Connecting Links Science 10 Unit 1: Sustainability of Ecosystems G.Burgess Sept.2006

Terms to know: Ecosystem Producer Primary consumer Secondary consumer Trophic level Detritivore Decomposer Pyramid of numbers Biomass Pyramid of biomass Pyramid of energy flow Carrying capacity Competition Intraspecific competition Interspecific competition Population density Density-dependent factors Productivity Biological magnification

Sustainability of Ecosystems Sustain / AbilityEcology / System =maintain =competency =Environment =organization :the ability for people to interact with the environment so that they may prosper and the environment may prosper as well. Question: Can we continue to mine for metal resources and fuel without destroying the environment? **The diamond mines of N.Territories must reintroduce the organisms and non-living materials that were present prior to the mining.

Human need for nature What materials do humans collect from the natural environment? IE. Where do we get the materials we eat? How do these materials interact with the environment?

Capturing Energy from the SUN. All organisms rely on the sun for energy. Energy makes it possible for organisms to perform growth, reproduction, nutrition, transport of materials, react to the environment, metabolize materials, assimilate and synthesize materials Energy is what enables our bodies to perform the chemical reactions required for life.

Ecosystem Includes all organisms in an area that interact with one and other, and the non-living environment (sunlight, water, soils, etc…) The interactions of organisms and the cycling of materials within an ecosystem can be shown through food chains and food webs. Organisms may be classified as producer or consumer depending on their roll in the ecosystem. Consumers may be classified as herbivores, carnivores, omnivores, detritivores, or decomposers.

Ecosystem Producer: all green plant, blue-green algae (cyanobacteria/ archaeobacteria) Any organism that is capable of creating its own food Consumer: all animals, fungi, animal like protists, some bacteria Any organism that relies on another for its food.

Types of Consumers Herbivores: plant eating organisms Carnivores: meat eating organisms Omnivores: Eats both plants and meat Detritivore: organisms that feed on dead decaying organic matter Decomposer: organisms that breakdown large compound (ie. proteins) into smaller compounds that may be used by producers

Food Chain/ Food Web Perform Laboratory Activity 1. Exploring Energy Cycling

Ecological Pyramids We use pyramids to express relationships between organisms. 1.Pyramid of Numbers: used to demonstrate the relation between the populations found with in trophic levels. ie. Fig 1.8 pp.14 demonstrates how the population is reduced as the trophic level increases. NOTICE: the population of grass compared to the population of mice. Which is larger? Why? Examine Fig.1.10 on pp.15. Why is the population of trees much smaller than the population of herbivorous insects? Food Pyramids

Ecological Pyramids 2.Pyramid of biomass: demonstrates a relationship between organisms by combining their size with their population. This pyramid shows how the biomass decreases as the trophic level increases. NOTICE: fig.1.12 shows how the pyramid can be reversed if the reproduction rate of the producer is faster than the reproduction rate of the consumer. QST: What would happen if the environment changed so that the phytoplankton could not reproduce as fast?

Ecological Pyramids 3.Pyramid of Energy Flow: shows the changes of total chemical energy that moves from trophic level to trophic level. Energy is continually lost as trophic levels increase Producers always have the most energy NOTICE: there is always a drop in energy between levels

Carrying Capacity The largest population that can be sustained by an environment. Factors that influence the carrying capacity; 1.Materials and energy: there is a limited supply of sunlight, water, soil nutrients, 2.Food Chains: the population of one species limits the populations of successive species 3.Competition: limits of food/shelter/mates/space for living generates competition amongst and between species. This inevitably influences the populations of individual species.

Competition Intraspecific competition: between members of same species. Interspecific competition: between different species Population density: refers to the population of a species that can survive in a certain area. This is closely linked with the carrying capacity for an area. Density-dependant factors: those factors that increase stress as the population increases. Density-independent factors: factors that limit population no matter what the size was initially.

Pop-Bottle Terrarium