Transcript Introduction

Number of
Species
on Earth
1,400,000 animal sp.
320,000 plant sp.
Estimated # of tropical species
(based on birds)
= 2-3 x temperate = 2.8-4.2 million
So total = 4.2-5.6 million
The Creator, if He exists, has
"an inordinate fondness for beetles". –
J.B.S. Haldane
Number of species in
different animal groups
3/4 of all animals
(>1 million species)
are insects!
GEOGRAPHICAL DISTRIBUTION OF SPECIES:
Terrestrial ecoregions
Olson, D. M., et al (2001). Terrestrial ecoregions of the world: A new map of life on Earth.BioScience 51(11): 933-938.
Ecoregion: a large area of land or water that contains a geographically distinct
assemblage of natural communities that
(a) share a large majority of their species and ecological dynamics;
(b) share similar environmental conditions, and;
(c) interact ecologically in ways that are critical for their long-term persistence.
52 Ecoregions in U.S.
261: California Coastal Chaparral Forest Shrub Province.
261: California Coastal Chaparral / Forest Shrub Province.
• Climate. -- Hot, dry summers; rainy, mild winters.
–
–
–
–
Annual temperatures average 50º to 65 º F (10 º to 18 º C).
Annual precipitation 10-50 in. with a pronounced summer drought.
Some moisture from fog in summer.
Fire is common, usually set by lightning during the summer dry
season.
• Vegetation.
– Riparian forest with many broadleaf species grows along streams.
Willow, Mulefat
– Sclerophyll forest on the hills and lower mountains. Live oak, white
oak
– Chaparral on steep hill and mountain slopes too dry to support oak
woodland or oak forest. Chamise and various manzanitas.
– Coastal Sage Scrub on exposed coastal areas. Buckwheat,
Deerweed, Coyote bush, Black Sage, White Sage, California
sagebrush, and bush lupine.
25 Biodiversity Hotspots
1.44% of the Earth's land surface, supporting ~70% of all plant species.
Account for 44% of all plant diversity, 35% of all terrestrial vertebrate species,
and 75% of all terrestrial animal species listed as threatened by the IUCNWorld Conservation Union.
California
Floristic
Province
CALIFORNIA
• Biologically, most diverse state in the
Union
• 40,000 species
• More federally listed (i.e. Endangered and
Threatened) species than any other
mainland state
• Human population expected to grow from
32 million to 49 million by 2025
Species Diversity by State
Endemic Species by State
Species Extinction by State
Listed Species by State
Endangered Species in the U.S.
Southern California: a "hot spot" of threatened biodiversity
Plants
Fish
Birds
Molluscs
(Dobson et al., Science 275, 550 (1997)
Threatened, Endangered and
Candidate Species in California
(terrestrial vertebrates)
California's
native Native
ecosystems
(a selection)
California’s
Ecosystems
selection)
Pe(arce
nt lost
Native grassland
Needlegrass steppe
San Diego County coastal strand
Southern San Joaquin Valley alkali sink scrub
San Diego County maritime sage scrub
Coastal redwood forest
Riparian woodland
Wetlands
Central Valley wetlands
Central Valley vernal pools
San Diego County vernal pools
San Diego County freshwater marsh
San Diego County coastal salt marsh
San Francisco Bay seasonal wetlands
Coastal sage scrub
% lost
99
99.9
100
99
92
85
89
91
95
66-88
97
90
88
90
70-90
Noss, R.F. (1994) Calif ornia's ecosy stem decline. Def enders 69 (4) 34-35
California's natural communities
Where have they gone?
Forests - logged
Native grasslands - converted to agriculture,
overgrazed, invaded by exotics
Wetlands - drained
Streams - channelized and dammed
Coastal sage scrub - converted to subdivisions,
shopping malls, highways
Sclerophylls: leaves are small , hard, stiff, waxy, evergreen
Mediterranean ecosystems
http://conserveonline.org/workspaces/global.med.assessment
CA
• Five distinct regions
• Hot, dry summers and cool, wet winters.
• 2.2% of the Earth's surface, but support 20% of the world's plant species.
• >50% of the plant species are endemic: found nowhere else
• All threatened by urbanization, land conversion, invasive species,
altered fire regimes, excess grazing, tourism and climate change.
California Ecosystems
Coastal Sage Scrub
• 0-1500 feet elevation
• California sagebrush (Artemesia californica), black sage, white sage,
buckwheat and other drought-deciduous shrubs
• ~90% lost to development
•California Quail, Callipepla californica
Chaparral
500-4,500 feet elevation.
•Evergreen dense canopy 5-15 feet high containing chamise, manzanita,
ceanothus, lemonade berry, scrub oak, toyon, mountain mahogany, yucca
•Leaves contain flammable resins, but the plants are fire-adapted
Oak Woodland
1,500-4,500 feet elevation.
•Evergreen oaks and sycamores
•Poison oak, elderberry, coffeeberry, manzanita.
Mixed Conifer Forest
> 4,500 feet elevation.
• Coulter pine, jeffrey pine, white fir, Incense cedar, black oak, canyon live
oak. Also shrubs and grasses
• Huge losses to timber harvesting
Desert
• East of the Peninsular Mountains
• Low rainfall, high evaporation
• Many plants are succulent: they store water in their stems and/or leaves
• Creosote bush, desert willow, agave, indigo bush, chuparosa,
beavertail cactus, cholla cacti, barrel cactus, smoke tree, saltbush,
ocotillo, palo verde tree, desert fan palm, lupine, primrose, and verbena.
Riparian
• Alongside streams and lakes
• Willow, sycamore, cottonwood, mule fat.
• Huge losses due to channelization and damming
http://www.prbo.org/calpif/plans.html
Wetlands
• Inundated or saturated by water at least part of the time.
• Five major types: marine, estuarine, lakes (including vernal pools), rivers,
and marshes, swamps and bogs.
• Most lost to draining, filling, harbor development http://www.beachcalifornia.com/wetlands-california-birds-photos.html
Vernal Pools
• Seasonally flooded depressions on an impermeable layer
• Specially adapted plants that flower in succession as the pool dries,
giving concentric rings of color
http://nathistoc.bio.uci.edu/