed canopy

deciduous and evergreen trees, photosynthesis and decomposition are inversely related

Deciduous Trees

lose leaves during winter or dry season

Evergreen Trees

drop their leaves slowly so they appear to always be green

How are photosynthesis and decomposition inversely related?

decomposition decreases faster with decreased precipitation and decreased temperature than photosynthesis, meaning there are more nutrients in organic material in high-latitude forests than in tropical forests

Tropical Forests

have nutrient-poor soil because all of the nutrients are tied up in living biomass

4 Types of Forests

tropical

subtropical

temperate

subarctic

3 Types of Tropical Forests

tropical rain forest

tropical moist deciduous forest

tropical dry broadleaf deciduous forest

Tropical Rain Forest

between 10 N and S of the equator, average temp of 30-35 C, average precipitation is 300 cm/year, little variation in temperature and precipitation year round, mosaic of constantly changing vegetation keeping it in dynamic equilibrium, one of the most diverse biomes on the planet

Tropical Rain Forest Stratification

top down: emergent canopy → canopy → lower canopy → shrubs → herbaceous layer → forest floor

each layer has its own collection of animals and microclimate

5 Tropical Rain Forest Plant Adaptations

drip tips

large leaves with holes

buttresses

epiphytes

strangler

Drip Tips

tropical rain forest plant adaptation, extended leaf tips to allow water to run off of the leaves

Large Leaves with Holes

tropical rain forest plant adaptation, lots of space for photosynthesis without risking collecting too much water on the leaves and causing them to rip

Buttresses

tropical rain forest plant adaptation, tree has a wide base to support them in shallow soil, tend to have shallow root systems because the nutrients are mostly in the top few inches of soil

Epiphytes

tropical rain forest plant adaptation, plants growing on plants

Strangler

tropical rain forest plant adaptation, plant that climbs a tree for support and eventually kills the tree

Vertical Stratification of Tropical Rain Forest

top down: nival → alpine → sub-alpine → cloud forest → montane → low land

Cloud Forest

in tropical rain forest, at cloud level, very misty

Tropical Moist Deciduous Forest

dry season and monsoon season, in thailand and india

Monsoon

caused by the ITCZ moving above and below the equator

Tropical Dry Broadleaf Deciduous Forest

in the region 10-20 N and S of the equator, long and hot drought season when trees tend to lose their leaves, common in southern mexico

2 Types of Subtropical Forests

subtropical broadleaf evergreen forest

subtropical coniferous forest

Subtropical Broadleaf Evergreen Forest

mild winters and frequent frost, trees have pneumatophores (knees)

in the caribbean, gulf coast, southern florida, and eucalyptus forest of australia

Subtropical Coniferous Forest

aka southern pines, in south atlantic and gulf states

2 Types of Temperate Forest

temperate deciduous/mixed forest

temperate coniferous forest

Temperate Deciduous/Mixed Forest

warm moist summers and cool winters, in WV and eastern north america, average temperature is 10 C, 75-150 cm/year precipitation, greatest concentration of animals just at or below the forest floor

Vertical Stratification of Temperate Deciduous/Mixed Forest

top down: canopy → lower canopy → shrubs/understory → herbaceous

2 Types of Temperate Coniferous Forest

temperate coniferous rain forest

pine barrens

Temperate Coniferous Rain Forest

type of temperate coniferous forest, in pacific northwest and southern appalachia

Pine Barrens

type of temperate coniferous forest, pines that grow on sand, fire-adapted

found on eastern long island and in southern new jersey

Fire-Adapted

feature of pine barrens, lightning starts small fires that burn off the under shrubs, some plants will not bloom without fire

2 Types of Subarctic Forests

montane forest

taiga

Montane Forest

type of subarctic forest, “mountain forest,” needle-leaf conifers, very little stratification because of the dense canopy, krummholz

rocky mountains, alps

Krummholz

crooked wood found in montane forest, caused by wind

Taiga (Boreal Forest)

type of subarctic forest, dominated by cold continental climate with short moist summers and cold dry winters, permafrost, a new biome formed from ~12,000 year old grasslands for mammoths

canada, russia, northern europe, alaska

Permafrost

permanently frozen ground, found in taiga, decreases soil drainage, chills soil, reduces soil depth, slows decomposition, reduces nutrient availability

Drunken Forest

when permafrost melts, trees fall over

Herbivores Present in Tagia

caribou, moose, porcupine, snowshoe hare, ptaemigans

Carnivores Present in Tagia

wolves, fisher martens, grizzly bears, lynx

Woodlands

terrestrial biome, area of trees with an open canopy, trees are the dominant vegetation, usually occurs in a temperate zone that is too dry to support a closed canopy, transition zone between forest and grassland

Examples of Woodlands

pinon/juniper in southwestern us

oak and sage brush in central valley california and rocky mountains

Type of Woodland

chaparral/mediterranean

Chaparral/Mediterranean

type of woodland, long/hot/dry summers and cool moist winters, lack an understory, low in nutrients, lots of scrub oak, fire-adapted

animals: sage grouse, jackrabbit, coyote, mule deer, rodent

Shrubland

type of terrestrial biome, dominant vegetation is shrubs, patchy environment

Shrub

plant with multiple woody stems and no central trunk, between 4-8 m tall, invest less energy and nutrients in above-ground biomass, shape improves light reception and heat dissipation

3 Types of Shrubland

semiarid

heath land

successional

Semiarid

type of shrubland, temperate and tropical regions, major component of woodland → savanna → grassland → desert, shrubland gradient

in the western us and northern mexico

Heathland

type of shrubland, dominant vegetation is dense growth of ancient primitive plants that are fire-adapted, found in cool temperate regions of northwestern europe

2 Types of Heathland

dry

wet

Dry Heath

type of heathland where the dominant vegetation is heather and gorse

Wet Heath

type of heathland where the dominant vegetation is sphagnum moss

Successional

type of shrubland, in cleared deciduous forests, ephemeral

in northern and western europe, eastern north america

Ephemeral

type of biome that lasts 15-20 years

Savanna

type of terrestrial biome, transitional zone between forest and grassland in tropical areas, relatively flat, low nutrients, warm continental climate, alternating wet and dry seasons, fire-adapted, 50-200 cm/year precipitation

Savanna Plant Characteristics

predominantly grass with occasional shrubs and low trees, highly developed root systems, tend to find horizontal microclimates especially under trees

Savanna Nutrient Cycling and Grazing

ants and termites dominate nutrient cycling of soil

subject to high grazing pressure from vast herds of herbivores and human farming

Savanna Herbivores

zebra, giraffes, water buffalo, wildebeest

Savanna Carnivores

jackal, hyena, lion

Savanna Insects

locust, termites, dung beetle, tsetse fly

Temperate Grassland

type of terrestrial biome, 25-80 cm/year of precipitation, high rate of evaporation, periodic severe droughts, fire and grazer adapted

How has the Earth’s coverage by temperate grasslands changed over time?

used to cover 42% of the surface, but is now down to 12% because of agriculture and overgrazing

Type of Temperate Grassland

domestic

Domestic

type of temperate grassland, created and maintained by human efforts for animal grazing, usually occur in cleared forest areas, has reached climax community in some parts of europe, will revert back to forest if abandoned (eastern us)