Ecosystems Chapter 4
What Shapes an Ecosystem? Biotic Factors: biological influences on organisms - any living thing that an organism interacts with - other animals or plants Abiotic Factors: physical, nonliving influences on organisms - temperature, precipitation, humidity, wind, nutrient availability, soil type, water, and sunlight Together, biotic & abiotic factors determine the survival and growth of an organism & the productivity of the ecosystem in which it lives
The Niche An organism’s habitat is its address An organism’s occupation is its NICHE NICHE – the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. - includes: 1. the type of food the organism eats 2. How it obtains it food 3. What other species uses it for food 4. Physical conditions required for survival 5. When & how it reproduces
Community Interactions Competition – when organisms try to use an ecological resource in the same place at the same time. There will always be a winner and a loser Predation – when one organism captures and feeds on another organism Cheetah is the predator and the gazelle is the prey Symbiosis – when two different species live closely together
3 Forms of Symbiosis Mutualism – when two species benefit from their relationship Ex: flower provides food for insect and insects help pollinate the flower. Commensalism – when one member benefits, but the other one is not helped nor harmed Ex: barnacles on whales Parasitism – when one lives on or inside another Ex: fleas or ticks suck blood from mammals
Clown fish & anemone Commensalism
Great white shark & seal Predation
Zebra & bird Mutualism
Ant & aphid flower Mutualism
Eel & cleaner fish Mutualism
Trout & leech Parasitism
Tomato hornworm & cocoons of braconid wasps. Parasitism
Caribbean soldierfish & isopod Parasitism
Grey whale & barnacles Commensalism
Vultures & dead Elephant Competition
Lion & water buffalo Predation
Trees in the forest Competition