Introduction to Interrelationships Predator-Prey Relationships - Handout

Interrelationships Interrelationships: relationships among organisms Occur within ecosystems as a variety of community interactions Written Response #4: What interrelationships may exist in the ecosystem pictures to the right?

Interrelationships Community interactions (3 main types): Predation: carnivores must obtain energy, often by hunting and eating live prey (predator-prey) Competition: when two or more organism try to claim limited resources at the same time Resources: food, space, water, air, habitats, mates Symbiosis: any relationship between two different species living together

Interrelationships Mutualism: both species benefit form the relationship (flowering plants and insects Parasitism: one organism benefits and one is harmed by the relationship Examples: mosquitoes and humans, fleas and dogs, some plant species

Interrelations Commensalism – One species benefits from the relationship and the other organism does not benefit or harm from the relationship. Example: Remora that rides attached to sharks and other fishes. Remora feed on the leftovers of their hosts’ meals. Example: Orchids growing on the branches of trees

Fun Videos… Bot Fly Guinea Worm Top Deadliest Human Parasites https://www.youtube.com/watch?v=23eimVLAQ2c Guinea Worm https://www.youtube.com/watch?v=sx4c6i82kFo Top Deadliest Human Parasites https://www.youtube.com/watch?v=LWbfvjuf_uw Kissing Bug https://www.youtube.com/watch?v=fx-th1zPMzw

Good Buddies - Handout

Interrelationships Ecology seeks to examine changes within ecosystems, which can vary greatly according to populations While ecosystems change, a balance must be maintained: habitats, communities and whole ecosystems change on a daily basis due to natural and man-made disruptions Written Response #5: What might cause ecosystems to change? Old organism die out, and new organisms arrive and pass on their genes

Interrelationships Ecological succession: the series of changes that an ecosystem encounters in a natural way Primary succession: occurs where no soil previously existed Example: lava flows on rock, lichen break up rock Pioneer species: 1st species to inhabit an area Secondary succession: occurs after an ecosystem has experienced a disruption Example: a forest fire burns woodlands Primary and Secondary Succession Video Stop at 5:11

Interrelationships As ecosystems go through change, populations change in response Population growth: the rate at which the total number of a particular species changes with time (may be positive or negative) Factors affecting population size: number of births (increase), number of deaths (decrease), and number of organisms that enter or exit the ecosystem

Interrelationships Limiting factor: any factor that can limit the rate of population growth Causes population growth to slow, stop, or drop

Lesson of the Kaibab - Handout

Interrelationships Density dependent factor: affect organisms based on population size As a population grows, it may affect it more (food sources) Density independent factor: affects organisms regardless of population size May affect a population of 10 organisms or 10,0000 organisms (weather)

Limiting Factors Reading - Handout

Ecosystem Project