ECOSYSTEM: Communities interacting with one another & the non-living environment Populations: Group of interacting individuals of the same species that occupy a specific area at the same time Communities Group of different populations occupying a particular place at the same time

Sub Atomic Particles Atoms Molecules Cells Tissue Organs – Organ Systems Organisms Populations Communities Ecosystems Biosphere Ecological Hierarchy

Atmosphere: Troposphere (17km) & Stratosphere (17-48km) Hydrosphere: water in every phase of matter that exists on earth Lithosphere: Earth’s crust & upper mantle WHAT SUSTAINS OUR ECOSYSTEMS? One-way flow of high-quality energy (sun – food chains – radiated heat) Cycling of Matter – nutrient cycles, decay, & renewal of matter Gravity – atmosphere and downward movement of chemicals & nutrients

SPECIATION 1,412,000 Species identified *Possibly between million altogether **Mostly microbes-bacteria/protozoa/fungi/yeast

oEvolved first – simple (asexual – binary fission) oMicroorganisms oBacteria (decomposer, diseases) oHabitat – Ubiquitous!! EVERYWHERE oComplexity Increases with Time oSingle Cell to Multicell oMicroorganisms to Large Predators oSingle cell – Protista; Yeast (fungi) oMulti cell – Fungi; Plants; Animals oAsexual & Sexual

Populations are DYNAMIC! They change in: 1)Size 2)Age Distribution 3)Density (# per unit of space) 4)Genetic Composition GENETIC DIVERSITY!! Complex interacting network of plants, animals, & microorganisms Aquatic & Terrestrial

PHOTOSYNTHESIS Evaporation wind Ozone - stratosphere Albedo effect greenhouse effect

Ecosystem rarely have distinct boundaries & are not self contained. ECOTONE – region containing a mixture of species from adjacent ecosystems or species not found in either ecosystem Watersheds often serve as a boundary for ecosystem because they offer a connection of nutrient cycling. Example: A wetland found between the ocean and the land

Classified Terrestrial Portions of the Atmosphere

– existence, abundance, & distribution of species in an ecosystem is determined by the falling into the range tolerated by that species. Law of Tolerance – existence, abundance, & distribution of species in an ecosystem is determined by the levels of one or more physical or chemical factors falling into the range tolerated by that species. Terrestrial  Sunlight  Temperature  Precipitation  Wind/Climate  Altitude  Soil/Nutrients (Fire) Aquatic  Sunlight  Temperature  Water Currents  Suspended Solids  Dissolved Oxygen ABIOTIC LIMITING FACTORS IN ECOSYSTEMS