2 What Shapes Ecosystems Abiotic and Biotic FactorsHabitat – physical location where an organism livesNiche – the use of the habitat by an organism (includes food, physical location, how it interacts with other organisms, etc.)
4 Ways in Which Species Interact These categories are based on whether each species causes benefit or harm to the other species.Other types of interactions are possible.Many interactions between species are indirect, some interactions do not fit in a category clearly, and other types seem possible but are rarely found. Therefore, many interactions are neither categorized nor well studied.
5 CompetitionCompetition – when different individuals or populations attempt to use the same resourceWithin a species – food, mates, territoryBetween species – food, waterCompetition can occur even if the individuals never meet.Flowers competing for the same pollinators
6 Community Interactions - Competition When members of different species compete for the same resources, we say that their niches overlap.These species will divide up the resources either by time or space – called niche restrictionEx. Warblers in coniferous trees will live only on certain levels of the treesEx. Diurnal v. Nocturnal insects - both need the same resources, but some are only active in the day and others at night
7 Community Interactions - Predation Predator/Prey RelationshipPredator – organism that hunts/killsPrey – organism that is food (e.g. cat and mouse)Sometime one predator may also be another organism’s prey
8 Specialists v. Generalists Species that eat mostly one type of prey are called specialistsEx. Canadian Lynx and the Snowshoe HareGeneralists will eat whatever is easiest to find and captureEx. Coyotes or Wolves
9 Symbiosis and Coevolution Symbiosis – two species who live closely togetherOvertime, species in close relationships may coevolve. These species may evolve adaptations that reduce the harm or improve the benefit of the relationship.
10 MutualismMutualism – symbiosis in which both organisms benefit – often each species depends on the otherEx. Flowers and their pollinators
11 Ex. Barnacles on a whale’s skin or CommensalismCommensalism – symbiosis in which one organism benefits and the other is neither helped nor harmed.Even seemingly harmless activity, however, might have an effect on another species.Ex. Barnacles on a whale’s skin orBirds nesting in trees
12 ParasitismParasitism – symbiosis in which one organism is helped and one is harmedParasite – the organism that feeds on another organismHost – the organism parasite takes its nourishment fromEx. Fleas and ticksThe difference between aparasite and a predator isthat a parasite does notusually kill its host.