Transcript Biodiversity of World Biomes

Biodiversity of World Biomes
Field Explorations with
Dr. Jacqueline S. McLaughlin
and
Dr. Stam M. Zervanos
Overview and Purpose
• Immerse students in the study of biodiversity through a
blended delivery of disciplinary knowledge (pre-trip Web-based
assignments, lectures and discussions in the field, post-trip
assignments) and an experiential field study.
• Learn the principle ecological and evolutionary mechanisms
leading to this biodiversity.
• Help students better understand the importance
and challenges of sustaining the world environments by
allowing them opportunities to gain first-hand knowledge of
the geography, economics, sociology, politics, history, and
culture of people in locations visited.
• Encourage students to become advocates for protecting
biodiversity.
The Biosphere
• In 2002 about 1.7 million species
had been discovered and
identified by biologists.
• The sum of Earth’s ecosystems, the
Biosphere encompasses all parts of
the planet inhabited by living
things.
Terrestrial Biomes
The term biome refers to a major type of terrestrial ecosystem that
typifies a broad geographical region.
• tundra (artic and alpine)
• temperate grassland
• temperate rain forest
• chaparral (Mediterranean)
• temperate deciduous forest
• tropical rain forest
• desert
• savanna
• taiga (coniferous, needle
leaf or boreal forests)
• polar ice
Distribution of Major Terrestrial Biomes
Biodiversity
• For at least 3.8 billion years, a complex web of life has been evolving here on
Earth.
• Biodiversity - short for biological diversity - is the variety of all living
organisms and their interactions. Scientists often speak of three levels of
diversity - species, genetic, and ecosystem diversity.
Ecosystem
Species
Genetic
Importance of Biodiversity
Reasons human cultures value biodiversity:
The rich variety of species in biological communities gives us food, wood, fibers,
energy, raw materials, industrial chemicals, and medicines, all of which pour
hundreds of millions of dollars into the world economy each year.
Moreover, people have a natural affinity for nature, a sense of “biophilia,”
wherein they assign a non-utilitarian value to a tree, a forest, and wild species of
all kinds (E. O. Wilson).
Importance of Biodiversity
Pollination
For every third bite you take, you can thank a pollinator.
Air and Water Purification
Biodiversity maintains the air we breathe and the water we drink.
Climate Modification
By giving off moisture through their leaves and providing shade,
plants help keep us and other animals cool.
Drought and Flood Control
Plant communities, especially forests and wetlands, help control floods.
Cycling of Nutrients
The elements and compounds that sustain us are cycled endlessly
through living things and through the environment.
Importance of Biodiversity
Habitat
Natural ecosystems provide habitat for the world’s species (forests, wetlands,
estuaries, lakes, and rivers – the world’s nurseries).
Food
All of our food comes from other organisms.
Natural Pest Control Services
Natural predators control potential and disease-carrying organisms in the
world.
Drugs and Medicines
Living organisms provide us with many drugs and medicines.
Biodiversity Threatened
• The current threat to biodiversity, and thus to the biosphere as we
know it, stems primarily from expanding human populations and
increased human consumption of natural resources.
THE WORLD POPULATION HAS TRIPPLED IN THE LAST 70
YEARS.
Based on the present rate of population growth.
One could conservatively predict the population to be by the year:
2,050 AD
12 Billion ???
2,100 AD
24 Billion ???
2,150 AD
48 Billion ???
2,200 AD
96 Billion ???
2,250 AD
192 Billion ???
2,300 AD
384 Billion ???
http://www.edu.ue-foundation.org/worldpop.html
Biodiversity Threatened
• While the population of a species is typically set by predation,
resources, disease and geography, the human population growth
curve has never been restricted. As a result, no species can compete
with humanity. This is our reality.
Biodiversity Threatened
Human population explosion continues while:
As much as 34% of the world’s fish species (51% of freshwater species), 25% of amphibians, 24%
of mammals, 20 % of reptiles, 14% of plants, and 12% of bird species are under threat of
extinction, according to the 2000 joint study by the World Conservation Union and Conservation
International and a 1999 study by the World Wildlife Fund.
As many as a quarter of 1 percent of the species in the world’s tropical rainforests (roughly 9,00026,000 species) are being extinguished or doomed to early extinction each year (25-71 species per
day).
According to estimates from the Food and Agricultural Organization and the United Nations
Programme, 76,000 square kilometers of tropical rainforest a year--the size of West Virginia or
Costa Rica-- is being permanently cleared or converted into shifting-cultivation cycle. Tropical
rainforests cover only 7% of the Earth’s land surface, but contain more than half the species in the
entire world.
During the past 150 years, humans have directly impacted and altered close to 47% of the global
land area according to the World Atlas of Biodiversity: Earth’s Living Resources for the 21st Century
released by the United Nations Environment Programme World Conservation Monitoring Centre
(UNEP-WCMC) in August 2002.
Under one bleak scenario, biodiversity will be threatened on almost 72% of Earth's land area by
2032.
Factors Leading to Biodiversity Loss
Multiple forces entrained by human activity reinforce one another and force species
down. These factors are summarized be conservation biologists under the acronym
HIPPO:
Habitat Destruction
Invasive Species
Pollution
Population
Overharvesting
The prime mover of the incursive forces around the world is the second P in HIPPO – too
many people consuming too much of the land and sea space and the resources they
contain.
- E. O. Wilson, The Future of Life
The Galapagos Islands
Alaska
Australia
Costa Rica
Biodiversity Online
http://www.clat.psu.edu/biodiversity/