Transcript ESC 110 Lecture - Chpt 5 (Web version)

Biomes and Biodiversity
(Chapter 5)
• Terrestrial biomes
• Aquatic habitats
• Biodiversity
What are biomes?
Bio = life + -ome = abstract entity, mass, or group
Thus, biomes are “masses of life,” large areas with
similar physical features, inhabited by similar types
of organisms
They are usually recognized by their vegetation
Biological Hierarchy
Biosphere
Biome
Community
Population
Organism
Biomes are related
to large-scale
climate features,
especially
temperature and
moisture
Text Fig. 5.2
Effective moisture is important
• The amount of moisture potentially available to
plants is, to a first approximation, determined
by the interaction of precipitation and
temperature
• Evapotranspiration
• Timing of precipitation in relation to seasonal
variation in temperature
Earth’s Temperature Zones
Text Appendix 4
Climate
Patterns
• Timing is
important
• Means don’t
always mean a lot
Text Fig. 5.4
World Biomes
Deserts
• Very low effective moisture
• Wide range of temperatures
(Photos of Mojave Desert, CA, Sonoran
Desert, AZ, and Great Basin Desert, UT)
Grasslands
• Low effective moisture
• Wide range of temperatures
• Grasslands include more than grasses
(Photos of native prairie, southern MT, one
with wildflowers and butterflies)
Mediterranean Shrublands
• Low-moderate moisture with dry
season
(Two photos of California shrublands:
• Chaparral, comprised mostly of evergreen plants
with thick leathery leaves
• Coastal sage scrub, comprised mostly of plants
with soft drought-deciduous leaves)
Woodlands
•Moderate moisture, often with a dry
season
(Photos of Pinyon-juniper woodland, AZ
and oak woodland/savanna, CA)
Temperate Deciduous
Broadleaf Forests
• Strong seasonal pattern: warm and moist
during growing season, then cold
(Photos of tree canopy, colorful fall leaves, and
spring wildflower that grows before trees leaf out)
Temperate Evergreen
Broadleaf Forests
• Less pronounced seasonal pattern: cool to warm
year-round, moist during growing season
(Photos of eucalyptus forest in Tasmania, Australia,
and eucalyptus leaves, flowers, and fruits)
Tropical Moist Forests
• Essentially season-less: warm and wet
year-round
• Masses of green, extremely high
productivity
(Photos of lowland rainforest in Costa Rica)
Tropical Seasonal Forests
• Warm and wet, with a dry season
• Less productive than tropical moist
forests
(Photos of forest in north Queensland, Australia)
Tundra
• Very cold year-round
• Occurs both at high latitudes (arctic
tundra) and high altitudes (alpine tundra)
• Can be wet or fairly dry
(Photos of alpine tundra in Rocky Mountains, CO,
alpine tundra plants and lichens in Olympic
Mountains, WA and Norway, and arctic tundra
north of Fairbanks, AK)
Conifer Forests
• Warm and wet enough to produce a
moderately long growing season
• Growing season limited by cold and/or
drought
(Photos of conifer forests in central AK, Great
Lakes region, Yosemite National Park, UW Pack
Forest, and the Rocky Mountains, CO, plus forest
floor lichens and shrubs)
Aquatic Biomes?
• Inland fresh waters (lakes, rivers, and
streams)
• Wetlands
• Estuaries
• Seas and oceans
Inland Fresh Waters
• Why doesn’t the biome concept
work for inland fresh waters?
(Photos of lake and stream)
Wetlands
• Upland areas that are saturated with water,
at least periodically
• Many different types and classifications
• Why doesn’t the biome concept work for
wetlands?
(Photos of three wetlands)
Estuaries
• Transitional areas between rivers and seas
or oceans
• Water usually brackish
(Photos of mangrove ‘swamp’ and salt marsh)
Seas and Oceans
• Important factors for organisms include
depth, distance to nearest land, and
latitude  any others?
• Could biome concept be applied?
(Photo of rocky coast, OR and aerial view of coral reef)
Biodiversity
•
•
•
•
•
Bio = life + diversi = various
What is it?
Importance and benefits
Threats
Protection and preservation
Types of Biodiversity
•
•
•
•
Genetic
Species
Ecological or functional
Plus many others 
Genetic Diversity
• The variety of different versions of the
same gene(s) within a species
(Photos of red, orange, yellow, and white Amanita
muscaria mushrooms)
Species Diversity
• The number and relative abundance
of different species in an area or
community
(‘Family portrait’ of different species of mushrooms)
Species Diversity
• Usually the diversity of two or more
areas or communities is compared
(Photos of lichen-covered rock and headstone)
How many
species are
there?
Some of these totals are gross
underestimates  which ones
would you guess?
Which are likely to be fairly
accurate?
Insect Biodiversity
The population geneticist JBS Haldane was
asked what might be learned about a Creator
by examining the world.
His response: ‘(s)he must have an inordinate
fondness for beetles.’
Ecological
Diversity
The number of
different functions
being performed in an
area or community
Text Fig. 3.22
Ecological Diversity
(Photos of four different kinds of mushrooms,
rotting a snag, large fallen tree branch, pine cone,
and pine needles)
Biodiversity Hotspots
Certain areas of the world have high percentages of species
that occur nowhere else on Earth (Text Fig. 5.20)
Benefits of Biodiversity
• Many organisms are of direct benefit to
humans
• However, biodiversity also has enormous
indirect benefits
Biodiversity and Ecosystem Services
Article from the
journal Nature
GLOBAL CHANGES
Population
Dynamics
Ecosystem
Functioning
Biological
Diversity
Landscape
Dynamics
SUSTAINABLE SYSTEMS
Biodiversity acts as a buffer against environmental change
Benefits of Biodiversity
• ‘Variety is the spice of life’
(Photos of mushrooms in baskets – one full of one
kind of brown mushroom, the other with
mushrooms of many shapes and colors)
Threats to Biodiversity
• There are both natural and human-caused
threats to biodiversity
• Just as the benefits of biodiversity are
both direct and indirect, so are the threats
Threats to Biodiversity
• Extinction
Threats to Biodiversity
• Habitat destruction and fragmentation
(Photos of agricultural fields, open-pit copper mine,
and skyscrapers)
Threats to Biodiversity
• Hunting,
fishing,
specimen
collecting
Text Fig. 5.29
Threats to Biodiversity
• Introduced species
(Photo of Scots broom, a widespread
intruder in western WA)
Protection of Biodiversity
• Hunting and fishing laws
(Photos of signs for commercial mushroom
buyer, ‘mushroom-picking permits required’,
and ‘no-picking forest products’)
Protection of Biodiversity
(Far Side cartoon: wildlife preserves)
Endangered Species Act
• Passed in 1973
• Listing of organisms in
danger of extinction
(endangered species) or
in danger of becoming
endangered (threatened
species)
Endangered Species Act
• Habitat Conservation Plans
• Landowners develop a plan for managing their
lands in such a way as to produce a long-term
benefit for listed species
• In return, they receive a permit allowing
‘incidental take’
Endangered Species Act
• City of Seattle’s Cedar River Watershed is
being managed in accordance with a
Habitat Conservation Plan