Post on 26-Mar-2018
Historical Humans in the Biosphere Hunting and Gathering Most of human history
Agriculture - farming Started about 11,000 years ago (after last
ice age)
Humans started changing the Earth somewhat
Modern agriculture 1800s & 1900s – science and technology
started to increase agricultural yields
Monoculture – large fields are planted with a single variety of plant year after year
Historical Humans in the Biosphere The Green Revolution Technology lead to the development
of large yields to help human need for food with increasing population
Challenges for the Future Monoculture leads to increases of
pests and disease
Enough water for irrigation
Protect natural resources
Urban Development Various issues with dense
populations: food production & transportation, waste, water supply, etc.
Renewable & Non-Renewable Resources A renewable resource can be
replaced by a living thing or biochemical cycles
Trees, water, sun, etc.
A non-renewable resource cannot be replaced by living processes in a reasonable amount of time
Coal, oil, natural gas (fossil fuels)
Sustainable Development Idea of using natural resources without depleting them and
providing for human needs without causing long term environmental harm Replanting forests Cleaning up water supplies Leave no trace Restrictions on travel/hiking, etc.
Land Resources There needs to be room for stuff to grow Soil erosion – the wearing away of surface soil by water and wind
Plowing
Desertification – a combination of farming, overgrazing, and drought in dry areas turn productive land into deserts Sahara
Land pollution Trash – the average American produces about
1.8 kg of solid waste daily – 657 kg/yr Destroy habitats and pollute areas
Pesticides, etc. can also lead to habitat degradation DDT
Forest Resources Wood, medical supplies, habitats
for animals, recreation, etc.
Deforestation
Done for farmland, development, paper, etc.
Can lead to severe erosion, lack of clean air, changes in microclimates
Forest Management
Selective cutting, replant trees, faster growing trees
Fishery Resources Fish are a valuable source of food for
humans
Overfishing decreases supplies and makes for an increased population recovery time
Sustainable Development
Limits
Aquaculture – raising of aquatic animals for human consumption
Air Resources Smog – mixture of chemicals that occurs as a gray-
brown haze in the atmosphere
Mostly from automobile exhaust
Threatens health of people – especially young, old, and asthmatics
Acid Precipitation – sulfur dioxide from burning coal and nitrogen oxides from automobile exhausts combine with water vapor Leaches calcium, potassium and other nutrients
from the soil Damages plant tissues Alters pH of lakes
Ozone layer damage – CFC’s break down 03
Increased skin cancers Possible cause for amphibian population decreasing
Water Resources We need clean water to drink, provide habitats for food,
grow crops, etc.
Fertilizers and animal wastes carried by runoff Causes algal blooms
These algae die, decay and remove oxygen from the water
Silt from erosion clogs gills, blocks sunlight
Detergents, metals, industrial chemicals from runoff
Debris in oceans and lakes
Gyres
Biological Diversity Biodiversity refers to the variety of life in an area
Most common measure is the number of species that live in a certain area
Terrestrial biodiversity tends to increase as you move towards the equator
2/3 of all land species on Earth are in tropical regions
The areas richest in any type of biodiversity are warm regions
Rain forests, coral reefs, tropical lakes
The size of the area also affects biodiversity
Larger areas tend to be more diverse (unless other things prevent or encourage life)
Importance of Biodiversity Organisms are adapted to live together in a
community If you take one away, there are consequences to the rest
Biodiversity brings stability to an ecosystem More resources, interactions, etc.
Biodiversity is important to humans Oxygen to breath, remove CO2
Diverse diet / Better crops (resistance)
Building materials
Possible pharmaceuticals
Loss of Biodiversity Extinction – the disappearance of a species when
the last of its members dies
Since 1980, almost 40 species of plants and animals have gone extinct in the U.S.
Can be natural or human-caused
Threatened Species – when the population of a species begins declining rapidly
In the US: sea otters, loggerhead turtles, bald eagle
Endangered Species – population numbers so low that extinction is possible
In the US: California Condor, Florida manatees
Threats to Biodiversity Habitat loss – the biggest threat
Take away resources for life
Habitat fragmentation – separation of wilderness areas from other wilderness areas
Roads – leads to less biodiversity
Animals that migrate or need large areas to hunt
Climates can change (take away shade)
Threats to Biodiversity Introduction of Exotics
Exotic species – organisms that are not native to a particular area
Can grow at an exponential rate due to a lack of competitors and a lack of predators
Take over niches of native species Sea lamprey in Great Lakes after Erie Canal
Goats on Santa Catalina Island
Greenhouse Effect
The capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating and warming the planet.
Without the thermal blanketing of the natural greenhouse effect, Earth’s climate would be about 33°C (about 59°F) cooler—too cold for most living organisms to survive.
Global Climate Change Nickname is global warming
Greenhouse Gases
1. Water vapor – not much control here
2. Carbon dioxide – respiration, burning
Pre-industrial revolution – 280 parts per million in atmosphere
2007 – 385 ppm
3. Methane – mining, rotting organic material, melting permafrost
Traps 30 times more heat than CO2
Doubled in atmosphere since industrial revolution
Global Climate Change
Nitrous Oxide – plowing farm soils and burning fossil fuels Traps 300 times more heat
than CO2
Increased 18% since before industrial revolution
Ozone – automobiles
Good up high, contributes to smog down low
Others – CFCs, aerosols All human produced
Global Climate Change In 1988 the United Nations Environment Program (UNEP) and the
World Meteorological Organization (WMO) established the Intergovernmental Panel on Climate Change (IPCC). The panel comprises thousands of the top climate scientists from around the world and releases a report every six years describing the state of scientific knowledge on global warming. The IPCC’s Fourth Assessment Report, released in 2007, offered the strongest scientific consensus to date on global warming. The panel concluded that it is “very likely” (more than 90 percent probability) that human activities are responsible for most of the warming since the mid-20th century; that it is “extremely unlikely” (less than 5 percent probability) that the warming is due to natural variability; and that it is “very likely” the warming is not due to natural causes alone. This level of certainty is extremely high, given the complexity of the climate system and of the influence of human activities on the climate.
Section 1 Review1. What are two reasons for a species to become
threatened or endangered?
2. Explain how land that gets broken up can contribute to loss of species diversity.
3. What is an edge effect? Explain how changes in an ecosystem’s edges can affect organisms.
4. How can exotic species affect populations of native species?
Conservation Biology Conservation Biology is the study and implementation
of methods to protect biodiversity.
Natural resource conservation - natural resources are those parts of the environment that are useful or necessary for living organisms.
Species conservation - protecting species from extinction and preserving biodiversity
MY FOOTPRINT
Legal Protection of Species 1973, the U.S. Endangered Species Act made it
illegal to harm any species on the endangered or threatened list
Illegal for federal agencies to fund any project that would harm these species
The Convention on International Trade in Endangered Species (CITES)
Established lists of species for which international trade is prohibited or controlled
Honored by 120 countries
Preserving Habitats One way is to create national
parks
First one in US was Yellowstone
Originally this was to preserve the geology
Protects natural environments and provides habitats for many organisms
Habitat Corridors Protected strips of land
that allow the migration of organisms from one wilderness to another
Isolated populations inbreed too much
Sustainable Use In National Parks, the land is managed
This philosophy strives to enable people to use natural resources in ways that will benefit them and maintain the ecosystem Some grazing
Harvest fruits
Hiking, camping, etc.
Preservation Programs Captive Breeding followed by
Reintroduction Programs
Release organisms into area where the species once lived
Ex: black-footed ferret
Ex: brown pelican after DDT
Seed banks for threatened and endangered plant species
Bighorn Sheep They are being
reintroduced to historical ranges in Utah
Gone in the 50s – 60s from everywhere but Colorado River corridor Habitat degradation, predation,
disease
30% of reintroductions successful nationwide, 50% in Utah Problems arise because their
habitat right next to an Urban area with 300,000 people What is that called?????
Disease from sheep causes lots of death
What Can I Do?1. Switch to compact fluorescent bulbs
2. Set thermostat to 55°F when sleeping
3. Set water heater temperature to 130°F
4. Choose seafood wisely
5. Buy EnergyStar appliances and electronics
6. Wash and rinse laundry in cold water
7. Buy locally produced food and produce
8. Drink from reusable glassware
9. Walk, bike, and carpool