Environmental Systems Topic 2 The Ecosystem EcoStructure Assessment Statements: 2.1.2-2.1.3; 2.1.6-2.1.7; 2.4.1-2.4.2

scope, in terms of levels of organization: Ecosphere ecology: study of relationships between organisms & their environment. scope, in terms of levels of organization: organism: any form of life population: a group of interacting individuals of same species community: populations of different species in given area ecosystem: community + non–living environment ecosphere: (=biosphere) all of Earth's ecosystems Realm of Ecology

Ecosystem Definition: a community of different species interacting with one another & with… Examples?

So what the heck is a Trophic Level? The Biotic Components of an ecosystem can be separated into what are known as Trophic Levels So what the heck is a Trophic Level?

A Trophic Level is…. The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.

Two Main Categories of Trophic Levels 1. Producers (also called ____________ = "self–feeders") make their own food from compounds obtained in the environment Usually by what process? Some bacteria use what other process? 2) Consumers (also called _____________ "other–feeders") get their energy & nutrients by feeding on other organisms or their remains. Use what process to make energy?

Types of Consumers primary consumers: (=herbivores) feed directly on ________________; secondary consumers: (=carnivores) feed on __________________; tertiary consumers: (=top carnivores)feed only on carnivores; omnivores: consumers that feed on _____________________ scavengers: feed on _________ organisms

More Consumers detritivores: feed on detritus (partially decomposed organic matter, such as leaf litter & animal dung) (ex: worms, beetles, etc.) decomposers: consumers that complete the breakdown & recycling of organic materials from the remains & wastes of other organisms (ex: Fungus, Bacteria) What is the difference between these?

Model of the Trophic Levels Producers 1oConsumers 2oConsumers 3oConsumers Detritivores &Decomposers

Food Chains and Food Webs What is the difference?

Food Chains are models that show the movement of energy in an ecosystem

Food Webs: Interconnections between food chains. Why is a food web more accurate than a food chain? Because most organisms usually eat a varied diet. ie: they don’t just eat one type of organism.

Habitat vs Niche habitat: the actual location where an organism lives. habitat is like "address" of an organism; Niche: the functional role of a species in an ecosystem. Includes: interactions with living (biotic) & nonliving (abiotic) components of ecosytem; role in flow of energy & cycling of matter. Niche is like the occupation of an organism

Population Interactions Predation – Symbiosis – Parasitism - Interaction in which one species (a parasite) lives in or on another (host) and obtains nourishment from it. Ex: Mutualism - an association in which both species derive benefit. Commensalism - one member benefits and the other neither benefits or is harmed.

Competition A common demand by two or more organisms. Organisms compete for…?

Two Types of Competition Intraspecific Competition - Competition between members of the same species. An example? Interspecific Competition - competition between different species Which type of competition is the most intense? Why?

What is a Biome? Region inhabited by certain types of plants and animals due to which two abiotic factors? Examples of Biomes?