Download Chapt 11: Terrestrial Flora and Fauna

Chapter 11: Terrestrial Flora and Fauna – p. 1 of 13
Chapter 11: Terrestrial Flora and Fauna
I.
II.
Ecosystems and Biomes
A. Ecosystem: A Concept for All Scales
1. ecosystem: an association of plants and animals along with the
surrounding nonliving environment and all the interactions in which the
organisms take part
2. ecosystem concept is built around the flow of energy
3. can be applied at various scales: global ecosystems; ecosystem of the
underside of a rock; etc.
B. Biome: A Scale for All Biogeographers
1. biome: any large, recognizable assemblage of plants and animals in
functional interaction with its environment
2. most appropriate scale for understanding world distribution patterns
3. biomes are usually identified and named on the basis of its dominant
vegetation which normally makes up bulk of the biomass
4. 10 major terrestrial biomes:
a. tropical rainforest
b. tropical deciduous forest
c. tropical scrub
d. tropical savanna
e. desert
f. Mediterranean woodland and scrub
g. Midlatitude grassland
h. Midlatitude deciduous forest
i. boreal forest
j. tundra (Arctic and alpine)
5. biome includes other vegetation as well as diverse animal species
6. significant and predictable relationships exist between the biota of a
biome and the associated climate and soil types
7. ecotone: the transition zone between biotic communities in which the
typical species of one community intermingle or interdigitate with those
of another
Terrestrial Flora
A. reasons geographers are interested in the natural vegetation:
1. over much of the planet, terrestrial flora is the most significant visual
component of the landscape
2. vegetation is sensitive indicator of other environmental attributes
3. vegetation influences human settlement and activities
B. Characteristics of Plants
1. perennials: plants that endure seasonal climatic fluctuations from year
to year
2. annuals: plants that perish during times of climatic stress (such as
winter) but leave behind a reservoir of seeds to germinate during the
next favorable period
C. Floristic Terminology
Chapter 11: Terrestrial Flora and Fauna – p. 2 of 13
1. plants that reproduce through spores:
a. Bryophytes
1) true mosses, peat mosses and liverworts
2) have never been very important
b. Pteridophytes
1) ferns, horsetails, club mosses
2) more important in past
2. plants that reproduce through seeds
a. gymnosperms/conifers (naked seeds)
1) carry their seeds in cones
2) more important in past
3) only large survivors are cone-bearing trees such as pines
b. angiosperms (vessel seeds)
1) flowering plants
2) seed encased in some sort of protective body: fruit, nut or pod
3) have dominated vegetation for last 50-60 million years
3. stem or trunk composition
a. woody plants: stems composed of hard fibrous material
b. herbaceous plants: soft stems
4. leaf loss
a. evergreen tree: sheds its leaves on a sporadic or successive basis
but always appears to be fully leaved
b. deciduous tree: experiences an annual period in which all leaves die and
usually fall from the tree, due either to a cold season or a dry season
5. leaf shape
a. broadleaf trees:
1) leaves are flat and expansive in shape
2) almost all broadleaf trees are deciduous except in rainy tropics
where everything is evergreen
b. needleleaf trees:
1) leaves are tough, leathery waxy needles
2) almost all needleleaf trees are evergreen
6. wood
a. hardwood: angiosperm trees that are usually broad leaved and
deciduous; wood has a relatively complicated cellular structure
b. softwood: gymnosperm trees; nearly all needleleaf evergreens;
wood has a simple cellular structure
D. Environmental Adaptations
1. intro
a. definite tolerance limits govern plant survival, distribution, and
dispersal
b. plants have evolved protective mechanisms to enlarge their
tolerance limits
2. Xerophytic Adaptations
a. xerophytes: plants that are structurally adapted to withstand
protracted dry conditions
Chapter 11: Terrestrial Flora and Fauna – p. 3 of 13
b. xerophytic adaptations:
1) roots are modified into shapes or sizes to enable them to seek
widely for moisture
2) stems are modified into fleshy, spongy structures that can store
moisture
a) plants with such fleshy stems are called succulents; ex. cacti
3) leaves are modified to decrease transpiration
a) surface is hard or waxy to inhibit water loss
b) surface is white and shiny to reflect insolation and reduce
evaporation
c) plants have tiny leaves or no leaves at all
d) leaves are replaced by thorns from which there is virtually no
transpiration
4) reproductive adaptation: plants lie dormant for years waiting for
moisture then complete entire reproductive cycle in a few days
3. Hygrophytic Adaptations
a. hydrophytes: plants living more or less permanently immersed in
water (water lily)
b. hygrophytes: moisture-loving plants that require frequent soakings
with water (ferns, moss, rushes)
c. hygrophytic adaptations:
1) extensive root systems for anchoring to soft ground
2) widening, flaring trunk near ground to provide better support
3) weak, pliable stems that can stand the current’s ebb and flow
E. Competition and the Inevitability of Change
1. plants are as competitive as animals
2. compete for nutrients from same soil and energy from same sun
3. the floristic pattern of Earth is impermanent
a. general sequential trend is toward taller plants and greater stability in
species composition
b. the longer plant succession continues, the more slowly change takes place
because more advanced associations contain species that live longer
c. climax vegetation: a stable plant succession of relatively constant
composition that develops at the end of a long, succession of changes
1) seral associations: stages leading up to climax vegetation
2) represent optimal floristic covering for that environmental context
3) an association in equilibrium with prevailing environmental conditions
F. Spatial Associations of Plants
1. identifying and mapping associations
a. boundaries on maps represent approximations
b. most world vegetation maps are maps of theoretical natural vegetation
1) ignore human interference
2) over extensive areas of Earth’s surface climax vegetation is the
exception rather than the rule
2. The Major Floristic Associations
a. Forests
Chapter 11: Terrestrial Flora and Fauna – p. 4 of 13
1)
2)
3)
4)
5)
trees growing so closely their individual leaf canopies overlap
shade precludes development of much undergrowth
require considerable annual precipitation
survive in widely varying temperature zones
except where inadequate moisture or short growing season, forest
are likely to become climax vegetation association in any area
b. Woodlands
1) tree-dominated plant association
2) trees spaced more widely apart
3) ground cover not inhibited by lack of sunlight
4) environment drier than forests
c. Shrublands
1) dominated by short woody plants: shrubs or bushes
2) wide latitudinal range
3) generally restricted to semiarid or arid locales
d. Grasslands
1) may contain scattered trees and shrubs, but dominated by
grasses and forbs (broadleaf herbaceous plants)
2) savanna: low-latitude grasslands characterized by tall grasses
3) prairie: mid-latitude grasslands characterized by tall grasses
4) steppe: midlatitude grasslands characterized by short grasses and
bunchgrass
5) associated with semiarid and subhumid climates
e. Deserts
1) widely scattered plants with much bare ground interspersed
2) climatic term
3) wide variety of plants: grasses, succulent herbs, shrubs, scraggly trees
4) some extensive desert areas devoid of all vegetation
f. Tundra
1) complex mix of very low plants, but no trees
2) perennially cold climates of high latitudes or high altitudes
g. Wetlands
1) limited geographic extent
2) swamps: trees are dominant plant forms
3) marshes: grasses and other herbaceous plants dominate
3. Vertical Zonation
a. significant elevation changes in short horizontal distances  various
plant associations in relatively narrow zones on mountain slopes
b. result of effects of elevation on temperature and precipitation
c. elevation changes are the counterpart to latitudinal changes
1) sea level to top of tall tropical peak is roughly equivalent to
horizontal journey from equator to Arctic
2) Fig 11-12 graphs northern hemisphere treeline (elevation at which
trees are unable to survive due to low summer temperatures and
moisture availability) variation with latitude: at 40oN latitude in
Colorado treeline is 10,000 feet
Chapter 11: Terrestrial Flora and Fauna – p. 5 of 13
III.
3) all vegetation zones are displaced downward with increasing
distance from the equator
4) accounts for vegetation complexity in mountainous areas
4. Local Variations
a. Exposure to Sunlight
1) adret slope: a slope oriented so that the sun’s rays arrive at a
relatively direct angle that is more effective in evaporating
available moisture
a) hot and dry
b) impact on vegetation
(1) sparser and smaller
(2) different species composition
2) ubac slope: a slope oriented so that the sun’s rays arrive at a
relatively low angle
a) cooler  less evaporation
b) more luxuriant vegetation of a richer diversity
3) differences between adret and ubac slopes decreases with
increasing latitude
b. Valley-bottom location
1) variation reflects difference in perennial availability of subsurface
moisture
2) riparian vegetation: anomalous stream-side growth, particularly
prominent in relatively dry regions, where stream courses may be
lined with trees, although no other trees are to be found in the landscape
Terrestrial Fauna
A. intro
1. animals occur in much greater variety than plants over Earth
2. less important as objects of geographical study:
a. animals much less prominent than plants in the landscape
b. environmental interrelationships are much less clearly evidenced by
animals
3. animals are sometimes more sensitive indicators than plants of
ecosystem health
B. Characteristics of Animals
1. animals are motile – capable of self-generated movement
2. animals cannot manufacture their own food
C. Kinds of Animals
1. Invertebrates
a. animals without backbones
b. more than 90% of all animal species
c. beetles are most numerous of animals: 40% of all insect species;
more than ¼ of all known animals
2. Vertebrates: animals that have a backbone that protects the main
nerve/spinal cord
a. fishes
b. amphibians
Chapter 11: Terrestrial Flora and Fauna – p. 6 of 13
c. reptiles
d. birds
e. mammals
1) placental (great majority): young grow and develop in the
mother’s body, nourished by the placenta
2) marsupial (135 species): mothers have pouches in which the very
undeveloped young live for weeks or months after birth
3) monotremes (echidna and duckbill platypus): egg-laying mammals
D. Environmental Adaptations
1. Physiological Adaptations
a. majority of animal adaptation to environmental diversity has been
anatomical and/or metabolic changes
b. examples: ear size, fur thickness, webbing, foot size, sweat glands
2. Behavioral Adaptations
a. advantage over plants: can move and therefore modify behavior to
minimize stress
b. examples: shelter, travel, shift from diurnal to nocturnal, migration,
hibernation, estivation (spending a dry-hot period in a torpid state)
3. Reproductive Adaptations
a. delay mating to postpone nest building
b. protracted egg, larval, or den stage
c. hastened estrus
E. People and the Environment: Changing Climate Affects Bird Population
1. bird populations can be especially sensitive to indicators of
climate change
a. many species have specific requirements for feeding, nesting,
and migration
b. because birds are quite mobile, they may respond fairly
quickly to local environmental changes
c. in warmer years birds do not fly as far south for the winter as
they do in cooler years and may spend their summers farther
north
2. 2009 National Audubon Society Christmas Bird Count - 40 year study
a. 177 of 305 North American bird species are wintering an
average of 35 miles farther north than 40 years ago
b. “center of abundance” for more than 60 bird species shifted 100
miles or more north
c. higher temperatures are most likely cause
3. other impacts
a. timing of bird migrations: several species are arriving in
Michigan 2-3 weeks earlier in the spring
b. nesting time:
1) birds in some locations are nesting earlier because plants are
blooming earlier which results in an earlier proliferation of
insects
Chapter 11: Terrestrial Flora and Fauna – p. 7 of 13
2) 20 of 65 species studied in Britain are laying eggs 9 days
sooner today than they did 35 years ago
4. because habitats may respond to climate change in different ways,
birds and other creatures may face a dislocated and altered habitat
F. Examples of Animal Adaptations to Desert Life
1. remain near a perpetual source of water (birds are more dependent on
an open source of water than any other non-aquatic animal)
2. follow rain in nomadic fashion
3. spend a great deal of time underground
4. be nocturnal
5. kangaroo rats can exist from birth to death without ever taking a drink!!
(surviving exclusively on moisture ingested with their food)
6. dromedary (one-humped camel)
a. anatomical adaptations
1) cleft lip designed to catch any moisture expelled from the nostrils
2) horizontal slits of nostrils can close tightly to keep out blowing sand
3) shaggy brows shade sun
4) double set of eyelids blocks blowing sand
b. physiological adaptations
1) body temperature range of 12oF reduces sweating
2) capable of rapid and complete rehydration in a short time period
7. delay reproductive processes during dry periods
G. Competition among Animals
1. between species: space and resources, plus direct antagonism of
predation
2. within species: territory, mates, food
H. Cooperation among Animals
1. symbiosis: a mutually beneficial relationship between 2 dissimilar
organisms
2. 3 forms:
a. Mutualism: mutually beneficial relationship between the 2 organisms,
such as a tickbird and African ungulate
b. Commensalism: 2 dissimilar organisms living together with no injury
to either, such as burrowing owls sharing prairie dog holes
c. Parasitism: one organism lives on or in another and obtains
nourishment from the host, which is usually weakened or sometimes
killed, such as mistletoe on forest trees
I. Zoogeographic Regions
1. distribution of animals over the world is more complex and irregular
than plants because they are mobile
2. broad distribution of animals is reflective of the distribution of energy
and food diversity:
a. richest faunal assemblages are in the permissive environment of
the humid tropics
b. sparsest representations of both species and individuals are in the
dry lands and cold lands
Chapter 11: Terrestrial Flora and Fauna – p. 8 of 13
IV.
3. 9 zoogeographic regions:
a. Ethiopian Region: tropical or subtropical with rich and diverse fauna;
primarily Sub-Saharan Africa
b. Oriental Region: similar faunal assemblage as Ethiopian Region but
less diversity; southern Asia
c. Palearctic Region: poorer fauna assemblage due to high latitude,
harsher climate; northern Asia, Europe, northern Africa
d. Neoarctic Region: nontropical portion of North America with poor
faunal assemblage with the exception of reptiles
e. Neotropical Region: all of South America and tropical North America
with a rich and distinctive fauna that reflects both a variety of habitats
and a considerable degree of isolation
f. Madagascar Region: distinctive fauna dominated by a relic
assemblage of unusual form, notably lemurs
g. New Zealand Region: unique fauna dominated by birds, many
flightless, and with no mammals
h. Pacific Islands Region: very limited faunal assemblage due to
isolation of islands
i. Australian Region: most distinctive fauna due to its lengthy isolation;
paucity of vertebrates
4. The Unique Biota of Australia
a. Australia's unique biota result of isolated evolution with
significant recent human-induced modifications
b. flora
1) >90% Australian native trees are members of a single genus,
Eucalyptus
2) Acacia genus dominates shrubs and bushes
c. fauna
1) rare and vulnerable species flourished in relative isolation from
competition and predatory pressures
2) dominated by marsupials, primitive mammalian order
3) only continental home of monotremes
4) limited and inconspicuous placental mammals
5) great profusion of feral livestock
The Major Biomes
A. Tropical Rainforest
1. selva: tropical rainforest
2. distribution of this biome close related to Af and Am climate:
consistent rainfall and relatively high temperatures
3. most complex and greatest species diversity of all terrestrial ecosystems
a. characteristic flora:
1) tall, high-crowned, broadleaf, evergreen trees
2) layered structure with complete canopy
3) sparse undergrowth (due to lack of light) except where there are
openings such as along rivers where you find jungles
4) epiphytes, vines and lianas hang from trees
Chapter 11: Terrestrial Flora and Fauna – p. 9 of 13
b. other ecosystem characteristics:
1) heavy shade, high humidity, windless air, continuous warmth
2) plant litter decomposes quickly
3) infertile soil; concentration of nutrients in vegetation rather than soil
c. characteristic fauna:
1) largely arboreal – principal food sources in canopy
2) large animals scarce
3) vast numbers invertebrates
B. Tropical Deciduous Forest
1. locational correlation with specific climatic type is irregular and
fragmented; many in transition zone between Af and Aw climates
2. comparison with the selva:
a. less dense canopy, shorter trees, fewer layers
b. many trees shed leaves during dry season
c. classic jungle conditions
d. faunal assemblage similar to rainforest
C. Tropical Scrub
1. widespread in the tropics and subtropics in drier portions of the
Aw climate and in some areas of BSh climates
2. less species diversity than the selva and tropical deciduous forest biomes
3. dominated by low-growing, scraggly trees and tall bushes, some
thorny
4. extensive grassy understory
D. Tropical Savanna
1. correlation with Aw (savanna climate) in regions where seasonal
rainfall contrasts are greatest
a. associated with the annual shifting of the ITCZ
2. characteristic flora
a. savanna: dominated by tall grasses without trees
b. parkland/park savanna: dominated by tall grasses with sprinkling of
trees and shrubs
c. much of savanna created by human interference: fires and grazing of
domestic animals
d. very pronounced seasonal rhythm
1) wet season: grasses grow tall and luxuriant
2) dry season: above ground portion of grasses die and many trees
and shrubs shed their leaves
3) wildfire season: natural burning every year that stimulates the
ecosystem
3. characteristic fauna:
a. African savanna: big game land of large ungulates and carnivores
b. South America savanna: sparse assemblage of large wildlife
c. Asian and Australian: intermediate between the other 2 regions
E. Desert
1. general decrease in precipitation as move away from the equator –
matched by gradation in biomes from selva to desert
Chapter 11: Terrestrial Flora and Fauna – p. 10 of 13
2. close correlation to BWh and BWk climates
3. distribution: subtropics and midlatitudes
4. flora
a. surprisingly variable
1) drought-resisting plants with structural modifications
2) drought-evading plants capable of hasty reproduction during brief
rainy times
b. sparse with considerable bare ground
c. scattering of shrubs with sporadic trees
5. fauna
a. inconspicuous
b. limited variety of large mammals
c. nocturnal to avoid heat of day
F. Mediterranean Woodland and Scrub
1. found in 6 widely scattered and relatively small areas of midlatitudes
2. pronounced dry summer/wet winter precipitation; correlates with Cs climate
3. flora
a. dominated by dense growth of woody shrubs
1) called chaparral in North America
2) many species of sclerophyllous plants
b. significant open grassy woodland
c. considerable scattering of trees
1) oaks in northern hemisphere
2) trees and shrubs primarily broadleaf evergreens
a) small leaves with leathery texture or waxy coating
b) deep roots
d. summer fires are common so many plants adapted to speedy
recovery after fires
e. winter floods follow summer fires → abrupt erosive runoff
G. Midlatitude Grassland
1. wide distribution in midlatitudes of North America and Eurasia
2. in northern hemisphere very close locational coincidence between
midlatitude grasslands and steppe climate (BSh and BSk) type
3. southern hemisphere less climatic correlation
a. pampa - Argentina
b. veldt – South Africa
4. flora
a. reason for grasses rather than trees or shrubs:
1) lack of adequate precipitation to support larger plant forms
2) frequency of fires prevent growth of tree or shrub seedlings
b. grass types
1) prairie: long grass in wetter areas
2) steppe: short grass in drier areas
c. trees mostly limited to riparian areas
d. shrubs and bushes on rocky sites
5. fauna
Chapter 11: Terrestrial Flora and Fauna – p. 11 of 13
a. extensive pasture for grazing animals
b. large numbers of relatively few species
c. larger migratory herbivores
d. many smaller animals spend all or part of life underground
H. Midlatitude Deciduous Forest
1. very little of original natural vegetation remains: large portions of this
biome cleared for agricultural and other human use
2. flora
a. characterized by fairly dense growth of tall deciduous, broadleaf
trees that have a complete canopy in summer with some exceptions:
1) eastern Australia: eucalyptus (broadleaf evergreens)
2) southeastern US extensive pines (needleleaf evergreens)
3) Pacific northwest: evergreen coniferous
b. forest floor relatively barren of undergrowth
3. fauna
a. richest assemblage of fauna in midlatitudes
b. animal life less conspicuous and numerous in winter – partly due to
migrations and hibernation
I. Boreal Forest
1. often called taiga
2. one of most extensive biomes with vast expanse in northern North
America and Eurasia
3. very close correlation with subarctic climate (Dfc) type
4. flora
a. simplest assemblage of plants of any biome
b. most trees conifer
1) nearly all needleleaf evergreens
2) tamarack or larch exception – drop needles in winter
3) broad homogeneous stands
4) deciduous stand limited variety and often seral situation
following a fire: birch, poplar, and aspen
c. ground usually covered with mosses and lichens
d. bogs and swamps are numerous due to poor drainage in summer
1) permafrost
2) drainage derangement result of glaciation
5. fauna
a. limited food supply  limited faunal species diversity
b. animal populations can fluctuate enormously
c. fur bearing animals and a few species of ungulates
d. birds
1) superabundant and diverse in summer
2) migrate to warmer latitudes in winter
J. Tundra
1. essentially a cold desert
2. moisture is so scarce and summers so short, trees unable to
survive
Chapter 11: Terrestrial Flora and Fauna – p. 12 of 13
V.
3. located along northern edge of the northern hemisphere
continents
4. correlates closely to ET climate distribution
5. flora
a. considerable mixture of species in dwarf forms
b. complete their annual cycles hastily during brief summer
6. fauna dominated by birds and insects in summer
7. Alpine Tundra
a. alpine version of tundra in high elevation mountain areas
Human Modification of Natural Distribution Patterns
A. Physical Removal of Organisms
1. “one of humankind’s most successful skills is the elimination of other
living things”
B. Habitat Modification
1. human modification:
a. changed soil environment through farming, grazing, engineering
and construction practices
b. degraded atmospheric environment
c. impounded, diverted, and polluted waters
d. affects native plants and animals
2. Tropical Rainforest Removal
a. rate of deforestation
1) 27 million acres/year
2) areas most impacted 1990-2005:
a) Brazil - greatest total area cleared (104 million acres)
b) Indonesia second (62 million acres)
c) Comoros greatest percent cleared (60%)
3) percent of original forest already gone:
a) > 50% in Africa
b) 45% in Asia
c) 40% in Latin America
b. impacts of deforestation:
1) loss of biotic diversity - mid-1990s tropical deforestation 
extermination of 2 species/hour
a) loss of unknown pharmaceutical products
b) extinction is irreversible
2) accelerated soil erosion
a) nutrients leached from soil of cleared forest
b) loses fertility in 2-3 years
3) drought
4) flooding
5) water quality degradation
6) declining agricultural productivity
7) greater poverty for rural inhabitants
8) increase in atmospheric carbon dioxide and other broad-scale
atmospheric alterations
Chapter 11: Terrestrial Flora and Fauna – p. 13 of 13
c. anticipated economic benefits usually temporary
1) overcrowding and poverty results in government opening up land
for settlement
2) infertility of tropical soil results in only 2-3 years of productivity
d. current efforts to promote agroforestry, planting crops with trees
rather than cutting down the trees
3. People and the Environment: Rainforest Loss in Brazil
a. Brazil contains ~ 1/3 of the world’s tropical forest
b. clearing land for settlement, agriculture, ranching and logging
c. expanding network of roads is opening up land
d. potentially sustainable crops: cacao and coffee
C. Artificial Translocation of Organisms
1. accidental and intentional introduction of exotics
2. exotic species: non-native/introduced species
3. usual outcome of exotic species
a. dies out in a short time because of environmental hazard and/or
competitive-predatory pressures
b. or, introduced species finds both a benign climate and an unfilled
ecological niche and flourishes extraordinarily
4. Biotic Rearrangement: The Sad Case of Florida
a. Florida major world center for animal and plant import industry
1) escape or are released
2) Florida: “biological cesspool” of introduced life forms
b. explosive human population growth  massive disruption of
Florida’s ecosystems  empty niches
c. exotic plants as threats:
1) melaleuca (paperbark tree): turning swamps into forests
2) Amazon water hyacinth: grow so quickly and thick, they impede
boat traffic and oxygen starve all other aquatic life
3) hydrilla (from Africa and SE Asia) clogged more than 150,000
acres of Florida’s waterways
4) walking catfish of SE Asia
a) eat all insect larva
b) eat other fish
c) can breath in air so can walk from one stream to another
d) wipe out all other fish species