Biogeography Exam 4

Terrestrial Biomes

T/F: terrestrial biomes are the origination of biogeography.

True

What are the main 3 defining factors of terrestrial biomes?

Temperature, precipitation, and plant community (vegetation)

What are some of the general patterns of terrestrial biomes?

• latitude and altitude gradients

• coastal to continental gradients

• mountain rain shadows (wet and dry sides, orographic precipitation)

• seasonal changes ( wet-dry, cold-hot) vs continuous conditions

What are some general terms used to describe the flora of terrestrial biomes?

deciduous vs evergreen

coniferous vs broadleaf

growth forms/plant types

• tree vs shrub

• grass vs fern

• moss vs club moss

• epiphytes vs vines vs lianas

Where are tropical rainforests located?

0°-15° north and south latitude

50% in South America, 30% in SE Asia, 20% in Central Africa

What is the temperature like in tropical rainforests?

25°-30° C avg

very little variation throughout year - continuous

Describe the precipitation trends of the tropical rainforest.

250-500 cm rainfall

wet summer season, semidry winter season

What kind of soil is found in tropical rainforests?

highly leached clay soils with low nutrients

• tight nutrient cycling held in biomass

high Fe (iron) content

What kind of trees are present in the strata of tropical rainforests?

broadleaf evergreen trees

How many strata is the vegetation of the tropical rainforest divided into?

5 (A-E)

Describe strata A of a tropical rainforest.

supercanopy:

few tall isolated trees

50-70m tall

Describe strata B of the tropical rainforest.

main canopy:

trees form continuous cover

20-40 m tall, smaller narrow leaves

arboreal 3D habitat - “city in the trees”

biologists and tourists - platforms, climbing

What are the characteristics of strata C of tropical rainforests.

subcanopy:

immature canopy trees and subdominant trees

10-20 m tall

patchy, under thinner canopy sections

slightly larger narrow leaves

Describe strata D in the tropical rainforest.

lower/under story:

immature trees, palms, tree ferns, light break species

5-10 m tall

diversity of leaf shapes

very patchy near light breaks

What are the characteristics of strata E in tropical rainforests.

ground story:

tree seedlings, ferns & shrubs, club mosses & mosses

large leaves with drip tips

fungi and decomp of leaf litter

Why do plants in the ground story (strata E) of tropical rainforests have drip tips?

to prevent moss/algae growth

How much photosynthetic light makes it under the canopy to the ground story (strata E) of tropical rainforests.

~1-3% of photosynthetic light

Which terrestrial biome has the highest diversity of plants and animals?

tropical rainforest (>80% of terrestrial species)

What percentage of terrestrial species inhabit tropical rainforests?

>80%

Provide examples of tree modifications/specializations regarding leaves and roots in the tropical rainforest.

leaves: drip tips, leaf size/shape

roots: buttresses and stilt roots, adventitious roots

What are examples of epiphyte modifications associated with tropical rainforests.

orchids, ferns, bromeliads

lianas and vines - form strata highways

• strangler figs

Describe adventitious roots found in the tropical rainforest.

grow on top of branches - in the rainforest, the best soil is on top of branches

There is a high degree of symbiosis in the tropical rainforest. Provide examples of pollinators associated with this biome.

insects, hummingbirds, bats, monkeys

specializations: wasp-fig, wasp-orchid

What are examples of seed dispersal related symbiosis in the tropical rainforest.

insects, birds, mammals

drop, gut passage

Provide examples of habitat symbiosis in tropical rainforests.

ant-acacia

sloth-algae

bromeliads-frogs

River and cave systems play an important role in tropical rainforests. What is the interface between river and rainforest called?

riparian interface/ecosystem

What are some problems faced by the tropical rainforest biome?

logging, ranching, farming, settlement, roads

example of past recovery - Maya in Central America

How much of the tropical rainforest biome is left, and how much is cleared each year?

~33% left with ~1% cleared per year

Where are tropical seasonal forests located? what biome do they border?

15°-20° north and south latitude

small biome

they border tropical rainforests in a narrow band

What is the average temperature of the tropical seasonal forest biome?

20°-25° C

small variation over the year

Describe the precipitation patterns of tropical seasonal forests?

150-250 cm rainfall

wet summer, dry winter

Describe the soil of tropical seasonal forests.

leached clay soils with low nutrients

• tight nutrient cycling held in biomass

high Fe (iron) content

Describe the vegetation of tropical seasonal forests. How many strata are there?

mixed deciduous and evergreen, broadleaf trees

3 strata

Describe the canopy of the Tropical Seasonal Forest.

trees forming broken cover

20-30 m tall

Describe the lower story of Tropical Seasonal Forests.

immature trees and palms

5-10 m tall

What makes up the ground story of Tropical Seasonal Forests?

tree seedlings and shrubs

<5 m

Describe the plant and animal diversity of Tropical Seasonal Forests.

medium plant diversity

high animal diversity - from rainforest

How much of the Tropical Seasonal Forest biome is left? What problems does this biome face?

~15% left

settlement and roads

Where are Tropical Coniferous Forests located? What biomes does it border?

15°-20° north and south latitude

border rain/seasonal forests in narrow bands

What is the average temperature of the Tropical Coniferous Forest biome?

20°-25° C average temperature

small variation over year

Describe the precipitation associated with Tropical Coniferous Forests.

150-250 cm rainfall

wet summer, dry winter

What is the primary difference between Tropical Coniferous Forests and Tropical Seasonal Forests?

Tropical Coniferous Forests have different soil and may be at a higher altitude.

What type of soil is associated with Tropical Coniferous Forests?

slightly sandy soils, mixed clay-sand

may be higher altitude - ridges

What type of vegetation is associated with Tropical Coniferous Forests?

pines, shrubs, few grasses

Describe the diversity of of Tropical Coniferous Forests.

low to medium plant and animal diversity

fire community

What problems are faced by Tropical Coniferous Forests?

lack of burns

settlement - roads

logging - replanting - tree farms

Where is the Tropical Savanna Biome located?

15°-20° (portions 10°, 30°) north and south latitude

largest part in Africa, some in South America, Australia, India

Describe the average temperature of Tropical Savannas.

20°-25° C avg

hot and cool seasons

What precipitation patterns are associated with the Tropical Savanna?

50-150 cm rainfall

wet summer, dry winter

Describe the soil of the Tropical Savanna biome.

mixed soil with high clay content, low nutrients

What types of vegetation are found in Tropical Savannas? Provide region specific examples.

grasses and forest patches

• Africa: baobabs and acacia

• Australia: eucalyptus and acacia

• South America: mixed, palms

• India: mixed, acacia

Describe the diversity of the Tropical Savanna biome.

medium animal diversity, low plant diversity

large mammals, grazers

fire community in part

What are some of the problems associated with Tropical Savannas?

agriculture - cattle overgrazing, farms

Where are Desert biomes generally located?

25°-35° north and south latitude - desert belt

largest part in northern hemisphere

• Sahara - Middle East, Central Asia

What temperatures are associated with Deserts?

wide temperature range

variation: daily, seasonal, by location

Describe the precipitation patterns of the Desert biome. Provide examples.

0-50 cm rainfall

usually short “wet” season

Atacama: some spots have no recorded rain

American deserts: wet end of spectrum

What types of vegetation are associated with Deserts?

Xerophytes - dry plants, specialized for water conservation

• succulents: cactus and euphorbs, yucca, agave, aloe, creocob

widely spaced distribution

Describe the diversity of the Desert.

low plant and animal diversity (good for reptiles)

high level of specialization for dry conditions

What are examples of plant specializations associated with the Desert biome?

large photosynthetic stems that store water

leaves with waxy surface

spines: shade + protection

What animal specializations are associated with Deserts?

behavior: nocturnal activity and burrowing

physiology: kidneys, water metabolism

What issues are associated with deserts?

desertification: spreading of deserts by bad land management and climate changes

urbanization

agriculture - irrigation and water issues

Where is the Chaparral (Mediterranean) biome located?

30°-40° north and south latitude

coastal biome - most around Mediterranean, parts of coastal southern California, Chile, South Africa, Australia

What is the average temperature of Chaparral?

14°-20° C avg

warm and cool seasons

What precipitation patterns are associated with Chaparral?

30-80 cm rainfall

wet winter - mudslides

very dry summer - fires

Describe the soil of the Chaparral biome.

rock-clay mixed soils, low nutrients

What vegetation types are found in Chaparral?

few grasses, mainly small shrubs

• short evergreen trees w/ small leaves

• few larger scattered trees in ravines

• sparse distribution

• concentration along water courses

• some desert specializations (prickly pear in US)

Describe the diversity associated with Chaparral.

low animal and plant diversity (overlap desert)

fire-adapted, not dependent

What problems impact Chaparral biomes?

large urbanization for a long time

agriculture for a long time

• particularly: olives, nuts, grapes - wine country

Where are Temperate Grasslands located? Provide examples.

30°-40° north and south latitude

• continental biomes: historically most in center of North America and Asia

• ex: Veld (South Africa), Pampas (South America), Steppe (Mid Asia), North American Prairie

Describe the temperatures associated with Temperate Grasslands.

wide temperature range

hot and cold seasons (ex: North Dakota)

What precipitation patterns are associated with Temperate Grasslands?

30-80 cm rain + snow fall

distributed across most of year

What type of soil is found in Temperate Grasslands?

high nutrient, organic soils

• multiple soil horizons, related to dormancy during cold season

Describe the vegetation of Temperate Grasslands.

grass and more grass

• few trees + shrubs bordering water

• small annuals and perennials - lots of flowers

• tall and short grass prairies

What type of diversity is associated with the Temperate Grassland biome?

low plant and animal diversity (large mammals)

fire community - not entirely dependent but very beneficial

What problems do Temperate Grasslands face?

agriculture - especially in North America

exotic invasive plants

Where are Temperate Deciduous Forests generally located?

35°-45° north and south latitude

• most in northern hemisphere: East North America, West Europe, part of East China, some in Australia

• often associated with low mountains

What temperatures are associated with Temperate Deciduous Forests?

wide temperature range

hot and cold seasons

Describe the precipitation associated with Temperate Deciduous Forests.

50-200 cm rain and snow fall

distributed across most of year

What type of soil is associated with Temperate Deciduous Forests?

medium nutrient, organic soil

What vegetation types are found in Temperate Deciduous Forests? How many strata?

mixed deciduous and evergreen trees in 3 strata

• hardwoods: ash, beech, oak, maple, poplar, hickory, cherry, chestnut

Describe the canopy of Temperate Deciduous Forests.

trees form somewhat continuous cover 15-30m tall

Describe the lower story of Temperate Deciduous Forests.

immature trees 5-10 m tall

Describe the ground story of Temperate Deciduous Forests.

tree seedlings, shrubs, ferns

Streams and creeks form important ______ (streamside) habitat in Temperate Deciduous Forests.

riparian

Describe the diversity of Temperate Deciduous Forests.

medium plant and animal diversity

What are some issues associated with Temperate Deciduous Forests.

logging - most are now 2nd+ growth forests

urbanization (New York, Manhattan Island)

acid rain

Where are Temperate Coniferous Forests located?

35°-45° north and south latitude

• most in northern hemisphere - west North America, parts of Asia

• often associated with mountains - altitude

  • may be above temperate forests

What temperatures are associated with the Temperate coniferous forest biome?

wide temp range

hot and cold seasons + altitude

Describe the precipitation patterns of Temperate coniferous forests.

50-200 cm rain + snow fall

distributed across most of year

What soil is found in Temperate coniferous forests.

mixed sandy-rocky soils

What vegetation types are found in Temperate coniferous forests.

pines, few grasses

• more open and bigger trees in comparison to tropical coniferous forests

Describe the diversity of the Temperate coniferous forest.

low-medium animal diversity, low plant diversity

fire-dependent community

• lodgepole pine: serotinous cones require fire to drop seeds

What are some issues that impact Temperate coniferous forests?

logging (2nd growth)

lack of burns

Where is the Taiga biome located?

45°-60° north latitude

most in Canada and Russia

Describe the temperature patterns of the Taiga.

wide temp range

short warm season, long cold season

What precipitation patters are associated with the Taiga?

20-150 cm rain + snow fall

distributed across most of year

What type of soil is found in the Taiga biome?

mixed sandy-small rocky soil, low nutrients

slightly acidic, thin needle litter layer

What type of vegetation is associated with Taiga?

conifers, few deciduous trees, small shrubs, few grasses, mosses

What level f diversity is associated with the Taiga?

low animal and plant diversity

high abundance of a few things

What is the primary problem faced by Taiga?

logging