3 Organisms: Energy Sources Producers: plants and bacteriaderive energy from inorganic sourcesphototrophs & chemotrophsConsumers: grazers, carnivores,etc.derive energy from living organisms (organic sources)Decomposers: fungi, scavengers, etc.derive energy from dead organic matter (organic sources)autotrophsImportant to remember that consumers can be grazers and / or carnivoresheterotrophs
4 Energy FlowThe ultimate source of energy in most ecosystems is the sun.
6 Producer – Photosynthesis – transform radiant energy into chemical energy
7 Ecosystem Structure: how the parts fit together Trophic Structure: major feeding relationships between organisms
8 Producers (Autotrophs) Those members of the community that manufacture organic compounds, such as glucose, from simple inorganic compounds, such as carbon dioxide, using an abiotic energy source, such as sunlight.Through their energy transforming actions, they make chemical energy available as organic compounds for their own use and, directly or indirectly, other members of the living community.
9 Consumers (Heterotrophs) Members of the community that must obtain their energy by eating other organisms or parts of them.All animals are consumers
10 Consumers (Hetertrophs) Consumer animals may be subdivided into the following groups;Herbivores – eat plantsCarnivores – eat animalsOmnivores – eat both plants and animalsDetrivores – eat decomposing organic matter (worms, beetles, crabs)
12 Radiant energy of sunlight TROPHIC LEVELSRadiant energy of sunlightTrees, shrubs, grasses and fernsProducers1st trophic levelPhytoplankton, algaeHerbivoresPlant-eating insects, small birds, possumsPrimary Consumers2nd trophic levelZooplankton, whelksCarnivoresAntechinus, owlsSecondary Consumers3rd trophic levelStarfish, small fishSnakes, eaglesTertiary Consumers4th trophic levelLarge fish, sharksOpen forest systemTemperate coastal sea ecosystem
13 Categories of Consumers primary consumers: (=herbivores) feed directly on producers;secondary consumers: (=carnivores) feed on primary consumers;tertiary consumers: feed only on carnivores;omnivores: consumers that feed on both plants & animals;scavengers: feed on dead organisms;decomposers (saprobes): consumers that complete the breakdown & recycling of organic materials from the remains & wastes of other organisms;detritivores: feed on detritus (partially decomposed organic matter, such as leaf litter & animal dung).
18 Factors Limiting Populations Law of tolerance: the ability of species to tolerate changes in their environment (physical or chemical factors). Pollution, global warming, habitat loss are some concerns associated with this.Limiting factor: any environmental factor that reduces survival or reproduction within a population.Ex: predation, temperatureLimiting factor principle: too much or too little of any abiotic factor can limit or prevent growth of a population, regardless if all other factors are near optimum range of tolerance.Ex: too much fertilizer will kill plants.