Symbiotic Species Interactions n Symbiosis relationship in which

Symbiotic Species Interactions n Symbiosis – relationship in which species live together in an intimate association. n n n Parasitism Mutualism Commensalism

Parasitism n One species (parasite) feeds on part of another organism (host) by living on or in the host. n n n Smaller than the host Remains closely associated with host and may weaken host over time Rarely kills its host

Mutualism n Two species interact in ways that benefit both n Nutritional mutualism n n Pollination, lichens, rhizobium, coral, bacteria Nutrition and protection n Birds and large animals, clownfish and anemones, mycorrihizae and plants

Figure 8 -12 Page 179 Oxpeckers and black rhinoceros Lack of mycorrhizae fungi on juniper seedlings in normal soil Clown fish and sea anemone Mycorrhizae fungi on juniper seedlings in sterilized soil

(a) Oxpeckers and black rhinoceros

(b) Clownfish and sea anemone

(c) Mycorrhizal fungi on juniper seedlings in normal soil

(d) Lack of mycorrhizal fungi on juniper seedlings in sterilized soil

Commensalism n symbiotic relationship that benefits one species but neither harms nor helps the other species

Ecological Succession n the gradual change in species composition in a given area n Primary Succession – gradual establishment of biotic communities on nearly lifeless ground n Secondary Succession – reestablishment of biotic communities in an area where some type of biotic community is already present

§ Primary succession begins with an essentially lifeless area where there is no soil.

n Early successional plant species, pioneer n Lichens, mosses n Trap windblown sediments, moisture n Break apart rocks n Midsuccessional plant species n Grasses, low shrubs n Late successional plant species n Mostly trees

Primary Ecological Succession Early successional Late Successional or Climax Community Midsuccessional Pioneer species Exposed rocks Lichens and mosses Small herbs and shrubs Heath mat Time Balsam fir, paper birch, and white spruce Jack pine, climax community black spruce, and aspen

n Secondary succession occurs when the natural community has been disturbed, removed, or destroyed. n This disturbance could be as a result of a fire, flood, or humans. n The key is that soil already exists so that this process many only take a 100 -200 years.

Secondary Ecological Succession Mature oak-hickory forest Young pine forest Annual weeds Perennial weeds and grasses Shrubs Time

Ecological Succession of Wildlife Species © 2004 Brooks/Cole – Thomson Learning Early Successional Species Midsuccessional Species Late Successional Species Wilderness Species Rabbit Quail Ringneck pheasant Dove Bobolink Pocket gopher Elk Moose Deer Ruffled grouse Snowshoe hare Bluebird Turkey Martin Hammond’s flycatcher Gray squirrel Grizzly bear Wolf Caribou Bighorn sheep California condor Great horned owl Ecological succession

Changes Affecting Ecosystems Catastrophic n Natural n n n n n Drought Flood Fire Volcanic eruption Earthquake Hurricane Landslide Disease Human-caused n n n n n Deforestation Overgrazing Plowing Erosion Pesticide application Fire Mining Urbanization Water and air pollution Loss and degradation of wildlife habitat Gradual n Natural n n n Climate change Immigration Adaptation and evolution Ecological succession Disease Human-caused n n n n n Salinization Soil compaction Groundwater depletion Water and air pollution Loss and degradation of wildlife habitat Introduction of nonnative species Overhunting and overfishing Toxic contamination Urbanization Excessive tourism

Predictability and the Balance of Nature Old Concept n Succession n Climax Community n New Concept Biotic change Mature community or vegetative patches Succession involves species competing for enough light, nutrients and space which will influence it’s trajectory and end result.

Species diversity Intermediate disturbance hypothesis 0 Percentage disturbance 100

Stability – the ability of living systems to withstand or recover from externally imposed changes or stresses. n Inertia – ability to resist being disturbed n Constancy – keep numbers within limits n Resilience – ability to bounce back

Precautionary Principle When evidence indicates an activity can harm human health or the environment, we should take precautionary measures to prevent harm even if some of the causeand-effect relationships have not been fully established scientifically.

Grizzly bear NORTH AMERICA More than 60% of the Pacific Northwest coastal forest has been cut down Eastern cougar Spotted owl Blackfooted Florida ferret panther 40% of North America’s range and cropland has lost productivity California condor Half of the forest in Honduras and Nicaragua has disappeared Mangroves cleared in Equador for shrimp ponds Endangered species Fish catch in the north-west Atlantic has fallen 42% since its peak in 1973 Chesapeake Bay is overfished and polluted Golden toad Coral reef destruction Every year 14, 000 square kilometers of rain forest is destroyed in the Amazon Basin Columbia has lost one-third of its forest PACIFIC OCEAN Environmental degradation Humpback whale Manatee Much of Everglades National Park has dried out and lost 90% of its wading birds Kemp’s ridley turtle Hawaiian monk seal Vanishing biodiversity St. Lawrence beluga whale Black lion tamarin SOUTH AMERICA Southern Chile’s rain forest is threatened Little of Brazil’s Atlantic forest remains ATLANTIC OCEAN

Poland is one of the world’s most polluted countries Imperial eagle 640, 000 square kilometers south of the Sahara have turned to desert since 1940 Many parts of ASIA former Soviet Union are polluted with industrial and radioactive waste Central Asia from the Middle East to China Giant has lost 72% of rangepanda and cropland Area of Aral Sea has Snow leopard Shrunk 46% EUROPE Mediterranean Japanese timber imports are responsible for much of the world’s tropical deforestation Saudi Arabia Deforestation in the Himalaya Asian causes flooding in Bangladesh Liberia elephant Oman Kouprey Eritrea Mali AFRICA Yemen 90% of the coral reefs India and are threatened in the Burkina Niger Ethiopia Sri Lanka Philippines. All virgin Faso Benin Chad Golden have almost forest will be gone Sierra tamarin no rain Nigeria by 2010 Leone forest left Togo Congo Uganda Sao Tome Rwanda Somalia In peninsular Malaysia 68% of the Queen Alexandra’s Burundi almost all forests have Birdwing butterfly Congo’s Angola been cut rain forest Indonesia’s is slated Zambia coral reefs are for cleaning INDIAN OCEAN threatened Nail-tailed wallaby and Aye-aye Fish catches in mangrove AUSTALIA Southeast Atlantic forests Madagascar has have dropped by more have been Much of lost 66% of its Black than 50% since 1973 cut in half Australia’s tropical forest rhinoceros range and cropland have turned to desert 6. 0 or more children per woman Blue whale A thinning of the ozone layer occurs over Antarctica during summer ANTARCTICA