Upload
cornelius-ethan-butler
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
1
Chapter 5: Biomes and Biodiversity
Principles of EnvironmentalScience - Inquiry and Applications,
3rd Editionby William and Mary Ann Cunningham
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2
3
Part 1: Biomes
Biomes
• Broadly defined life zones
• Environments with similar climates, topographies, soil conditions, and biological communities
• Distribution mainly dependent on temperature and precipitation
4
ADD FIG. 5.1
5
Biomes of the World
6
ADD FIG. 5.4
7
8
9
10
11
12
13
Part 2: Biodiversity
• Genetic diversity - variety of different versions of the same genes within a species
• Species diversity - number of different kinds of organisms within an ecosystem
• Ecological diversity - complexity of a biological community (number of niches, trophic levels, etc.)
Biodiversity - the variety of living things - three types essential:
14
How many species are there?
15
Biodiversity Hotspots
Most of the world's biodiversity concentrations are near the equator (tropical rainforests, coral reefs).
16
Part 3: How do we benefit from biodiversity?
• Food
• Drugs and medicines
• Ecological benefits
• Aesthetic and cultural benefits
17
Fig. 5.21
18
19
Aesthetic and culturalbenefits
Bird watching and other wildlife observationcontribute more than $29 billion each year to the U.S. economy.
20
Part 4: What Threatens Biodiversity?
Extinction - the elimination of a species
• Natural process - one species lost every 10 years
• Process been accelerated by human impacts on populations and ecosystems
• E.O. Wilson - we are currently losing thousands of species a year
21
22
Part 5: Human-Caused Reductions in Biodiversity
• Habitat destruction and fragmentation• Hunting and fishing• Commercial products and live specimens• Predator and pest control• Exotic species introduction• Diseases• Pollution• Genetic assimilation
23
About 200 years ago, the American passenger pigeon was probably the world's most abundant bird.
Population: 3-5 billion
Over hunting and habitat destruction caused its extinction.
24
Trade in Products from Endangered Species
25
Trade in Wildlife
About 75% of all saltwater tropical aquarium fish sold come from coral reefs of the Philippines and Indonesia, where they are commonly caught with dynamite or cyanide.
26
Part 6: Protecting Biodiversity
• Hunting and fishing laws• The Endangered Species Act (ESA)• Recovery plans• Reintroductions• Minimum viable population• Private land and critical habitat• Reauthorization of the ESA• International wildlife treaties
27