Conservation Biology - 1. Introduction to Conservation Biology
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Conservation Biology: Lecture Notes
1. Introduction to Conservation Biology
Why Conservation Biology?
•Expanding human demands…
•Every natural ecosystem has been changed, most profoundly changed.
•Extinctions, altered functioning of ecosystems, reduced availability of resources, soil erosion.
•Cause? The world’s human population is currently 6.4 billion people and is growing.
Some historical context:
•Humans ‘may’have been responsible for mega-fauna extinctions in the Americas shortly after
human colonization from Asia about 11,000 years ago.
•Aristotle (382 –334 B.C.) commented on the widespread destruction of forests in the Baltic
•Barren landscapes of Turkey, Syria, Iraq, and Iran are unnatural deserts that resulted from
massive exploitation of fragile woodlands.
•India, Bangladesh, and Pakistan -major changes over the past 2000+ years
•Deforestation of Europe by the early 18th Century, forest areasmaintained as private game
management and royal preserves.
•In Great Britain, many of the native forests were gone by the 12th Century.
•Southeastern Ontario has been largely deforested during the past 150 years.
But never like today…
•We now consume a large fraction of the planet’s resources
•We now consume 20-40% of the planet’s annual net primary productivity (energy from the sun
transformed to plant biomass)–35% of the NPP from oceanic shelves.–We also consume 60%
of freshwater runoff (irrigation, drinking water)
•Consumption is highly unequal–US: 4% of the world’s population but 30% oil consumption.
•–83% of the earth’land surface shows evidence of our impacts…
•Urbanity, suburban sprawl, roads
•Pollution–Fertile grasslands = 98%
Room for optimism? Sure!
•Population growth rates are declining in many regions; growth rates are negative in some