Accelerated Bio Ecology Part II

1
Accelerated Bio Ecology Part II

• Chapter 20 Community Ecology
• Chapter 22 Humans in the Environment

2
20-1 Species Interactions of Communities

• Communities contain interacting populations of
  many species. 3 major types of interactions
  between species
• PREDATION predator eats all or part of an
  individual ? the prey
• Predators survival depends on ability to capture
  food
• Adaptations of predators venom, flesh-cutting
  teeth, sticky webs, speed
• Preys survival depends on ability to avoid
  capture
• Adaptations of prey camouflage, chemical
  defenses (plants animals), mimicry (resembles
  another species) , thorns, spines

3
2) COMPETITION

• limited resources force competition among living
  things in same niche.
• among same species intraspecific competition
• between different species interspecific
  competition
• all competition almost always produces a
  winner and a loser (dies out)
• ex two species of paramecium kept in same
  cultureone species out competed the other.
• the competitive exclusion principle no
  two species can occupy the same niche at the same
  time.
• dividing resources can be a truce in the
  competition for resources
• ex one spruce tree can provide for three
  different niches of warbler birds feeding on
  high, middle, and low branches
• by dividing resources, competition helps
  determine the number and types of species in a
  community AND the niche each species occupies

4
Predation, Herbivory and Keystone Species

• predator-prey predators affect the amount of
  prey and where prey can live and feed
• herbivore-plant herbivores affect both the size
  and distribution of plants and determine where
  those plants can grow
• keystone species a change in one species can
  have drastic effects on many other species in the
  community
• ex Pacific NW sea urchins eat giant kelp
  stalks. Sea otters eat sea urchins.
• Otters are a keystone species- they keep the sea
  urchin population in check
• Over hunting of the otters allowed urchin
  population to explode ? giant kelp forests
  destroyed by urchin activity
• with no kelp, many animals were without a
  habitat
• otters are now protected species, urchin
  population is under control and kelp forests have
  rebounded

5
3) Symbiotic Relationships

• symbiosis together living.
• any relationship where 2 species live in
  close association with each other.
• 3 main types of symbiotic relationships
• A) mutualism (win-win) Both benefit.
• ex sea anemone and clown fish. Clown fish
  gets a protected home and the anemone gets a
  defender when attacked
• B) parasitism (win-lose) One benefits at
  the harm of the other (host)
• ex tapeworm inside a human. Tapeworm
  absorbs digested food of host, the
  hosts cells starved for nutrition.
• C) commensalism (win-no harm/help)
  One benefits while the other is neither
  harmed nor helped
• ex barnacles on a whale. Barnacles benefit
  by motion of whale and the movement of food
  particles over them. No benefit or harm
  comes to the whale.

6
20-2 Ecological Succession Primary and Secondary

• Succession a progressive, predictable ecological
  change in a community over time
• In 1833, volcanic island of Krakatau completely
  destroyed by an eruption left completely
  barren.
• 2 years later, grasses are present
• 14 years later, 49 plant species and lizards,
  birds, insects, and bats
• by 1929, a forest with 300 plant species were
  present.
• today the island is a mature rainforest
• HOW? Primary Succession
• begins with no remnants of the previous
  community
• pioneer species are first to colonize barren land
• ex lichen (fungus and algae) turn rock into
  soil, turn N2 gas into useful
  nitrogen forms, and add organic material to the
  soil
• certain grasses are also pioneer species

7

• Secondary succession occurs after a major event
  disturbs
• a community (fire, flood, earthquake, hurricane)
• SOIL survives the disturbance
• plants re-colonize the area faster than in
  primary succession
• can also follow human activities like forest
  clearing and farming
• once plants are established, herbivores can move
  in and make use of the food supply. Then,
  carnivores can move in
• if ecosystem is healthy, it may be restored to
  its natural state prior to disturbance
  (the climax community)
• sometimes the human impact is so traumatic, a
  full recovery through succession is
  not possible

8
Chapter 22Human Environmental Impact
Humans affect regional and global environments
through agriculture, development, and industry in
ways that have an impact on the quality of
Earths natural resources, including soil, water,
and the atmosphere.

• Humans
• Rely on Earths life-support systems
• Affect our environment when we
• Obtain food
• Eliminate waste products
• Build places to live

9
The Effect of Human Activity

• Agriculture - Supplies a dependable food source
  that can be stored for later use
• Positives
• Enabled human settlements that ultimately led to
  modern civilization
• Negatives
• Impacts natural resources as gt7 billion people!!!
  need
• Food
• Fresh water
• Fertile soil
• Fossil fuels (fertilizer farm equipment)
• Development - Trend to move to suburbs cities
• Positives
• High standard of living
• Negatives
• Produce lots of waste that affect air, water,
  soil resources
• Uses up farmland
• Divides natural habitats into fragments

10
The Effect of Human Activity

• Industrial Growth Industry scientific
  know-how
• Positives
• Modern conveniences of life
• Comfortable homes, clothes, electronic devices
• Negatives
• Require energy and consume power
• Need to burn fossil fuels (coal, oil, natural
  gas)
• Wastes discarded into air, water, soil

11
Sustainable Development

• Renewable and Nonrenewable Resources
• Renewable can be renewed or replaced by a
  healthy ecosystem
• A single southern white pine
• Nonrenewable natural processes cannot replenish
  them in a reasonable amount of time
• Fossil fuels (formed from buried organic material
  over millions of years)
• A whole forest of white pines

12
Sustainable Development

• Sustainable Resource Use
• Sustainable development
• Provides for human needs wants
• Preserves the ecosystems that produce natural
  resources
• What does it look like?
• Does not cause harm to the soil, water, and
  climate
• Consumes as little energy and material as
  possible
• Flexible to survive environmental
  stress/disasters
• Takes into account human economic systems as well
  as ecosystem goods and services
• SURVIVE AND IMPROVE

13
Using Resources Wisely Soil

• Why is it needed?
• When healthy, supports agriculture and forestry
• Topsoil absorbs/retains moisture but allows
  water to drain
• What are we doing to destroy it?
• Allowing soil erosion nutrients are washed
• away with rain
• Desertification over-plowing, overgrazing,
  allowing land to be barren between plantings
• Deforestation loss of forests
• Forests help to hold soil in place, absorb CO2,
  absorb freshwater

• How can we protect it?
• Leaving stems and roots in place between
  plantings
• Crop-rotation
• Contour Plowing and Terracing creating steps to
  
• prevent water and soil from flowing downward
• Creating tree farms (makes trees a renewable
  resource)

14
Using Resources Wisely Freshwater

• Why is it needed?
• Drinking water
• Industry
• Transportation
• Energy
• Waste Disposal
• What are we doing to destroy it?
• Overuse (Ogallala aquifer took 1
• million years to collect)
• Pollution
• factories, oil spills
• Industrial/Agricultural Chemicals
• Biomagnification pollutants (like DDT, PCBs,
  heavy metals) magnify as they move through the
  food chain from primary producers to primary
  consumers, etc. Biomagnification clip
• Residential Sewage (?)

15
Freshwater Resources

• How can we protect it?
• Protection of natural resources involved in water
  cycle
• Plants can filter out pollutants
• Watershed conservation protecting
• all inter-connected bodies of water
• Pollution control
• Sewage treatment
• Decrease pesticide use
• Use biological controls instead
• of poisonous sprays
• Water conservation
• Drip irrigation

16
Using Resources Wisely Atmospheric

• Why is it needed?
• Oxygen
• Absorption of UV radiation
• Regulation of global temperature
• What are we doing to destroy it?
• Pollution (Industry, Burning Fossil Fuels)
• Smog - Ground Level Ozone
• Causes respiratory diseases
• Acid Rain nitrogen and sulfur oxides mixing
• with precipitation
• Damages plants, releases toxic elements from soil
• Greenhouse Gases burning of fossil fuels
  releases CO2, CH4 and H2O
• Releases carbon dioxide into the air, contributes
  to global warming and climate change
• Particulates microscopic particles of ash and
  dust released by industry
• Can be inhaled and cause respiratory problems
• How can we protect it?
• Emission standards
• Clean-air regulations
• Unleaded gasoline

17
Biodiversitytotal of all the genetically-based
variation in all organisms in the biosphere

• Value of Biodiversity
• Ecosystem Diversity - variety of habitats,
  communities, and ecological processes in that
  biosphere
• 1.8 million species already identified!
• 30 million more estimated yet to be discovered!!
• Species Diversity - number of different
  organisms in a particular area
• Genetic Diversity sum total of all different
  forms of genetic information carried by a
  particular species
• Benefits of Biodiversity
• Sources of medicines
• Genetic diversity used to increase pest
  resistance
• Keystone species (if removed) can change entire
  ecosystem

18
Biodiversity

• Threats to Biodiversity
• Altering habitats
• Hunting
• Introducing Invasive Species
• Releasing Pollution
• Contributing to Climate Change
• Conserving Biodiversity
• Protect Individual Species
• Preserve Habitats and Ecosystems
• Consider Local Interests

19
Meeting Ecological Challenges

• Ecological Footprint total area of functioning
  land and water ecosystems needed both to provide
  the resources an individual or population uses
  and to make harmless the wastes that an
  individual or population generates
• The average American has an ecological footprint
  that is
• 4x larger than global average
• 2x that of England Ecological Footprint Clip
• gt2x that of Japan
• 6x that of China

20
Ozone Layer

• Why is it needed?
• Ozone Layer molecules of O3
• At ground level pollutant
• Upper atmosphere protection against harmful UV
  radiation which can cause cancer, eye damage and
  decreased immunity
• What are we doing to destroy it?
• Primary problem is CFCs (Chloroflurocarbons)
• Found in refrigerants, aerosol cans and plastic
  foams
• How can we protect it?
• CFCs banned in the late 80s (Montreal Protocol),
  however residual CFCs can remain in the
  atmosphere for more than 30 years!!

21
Fisheries

• What is the problem?
• Despite increased efforts and new technology,
  seafood catch numbers continue to decline
• What are we doing to destroy it?
• Overfishing Fish thought to be a renewable
  resource
• Death rates (commercial fishing) surpassed the
  birth rates of the fish
• How can we protect it?
• Regulations put in place to limit fish catches
• Certain areas closed to fishing until populations
  recovered (Sustainable Fisheries Act)
• Aquaculture farming of aquatic animals

22
Climate Change

• Whats the Problem?
• Global warming increase in average temperature
  of our planet (0.74ºC between 1906 and 2005) with
  11 of the 12 warmest years occurring between
  1995-2006
• Melting sea ice
• Rising sea levels
• What are we doing to destroy it?
• Enhanced Greenhouse Effect not allowing solar
  heat to move back into outer space
• Burning fossil fuels
• Automobile exhaust
• Industrial pollution
• How can we protect it?
• Alternative energy sources (water, wind, solar)
• Decrease our ecological footprint