 Why are there so many living organisms on Earth, and so many different species? How do the characteristics of the nonliving environment, such as soil quality and water salinity, help determine which organisms thrive in particular areas? These questions are central to the study of ecosystems— communities of living organisms in particular places and the chemical and physical factors that influence them. Learn how scientists study ecosystems to predict how they may change over time and respond to human impacts.

Ecology is the scientific study of relationships in the natural world. It includes relationships between organisms and their physical environments (physiological ecology); between organisms of the same species (population ecology); between organisms of different species (community ecology); and between organisms and the fluxes of matter and energy through biological systems (ecosystem ecology).

1All Ecosystem exist and real like a pond, forest, ocean or even an aquarium. 2. Ther is a regular circulation of nutrients in ecosystem between the living and non living. 3. Important feature of Ecosystem is the adaptation to local environmental conditions. 4. The series of cycle involved water cycle, oxygen cycle, nitrogen cycle.

There are essentially two kinds of ecosystems; Aquatic and Terrestrial. Any other sub-ecosystem falls under one of these two headings. 1. Natural Ecosystem. 2. Man made Ecosystem.

It is an ecosytem developed under natural conditions without any appreciable human interference. Natural ecosystem an be terrestial ecostem, (forest ecosystem, lake ecosytem, pond ecosystem) or aquatic ecosystem ( fresh water ecosytm, ocean ecosytem etc.)

These are the artificial ecosystems which rely on the human efforts to sustain. They do not possess a self regulating mechanism. They have almost no diversity and have simple food webs. The cycling of nutrients is negligible. The inputs are provided by the human efforts. The man made ecosystems include the villages, towns, cities, rivers, orchids, dams, gardens, lakes and agriculture. The agriculture consists of the animal husbandry and the production of crops. The agriculture is the first manmade ecosystem which occurred with the increase in human population.

The Connections Among Life

Producer: Organism which produces its own food by using energy from the sun mycinnoc.html tadin%20map1.htm tree.jpg ckso.uhome.net/gallery/ grass.jpg thumbs_d/thumbs_p.html

Consumer: Organism which doesn’t make its own food, but gets it from eating plants or other animals index.asp JIGSAWPUZZLES3years+.html Sep_00/happymeal.cfm?path=hw cmdetail.html birding/story.htm

Decomposer: Organism which digests or breaks down formerly living material research.htm graphics/mush11.jpg uc.rutgers.edu/medrel/photos/ bacteria-green.jpg graphics/earth11.jpg

 Herbivores are animals that eat ONLY plants.  They need a lot of energy to stay alive.  Many have to eat all day long to get enough energy.  Some herbivores have a special digestive system so they are able to eat grasses.

 A manatee is a mammal that lives in the water.  They are herbivores.  They eat 150 pounds of plants each day!  Manatees live in ocean waters off the coast of Florida.

 A carnivore is an animal that gets its food from eating other animals.  They are also called a “meat eater

 Omnivores are animals that eat both plants and other animals.  Many will eat the eggs of other animals.  Some omnivores are scavengers which means they eat dead animals.  Most will eat plants that produce fruit and vegetables. They also eat the fruit and vegetables.

 An ecological pyramid (also trophic pyramid or energy pyramid) is a graphical representation designed to show the biomass or biomass productivity at each trophic level in a given ecosystem.  Biomass is the amount of living or organic matter present in an organism. Biomass pyramids show how much biomass is present in the organisms at each trophic level, while productivity pyramids show the production or turnover in biomass.

Ecological pyramids begin with producers on the bottom (such as plants) and proceed through the various trophic levels (such as herbivores that eat plants, then carnivores that eat herbivores, then carnivores that eat those carnivores, and so on).

 Three types of ecological pyramids  Pyramid of Energy  Pyramid of Biomass  Pyramid of Numbers

 Pyramid of Energy  Indicates the total amount of energy present in each trophic level  Shows the loss of energy from one trophic level to the next  Shows that the energy transfer from one trophic level to the next is accompanied by a decrease due to the conversion of potential energy into kinetic energy and heat energy  Only 10% of the overall movement of potential energy is transferred to the next tropic level

energy transferred energy lost

 Pyramid of Biomass  Indicates the total dry mass of the organisms in each trophic level  The size of the organism is over-emphasized and it can happen that the mass of level 2 is greater than that of level 1, because the productivity of level 1 is not taken into consideration  Thus an enormous mass of grass is required to support a smaller mass of gazelle, which in turn would support a smaller mass of lions.

tertiary consumers secondary consumers primary consumers producers 75 g/m2 150g/m2 675g/m2 2000g/m2

 Pyramid of Numbers  Shows the number of organisms in each trophic level and does not take into consideration the size of the organisms and over-emphasizes the importance of small organisms  In a pyramid of numbers the higher up one moves, so each consecutive layer or level contains fewer organisms than the level below it

tertiary consumers secondary consumers primary consumers producers ,000 5,000,000

 Simplistically:  This pattern of energy flow among different organisms is the TROPHIC STRUCTURE of an ecosystem. heat Producers Consumers Decomposers heat

 Energy flow is a one-directional process.   sun---> heat (longer wavelengths)  FIRST LAW of THERMODYNAMICS:  Energy can be converted from one form to another, but cannot be created or destroyed.

 Transformations of energy always result in some loss or dissipation of energy  or  In energy exchanges in a closed system, the potential energy of the final state will be less than that of the initial state  or  Entropy tends to increase (entropy = amount of unavailable energy in a system  or  Systems will tend to go from ordered states to disordered states (to maintain order, energy must be added to the system, to compensate for the loss of energy

 Natural, gradual changes in the types of species that live in an area; can be primary or secondary  The gradual replacement of one plant community by another through natural processes over time

 Begins in a place without any soil ◦ Sides of volcanoes ◦ Landslides ◦ Flooding  Starts with the arrival of living things such as lichens that do not need soil to survive Called PIONEER SPECIES  Soil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller pieces  When lichens die, they decompose, adding small amounts of organic matter to the rock to make soil

 New bare rock comes from source: ◦ volcanic lava flow cools and forms rock

 Begins in a place that already has soil and was once the home of living organisms Occurs faster and has different pioneer species than primary succession Example: after forest fires

Primary Consumers Secondary Consumers Tertiary Consumers

Producers are the beginning of a simple food chain. Producers are plants and vegetables.

All energy comes from the Sun and plants are the ones who make food with that energy. They use the process of photosynthesis in Plants also make loads of other nutrients for other organisms to eat.

Tertiary consumers (3 rd order) –Eat the primary and secondary consumers ( CARNIVORES ) ex: wolf eats cat and squirrel Secondary consumers (2 nd Order) –Eat the primary consumers (CARNIVORES) example: cat eats squirrel Primary consumers (1 st Order) –Worms, insects, squirrels, mice: all eat plants (HERBIVORES) ex: squirrel eats acorns

The last links in the chain are the decomposers. (They break things down) Like bacteria, mold, fungi, mushrooms If you die, they eat you. If you lose a leaf, they eat it. Whenever something that was alive dies, the decomposers get it.